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  • Identification and quantification of triacylglycerols in human milk fat using ultra-performance convergence chromatography and quadrupole time-of-flight mass spectrometery with supercritical carbon dioxide as a mobile phase
    Food Chem. (IF 4.946) Pub Date : 2018-09-25
    Xinghe Zhang, Ce Qi, Yiren Zhang, Wei Wei, Qingzhe Jin, Zhimin Xu, Guanjun Tao, Xingguo Wang

    An ultra-performance convergence chromatography (UPC2) method coupled with quadrupole time-of-flight mass spectrometry (Q-TOF-MS), was developed for the determination of complicated triacylglycerols (TAGs) in human milk fat. The use of supercritical carbon dioxide as the mobile phase improved the chromatographic separation of the TAGs significantly. By optimizing the scan modes of Q-TOF-MS and selecting parent ions for MS/MS ionization, the fragment ions of each TAG including TAG isomers with overlapping retention time were adequately resolved for identification and quantification. A total of 95 different TAGs were identified in the human milk samples from Chinese mother volunteers, with O-P-L representing the main TAG, followed by O-P-O and O-L-L. In addition, the compositions and contents of TAGs in different fats and oils were successfully measured. The developed method can serve as an advanced and reliable analytical tool for the determination of complicated TAGs in various biological samples.

    更新日期:2018-09-25
  • Studying the real-time interplay between triglyceride digestion and lipophilic micronutrient bioaccessibility using droplet microfluidics. 2 Application to various oils and (pro)vitamins
    Food Chem. (IF 4.946) Pub Date : 2018-09-25
    Hoang Thanh Nguyen, Mélanie Marquis, Marc Anton, Sébastien Marze

    The kinetics of micellar solubilization of lipophilic micronutrients (bioaccessibility) in relation with triglyceride digestion remains poorly known. To study this interplay in real-time, a droplet microfluidic method was designed and used as reported in the first part of this article series. In this second part, the interplay between the micellar solubilization of (pro)vitamins (beta-carotene or retinyl palmitate) and the digestion of triglyceride oils (tricaprylin TC, or high-oleic sunflower seed oil HOSO, or fish oil FO) during simulated gastrointestinal digestion was investigated. The relation between the release of both micronutrients and of triglyceride lipolytic products was found to be non-linear. The kinetics of beta-carotene was found to follow the kinetics of lipolytic products, depending on the oil type (TC > HOSO > FO). The effect of the gastric phase on the intestinal phase was also found to follow this order, mostly due to partial lipolysis during the gastric phase.

    更新日期:2018-09-25
  • Physicochemical properties and mineral content of honey samples from Vojvodina (Republic of Serbia)
    Food Chem. (IF 4.946) Pub Date : 2018-09-25
    Marijana B. Sakač, Pavle T. Jovanov, Aleksandar Z. Marić, Lato L. Pezo, Žarko S. Kevrešan, Aleksandra R. Novaković, Nataša M. Nedeljković

    Forty-five honey samples of three honey types – two monofloral (acacia and sunflower) and one polyfloral (meadow) were collected from the Autonomous Province of Vojvodina (Republic of Serbia) and analysed for their physicochemical parameters (moisture, acidity, pH, ash, electrical conductivity, glucose, fructose, hydroxymethylfurfural (HMF), CIE L∗a∗b∗ colour and mineral content). All tested physicochemical parameters were in agreement with the EU regulation except for moisture (4 samples) and HMF content (1 sample).Principal component analysis (PCA) was used for assessing the effects of three honey types on all investigated physicochemical parameters. According to PCA, acacia honey samples can be clearly isolated and form a cluster, while, regarding other honey types, PCA can offer the possibility to distinguish sunflower and meadow honey samples regarding examined physicochemical parameters and mineral content.

    更新日期:2018-09-25
  • An enhanced sensitivity and cleanup strategy for the nontargeted screening and targeted determination of pesticides in tea using modified dispersive solid-phase extraction and cold-induced acetonitrile aqueous two-phase systems coupled with liquid chromatography-high resolution mass spectrometry
    Food Chem. (IF 4.946) Pub Date : 2018-09-25
    Feiquan Wang, Shaohua Li, Hua Feng, Yajun Yang, Bin Xiao, Dawei Chen

    At present, matrix interferences in tea are still a great challenge for analysis of multi-pesticide residues. Herein, a simple sample preparation method was developed based on the modified dispersive solid-phase extraction (DSPE) procedure and cold-induced acetonitrile aqueous two-phase systems (ATPS). In modified DSPE procedure, polyvinylpolypyrrolidone (PVPP) was selected as the matrix dispersive adsorbent to remove polyphenols from the tea with the removal rate of >98.3%. Using cold-induced acetonitrile ATPS, caffeine of the tea extract was sharply reduced by 81.2%, and a 0.798-3.167 of enrichment factor for the representative pesticides was achieved. In liquid chromatography-high resolution mass spectrometry analysis, a full scan/data independent acquisition approach was used for the nontargeted screening and targeted determination of pesticides. In data analysis, an in-house database of pesticides was constructed, and a simple accurate mass calibration method was used to correct the accurate mass variation, which was conducive to reduce the number of false detects.

    更新日期:2018-09-25
  • Effects of heat treatment under low moisture conditions on the protein and oil in soybean seeds
    Food Chem. (IF 4.946) Pub Date : 2018-09-25
    Yukiko Mizutani, Masayuki Shibata, Saeko Yamada, Yuko Nanbu, Motohiko Hirotsuka, Yasuki Matsumura

    The effects of autoclave and microwave heating on the protein and oil in soybean seeds were investigated under low moisture conditions. The nitrogen solubility index (NSI) decreased on heating. The reduction in the NSI was accompanied by an increase in the size and deformation of the oil bodies in the cellular tissue of soybean seeds. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis analysis revealed that lipoxygenase was susceptible to heat denaturation, but 7S and 11S globulins were only partially denatured. The partial denaturation of the proteins was confirmed by Fourier transform infrared spectroscopy measurements. The ratio of oil to protein peaks increased with increasing heating, suggesting the exudation of oil to the surface or outside of oil bodies. Microwave heating is more efficient in changing the oil distribution in soybean seeds than autoclave heating. On the other hand, the degree of protein denaturation is lower after microwave heating.

    更新日期:2018-09-25
  • One-step chromatographic method to purify α-lactalbumin from whey for nanotube synthesis purposes
    Food Chem. (IF 4.946) Pub Date : 2018-09-25
    Clara Fuciños, Pablo Fuciños, Natalia Estévez, Lorenzo M. Pastrana, Antonio A. Vicente, María Luisa Rúa

    A one-step anion-exchange chromatography method (NaCl gradient elution on a DEAE Sepharose™ Fast Flow gel column) was developed to purify α-lactalbumin (α-LA) from whey protein isolate. α-LA nearly 100% pure (based on the total protein content) was obtained with a yield of about 39%. Besides pure α-LA, which was the main objective of this work, highly pure β-lactoglobulin was also obtained with a yield of about 59%. The high purity of the obtained α-LA samples allowed its use to synthesise protein nanotubes with excellent gelation properties for their use as food thickeners and bioactive carriers. The samples’ purity degree obtained (based on the total protein content) was critical in the formation of proper nanotubes instead of random aggregates, which produced opaque and weak gels, less useful for food applications.

    更新日期:2018-09-25
  • In vivo analysis of two new fungicides in mung bean sprouts by solid phase microextraction-gas chromatography-mass spectrometry
    Food Chem. (IF 4.946) Pub Date : 2018-09-25
    Zhen Shi, Dan Chen, Tian-Tian Chen, Ge Wei, Chun-Yan Yin, Hui Xu, Guang-Fu Yang

    A novel solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) method was developed to quantify two new fungicide residuals (Y13149, Y12196) in mung bean sprouts. With a stable and biocompatible elcetrospinning nanofiber (polystyrene/graphene@silica, PS/G@SiO2) as coating, the SPME fiber was directly inserted into the stem of mung bean sprout to in-situ in-vivo sampling and extraction, followed by GC-MS analysis. Under the optimal conditions, satisfactory average recoveries of 99 % and 72 % were obtained for Y13149 and Y12196 with the relative standard deviations (RSDs) under 16.3 %, indicating good precision and anti-matrix ability of the method. The result also exhibited low detection limit (0.06-0.08 μg·L-1) and wide liner range (0.3-100 μg·L-1) with the correlation coefficients (R2) of 0.9989. The established method was applied successfully to trace the accumulation and distribution of fungicides in mung bean sprouts, and it provides a simple, rapid and reliable quantitative method for food analysis.

