Recent trends in methods used to obtain natural food colorants by freeze-drying

https://doi.org/10.1016/j.tifs.2020.06.005Get rights and content

Highlights

  • Natural colorant can be obtained by freeze-drying with and without the stabilizers.

  • Industrial waste, fruit peels, or petals of various flowers can be used in the future.

  • Freeze-dried whole plant has several functions (color, fiber, vitamin, mineral).

Abstract

Background

Natural food colorants obtained from plants are of growing interest, as they are safe and healthy and positively affect the color of the food; in addition, they may have further positive effects on its properties. Many studies have shown different methods of obtaining natural food colorants. To date, there are some review studies on natural food colorants, but there are no studies describing the process of the freeze-drying method and the pretreatments used.

Scope and approach

In this review, we describe the freeze-drying methods and pretreatments used in the measurement of the quality of the obtained food colorants. In addition, we review studies describing natural sources of colorants and examples of their applications in food. Future trends in the research related to natural food colorants have also been reviewed.

Key findings and conclusion

The most commonly used procedure for obtaining natural colorants consists of several basic steps: extraction, filtration, concentration, and freeze-drying. Freeze-drying is one method which can yield good quality product from whole or part plants, including without the addition of color stabilizers. Some interesting future techniques could be the use of industrial waste, fruit peels, or petals of various flowers in the production of natural pigments. The freeze-drying technique could be ideal for functional additives that combine several functions (color, fiber, minerals, and vitamins). The determination of antiseptic properties of natural colorants obtained by freeze-drying is also valuable.

Introduction

Food colorants are increasingly used in the food industry(Aberoumand, 2011; Coronel-Aguilera & San Martín-González, 2015; Fernandez, Torres-Giner, & Lagaron, 2009; Houghton & Hendry, 2012; Shipp & Abdel-Aal, 2010). Despite the reported immune suppression or intolerance reactions after consumption of synthetic food colorants (Feketea & Tsabouri, 2017), the usage of natural food colorants has been increasing worldwide (Agrawal, 2013; Low, Tan, Lim, & Chan, 2017; Mahdavi, Jafari, Ghorbani, & Assadpoor, 2014; Obón et al., 2009).

Natural colorants from plant sources enjoy more interest as they impart positive effects on human health (Konczak & Zhang, 2004), and they can also be used as functional additives (Cevallos-Casals, Byrne, Okie, & Cisneros-Zevallos, 2006; Dziki et al., 2015; Moreno, García-Viguera, Gil, & Gil-Izquierdo, 2008; Nontasan, Moongngarm, & Deeseenthum, 2012). However, natural pigments have limited usage due to their lower stability and greater interactions with other food ingredients (Castellar, Obón, Alacid, & Fernández-López, 2003; Idham, Muhamad, & Sarmidi, 2012; Rein & Heinonen, 2004; Sigurdson, Tang, & Giusti, 2017; Wrolstad, Durst, & Lee, 2005); therefore, it is necessary to choose appropriate methods to obtain an effective product.

Much research has been published related to the extraction of natural food colorants (Caldas-Cueva et al., 2016; Gorbunova, Bannikova, Evteev, Evdokimov, & Kasapis, 2018; Ranjan Sarkar, Das, Bhagawati, & Ch Goswami, 2012; Sivakumar, Vijaeeswarri, & Anna, 2011). Conventional technologies of extraction often use high temperatures and toxic solvents (Barba, Galanakis, Esteve, Frigola, & Vorobiev, 2015). However, the extraction step using bio-solvents or organic solvents or novel technique-assisted extraction is very important to obtain high color yield and other qualities such as high levels of phytochemicals and other active compounds (Ngamwonglumlert, Devahastin& Chiewchan, 2017). In recent years, the technique of microencapsulation of colorants by spray-drying has become very popular (García-Lucas et al., 2017; Namazkar & Ahmad, 2013; Priya & Preetha, 2016; Zhang & Zhong, 2013). In this technique, it is also necessary to use different stabilizers (Lacerda et al., 2016; Wiesenborn, Zbikowski, & Nguyen, 1995). However, freeze-drying allows good quality product to be obtained from all or part of the plant without the addition of color stabilizers(Dziki et al., 2018; Nemzer et al., 2011; Rudy et al., 2015). This drying technique is the most suitable for materials sensitive to high temperatures (Dong, Hu, Chu, Zhao, & Tan, 2017; Hua, Liu, & Zhang, 2010; Ray, Raychaudhuri, & Chakraborty, 2016). Ray et al. (2016)only mentioned the freeze-drying technique as the best for drying active compounds.

