Effects of gamma ray irradiation-induced protein hydrolysis and oxidation on tenderness change of fresh pork during storage
Introduction
Meat irradiation is recognized as a safe and effective method to attain meat preservation. The use of high-energy gamma rays or accelerated electrons to irradiate fresh meat may extend shelf-life and inhibit proliferation of pathogenic bacteria (Mirmoghtadaie, Aliabadi, & Hosseini, 2016). When the foods are irradiated, many free radicals are generated which could cause the changes of food components, such as the lipids and proteins in meat (Ahn & Lee, 2004). So, the effect of irradiation treatment on the quality changes of meat products is always a very interesting research topic.
Tenderness is a very organoleptic trait of meat and meat products. In fresh muscle, its tenderness development is also dependent on the muscle type, postmortem storage time, integrity of the skeletal muscle fiber and the activity of endogenous enzymes (Lonergan, Zhang, & Lonergan, 2010). Irradiation is generally known to cause tender texture in meat due to the physical disruption of myofibrils (Kanatt, Chawla, & Sharma, 2015; Yim, Jo, Kim, Seo, & Nam, 2016). However, Yoon (2003) reported that low dose (range from 2.2 to 2.9 kGy) of gamma irradiation could cause significant textural toughening of cooked chicken breast meat by the contraction of the sarcomere width. Rowe, Maddock, Lonergan, and Huff-Lonergan (2004) also reported that irradiation could inactivate the μ-calpain activity during early postmortem (PM), which result in the decrease of myofibrillar proteolysis and consequently retard the tenderization of beef steaks. From these reports, it can be seen that the effect of gamma irradiation treatment on fresh muscle tenderness change is closely dose-dependent. But the specific dose-dependent relationship is purely different in different reports.
In addition to hydrolysis or physical disruption of myofibrils, protein oxidation is also considered to be an important factor affecting meat tenderness (Dogbevi, Vachon, & Lacroix, 1999a; Malheiros et al., 2019). Protein oxidation occurring in muscle can generally result in the generation of carbonyl groups, protein polymers, and peptide scissions (Ooizumi & Xiong, 2004). Furthermore, the oxidation stress can also affect the structural proteins proteolysis and degradation such as myosin, actin, troponin, and desmin (Lana & Zolla, 2016). As known, the oxidative stress caused by irradiation is very obvious in meat products. But few researches have been studied to investigate the impact of irradiation on muscle protein oxidation from proteomic perspective as well as its potential contribution to tenderness development during further storage.
Therefore, the main objective of this study was to investigate the influence of irradiation dose on protein oxidation, proteolysis, and the tenderness changes of raw chilled pork prepared with vacuum-packaging during storage. The results of this study will provide theoretical basis for the irradiated pork tenderness changing mechanism during postmortem storage.
Section snippets
Sample preparation
A total of 60 biceps femoris muscles (50 ± 5 g per biceps femoris) from a same Taihu × Duroc × York crossbreed pig carcass (100–150 kg live weight) were purchased from a local slaughterhouse. After 24 h of chilling at 4 °C in a cold chamber, all the 60 muscle pieces were randomly divided into four groups (15 pieces each) and vacuum packaged with impermeable nylon/polyethylene compound bags for irradiation treatment.
Irradiation and sampling
Four groups of vacuum packaged muscle samples were separately loaded in four
Effect of different irradiation doses on the total protein carbonyls of irradiated pork
Variance analysis results indicated that all of the effects of irradiation dose, storage time, and their interaction on the total carbonyl content were extremely significant (P < .01). Irradiation treatment could significantly promote the muscle protein carbonylation (Table 1). But, the promoting effect was not increased as a dose-dependent way at 0 day storage (after storage 3 h). Rowe, Maddock, L,onergan, and Huff-Lonergan (2004) also found that the total carbonyl content was higher (P < .05)
Conclusions
In the present study, proteolysis and protein oxidation did play a critical role in tenderness development of irradiated pork during storage time. In general, as shown in Fig. 2, the physical disruption of muscles and the sensitivity of meat proteins to induce potential aggregation during storage were observed to be dose-dependent (≤ 7 kGy). Although irradiation and increasing dose level compromised the effectiveness of calpain system in pork muscle, it can significantly promote protein
Author statement
I have made substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work.
I have drafted the work or revised it critically for important intellectual content. And I have approved the final version to be published.
I agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
All persons who have made
Declaration of Competing Interest
The authors declare that ‘NO Conflict of interest’ exist in this research article.
Acknowledgements
This research was supported by the Fundamental Research Funds for the Central University (2662019PY033), and National Natural Science Foundation of China (No. 31871824).
References (27)
- et al.
Physicochemical and microbiological changes in irradiated fresh pork loins
Meat Science
(1999) Tissue sulfhydryl groups
Archives of Biochemistry and Biophysics
(1959)- et al.
Effect of radiation processing on meat tenderisation
Radiation Physics and Chemistry
(2015) - et al.
Effects of lactate/phosphate injection enhancement on oxidation stability and protein degradation in early postmortem beef cuts packaged in high oxygen modified atmosphere
Meat Science
(2010) - et al.
Proteolysis in meat tenderization from the point of view of each single protein: A proteomic perspective
Journal of Proteomics
(2016) - et al.
Carbonyl assays for determination of oxidatively modified proteins
Methods in Enzymology
(1994) - et al.
Effect of dofferent irradiation dose treatment on the lipid oxidation, instrumental color and volatiles of fresh pork and their changes during storage
Meat Science
(2017) - et al.
High-oxygen packaging atmosphere influences protein oxidation and tenderness of porcine longissimus dorsi during chill storage
Meat Science
(2007) - et al.
Influence of oxidation damage to proteins on meat tenderness using a proteomics approach
Meat Science
(2019) - et al.
Recent approaches in physical modification of protein functionality
Food Chemistry
(2016)
Small peptides hydrolysis in dry-cured meats
International Journal of Food Microbiology
Hydrophobicity as the signal for selective degradation of hydroxyl radical-modified hemoglobin by the multicatalytic proteinase complex proteasome
Journal of Biological Chemistry
Intramuscular connective tissue and its role in meat quality
Meat Science
Cited by (29)
Effects of irradiation on the quality of fresh waxy corn
2024, Radiation Physics and Chemistry