    更新日期:2018-09-25
  • Quantification of Aflatoxin B1 in Vegetable Oils Using Low Temperature Clean-up Followed by Immuno-Magnetic Solid Phase Extraction
    Food Chem. (IF 4.946) Pub Date : 2018-09-22
    Xi Yu, Zhanming Li, Mengzhe Zhao, Siew Cheng Stella Lau, Hui Ru Tan, Wei Jie Teh, Hongshun Yang, Chao Zheng, Yuquan Zhang

    In the present study, a convenient and highly efficient method was developed to quantify aflatoxin B1 (AFB1) in oil samples. Low temperature clean-up (LTC) followed by immuno magnetic solid phase extraction (IMSPE) was used to clean up oil samples. LTC assisted in freezing out the interference from the oil matrix while IMSPE further helped to preconcentrate the targeted analyte. For IMSPE, we synthesised and characterised anti-AFB1 monocolonal antibody-functionalised magnetic nanoparticles. Oil sample extraction was then carried out using LTC-IMSPE. The proposed method showed satisfactory efficiency and reproducibility with recovery rates being within the range of 79.6−117.9%, with a relative standard deviation below 11.48%. The sensitivity of the method was satisfactory with the limits of detection and quantification being as low as 0.0048 and 0.0126 ng·g-1, respectively. Real sample analysis was carried out for five kinds of different vegetable oils. The results suggest that the method developed is very sensitive and accurate.

    更新日期:2018-09-25
  • Physicochemical characteristics of fat blend from hydrogenated coconut oil and acyl migrated palm mid-fraction
    Food Chem. (IF 4.946) Pub Date : 2018-09-22
    Jung-Ah Shin, Yoon-Ji Heo, Ki-Teak Lee

    Palm mid-fraction (PMF), which has a high content of symmetric POP, was converted to asymmetric PPO (APMF) via acyl migration. After solvent fractionation, the liquid phase of acyl migrated PMF (APMF-L) was obtained and blended with hydrogenated coconut oil (HCO, 50:50, w/w) to produce a fat blend (namely, an alternative fat blend) which had reduced saturated fatty acid content while having similar melting behavior to HCO. In an alternative fat blend, the major fatty acids were lauric (27.94), palmitic (26.93) and oleic (15.75 mol%) acid. The solid fat index was quite similar to that of HCO, especially at 28∼44 °C. Nevertheless, an alternative fat blend had lower saturated fatty acid content, by 18%, compared to HCO. The content of highly atherogenic myristic acid was reduced by approximately 40%. The alternative fat blend in this study could be used as a raw material for non-dairy cream with low saturated fat content.

    更新日期:2018-09-25
  • Studying the real-time interplay between triglyceride digestion and lipophilic micronutrient bioaccessibility using droplet microfluidics. 1 Lab on a chip method
    Food Chem. (IF 4.946) Pub Date : 2018-09-22
    Hoang Thanh Nguyen, Mélanie Marquis, Marc Anton, Sébastien Marze

    This article is the first part of a series reporting on real-time digestion kinetics of triglyceride droplets containing different lipophilic micronutrients. This part focuses on the design, fabrication, and operation of a polydimethylsiloxane microfluidic device which enables the generation and digestion of oil droplets. The micro-channels were made hydrophilic to obtain oil droplets in an aqueous continuous phase. Optimized chip design and outlet control were implemented to provide efficient oil droplet generation, manipulation, and immobilization on a single chip. Highly monodisperse oil droplets were generated, immobilized in an array of traps and monitored in real time by fluorescence using a confocal microscopy method. The device was used to study the kinetics of beta-carotene release during tricaprylin digestion (intestinal lipolysis and micellar solubilization). The effect of the gastric phase on beta-carotene degradation was also investigated using the same method.

    更新日期:2018-09-25
  • Effect of the solvent composition on the profile of phenolic compounds extracted from chia seeds
    Food Chem. (IF 4.946) Pub Date : 2018-09-22
    Maristela Alves Alcântara, Isabelle de Lima Brito Polari, Bruno Raniere Lins de Albuquerque Meireles, Anderson Eduardo Alcântara de Lima, Jayme Cesar da Silva Junior, Érica de Andrade Vieira, Nataly Albuquerque dos Santos, Angela Maria Tribuzy de Magalhães Cordeiro

    This study investigated the efficiency of the extraction of phenolic compounds from seeds of chia, Salvia hispanica L. utilizing the statistical tool of mixture planning, simplex- lattice design. The solvents used were acetone, ethanol and water and the responses analyzed were total phenolic content (TPC), antioxidant activity by the capture of the free radical DPPH and ferric reduction ability (FRAP). Moderately polar mixtures were highly efficient to extract the antioxidant phenolic compounds. The best results were obtained for the water-acetone (1/3-2/3) binary mixture, presenting TPC, DPPP and FRAP values of 58.44 mg GAE/g, 250.20 μmol TE/g and 720.15 μmol TE/g, respectively. The best ternary mixture was water-ethanol-acetone (1/6-1/6-2/3), with 60.96 mg GAE/g, 380.53 μmol TE/g and 990.15 μmol TE/g, respectively. The phenolic profile showed that the acids rosmarinic, caffeic, salicylic and the flavonoids myricetin and quercetin are the compounds that most contribute to the elevated antioxidant activity.

    更新日期:2018-09-25
  • Reliable determination of tropane alkaloids in cereal based baby foods coupling on-line spe to mass spectrometry avoiding chromatographic step
    Food Chem. (IF 4.946) Pub Date : 2018-09-24
    Jesús Marín-Sáez, Roberto Romero-González, Antonia Garrido Frenich

    Cereal based foods are a major part of the infant diet and they can be contaminated with Solanaceaes and other plants containing tropane alkaloids. This study was focused on the optimisation of an extraction procedure based on a solid-liquid method and an online SPE system, directly coupled to different mass spectrometry analysers as Orbitrap and triple quadrupole (QqQ), removing the chromatographic separation step. Total running analysis time was 15.8 min (17.3 min in the QqQ system). The developed method was validated obtaining recoveries ranging from 66-98% and 68-97% for the Orbitrap and QqQ respectively (RSD lower than 14.3%) and limits of quantification from 0.5-5 µg kg-1 and 0.5-10 µg kg-1 for the QqQ and Orbitrap analyser respectively. The validated method was applied to several cereal based baby food samples, finding a positive sample containing atropine (11.5 µg kg-1), scopolamine (2.8 µg kg-1) and apoatropine (7.5 µg kg-1).

    更新日期:2018-09-25
  • Comparative proteomics of goat milk during heated processing
    Food Chem. (IF 4.946) Pub Date : 2018-09-24
    Di Chen, Xiangying Li, Xuan Zhao, Yusi Qin, Jianmin Wang, Cunfang Wang

    Milk proteins have shown to be very sensitive to heated processing. This study investigated the heat-dependent changes of goat milk proteins using label-free quantification (LFQ). A total of 843 proteins were identified in all the samples, of which 625 proteins were quantified. There were 527, 543, 537, 533 and 539 proteins quantified in the control group (CG) and heated groups (HGs: HG1, HG2, HG3 and HG4), respectively, and 438 proteins were common to all groups. The effects of high temperature/short time (HTST) treatment on proteins were similar to ultra-pasteurization (UP) and ultra-high temperature (UHT), but the low temperature/long time (LTLT) was different. Proteomics analysis demonstrated that heated processing increases the digestibility of proteins and is beneficial for anti-atherosclerosis therapy. These results expand the knowledge of the protein compositions from different heated processing. And it can further the utilization of the protein component of goat milk for human nutrition and health.

    更新日期:2018-09-25
  • Mapping the location of DATEM in multi-phase systems: Synthesis and characterization of spin-label probe analogues
    Food Chem. (IF 4.946) Pub Date : 2018-09-24
    Sampson Anankanbil, Jens Henrik Mose, Bianca Pérez, Weiwei Cheng, Jacob Nedergaard Pedersen, Zheng Guo

    Electron paramagnetic resonance (EPR) spectroscopy has emerged as a fast, reliable, non-invasive and sensitive method to determine the distribution, localization and reactivity of labelled ingredients in micro-heterogeneous systems. However, the commercially available probe molecules are very limited. In the present work, five new nitroxide [(4-hydroxy-2, 2, 6, 6-tetramethylpiperidin-1-oxyl (TEMPOL)] derivatives (1b-5b) of diacetyl tartaric acid esters of monoglycerides (DATEM) (1a-5a), a widely used food emulsifier, were synthesized under Steglich conditions and characterized by MS (mass-spectrometry), FT-IR (Fourier-transform infrared spectroscopy), EPR, NMR (nuclear magnetic resonance spectroscopy), fluorescence spectroscopy, and DSC (differential scanning calorimetry) analysis. Phase partitioning studies proved that the new spin labels are adequately capable of describing the localizations and partitioning of the corresponding DATEM in multi-phase systems. Findings disclosed in this work will provide new knowledge on ingredient reactivity and localization in multi-phase systems; which is vital to aid the design of more efficient delivery systems for bioactive compounds.