Review articles by Mortensen (2006) and Sigurdson et al. (2017) describe some of the more commonly used natural food colorants. These reviews summarize major sources of natural colorants. Possible applications of natural pigments and their chemical characteristics are also discussed.

Other reports provide a different approach to the production of currently allowed natural and synthetic food colorants. They describe the historical perspective of those colorants. They also describe the techniques that have been used to improve the attractiveness and stability of color and extend their shelf life. Trends and perspectives of food colorants used in food science are also partially specified (Martins, Roriz, Morales, Barros, & Ferreira, 2016). Carotenoids, anthocyanins, betanins, and chlorophylls have been generally and selectively described in the context of human health, factors affecting their quality, and the type of methods used to obtain them (Rodriguez-Amaya, 2016). Another review describes the potential application of betalains in functional foods (Gengatharan, Dykes, & Choo, 2015).

This review complements recent reports with regard to the points that have not been discussed earlier. It summarizes current research about food colorants obtained by freeze-drying methods. It shows recently used procedures including pretreatments for obtaining colorants. This is the first review to specify measurement of properties of food colorants. It is noteworthy that the abovementioned reviews do not describe methods to assess the quality of food colorants. Therefore, in this review, we discuss the color parameters of recently obtained freeze-dried colorants. We also discuss the changes in color caused by different factors and the use of these natural pigments in food matrices. Finally, we discuss the potential future directions of research with respect to natural food colorants. This is the first review study about freeze-drying techniques to obtain natural food colorants.

Section snippets

Natural sources of freeze-dried colorants

Fruits, vegetables, and flowers are usually the natural sources of pigments (Delgado-Vargas, Jiménez, Paredes-López, & Francis, 2000; Özen, Akbulut, & Artik, 2011; Sinha, Saha, & Datta, 2012; Yoshida, Mori, & Kondo, 2009). In addition, pigments can be obtained from different by-products (Chedea, Kefalas, & Socaciu, 2010; Jing & Giusti, 2005; Morales, Barros, Ramírez-Moreno, Santos-Buelga, & Ferreira, 2015; Schieber, Stintzing, & Carle, 2001). Table 1 shows some of the plant materials recently

Methods used to obtain natural food colorants by freeze-drying

We analyzed some of the recent studies and summarized the different methods applied in the pretreatment and freeze-drying process. Fig. 1 shows the details of various processes used to obtain food colorants from plant material. It was observed that one of the most common methods using freeze-drying consists of extraction, filtration, concentration and freeze-drying.

In the first stage, the natural colorants are very often extracted to obtain an appropriately colored pigment. Table 2, Table 3

Methods of quality measurements of freeze-dried colorants

Fig. 2 presents the methods of quality measurements of freeze-dried colorants.

Many studies have reported the quality of freeze-dried powders, but there are only a few studies that present a comprehensive assessment of the food colorants. For example, Liaotrakoon et al. (2012) measured the dry matter, bulk density, pH, and vitamin C content of colorants extracted from dragon fruits. De Souza et al. (2015) analyzed samples for moisture content, moisture sorption isotherms, water solubility,

Color values of freeze-dried food colorants

Table 4 shows the color parameters of freeze-dried food colorants. The color parameters of freeze-dried red dragon fruit pulp and peel were evaluated by Liaotrakoon et al. (2012). Their results show that, after processing the juice, the L* value of the dried fruit peel slightly decreased, whereas the L* value of the fruit pulp increased. The a* value increased, and b* value decreased the visual color of freeze-dried dragon fruit pulp. The peel showed a red-purple color. The total content of

Color stability in freeze-dried colorants

The inherent instability of pigments is the main problem associated with natural colorants. Studies on the stability of freeze-dried pigments are valuable for the food industry, but still insufficient, because not many authors deal with this issue (Çinar, 2004). Color changes during storage of freeze-dried colorants were evaluated by Duangmal et al. (2008). The authors found that, during storage, there were minor changes in lightness and hue for all samples which was caused by degradation of

Advantages of the freeze-drying technique in the production of natural food colorants

