Volatile profiles, lipid oxidation and sensory characteristics of irradiated meat from different animal species

Identification of key physicochemical properties and volatile flavor compounds for the sensory formation of roasted tilapia

Tilapia is suitable for industrial roasting production because of its good flavor and processing adaptability. In this study, the key physicochemical properties and volatile compounds for sensory formation of roasted tilapia were identified after roasting condition optimization. The highest sensory score was obtained at 215 °C, 45 min, and 4% oil. During roasting, the a*, b*, hardness, chewiness, and oxidation of proteins and lipids significantly increased, the moisture content decreased, and the myofibrillar protein aggregation was observed by scanning electron microscope. After identification and quantification by headspace-gas chromatography-ion mobility spectrometry, 10 compounds with odor active value ≥1 were selected as characteristic flavor compounds. The correlation network indicated that the sensory formation mainly resulted from Maillard reaction, myofibrillar protein aggregation, and improvement of pleasant volatile flavor compounds induced by oxidation of proteins and lipids and water loss. This study provides an important theoretical basis and technical support for roasted tilapia production.

The Effect of Irradiation on Meat Products

The effects of irradiation on meat constituents including water, proteins, and lipids are multifaceted. Irradiation leads to the decomposition of water molecules, resulting in the formation of free radicals that can have both positive and negative effects on meat quality and storage. Although irradiation reduces the number of microorganisms and extends the shelf life of meat by damaging microbial DNA and cell membranes, it can also accelerate the oxidation of lipids and proteins, particularly sulfur-containing amino acids and unsaturated fatty acids. With regard to proteins, irradiation affects both myofibrillar and sarcoplasmic proteins. Myofibrillar proteins, such as actin and myosin, can undergo depolymerization and fragmentation, thereby altering protein solubility and structure. Sarcoplasmic proteins, including myoglobin, undergo structural changes that can alter meat color. Collagen, which is crucial for meat toughness, can undergo an increase in solubility owing to irradiation-induced degradation. The lipid content and composition are also influenced by irradiation, with unsaturated fatty acids being particularly vulnerable to oxidation. This process can lead to changes in the lipid quality and the production of off-odors. However, the effects of irradiation on lipid oxidation may vary depending on factors such as irradiation dose and packaging method. In summary, while irradiation can have beneficial effects, such as microbial reduction and shelf-life extension, it can also lead to changes in meat properties that need to be carefully managed to maintain quality and consumer acceptability.

Correlations of dynamic changes in lipid and protein of salted large yellow croaker during storage

Protein and lipid are two major components that undergo significant changes during processing of aquatic products. This study focused on the protein oxidation, protein conformational states, lipid oxidation and lipid molecule profiling of salted large yellow croaker during storage, and their correlations were investigated. The degree of oxidation of protein and lipid was time-dependent, leading to an increase in carbonyl content and surface hydrophobicity, a decrease in sulfhydryl groups, and an increase in conjugated diene, peroxide value and thiobarbituric acid reactive substances value. Oxidation caused protein structure denaturation and aggregation during storage. Lipid composition and content changed dynamically, with polyunsaturated phosphatidylcholine (PC) was preferentially oxidized compared to polyunsaturated triacylglycerol. Correlation analysis showed that the degradation of polyunsaturated key differential lipids (PC 18:2_20:5, PC 16:0_22:6, PC 16:0_20:5, etc.) was closely related to the oxidation of protein and lipid. The changes in protein conformation and the peroxidation of polyunsaturated lipids mutually promote each other's oxidation process.

Volatile Compound Markers in Beef Irradiated with Accelerated Electrons

This study focuses on the behavior of volatile organic compounds in beef after irradiation with 1 MeV accelerated electrons with doses ranging from 0.25 kGy to 5 kGy to find reliable dose-dependent markers that could be used for establishing an effective dose range for beef irradiation. GC/MS analysis revealed that immediately after irradiation, the chemical yield and accumulation rate of lipid oxidation-derived aldehydes was higher than that of protein oxidation-derived aldehydes. The nonlinear dose-dependent relationship of the concentration of volatile organic compounds was explained using a mathematical model based on the simultaneous occurrence of two competing processes: decomposition of volatile compounds due to direct and indirect action of accelerated electrons, and accumulation of volatile compounds due to decomposition of other compounds and biomacromolecules. A four-day monitoring of the beef samples stored at 4 °C showed that lipid oxidation-derived aldehydes, protein oxidation-derived aldehydes and alkanes as well as alcohol ethanol as an indicator of bacterial activity were dose-dependent markers of biochemical processes occurring in the irradiated beef samples during storage: oxidative processes during direct and indirect action of irradiation, oxidation due to the action of reactive oxygen species, which are always present in the product during storage, and microbial-enzymatic processes. According to the mathematical model of the change in the concentrations of lipid oxidation-derived aldehydes over time in the beef samples irradiated with different doses, it was found that doses ranging from 0.25 kGy to 1 kGy proved to be most effective for beef irradiation with accelerated electrons, since this dose range decreases the bacterial content without considerable irreversible changes in chemical composition of chilled beef during storage.