    更新日期:2018-09-25
  • Multi-residue methodology for the determination of 16 coccidiostats in animal tissues and eggs by Hydrophilic Interaction Liquid Chromatography - Tandem Mass Spectrometry
    Food Chem. (IF 4.946) Pub Date : 2018-09-24
    Marilena E. Dasenaki, Nikolaos S. Thomaidis

    A simple, sensitive and efficient confirmatory method was developed and validated for the determination of 16 coccidiostats in animal tissues and eggs using hydrophilic interaction liquid chromatography–tandem mass spectrometry (HILIC-MS/MS). The sample preparation consisted of a solid-liquid extraction with ACN and dispersive SPE cleanup with MgSO4 and C18. Analysis was realized in an Acquity BEH HILIC silica column, in SRM mode. Both positive and negative ionization was performed, using polarity switching. Isocratic elution was used with a mobile phase of ACN: aqueous ammonium formate 1 mM with 0.1% formic acid (80:20, v/v). Method validation was performed in eggs, poultry, bovine, ovine, porcine and rabbit tissue and exceptionally low LODs were achieved, varying from 0.004 μg kg-1 (decoquinate in porcine tissue) to 0.560 μg kg-1 (halofuginone in eggs). The developed methodology was applied in 82 muscle and egg samples through the Greek National Residue Control Plan for coccidiostats.

    更新日期:2018-09-25
  • Structure-antioxidant capacity relationship of dihydrochalcone compounds in Malus
    Food Chem. (IF 4.946) Pub Date : 2018-09-24
    Zhengcao Xiao, Yule Wang, Jinxiao Wang, Pengmin Li, Fengwang Ma

    The antioxidant capacity (AC) of six dihydrochalcone compounds was evaluated using DPPH and ABTS assays. In water-based solution 3-hydroxyphlorizin exhibited the highest AC among all dihydrochalcones. In acetone and acidic solutions (pH = 2.5 or 2.0), presence of an o-dihydroxyl at the B-ring increased AC, whereas glycosylation at the A-ring decreased AC of dihydrochalcones. By comparing the AC of dihydrochalcones with similar structures, it was found that the o-dihydroxyl at the B-ring and 2’-hydroxyl group at the A-ring were critical for maintaining the AC of dihydrochalcones by promoting hydrogen atom transfer or single electron transfer mechanism. Sequential proton-loss electron transfer commonly occurred during free radical scavenging in water-based solution. Moreover, we report a unique phenomenon in which glycosylation at the 2’-position enhanced the dissociation ability of the 4’-hydroxyl group and increased the AC of dihydrochalcones containing o-dihydroxyl. We speculate that this increase in AC might occur through intramolecular electron transfer.

    更新日期:2018-09-25
  • Determination of vitamin K composition of fermented food
    Food Chem. (IF 4.946) Pub Date : 2018-09-24
    Marko Tarvainen, Mikael Fabritius, Baoru Yang

    A rapid ultra-high performance liquid chromatography–atmospheric pressure chemical ionization tandem mass spectrometric (UHPLC-APCI-MS/MS) method was developed for the analysis of vitamin K compounds: phylloquinone (PK) and menaquinones (MK-n). Non-chlorinated mobile phase composition was optimized for separation of eight vitamin K compounds on a reversed phase column in 10 minutes. Sample treatment with liquid and solid phase extractions and by the use of MK-4 as an internal standard enabled the quantitation of microgram level of vitamin K compounds in food. The method was used to screen and quantitate vitamin K from 17 fermented food products. The highest amount of PK was detected in kimchi (42 µg/100 g), whereas the highest MK-7 content was detected in natto (902 µg/100 g). Some MK-9 was present in kefir (5 µg/100 g). Two Chinese fermented soybean pastes contained significant amount of MK-6 (5–36 µg/100 g), MK-7 (12–86 µg/100 g), and MK-8 (22–44 µg/100 g).

    更新日期:2018-09-25
  • Food fraud in oregano: pesticide residues as adulteration markers
    Food Chem. (IF 4.946) Pub Date : 2018-09-24
    Lucie Drabova, Gerardo Alvarez-Rivera, Marie Suchanova, Dana Schusterova, Jana Pulkrabova, Monika Tomaniova, Vladimir Kocourek, Olivier Chevallier, Christopher Elliott, Jana Hajslova

    Oregano, a widely used and popular herb, is particularly vulnerable to fraud. Less valued plants, adulterants that are often used for dilution, may introduce into this commodity additional contaminants such as pesticide residues. In this study, more than 400 pesticides were screened in a representative set of 42 genuine and 34 adulterated dried oregano samples collected from various locations across Europe. The results obtained by advanced mass spectrometry-based methods, showed, that some pesticide residues could be detected in virtually all tested samples, nevertheless, on average, higher contamination was found in the adulterated oregano samples. Increased incidence of insecticides such as cyfluthrin, permethrin and cyhalothrin was typical for these samples, moreover, pyriproxyfen was detected exclusively in adulterated samples. Thus, based on a critical assessment of pesticide profiles, suspected adulterated oregano samples can be selected for follow up authenticity testing.

    更新日期:2018-09-25
  • Effects of boiling, ultra-high temperature and high hydrostatic pressure on free amino acids, flavor characteristics and sensory profiles in Chinese rice wine
    Food Chem. (IF 4.946) Pub Date : 2018-09-21
    Yijin Yang, Yongjun Xia, Guangqiang Wang, Leren Tao, Jianshen Yu, Lianzhong Ai

    Traditional sterilization leads to poor vinosity of Chinese rice wine (CRW). Effects of boiling, ultra-high temperature (UHT) and high hydrostatic pressure (HHP) on CRW quality were investigated. Thermal treatment resulted in a decrease of total free amino-acids (FAA), whereas HHP-treatment caused an increase. However, UHT and HHP treatments had little effect on FAA with sweet and umami-like flavor. HHP-treated CRW contained 7.35% higher content of flavors relative to untreated wine, while thermally-treated CRW revealed 4.68–8.61% losses. Based on principal component analysis, CRW processed at 400 or 600 MPa for 10 min exhibited similar flavor to the untreated wine, which was highly associated with long-chain fatty acid ethyl esters (C13-C18). Moreover, partial least squares regression demonstrated that sensory attributes of cereal aroma and astringency were highlighted after thermal treatment, while fruit aroma, continuation and full body were dominant after HHP treatment. HHP treatment effectively enhanced the quality of CRW, which could be applied in other alcoholic beverages.

    更新日期:2018-09-22
  • Measurement of the interaction between mucin and oenological tannins by Surface Plasmon Resonance (SPR); Relationship with astringency
    Food Chem. (IF 4.946) Pub Date : 2018-09-21
    J. Gombau, P. Nadal, N. Canela, S. Gómez-Alonso, E. García-Romero, P. Smith, I. Hermosín-Gutiérrez, J.M. Canals, F. Zamora

    The interaction between stomach porcine mucin and 3 oenological tannins (extract of ellagitannins from oak, extract of gallotannins from gall nuts and extract of proanthocyanidins from grape seeds) was measured by Surface Plasmon Resonance (SPR). These tannins were analysed and their astringency was determined using the Astringency Index method and by tasting. The interaction constants were determined using a Biacore SPR device (1:1 Langmuir binding model). The results indicate that the ellagitannins are more astringent than gallotannins and those, in turn, are more astringent than seed proanthocyanidins if the richness of the commercial extracts is considered. The astringency index of these tannins had high correlation and regression coefficients with their kinetic and thermodynamic dissociation constants. This data support a hypothesis that astringency depends not only on the thermodynamic tendency to form the complex between tannins and salivary proteins but also probably on the time required to dissociate the complex.

    更新日期:2018-09-21
  • Structural and interfacial characteristics of oil bodies in coconuts (Cocos nucifera L.)
    Food Chem. (IF 4.946) Pub Date : 2018-09-21
    Anant C. Dave, Aiqian Ye, Harjinder Singh
    更新日期:2018-09-21
  • Optimization of heat- and ultrasound-assisted extraction of anthocyanins from Hibiscus sabdariffa calyces for natural food colorants
    Food Chem. (IF 4.946) Pub Date : 2018-09-21
    José Pinela, M.A. Prieto, Eliana Pereira, Inès Jabeur, Maria Filomena Barreiro, Lillian Barros, Isabel C.F.R. Ferreira

    Heat- and ultrasound-assisted extraction methods were applied to recover anthocyanins from Hibiscus sabdariffa calyces. The extraction variables, time (t), ethanol proportion (S), and temperature (T) or ultrasonic power (P), were combined in a 5-level experimental design and analysed by response surface methodology for process optimization. The delphinidin-3-O-sambubioside (C1) and cyanidin-3-O-sambubioside (C2) levels were monitored by LC-DAD-ESI/MSn and used as response criteria. The developed models were successfully fitted to the experimental data and used to determine optimal extraction conditions. UAE was the most efficient method yielding 51.76 mg C1+C2/g R under optimal conditions (t= 26.1 min, P=296.6 W and S= 39.1% ethanol, v/v). The dose-response effects of the solid/liquid ratio on the extraction rate were also determined. The anthocyanin levels herein reported are higher than those found in the literature, which support the potential use of H. sabdariffa as a sustainable source of natural colorants with application in different industrial sectors.