Freeze-drying is a valuable technique for the drying of materials sensitive to high temperatures(Ray et al., 2016). Liaotrakoon et al. (2012) found that freeze-drying resulted in a minor loss of vitamin C content, which was a result of low-temperature and the use of a vacuum. Agudelo, Barros, Santos-Buelga, Martínez-Navarrete, and Ferreira (2017) compared spray-dried samples with those of the freeze-dried grapefruit and found that the freeze-dried samples contained a much higher amount of trace

Conclusion

Future trends in the study of natural colorants should focus on the usage of food industry waste (pomace, peels, flower petals) as the most economical and promising source of food colorants.

For the production of natural colorants by freeze-drying, various extraction methods have been used and to follow new trends it is proposed to use organic solvents or novel techniques using assisted extraction. Due to the advantages of the extraction process, high-yield colorants can be obtained.

The next

Funding sources

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

References (112)

  • D. Dziki et al.

    Ground green coffee beans as a functional food supplement - preliminary study

    Lebensmittel-Wissenschaft und -Technologie- Food Science and Technology

    (2015)
  • S. Ersus Bilek et al.

    The effects of industrial production on black carrot concentrate quality and encapsulation of anthocyanins in whey protein hydrogels

    Food and Bioproducts Processing

    (2017)
  • G. Feketea et al.

    Common food colorants and allergic reactions in children: Myth or reality?

    Food Chemistry

    (2017)
  • A. Fernandez et al.

    Novel route to stabilization of bioactive antioxidants by encapsulation in electrospun fibers of zein prolamine

    Food Hydrocolloids

    (2009)
  • A. Figiel

    Drying kinetics and quality of beetroots dehydrated by combination of convective and vacuum-microwave methods

    Journal of Food Engineering

    (2010)
  • D.D.G.C. Freitas-Sá et al.

    Effect of jabuticaba (Myrciaria jaboticaba (Vell) O. Berg) and jamelão (Syzygium cumini (L.) Skeels) peel powders as colorants on color-flavor congruence and acceptability of yogurts

    Lebensmittel-Wissenschaft & Technologie

    (2018)
  • A. Gengatharan et al.

    Betalains: Natural plant pigments with potential application in functional foods

    Lebensmittel-Wissenschaft und -Technologie- Food Science and Technology

    (2015)
  • N. Gorbunova et al.

    Alginate-based encapsulation of extracts from beta Vulgaris cv. beet greens: Stability and controlled release under simulated gastrointestinal conditions

    Lebensmittel-Wissenschaft & Technologie

    (2018)
  • A. Hidalgo et al.

    Microencapsulates and extracts from red beetroot pomace modify antioxidant capacity, heat damage and colour of pseudocereals-enriched einkorn water biscuits

    Food Chemistry

    (2018)
  • R. Indrawati et al.

    Encapsulation of Brown seaweed pigment by freeze drying: Characterization and its stability during storage

    Procedia Chemistry

    (2015)
  • S.P. Ishwarya et al.

    Spray-freeze-drying: A novel process for the drying of foods and bioproducts

    Trends in Food Science & Technology

    (2015)
  • E.C.Q. Lacerda et al.

    Starch, inulin and maltodextrin as encapsulating agents affect the quality and stability of jussara pulp microparticles

    Carbohydrate Polymers

    (2016)
  • J. Lee et al.

    Lipophilic pigments differentially respond to drying methods in tea (Camellia sinensis L.) leaves

    Lebensmittel-Wissenschaft und -Technologie- Food Science and Technology

    (2015)
  • M.A. van Leeuwe et al.

    An optimized method for automated analysis of algal pigments by HPLC

    Marine Chemistry

    (2006)
  • N. Martins et al.

    Food colorants: Challenges, opportunities and current desires of agro-industries to ensure consumer expectations and regulatory practices

    Trends in Food Science & Technology

    (2016)
  • A. Michalska et al.

    Drying-induced physicochemical changes in cranberry products

    Food Chemistry

    (2018)
  • P. Morales et al.

    Xoconostle fruit (opuntia matudae scheinvar cv. rosa) by-products as potential functional ingredients

    Food Chemistry

    (2015)
  • M.R. Moßhammer et al.