Impact of Gamma Irradiation and Kale Leaf Powder on Amino Acid and Fatty Acid Profiles of Chicken Meat under Different Storage Intervals

The present study was planned to determine the effect of kale leaf powder and gamma rays on variations in the pH, amino acid and fatty acid profiles of chicken meat at different storage intervals. Significant changes (p ≤ 0.05) in the pH, amino acid and fatty acid profiles of chicken meat following different treatments (KLP (1% and 2%) and gamma irradiation (3k Gy)) were reported at 0, 7 and 14 days of storage. The pH value of the chicken meat sample decreased with the addition of kale leaf powder, whereas the value increased following a gamma irradiation dose of 3 kGy and with the passage of time. During different storage intervals, the minimum reduction in the amino acid and fatty acid quantities in the chicken meat samples was reported after gamma irradiation treatment. However, with the addition of KLP, the amount of amino acids and fatty acids in the chicken meat samples increased. Conclusively, the pH was observed to be reduced in the meat following combined treatment (irradiation + KLP), whereas the 2% KLP treatment improved the amino acid and fatty acid profiles of the chicken samples.

Polysaccharide-Based Edible Films Incorporated with Essential Oil Nanoemulsions: Physico-Chemical, Mechanical Properties and Its Application in Food Preservation-A Review

Edible films with essential oils (EOs) are becoming increasingly popular as an alternative to synthetic packaging due to their environmentally friendly properties and ability as carriers of active compounds. However, the required amounts of EOs to impart effective antimicrobial properties generally exceed the organoleptic acceptance levels. However, by nanoemulsifying EOs, it is possible to increase their antimicrobial activity while reducing the amount required. This review provides an overview of the physico-chemical and mechanical properties of polysaccharide-based edible films incorporated with EOs nanoemulsions and of their application to the preservation of different food types. By incorporating EOs nanoemulsions into the packaging matrix, these edible films can help to extend the shelf-life of food products while also improving the quality and safety of the food product during storage. It can be concluded that these edible films have the potential to be used in the food industry as a green, sustainable, and biodegradable method for perishable foods preservation.

Effect of gamma irradiation on the quality characteristics of frozen yacare caiman (Caiman crocodilus yacare) meat

This study investigated the effect of gamma irradiation (0, 3 and 5 kGy) on the quality characteristics of yacare caiman (Caiman crocodilus yacare) meat under typical storage and commercialization conditions (-18 °C for 150 days). The overall quality characteristics (texture profile, TBARS values, water-holding capacity and cooking loss) of the irradiated samples were not significantly affected (P > 0.05) during frozen storage. However, irradiation promoted the formation of volatile compounds from lipid oxidation known to be important markers in meat odor, particularly hexanal, pentanal and 1-hexanol, in samples treated with 5 kGy after 150 days of frozen storage. The results obtained indicate the need for further research to determine the effect of the doses tested on the sensory attributes of yacare caiman meat.

Analysis of flavor compounds in marinated chicken wings after irradiation and natural antioxidant (phytic acid and tea polyphenols) treatment

Marinated chicken wings is one of the popular marinated meat products in China. Here, electronic nose (e-nose) and solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) were used to detect volatile components of four different treatment marinated chicken wings (neither irradiated nor added phytic acid and tea polyphenols, A1; added phytic acid and tea polyphenols but no irradiated, A2; irradiated with 4 kGy irradiation but not added phytic acid and tea polyphenols, A3; irradiated with 4 kGy irradiation and added phytic acid and tea polyphenols, A4). Then odor activity value (OAV) and principal component analysis (PCA) were utilized to analyze their key flavor compounds. E-nose analysis found that antioxidant has a great impact on the odor of the marinated chicken wings, while the irradiation treatment has little effect on it. Besides, the irradiation treatment can reduce the unpleasant odor caused by antioxidants in certain. Through SPME-GC-MS, 101 volatile compounds were identified in four groups. After analysis, the antioxidants can inhibit the production of some volatile compounds, while irradiation treatment will relieve this phenomenon. This result is consistent with the e-nose. Following OAV, PCA analysis and sensory evaluation further verified the above conclusions.