    更新日期:2018-09-21
  • Comparison of concentration and health risks of 9 Fusarium mycotoxins in commercial whole wheat flour and refined wheat flour by multi-IAC-HPLC
    Food Chem. (IF 4.946) Pub Date : 2018-09-21
    Yingyue Zhang, Fei Pei, Yong Fang, Peng Li, Yan Zhao, Fei Shen, Yanyu Zou, Qiuhui Hu

    Multiple mycotoxins can contaminate foods simultaneously leading to increased risks for human health. To assess exposure and health risks of 9 mycotoxins, we employed a multiple immunoaffinity column - high performance liquid chromatography method to determine their concentrations of 35 whole wheat flour and 50 refined wheat flour samples from China. The recoveries of the validated method were 75.78 to 118.24%, and the limits of detection and quantification were 1.5 to 20 and 5.0 to 60 µg kg−1, respectively. Multiple mycotoxins were detected in 37.1% of whole wheat flour and 8% of refined wheat flour. In the worst-case scenario, the hazard index was 222.69% for male and 253.97% for female with a cumulative exposure to Fusarium mycotoxins through consuming whole wheat flour, and deoxynivalenol was the main mycotoxin detected. In conclusion, whole wheat flour should be regarded with more health concern because of cumulative effects of co-occurred mycotoxins.

    更新日期:2018-09-21
  • Efficient extraction of heavy metals from collagens by sulfonated polystyrene nanospheres
    Food Chem. (IF 4.946) Pub Date : 2018-09-20
    Yaotian Peng, Yi Shen, Moyan Ge, Ziyan Pan, Weiming Chen, Bin Gong

    This work reports the feasibility of utilizing sulfonated polystyrene nanospheres (SPS NSs) to extract heavy metals from collagen solutions. We have endeavored to present a detailed study on the adsorption characteristics and mechanism of heavy metals including Pb2+, Mn2+, Cr3+ and Cd2+. The adsorption isotherms were fitted by the Langmuir and Freundlich models while the adsorption kinetics data were described by the pseudo-first-order, pseudo-second-order and intraparticle diffusion equations. The adsorption isotherms were better fitted by the Langmuir model, leading to theoretical maximum capacities of 50.7, 15.0, 8.7 and 39.0 mg g-1 for the adsorption of Pb2+, Mn2+, Cr3+ and Cd2+, respectively. Isothermal titration calorimetry (ITC) measurements were conducted to detect the heat exchange of the adsorption processes. As a proof of concept, SPS NSs were practically applied in sequestrating heavy metals from Talapia-fish-scale derived collagen. The effects of pH of the collagen solutions in the removal of metals were investigated. By a single treatment, the concentrations of the metal ions were decreased to the regulatory standards whilst the concentration of collagen proteins was well maintained.

    更新日期:2018-09-21
  • Isolation and identification of immunomodulatory Se-containing peptides from selenium-enriched rice protein hydrolysates
    Food Chem. (IF 4.946) Pub Date : 2018-09-20
    Yong Fang, Xin Pan, Ermin Zhao, Yi Shi, Xinchun Shen, Jian Wu, Fei Pei, Qiuhui Hu, Weifen Qiu

    The RAW264.7 cell model was employed to screen immunomodulatory Se-containing peptides from selenium-enriched rice protein hydrolysates (SPHs). Moreover, the Se-containing peptides of high-activity protein hydrolysates were purified by Sephadex G-25, and identified by reversed phase ultra performance liquid chromatography coupled with triple quadrupole time-of-flight mass spectrometry. The results showed that 25 peptide sequences containing selenomethionine (SeMet) information above 90% of probability confidence were found in a fraction of alcalase hydrolysates. SeMDPGQQ and TSeMMM of 100% probability confidence were speculated as two novel Se-containing peptide sequences. The artificially synthesized peptide TSeMMM was subsequently verified by an excellent immunomodulatory activity at a concentration of 80 μg/ml. In conclusion, the immunomodulatory activity of SPHs was correlated to SeMet sequence in the structure of Se-containing peptides, and TSeMMM with a stronger immunomodulatory activity demonstrated potential as functional food additives for improving human health.

    更新日期:2018-09-21
  • Profile of phenolic compounds and antioxidant activity of finger millet varieties
    Food Chem. (IF 4.946) Pub Date : 2018-09-20
    Jinle Xiang, Franklin B. Apea-Bah, Victoria U. Ndolo, Mangani C. Katundu, Trust Beta

    The profiles of phenolic compounds and antioxidant capacities of four finger millet varieties harvested in northern Malawi were investigated. The total phenolics, flavonoids and condensed tannins in the free fractions ranged from 114.43 to 179.19 mg ferulic acid equivalent (FAE)/100g, 90.24 to 202.94 mg catechin equivalent (CE)/100g and 31.76 to 83.59 mg CE/100g, respectively. Total phenolic contents of the bound fractions ranged from 58.27 to 123.23 mg FAE/100g. Twenty phenolic compounds were identified in the free fractions including eighteen flavonoids, with catechin and epicatechin being the predominant flavonoids. Seventeen phenolic compounds were identified in the bound fractions, with ferulic acid being the predominant one. Ten of the identified polyphenols were firstly reported in finger millet. Darker colored finger millet varieties had higher phenolic contents and antioxidant properties than the lighter colored ones. Finger millet can be used as healthy food material and natural antioxidant resource.

    更新日期:2018-09-21
  • Development of Stable High Internal Phase Emulsions by Pickering Stabilization: Utilization of Zein-Propylene Glycol Alginate-Rhamnolipid Complex Particles as Colloidal Emulsifiers
    Food Chem. (IF 4.946) Pub Date : 2018-09-20
    Lei Dai, Shufang Yang, Yang Wei, Cuixia Sun, David Julian McClements, Like Mao, Yanxiang Gao

    In this study, zein-propylene glycol alginate-rhamnolipid complex particles were prepared with suitable three-phase contact angles (θ) for stabilizing oil-in-water Pickering high internal phase emulsions (HIPEs). At a fixed oil phase volume (φ = 0.75), particle concentration influenced the stability, physical properties, and rheology of HIPEs. Confocal laser scanning microscopy showed that complex particles formed a densely packed particle layer around the oil droplets and a three-dimensional network in the continuous phase, highlighting the potential for the complex particles to act as effective HIPE stabilizers. The storage modulus (G’) was higher than loss modulus (G’’) over the entire angular frequency range, suggesting HIPEs had an elastic gel-like structure. The HIPEs had good stability across a range of environmental conditions (pH, temperatures and salt concentrations). These findings may extend the application of zein in foods and the HIPEs formed may be used as novel delivery system for bioactives.

    更新日期:2018-09-21
  • Characterization of binding behaviors of Cd2+ to rice proteins
    Food Chem. (IF 4.946) Pub Date : 2018-09-20
    Wei Feng, Tiantian Dong, Keqiang Li, Tao Wang, Zhengxing Chen, Ren Wang

    In this paper, for the first time the binding behavior of cadmium (Cd2+) to rice proteins (RPs) was studied. The results showed that the equilibrium of binding was reached within 30 min at 303 K with a maximum binding amount (q) of 15.26 mg/g, and the pH was an important factor positively influencing q. At both 308 K and 313 K, the binding of Cd2+ to RPs belonged to spontaneous, endothermic interactions with high-affinity, assigned to a multidentate coordination. Except for acetate, all the investigated competing coordination agents, such as edetate, pyrophosphate and citrate, showed inhibitory effects on RPs-Cd2+ binding, and edetate seemed to be the most effective one. At pH 6.5, calcium, copper and zinc began to restrict RPs-Cd2+ binding when the metal ion concentration reached 500 mg/kg, and the decreasing of pH would strengthen the inhibitory effects of the investigated metal ions including ferric ions.

    更新日期:2018-09-21
  • Diffuse reflectance spectroscopy to quantify the met-myoglobin proportion and meat oxygenation inside of pork and beef
    Food Chem. (IF 4.946) Pub Date : 2018-09-20
    Thien nguyen, Sungchul Kim, Jae Gwan Kim

    The potential of diffuse reflectance spectroscopy (DRS) to quantify the met-myoglobin (met-Mb) proportion and meat oxygenation inside of pork and beef was examined. First, reflection spectra were obtained from pork (n = 52) and beef (n = 43) samples under fresh and stored conditions. Second, the DRS algorithm was applied to the reflectance spectra to calculate the met-Mb proportion and oxygenation of the meat. Lastly, a regression model was developed showing the change in the met-Mb proportion and oxygenation during met-Mb formation and degradation. A linear relationship existed between the DRS-based computed data and the known met-Mb proportion with a high correlation (R2 = 0.9999) and a low error (0.86%). Measurement of the meat samples revealed a linear increment of the met-Mb proportion (R2 = 0.77) and a quadratic change in the oxygenation (R2 = 0.44) during the met-Mb formation process. This study demonstrated the ability of DRS to quantitatively analyze the relative content of myoglobin derivatives in both pork and beef.