    Evaluation of different methods for the production of juice concentrates and fruit powders from cactus pear

    Innovative Food Science & Emerging Technologies

    (2006)
  • B. Nemzer et al.

    Betalainic and nutritional profiles of pigment-enriched red beet root (Beta vulgaris L.) dried extracts

    Food Chemistry

    (2011)
  • S. Nestora et al.

    Solid-phase extraction of betanin and isobetanin from beetroot extracts using a dipicolinic acid molecularly imprinted polymer

    Journal of Chromatography A

    (2016)
  • S. Nontasan et al.

    Application of functional colorant prepared from black rice bran in Yogurt

    APCBEE Procedia

    (2012)
  • D.P.S. Oberoi et al.

    Effect of drying methods and maltodextrin concentration on pigment content of watermelon juice powder

    Journal of Food Engineering

    (2015)
  • J.M. Obón et al.

    Production of a red-purple food colorant from Opuntia stricta fruits by spray drying and its application in food model systems

    Journal of Food Engineering

    (2009)
  • M.C. Otálora et al.

    Encapsulation of cactus (Opuntia megacantha) betaxanthins by ionic gelation and spray drying: A comparative study

    Food Research International

    (2018)
  • G. Özkan et al.

    Enzyme-assisted extraction of stabilized chlorophyll from spinach

    Food Chemistry

    (2015)
  • M.A. Pavan et al.

    Water sorption behavior and thermal analysis of freeze-dried, Refractance Window-dried and hot-air dried açaí (Euterpe oleracea Martius) juice

    Lebensmittel-Wissenschaft und -Technologie- Food Science and Technology

    (2012)
  • S. Ray et al.

    An overview of encapsulation of active compounds used in food products by drying technology

    Food Bioscience

    (2016)
  • D.B. Rodriguez-Amaya

    Natural food pigments and colorants

    Current Opinion in Food Science

    (2016)
  • S. Rudy et al.

    Influence of pre-treatments and freeze-drying temperature on the process kinetics and selected physicochemical properties of cranberries (Vaccinium macrocarpon Ait.)

    Lebensmittel-Wissenschaft und -Technologie- Food Science and Technology

    (2015)
  • M.C. P. de A. Santiago et al.

    Effects of encapsulating agents on anthocyanin retention in pomegranate powder obtained by the spray drying process

    Lebensmittel-Wissenschaft und -Technologie- Food Science and Technology

    (2016)
  • A. Schieber et al.

    By-products of plant food processing as a source of functional compounds - recent developments

    Trends in Food Science & Technology

    (2001)
  • K. Sinha et al.

    Extraction of natural dye from petals of Flame of forest (Butea monosperma) flower: Process optimization using response surface methodology (RSM)

    Dyes and Pigments

    (2012)
  • S. Siriamornpun et al.

    Changes in colour, antioxidant activities and carotenoids (lycopene, β-carotene, lutein) of marigold flower (Tagetes erecta L.) resulting from different drying processes

    Journal of Functional Foods

    (2012)
  • H.E.-B. Abd Hanaa et al.

    Evaluation of marine alga Ulva Lactuca L. as a source of natural preservative ingredient

    EJEAFChe, Electronic Journal of Environmental, Agricultural and Food Chemistry

    (2008)
  • A. Aberoumand

    A Review article on edible pigments properties and sources as natural biocolorants in foodstuff and food industry

    World Journal of Dairy & Food Sciences

    (2011)
  • B. Acar et al.

    Freeze‐drying kinetics and diffusion modeling of saffron (Crocus sativus L.)

    Journal of Food Processing and Preservation

    (2014)
  • B. Acar et al.

    Freeze drying of saffron (crocus sativus L.)

    Drying Technology

    (2011)
  • A. Agrawal

    Scope of betalains as a food colorant

    International Journal of Advanced Scientific and Technical Research

    (2013)
  • B. Aishah et al.

    Anthocyanins from Hibiscus sabdariffa, melastoma Malabathricum and Ipomoea batatas and its color properties

    International Food Research Journal

    (2013)
  • V. Arya et al.

    Preliminary phytochemical analysis of the extracts of Psidium leaves

    Journal of Pharmacognosy and Phytochemistry

    (2012)
  • Cited by (50)

    • Advances in protein-based microcapsules and their applications: A review

      2024, International Journal of Biological Macromolecules
    View all citing articles on Scopus
    View full text