Measurement of Antioxidant Capacity of Meat and Meat Products: Methods and Applications

At present, a wide variety of analytical methods is available to measure antioxidant capacity. However, this great diversity is not reflected in the analysis of meat and meat products, as there are a limited number of studies on determining this parameter in this complex food matrix. Despite this, and due to the interest in antioxidants that prevent oxidation reactions, the identification of antioxidants in meat and meat products is of special importance to the meat industry. For this reason, this review compiled the main antioxidant capacity assays employed in meat and meat products, to date, describing their foundations, and showing both their advantages and limitations. This review also looked at the different applications of antioxidant properties in meat and meat products. In this sense, the suitability of using these methodologies has been demonstrated in different investigations related to these foods.

Composition of Volatile Compounds in Heat-Treated Meat from Polish Native Sheep Breeds Using HS-SPME-GC/MS – Chemometric Classification Based on Breed and Age

In order to characterize the volatile compounds composition of lamb meat, 3 groups of baked leg muscle samples from two Polish native sheep breeds: Świniarka aged 9 months (S9), Wrzosówka aged 9 months (W9), and Wrzosówka aged 7 months (W7), were analyzed by HS-SPME-GC/MS, followed by multivariate statistics comprising the F-ratio method for variables pre-selection, and PCA-LDA analysis. Ninety seven volatile compounds were determined, out of which 74 were identified. The largest classes of volatile compounds were aldehydes and furans followed by alcohols, hydrocarbons, ketones, and sulfur and nitrogen compounds. Statistically significant differences between the S9, W9, and W7 groups were observed for 11 volatiles, i.e.: pentanal; hexanal; 1,3-octadiene; benzaldehyde; 3-ethyl-2-methyl-1,3-hexadiene; 3-octen-2-one; 2-octenal; 2-hexylfuran; tetradecanal; pentadecanal; hexadecanal. The HS-SPME-GC/MS method coupled with chemometrics, based on the relative intensity spectral data of these volatiles, proved to be an effective tool for the discrimination of lambs according to breed and age. The classification accuracy value for the S9, W9, and W7 groups was 100%.

Effect of edible composite film based on chitosan and cumin essential oil-loaded nanoemulsion combined with low-dose gamma irradiation on microbiological safety and quality of beef loins during refrigerated storage

This research was conducted to assess the combined effect of chitosan (Ch) film containing cumin essential oil nanoemulsion (CNE) and low-dose gamma irradiation (GI) at 2.5 kGy on microbiological safety and quality of beef loins during 21 days of chilled storage. The growth of mesophilic and psychrophilic bacteria, Enterobacteriaceae, and lactic acid bacteria were retarded in all treated groups (Ch, GI, Ch + CNE, Ch + GI, and Ch + CNE + GI groups) compared to control group during storage time. The treatments also slowed down the increasing level of total volatile basic nitrogen and pH during storage, while irradiation increased the levels of thiobarbituric acid reactive substances and protein carbonyls in beef loins. All treatments except Ch were effective to control the growth of inoculated pathogenic bacteria, including Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella typhimurium, in loin samples. The combination of Ch + CNE + GI was the most effective treatment to control the population of microbial flora and inoculated pathogens, slow down some physicochemical changes, and enhance the storage life of beef loins. As a result, the combination of active chitosan film and low-dose gamma irradiation can ensure microbiological safety and is suggested for long time preservation of beef during chilled storage.

Modeling the Growth and Interaction Between Brochothrix thermosphacta, Pseudomonas spp., and Leuconostoc gelidum in Minced Pork Samples

The aim of this study was to obtain the growth parameters of specific spoilage micro-organisms previously isolated in minced pork (MP) samples and to develop a three-spoilage species interaction model under different storage conditions. Naturally contaminated samples were used to validate this approach by considering the effect of the food microbiota. Three groups of bacteria were inoculated on irradiated samples, in mono- and in co-culture experiments (n = 1152): Brochothrix thermosphacta, Leuconostoc gelidum, and Pseudomonas spp. (Pseudomonas fluorescens and Pseudomonas fragi). Samples were stored in two food packaging [food wrap and modified atmosphere packaging (CO2 30%/O2 70%)] at three isothermal conditions (4, 8, and 12°C). Analysis was carried out by using both 16S rRNA gene amplicon sequencing and classical microbiology in order to estimate bacterial counts during the storage period. Growth parameters were obtained by fitting primary (Baranyi) and secondary (square root) models. The food packaging shows the highest impact on bacterial growth rates, which in turn have the strongest influence on the shelf life of food products. Based on these results, a three-spoilage species interaction model was developed by using the modified Jameson-effect model and the Lotka Volterra (prey-predator) model. The modified Jameson-effect model showed slightly better performances, with 40-86% out of the observed counts falling into the Acceptable Simulation Zone (ASZ). It only concerns 14-48% for the prey-predator approach. These results can be explained by the fact that the dynamics of experimental and validation datasets seems to follow a Jameson behavior. On the other hand, the Lotka Volterra model is based on complex interaction factors, which are included in highly variable intervals. More datasets are probably needed to obtained reliable factors, and so better model fittings, especially for three- or more-spoilage species interaction models. Further studies are also needed to better understand the interaction of spoilage bacteria between them and in the presence of natural microbiota.