    更新日期:2018-09-21
  • Changes in physico-chemical properties, microstructure, protein structures and intermolecular force of egg yolk, plasma and granule gels during salting
    Food Chem. (IF 4.946) Pub Date : 2018-09-20
    Lilan Xu, Yan Zhao, Mingsheng Xu, Yao Yao, Na Wu, Huaying Du, Yonggang Tu

    Changes in physico-chemical properties, microstructure, protein structures and intermolecular force of egg yolk, plasma and granule gels during salting were investigated, using low-field nuclear magnetic resonance (LF-NMR), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and chemical analysis. The results showed that the contents of soluble protein and free sulfhydryl increased and, with D2O treatment, T21 and T22 decreased in egg yolks and plasma salted for 2 d. The particles of egg yolks, plasma and granules in the later stage of salting were disrupted and they liberated their constituents (phospholipids, neutral lipids and proteins), which randomly aggregated. The treatment with NaCl changed the spatial structure of egg yolk proteins. The results suggested that the oil exudation of salted egg yolks was mainly due to structural changes in the low-density lipoproteins. Granules were shown to contribute to the higher hardness and gelation of salted egg yolks.

    更新日期:2018-09-20
  • Geographical discrimination of red garlic (Allium sativum L.) produced in Italy by means of multivariate statistical analysis of ICP-OES data
    Food Chem. (IF 4.946) Pub Date : 2018-09-20
    Angelo Antonio D'Archivio, Martina Foschi, Rosaria Aloia, Maria Anna Maggi, Leucio Rossi, Fabrizio Ruggieri

    Sixty-five samples of red garlic (Allium sativum L.) coming from four different production territories of Italy were analysed by means of inductively coupled plasma optical emission spectrometry. The garlic samples were discriminated according to the geographical origin using the content of seven elements (Ba, Ca, Fe, Mg, Mn, Na and Sr). Both classification and class modelling methods by using linear discriminant analysis (LDA) and soft independent model class analogy (SIMCA), respectively, were applied. Classification ability and modelling efficiency were evaluated on an external prediction set (21 garlic samples) designed by application of duplex Kennard-Stone algorithm. All the calibration and prediction samples were correctly classified by means of LDA. The class models developed using SIMCA exhibited high sensitivity (almost all the calibration and external samples were accepted by the respective classes) and good specificity (the majority of extraneous samples were refused by each class model).

    更新日期:2018-09-20
  • Predicting calcium in grape must and base wine by FT-NIR spectroscopy
    Food Chem. (IF 4.946) Pub Date : 2018-09-20
    Joana Vestia, João Mota Barroso, Helena Ferreira, Luís Gaspar, Ana Elisa Rato

    Calcium content in sparkling wines may not exceed 80 mg/L due to the risk of aggregation with alginate capsules. The high calcium content usually found in wine and must emphasizes the need to develop alternative and appropriate techniques faster and cleaner than atomic absorption spectrometry (AAS). To obtain a robust model to predict calcium content, FT-NIR spectroscopy was used in 98 base white wine samples and 60 must samples from an Alentejo winery. The reference method for calcium determination was AAS technique, with a dry ashing sample procedure, as a prior treatment.Results confirmed the ability of FT-NIR as an alternative technique to AAS, to predict calcium content in grape must and base wine. Advance knowledge of the calcium content in the grape must will help avoid obtaining a mixture of musts with a high calcium content in the same container.

    更新日期:2018-09-20
  • Quantification of polycyclic aromatic hydrocarbons and phthalic acid esters in deodorizer distillates obtained from soybean, rapeseed, corn and rice bran oils
    Food Chem. (IF 4.946) Pub Date : 2018-09-20
    Longkai Shi, Li Zheng, Ruijie Liu, Ming Chang, Jianhua Huang, Qingzhe Jin, Xingguo Wang

    In this study, simple GC-MS methods for analysising sixteen PAHs and seven PAEs were individually established. The LOQs for PAHs and PAEs were ranging from 0.18 to 0.42 μg/kg and 0.19 to 1.50 μg/kg, respectively. The recoveries for DD samples were in the range of 84.8%-115.5% and 84.2%-109.3% for PAHs and PAEs, respectively. Furthermore, PAHs and PAEs concentrations in soybean, rapeseed, corn and rice bran oil distillates were evaluated. PAHs were found in all the DD samples and the concentrations of BaP, PAH4 and total PAHs were 0.89-55.58, 8.11-326.07 and 115.77-966.40 μg/kg, respectively. Correspondingly, total PAEs concentrations ranged from 2.45 to 24.52 mg/kg, and the mean value was 7.76 mg/kg. The results illustrated that the contents of PAHs and PAEs in the DDs were extremely higher than those in the edible oils, thus indicating that specific issues should be considered in the vegetable oil DDs and DD-based products.

    更新日期:2018-09-20
  • Effects of nitro- and amino-group on the antioxidant activity of genistein: a theoretical study
    Food Chem. (IF 4.946) Pub Date : 2018-09-19
    Lingling Wang, Fengjian Yang, Xiuhua Zhao, Yuanzuo Li

    Five novel compounds (Gen-NO2, Gen-2NO2, Gen-NH2, Gen-2NH2 and Gen-6NH2) have been designed via introducing an electron-withdrawing group –NO2 and an electron-donating group –NH2 into the structure of genistein. The effects of –NO2 and –NH2 groups on the antioxidant ability of genistein were investigated via quantum chemistry method in gas and methanol phases. The crucial parameters related to three antioxidant mechanisms were calculated. Moreover, the frontier molecular orbital, natural bond orbital and global descriptive parameters were calculated to evaluate the reactivity of genistein and its derivatives. Calculated results indicate the antioxidant process of genistein and its derivatives inclines to the hydrogen atom transfer (HAT) and sequential proton loss electron transfer (SPLET) mechanisms in gas and methanol phases, respectively. Moreover, introducing –NH2 group into genistein can improve its antioxidant activity owing to the outstanding activities of amino-substituents of genistein, which will provide valuable guidance for the synthesis of new antioxidants experimentally.

    更新日期:2018-09-20
  • Evaluation of casein as a binding ligand protein for purification of alpha-lactalbumin from beta-lactoglobulin under high hydrostatic pressure
    Food Chem. (IF 4.946) Pub Date : 2018-09-19
    Alice Marciniak, Shyam Suwal, Guillaume Brisson, Michel Britten, Yves Pouliot, Alain Doyen

    Fractionation of β-lactoglubulin (β-lg) and α-lactalbumin (α-la) using conventional separation technologies remains challenging mainly due to similar molecular weight. Herein, casein (CN) was used as ligand protein to specifically aggregate β-lg under high hydrostatic pressure (HHP) in order to separate α-la after acidification to pH 4.6. Specifically, we studied the effect of different concentration of CN on α-la purity and recovery. Model solutions of α-la, β-lg and CN (from 0 to 5 mg/mL) were pressurized (600 MPa - 5 min). After acidification and centrifugation of pressure-treated solutions, purity of α-la was increased up to 78% with a recovery of 88% for solution without CN. In contrast with our initial hypothesis, the presence of CN decreased β-lg pressure-induced aggregation and co-precipitation upon acidification and significantly reduced purity (∼ 71%). Therefore, our results suggest a chaperone-like activity of CN on β-lg pressure-induced aggregation which needs further investigation.

    更新日期:2018-09-20
  • Development of a new format of competitive immunochromatographic assay using secondary antibody–europium nanoparticle conjugates for ultrasensitive and quantitative determination of ochratoxin A
    Food Chem. (IF 4.946) Pub Date : 2018-09-19
    Marjan Majdinasab, Mohsen Zareian, Qi Zhang, Peiwu Li

    In this study, to enhance the sensitivity of conventional immunochromatographic assay (ICA) two strategies including using a high sensitive label and changing the assay format, were simultaneously applied to develop an ultrasensitive format of ICA. In new format, primary monoclonal antibody against ochratoxin A (OTA) was used without any labeling, and a secondary polycolonal antibody was labeled with europium fluorescent nanoparticles (EuNPs). Detection was performed in a single step by inserting the test strip into a microtube containing all reagents. The results were obtained within 12 min and read by a portable fluorescent strip reader. Salient features of the new format of ICA compared with conventional format include: (1) A 100-fold decrease in limit of detection (LOD) due to application of two amplification strategy; (2) Reduction in expensive monoclonal antibody consumption. The established method was evaluated for the quantitative determination of OTA with LOD as low as 0.4 pg mL-1.

    更新日期:2018-09-20
  • Applicability and reliability of the glucose oxidase method in assessing α-amylase activity
    Food Chem. (IF 4.946) Pub Date : 2018-09-19
    Rizliya Visvanathan, Chathuni Jayathilake, Ruvini Liyanage, Ramiah Sivakanesan

    Glucose oxidase (GOD) is an enzyme widely used in glucose monitoring systems owing to its high specificity towards glucose. However, in our previous work maltose was found to show significant interaction with GOD and based on this observation, a novel microplate based method was developed to assess α-amylase inhibitory activity (GOD method). Concerns regarding the interaction of GOD with maltose has limited the widespread use of the GOD method in assessing α-amylase activity. The present paper provides answers for concerns regarding the interaction of GOD with maltose using HPLC studies and application of the GOD method in assessing α-amylase activity. According to the results, the newly developed GOD method can be considered as a well-suited method for the determination of α-amylase activity and as an easy method to do kinetic studies compared to other available methods.

    更新日期:2018-09-20
  • Ancient olive trees as a source of olive oils rich in phenolic compounds
    Food Chem. (IF 4.946) Pub Date : 2018-09-19
    Nuno Rodrigues, Susana Casal, Teresa Pinho, António M. Peres, Albino Bento, Paula Baptista, José Alberto Pereira

    Olive oil phenolic compounds are receiving increased attention due to its influence on sensory characteristics and to scientific evidences of positive health effects. In this work, 28 ancient olive trees were selected and, during four consecutive seasons (2014-2017), oils were extracted and their phenolic fraction characterized. Hydroxytyrosol and tyrosol secoiridoids were the predominant groups, with contents between 32 to 496 mg of tyrosol equivalents/kg. Based on principal component analysis it could be concluded that the individual phenolic contents enabled the unsupervised grouping of olive oils by crop year. Furthermore, linear discriminant analysis allowed achieving sensitivities greater than 90%. It was shown that some specimens consistently allowed obtaining oils with high phenolic contents (≥500mg tyrosol equivalents/kg). The identification of centenarian specimens for breeding based on their potential to produce oils with high levels of healthy compounds is of utmost interest, contributing to preserve the genetic heritage.

    更新日期:2018-09-20
  • Effects of Atmospheric Pressure Plasma Jet on the Conformation and Physicochemical Properties of Myofibrillar Proteins from King Prawn (Litopenaeus vannamei)
    Food Chem. (IF 4.946) Pub Date : 2018-09-19
    Flora-Glad Chizoba Ekezie, Jun-Hu Cheng, Da-Wen Sun

    The aim of this study was to ascertain the impact of atmospheric pressure plasma jet treatment (APPJ) as a function of treatment times (0, 2, 4, 6, 8 and 10 min) on the conformation and physicochemical properties of myofibrillar proteins (MPs) extracted from king prawn (Litopenaeus vannamei). The results showed that the pH and protein solubility were decreased after 10 min treatment of APPJ. These results were also confirmed by dynamic light scattering, which indicated an increase in mean particle diameter of MPs from 654 to 2297 nm. Complementary methodologies used to characterize the structural changes confirmed the exposure of hydrophobic groups and promotion of protein-protein interactions. These occurrences were particularly more intense at the longest treatment duration. The high energetic and oxidizing species contained in the plasma gas may have considerable implications on the physical and structural characteristics of MPs from king prawn.

    更新日期:2018-09-20
  • Lasiodiplodia theobromae (Pat.) Griff. & Maubl. reduced energy status and ATPase activity and its relation to disease development and pericarp browning of harvested longan fruit
    Food Chem. (IF 4.946) Pub Date : 2018-09-19
    Shen Zhang, Hetong Lin, Mengshi Lin, Yifen Lin, Yihui Chen, Hui Wang, Yixiong Lin, John Shi

    This study aimed to investigate the effects of Lasiodiplodia theobromae (Pat.) Griff. & Maubl (L. theobromae) inoculation on the energy status and activity of adenosine triphosphatase (ATPase) during L. theobromae-induced disease development and pericarp browning of harvested ‘Fuyan’ longan (Dimocarpus longan Lour. cv. Fuyan) fruit. The results showed that, compared to the control longans, L. theobromae-inoculated longans displayed higher indices of fruit disease and pericarp browning, lower pericarp ATP and ADP contents, higher AMP content, lower level of energy charge, as well as lower activities of Ca2+-ATPase, Mg2+-ATPase and H+-ATPase in membranes of plasma, vacuole, and mitochondria. These results indicated that the infection of L. theobromae reduced energy status and ATPase activities, caused ions disorder, damaged the integrity and function of the cell and organelles including vacuole and mitochondria in pericarp of longan fruit, which contributed to L. theobromae-promoted disease development and pericarp browning of harvested longan fruit during storage.

    更新日期:2018-09-20
  • Effect of tannic acid on the structure and activity of Kluyveromyces lactis β-galactosidase
    Food Chem. (IF 4.946) Pub Date : 2018-09-19
    Cíntia Tiemi Misugi Kayukawa, Marco Aurélio Schüler de Oliveira, Elaine kaspchak, Heloisa Bruna Soligo Sanchuki, Luciana igarashi-Mafra, Marcos Rogério Mafra

    Tannins are compounds with antinutrient properties that hinder food digestibility, prejudicing human and animal nutrition. This work aimed to evaluate the negative effects of tannic acid on Kluyveromyces lactis β-galactosidase catalytic activity and correlate these changes with the protein structure. β-Galactosidase activity decreased in the presence of tannins, which caused changes to the structure of the enzyme, as demonstrated by circular dichroism. It was verified that tannin binds to the protein by a static mechanism. Additionally, isothermal titration calorimetry suggested that tannic acid modified the molecular interaction between β-galactosidase and o-nitrophenyl-β-D-galactoside, reducing their affinity and prejudicing the protein activity. This study helps to understand the effects of tannins on the β-galactosidase structure and how they are related to the enzyme catalytic activity. The alterations in the conformation and activity of the enzyme should be taken into consideration when dairy products are consumed with tannin-rich food.

    更新日期:2018-09-20
  • Co-melting behaviour of sucrose, glucose & fructose
    Food Chem. (IF 4.946) Pub Date : 2018-09-19
    Yong Wang, Tuyen Truong, He Li, Bhesh Bhandari

    The co-melting behaviour of sugar mixtures, comprising sucrose, glucose and fructose at various binary (3:1, 1:1, 1:3, 1:7, 1:15) and ternary (4:1:1, 2:1:1, 1:1:1, 2:5:5, 2:11:11, 1:4:1, 1:10:1) ratios, was studied using DSC. The melting temperature of sucrose was found to decrease in the presence of either fructose or glucose. In the sugar mixtures, the melting enthalpy of sucrose decreased compared with the proportional calculated values, using the percentage equation, whilst the melting enthalpy of fructose or glucose increased at the same time, implying the melting or dissolution of sucrose together with fructose or glucose. The tested enthalpy is usually higher than the calculated enthalpy for fructose, but lower than the calculated enthalpy for sucrose. Microscopic pictures showed that sucrose crystals could melt and dissolve gradually in the fructose melt liquid. This study provides useful information for both fundamental understanding of sugars co-melting and food industry applications.

    更新日期:2018-09-20
  • Stability and recovery of cyclodextrin encapsulated catechin in various food matrices
    Food Chem. (IF 4.946) Pub Date : 2018-09-20
    Siyin Ho, Yin Yin Thoo, David James Young, Lee Fong Siow

    Catechin is astringent in taste, sparingly soluble in water and sensitive to oxygen, light and pH. These properties restrict its application in food products. The present study investigated the stability of inclusion complex (IC) and catechin in various food matrices and investigated in vitro recovery profile of catechin and IC in liquid, semi-solid and solid food matrices. Besides, the sensory profile of IC added yogurt was also determined. Results showed that IC and catechin was more stable in solid matrix compared to semi-solid and liquid matrices. IC added in milk and yogurt show the highest percentage recovery of catechin compared to IC added in cheese and catechin added in all the matrices in in vitro digestive system. Through IC, β-CD masked the bitterness of catechin. These results suggest that protection of antioxidant such as catechin by β-CD inclusion complex may have applications in functional foods and health supplements.