Chicken fillets subjected to UV-C and pulsed UV light: Reduction of pathogenic and spoilage bacteria, and changes in sensory quality

We have compared the efficacy of continuous ultraviolet (UV-C) (254 nm) and pulsed UV light in reducing the viability of Salmonella Enteritidis, Listeria monocytogenes, Staphylococcus aureus, enterohemorrhagic Escherichia coli, Pseudomonas spp., Brochothrix thermospacta, Carnobacterium divergens, and extended-spectrum β-lactamase producing E. coli inoculated on chicken fillet surface. Fluences from 0.05 to 3.0 J/cm2 (10 mW/cm2, from 5 to 300 s) used for UV-C light resulted in average reductions from 1.1 to 2.8 log cfu/cm2. For pulsed UV light, fluences from 1.25 to 18.0 J/cm2 gave average reductions from 0.9 to 3.0 log cfu/cm2. A small change in the odor characterized as sunburnt and increased concentration of volatile compounds associated with burnt odor posed restrictions on the upper limit of UV treatment, however no sensory changes were observed after cooking the meat. Treatments under modified atmosphere conditions using a UV permeable top film gave similar or slightly lower bacterial reductions.

PRACTICAL APPLICATIONS

Ultraviolet (UV) light may be used for decontaminating the surface of food products and reduce viability of pathogenic and spoilage bacteria. Exposure of raw chicken fillet surface to various doses of continuous UV-C or pulsed UV light proposed in the present work represent alternatives for microbiological improvement of this product. Chicken fillets can be treated in intact packages covered with UV permeable top film, thus avoiding recontamination of the meat. UV-C light treatment is a low cost strategy with low maintenance, whereas pulsed UV light involves more elaborate equipment, but treatment times are short and less space is required. Both methods can be helpful for producers to manage the safety and quality of chicken fillets.

Exogenous and Endogenous Factors Influencing Color of Fresh Meat from Ungulates

Biochemistry of post-mortem muscle tissue is complex, and several factors affect the fresh meat color and color stability, both of which influence consumer acceptance. Therefore, improving meat color and meat color stability is of significant value to the meat industry and consumers. While extensive literature is available on the color and color stability of domestic ungulates, literature on wild ungulates is notably lacking. With an increasing global demand for meats from wild ungulates, it is critical to identify the knowledge gaps regarding their color and color stability. The objective of this paper is to overview the exogenous and endogenous factors influencing the color and color stability of fresh meats from domestic and wild ungulates. The literature highlighted that the pre- and post-harvest factors influencing meat color and meat color stability are interrelated and not mutually exclusive. Current research indicates that the effects of several of these factors are specific to species, breed, and muscle source. Novel ways to manipulate these factors using a biosystems approach should be explored to improve color attributes of fresh ungulate meats.

Effect of Oregano Essential Oil (Origanum vulgare subsp. hirtum) on the Storage Stability and Quality Parameters of Ground Chicken Breast Meat

A study was conducted to investigate the effect of oregano essential oil on the oxidative stability and color of raw and cooked chicken breast meats. Five treatments, including (1) control (none added); (2) 100 ppm oregano essential oil; (3) 300 ppm oregano essential oil; (4) 400 ppm oregano essential oil; and (5) 5 ppm butylated hydroxyanisole (BHA), were prepared with ground boneless, skinless chicken breast meat and used for both raw and cooked meat studies. For raw meat study, samples were individually packaged in oxygen-permeable bags and stored in a cold room (4 °C) for 7 days. For cooked meat study, the raw meat samples were vacuum-packaged in oxygen-impermeable vacuum bags and then cooked in-bag to an internal temperature of 75 °C. After cooling to room temperature, the cooked meats were repackaged in new oxygen-permeable bags and then stored at 4 °C for 7 days. Both raw and cooked meats were analyzed for lipid and protein oxidation, volatiles, and color at 0, 3, and 7 days of storage. Oregano essential oil significantly reduced (p < 0.05) lipid and protein oxidation, and improved color stability of raw and cooked meat. However, oregano oil at 400 ppm showed the strongest effect for all these parameters. Hexanal was the major aldehyde, which was decreased significantly (p < 0.05) by oregano oil treatment, in cooked meat. Overall, oregano essential oil at 100–400 ppm levels could be a good preservative that can replace the synthetic antioxidant in chicken meat.