    更新日期:2018-09-20
  • Electron spin resonance (ESR) spectroscopy study of cheese treated with accelerated electrons
    Food Chem. (IF 4.946) Pub Date : 2018-09-18
    Rosa Escudero, Jose Segura, Raquel Velasco, Margarita Valhondo, M. Dolores Romero de Ávila, Ana Belén Garcia-Garcia, M. Isabel Cambero

    The generation, accumulation and decay of free radicals in six varieties of cheese, irradiated (0–4 kGy) in an electron accelerator, have been studied by electron spin resonance (ESR) spectroscopy. Remarkably, the ESR spectra of all untreated cheeses showed only one singlet signal with a g-factor of 2.0064 ± 0.0005. Surprisingly, the ESR spectra of irradiated samples presented a new signal with g–factor of 2.0037 ± 0.0003 which was independent of the type of cheese, and which might be due to free radicals from the radiolysis of proteins. Surface regression models (P < 0.0001) established the relationship among signal intensity, absorbed dose (0, 1, 2 and 4 kGy) and storage time (0 to 180 days) for the different types of cheese. Results suggested that the analysis by ESR (or electron paramagnetic resonance, EPR) is suitable to evaluate, either qualitatively or quantitatively, the irradiation treatment of different types of cheese.

    更新日期:2018-09-18
  • Effect of nitric oxide and calpastatin on the inhibition of µ-calpain activity, autolysis and proteolysis of myofibrillar proteins
    Food Chem. (IF 4.946) Pub Date : 2018-09-18
    Rui Liu, Steven Lonergan, Edward Steadham, Guanghong Zhou, Wangang Zhang, Elisabeth Huff-Lonergan

    The aim of this study was to investigate the dual effect of the nitric oxide donor NOR-3 and calpastatin on µ-calpain activity, autolysis, and proteolytic ability. µ-Calpain and calpastatin were purified and allocated to the following five treatments: µ-calpain, µ-calpain+calpastatin, µ-calpain+NOR-3, µ-calpain+calpastatin+NOR-3, and µ-calpain+NOR-3+calpastatin. µ-Calpain autolysis and the activity against purified myofibrils was initiated by addition of calcium. Results showed that NOR-3 could induce µ-calpain S-nitrosylation and effectively block the activity via the inhibition of µ-calpain autolysis. Calpastatin inhibited µ-calpain activity in a dose-dependent manner. The combined treatment of NOR-3 and calpastatin exerted a further inhibitory effect on µ-calpain activity, autolysis and proteolysis which was affected by the addition order of NOR-3 and calpastatin. Our data suggest that S-nitrosylation may play a regulatory role in mediating µ-calpain activity in the presence of calpastatin.

    更新日期:2018-09-18
  • Characterisation and geographical traceability of Italian goji berries
    Food Chem. (IF 4.946) Pub Date : 2018-09-17
    Daniela Bertoldi, Lina Cossignani, Francesca Blasi, Matteo Perini, Alice Barbero, Silvia Pianezze, Domenico Montesano

    This work characterises and distinguishes Italian and Asian goji berries, combining three analytical approaches to determine 5 light stable isotope ratios, 57 mineral elements and 14 carotenoids.The study analyses stable isotope ratios and provides full HPLC-DAD-MS characterisation of the carotenoid fraction in goji berries for the first time. The isotopic composition of Italian berries was characterised by δ13C values ranging between -28.2 and -25.7‰, δ15N between 2.3 and 7.3‰, δ34S between 2.6 and 7.9‰, and D/H between -112 and -49‰.Italian goji berries were shown to have a particular composition and interesting nutritional characteristics, specifically a higher total carotenoid content (355 mg/100g dw mean content vs 198 mg/100g dw) and higher content of some micronutrients: K, B, Cu, Mo, Se, and Zn.On the basis of δ34S, Y, U, Cu, Rb, zeaxanthin palmitate and total carotenoid content, discriminant analysis correctly classified all samples according to their geographical origin.

    更新日期:2018-09-18
  • Evaluation of the Perceptual Interaction among Ester Aroma Compounds in Cherry Wines by GC-MS, GC-O, Odor threshold and Sensory analysis: An insight at the molecular level
    Food Chem. (IF 4.946) Pub Date : 2018-09-17
    Yunwei Niu, Pinpin Wang, Zuobing Xiao, Jiancai Zhu, Xiaoxin Sun, Ruolin Wang

    The ester aroma profiles of five Chinese cherry wines and the perceptual interaction among esters were investigated in this study. 24 esters were identified by Gas chromatography-olfactometry (GC-O) and Gas Chromatography-Mass Spectrometer (GC-MS). According to addition/omission analysis, seven volatile compounds among them were selected and studied using sensory profiling and multivariate statistic methods such as Principal Component Analysis (PCA). In sensory analysis, a significant reduction of olfactory threshold for total aromatic reconstitution was induced by the addition among each of them in Feller’s additive model, which demonstrated their synergistic effects. The σ/τ plot showed that most of them were followed by a partial addition behavior. Furthermore, PCA indicated that the addition among each of them had a significant effect on fruity, floral, sweet and fermentation aroma intensity. Specifically, ethyl decanoate and methyl salicylate at sub-threshold concentrations were also likely to contribute to overall aroma. The results of perceptual interaction were mainly influenced by chemical structure and molecular polarity.

    更新日期:2018-09-18
  • Cultivar-specific responses in red sweet peppers grown under shade nets and controlled-temperature plastic tunnel environment on antioxidant constituents at harvest
    Food Chem. (IF 4.946) Pub Date : 2018-09-17
    Chembi Solomon Lekala, Khalil Saber H. Madani, Anh Dao Thi Phan, Martin Makgose Maboko, Helen Fotouo, Puffy Soundy, Yasmina Sultanbawa, Dharini Sivakumar

    Antioxidant constituents such as carotenoids (capsanthin, phytoene, lutein, β-cryptoxanthin), polyphenols content (p-coumaric, ferulic, p-hydroxybenzoic, caffeic acid, sinapic acid, and quercetin-3-glucoside) and marketable yield were investigated in 11 sweet pepper cultivars grown under controlled temperature plastic tunnel and white shade net. Marketable yield was not affected by either of the environments, while the interaction between cultivar and growing environment significantly affected the accumulation of antioxidant constituents. The principal component analysis illustrated that controlled temperature plastic tunnel improved the accumulation of carotenoid components and ascorbic acid and vitamin C content in most cultivars. On the contrary, white shade nets favoured the accumulation of phenolic compounds and ORAC activity in most cultivars. A strong correlation was noted between phytoene and carotenoid components in this study (capsanthin r = 0.60; P < 0.001; lutein r = 0.75; P < 0.001; β-carotene r = 0.78; P < 0.001) while ORAC correlated with phenolic compounds. Based on this study, it is possible to refine the choice of environment and cultivar to enhance individual antioxidant constituent groups to improve health benefits for consumers.

    更新日期:2018-09-18
  • Stability of a cyanidin-3-O-glucoside extract obtained from Arbutus unedo L. and incorporation into wafers for colouring purposes
    Food Chem. (IF 4.946) Pub Date : 2018-09-17
    Cecilia Jiménez López, Cristina Caleja, M.A. Prieto, Marina Sokovic, Ricardo C. Calhelha, Lillian Barros, Isabel C.F.R. Ferreira

    An extract from Arbutus unedo fruits, rich in anthocyanins, was studied as a natural colorant with bioactive properties (antioxidant, antimicrobial and cytotoxic). The aqueous stability of the extract was monitored using the anthocyanins’ content as response (determined by HPLC-DAD) in function of time, temperature and pH. Aided by mechanistic/phenomenological models, the conditions that favours the stabilization of the extract were provided, highlighting the suitability of the colorant for pastry/bakery products. As a case study, the extract was incorporated into wafers and the changes on the nutritional profile, free sugars, fatty acids and antioxidant properties were monitored during 6 days of storage. The results provide information for: i) potential application of the rich extract in anthocyanins for producing a natural colorant with bioactive properties; and ii) shelf-life predictions. The extract incorporation did not cause changes in the nutritional components of wafers but added colorant and antioxidant properties.

    更新日期:2018-09-18
  • Stability and colour evaluation of red cabbage waste hydroethanolic extract in presence of different food additives or ingredients
    Food Chem. (IF 4.946) Pub Date : 2018-09-17
    Antoanela Patras

    Red cabbage waste is a valuable source of anthocyanins which may be used as natural food dye. Excepting the colouring agents, food/beverage contains compounds from the matrix or other additives/ingredients. Present study reveals the influences of nineteen food additives/ingredients on the stability, colour parameters and radical scavenging activity during 20 weeks of storage of red cabbage waste hydroethanolic extract (initial pH=6.31) under aerobic atmosphere, in the dark, at 4°C. At studied concentration (0.2%), most important changes were produced by tartaric and citric acids: decrease of monomeric anthocyanins content, lightness, radical scavenging activity, and increase of polymeric colour, browning and degradation indices, chroma and red colour parameter, blue colour parameter and hue angle, inducing very important overall colorimetric differences. Similar influences, but much attenuated, proved ascorbic and benzoic acids. During storage, the untreated extracts revealed a very high stability, and also mostly of treated extracts (especially with sugars).

    更新日期:2018-09-18
  • 更新日期:2018-09-18
  • Potentiality of front-face fluorescence and mid-infrared spectroscopies coupled with partial least square regression to predict lipid oxidation in pound cakes during storage
    Food Chem. (IF 4.946) Pub Date : 2018-09-18
    Zeineb Nhouchi, Eliot Patrick Botosoa, Christine Chene, Romdhane Karoui

    The potentialities of front-face fluorescence (FFF) and mid-infrared (MIR) spectroscopies coupled with partial least square regression (PLSR) were compared to predict the lipid oxidation of pound cakes. The level of lipid oxidation in pound cakes determined using classical methods showed some changes. Similarly, the fluorescence emission (305-490 nm) and excitation (252-390 nm) spectra and MIR spectra scanned in the 4000-900 cm-1 region showed some changes in pound cakes as a function of both storage time and the type of oil used in the formulation. The application of PLSR to the MIR spectra, provided excellent predictive results for free fatty acid (R2 = 0.97) and peroxide values (R2 = 0.87). Similar results were obtained from both tryptophan and MIR spectra for the prediction of TOTOX (R2 > 0.86) demonstrating the efficiency of the MIR and FFF spectroscopies to qualify and quantify the level of lipid oxidation in pound cakes.

    更新日期:2018-09-18
  • Structural and physicochemical characteristics of lycoris starch treated with different physical methods
    Food Chem. (IF 4.946) Pub Date : 2018-09-17
    Fan Zhang, Yuan-Yuan Zhang, Kiran Thakur, Jian-Guo Zhang, Zhao-Jun Wei

    The effects of microwave treatment (MT), heat-moisture treatment (HMT) and autoclaving treatment (GT) on the structural and physicochemical characteristics of lycoris starch (LS) were investigated. The HMT-LS and GT-LS particles were larger and rougher with block-like characteristics compared to the LS particles. The XRD results revealed that HMT and GT converted native starch (A-type) into B-type starch. The density of the starch crystallization zone after HMT and GT was higher than that of LS, while MT had the weakest effect. The solubility and swelling power of MT-LS, HMT-LS and GT-LS were significantly (p<0.05) lower at 65 and 95 °C, but opposite trends were observed at 55 °C. The RVA viscograms for MT-LS, HMT-LS, and GT-LS showed a lower breakdown and setback value compared to that of LS, reflecting stronger starch aggregations and lower retrogradation tendencies. Additionally, both G’ and G” of the treated starch were lower, which indicated weaker gel structures.

    更新日期:2018-09-17
  • Co-localization of glucose oxidase and catalase enabled by a self-assembly approach: Matching between molecular dimensions and hierarchical pore sizes
    Food Chem. (IF 4.946) Pub Date : 2018-09-15
    Wei Zhuang, Jinsha Huang, Xiaojing Liu, Lei Ge, Huanqing Niu, Zhenfu Wang, Jinglan Wu, Pengpeng Yang, Yong Chen, Hanjie Ying
    更新日期:2018-09-17
  • Metabolomic Studies of Volatiles from Tomatoes Grown in Net-House and Open-Field Conditions
    Food Chem. (IF 4.946) Pub Date : 2018-09-15
    Jisun H.J. Lee, G.K. Jayaprakasha, Carlos A. Avila, Kevin M. Crosby, Bhimanagouda S. Patil

    In the present study, the influence of production systems (net-house and open-field) on volatile profiles of three Texas A&M University (TAMU) and five commercial tomato varieties was investigated. Forty metabolites were determined using headspace solid phase microextraction (HS-SPME) equipped with gas chromatography and mass spectrometry (GC-MS). The data was evaluated by multivariate analyses to discriminate the effects of genotype and production system, and to identify potential biomarker(s). The levels of hexanal, p-cymene, and (E)-2-hexenal from TAMU tomato varieties were distinct from those of commercial varieties. Similarly, 16 metabolites were considerably affected by the production systems, and majority of these volatiles were significantly higher in the net-house-grown tomatoes. Multivariate analysis also allowed identifying geranylacetone and d-limonene as potential biomarkers to classify tomatoes according to production systems. These findings underline the importance of the selection of variety and production system to preserve or improve desirable aroma traits in tomatoes.

    更新日期:2018-09-17
  • Nondestructive determination of freshness indicators for tilapia fillets stored at various temperatures by hyperspectral imaging coupled with RBF neural networks
    Food Chem. (IF 4.946) Pub Date : 2018-09-15
    Ce Shi, Jianping Qian, Wenying Zhu, Huan Liu, Shuai Han, Xinting Yang

    This study develops a reliable radial basis function neural networks (RBFNNs) to estimate freshness for tilapia fillets stored under non-isothermal conditions by using optimal wavelengths from hyperspectral imaging (HSI). The results show that, for tilapia fillet stored at −3, 0, 4, 10, and 15 °C and non-isothermal conditions, total volatile basic nitrogen (TVB-N), total aerobic counts (TAC), and the K value increase whereas sensory scores decrease with increasing storage time. To simplify the models, nine optimal wavelengths were selected by using the successive projections algorithm (SPA), following which SPA–RBFNN models were built based on the selected wavelengths and the values of TVB-N, TAC, K, and sensory evaluations for tilapia fillets store isothermally. The ability of the models based on HSI to predict the freshness indicators were verified for tilapia fillets stored under non-isothermal conditions. HSI thus has an excellent potential for nondestructive determination of freshness in tilapia fillets.

    更新日期:2018-09-17
  • Postmortem Ageing Influences the Thawed Meat Quality of Frozen Lamb Loins
    Food Chem. (IF 4.946) Pub Date : 2018-09-15
    Guixia Li, Zheng Li, Xin Li, Ying Wang, Jie Zhu, Dequan Zhang

    The aim of this study was to determine the effect of postmortem ageing on quality attributes of frozen/thawed lamb loins. The loins (M. Longissimus dorsi; n = 30) were randomly divided into six groups: five frozen treatment groups and the control (4 °C for 120 h). Treatment groups were frozen for 3 weeks and thawed at 4°C overnight, muscles were preserved at 4°C until 120 h. Compared to the control, pH values and color of frozen meat declined (P<0.05) after ageing for 72 h, lower shear force values and higher water loss with earlier freezing were due to extensive degradation of myofibril protein. These results indicated the loins frozen in earlier period could accelerate ageing rate, but impaired meat quality inevitably, freezing between 12 h and 24 h postmortem was a better consideration.

    更新日期:2018-09-17
  • 更新日期:2018-09-17
  • Understanding the causes of calcium carbonate crystal growth and inhibition during the carbonatation refining of raw sugars
    Food Chem. (IF 4.946) Pub Date : 2018-09-14
    Marsha Cole, Gillian Eggleston, Ya-Jane Wang

    The inhibitory activity of soluble and insoluble starch (0 to 550 ppm/Brix) in factory raw sugars were investigated using simulated refinery carbonatation clarification reactions to underpin what causes the undesirable formation of CaCO3 crystal fines (≤5 μm). It was found that CaCO3 crystal growth was inhibited mostly by soluble starch by forming starch-Ca2+ metal complexes. Insoluble (granular) starch, however, had a greater affinity for inhibiting CaCO3 crystallization because it retained the carbonatation clarification reactants, i.e., Ca2+and OH-, in the granule interior which caused granule gelatinization and increased viscosity of the melt liquor. Causes for poor press filterability and CaCO3 fines using raw sugar melts were found to be complex and attributed to the combinatorial roles that both soluble and insoluble starch have, among other impurities. More studies are now warranted at the carbonatation refinery to correlate processing characteristics with raw sugars quality attributes to underpin how each impurity impedes carbonatation.

    更新日期:2018-09-15
  • Insight into the evolution of flavor compounds during cooking of common beans utilizing a headspace untargeted fingerprinting approach
    Food Chem. (IF 4.946) Pub Date : 2018-09-14
    Claire M. Chigwedere, Wondyfraw W. Tadele, Junjie Yi, Scheling Wibowo, Biniam T. Kebede, Ann M. Van Loey, Tara Grauwet, Marc E. Hendrickx

    Beans age during storage leading to prolonged cooking times. Chemical reactions that occur during cooking lead to volatile production and flavor generation. Whereas few studies profiled the volatile fingerprint of either non-cooked beans or beans cooked for a specific time, this study explored the evolution of volatiles through headspace fingerprinting of beans cooked at 95 °C to different extents. The influence of aging of beans on this evolution was investigated. Cooking time clearly influenced the evolution of volatiles for both fresh (non-aged) and aged beans. Aged beans exhibited more discriminant compounds than fresh beans regardless of texture considerations due to differences in pre-history of the beans. Strecker aldehydes, sulphur compounds and furan compounds were identified as marker compounds and were linked to mainly lipid oxidation and Maillard reactions. In conclusion, both aging prior to cooking and the cooking process itself largely influence the evolution of volatile compounds during cooking.

    更新日期:2018-09-15
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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