Effect of Packaging and Antioxidant Combinations on Physicochemical Properties of Irradiated Restructured Chicken Rolls

Effects of double packaging (combinational use of aerobic and vacuum conditions) and antioxidants on physicochemical properties in irradiated restructured chicken rolls were determined. Chicken breast treated with antioxidants (none, sesamol+a-tocopherol) was used to process restructured chicken breast rolls. The sliced rolls were vacuum, aerobic, or double packaged (vacuum for 7 d then aerobic for 3 d) and electron beam irradiated at 2.5 kGy. Color, 2-thiobarbituric acid reactive substances (TBARS), oxidation reduction potentials (ORP), and volatile profiles of the samples were determined at 0 and 10 d. Irradiation made restructured chicken rolls redder (p<0.05), and the increased redness was more distinct in irradiated vacuum-packaged than irradiated aerobic or double packaged meats. TBARS values of antioxidant-treated double packaged rolls were lower than even nonirradiated vacuum-packaged meat, and those were distinct at 10 d (p<0.05). ORP and lipid oxidation values were lower in irradiated vacuum and double packaged samples than those in irradiated aerobic packaged ones at 0 d (p<0.05). Irradiation of restructured chicken rolls increased the amount of total volatiles. Considerable amounts of off-odor volatiles were reduced or not detected by double packaging and antioxidant treatment at 10 d. Therefore, the combined use of antioxidants and double packaging would be useful to reduce redness and control the oxidative quality changes of irradiated restructured chicken rolls.

Comparison of Dried Plum Puree, Rosemary Extract, and BHA/BHT as Antioxidants in Irradiated Ground Beef Patties

Fresh ground beef patties with (1) no antioxidant (control), (2) 0.02% butylated hydroxyanisole/butylated hydroxytoluene (BHA/BHT), (3) 3% dried plum puree, or (4) 0.25% rosemary extract were aerobically packaged, irradiated at target doses of 0, 1.5, or 2.0 kGy (1.7 and 2.3 kGy actual doses), and stored at 4°C. The samples were evaluated for lipid oxidation on 0, 3, 7, 14, 21, and 28 days of storage after irradiation. When compared to the control, all antioxidant treatments were effective in retarding (P < 0.05) irradiation-induced lipid oxidation during storage as determined by 2-thiobarbituric acid reactive substances (TBARs) values. Rosemary extracts had the same antioxidant effect (P > 0.05) as BHA/BHT in irradiated and nonirradiated beef patties, followed by the dried plum puree treatment. Irradiation increased TBARs values, but no differences were noted in oxidation between irradiation dose levels.

Effects of vacuum or modified atmosphere packaging in combination with irradiation for control of Escherichia coli O157:H7 in ground beef patties

The efficacy of controlling Escherichia coli O157:H7 in ground beef patties by combining irradiation with vacuum packaging or modified atmosphere packaging (MAP) was investigated. Fresh ground beef patties were inoculated with a five-strain cocktail of E. coli O157:H7 at 5 log CFU/g. Single patties, packaged with vacuum or high-CO(2) MAP (99.6% CO(2) plus 0.4% CO), were irradiated at 0 (control), 0.5, 1.0, or 1.5 kGy. The D(10)-value for this pathogen was 0.47 ± 0.02 kGy in vacuum and 0.50 ± 0.02 kGy in MAP packaging. Irradiation with 1.5 kGy reduced E. coli O157:H7 by 3.0 to 3.3 log, while 0.5 and 1.0 kGy achieved reductions of 0.7 to 1.0, and 2.0 to 2.2 log, respectively. After irradiation, the numbers of survivors of this pathogen on beef patties in refrigerated storage (4°C) did not change significantly for 6 weeks. Temperature abuse (at 25°C) resulted in growth in vacuum-packaged patties treated with 0.5 and 1.5 kGy, but no growth in MAP packages. This study demonstrated that combining irradiation with MAP was similar in effectiveness to irradiation with vacuum packaging for control of E. coli O157:H7 in ground beef patties during refrigerated storage. However, high-CO(2) MAP appeared to be more effective after temperature abuse.

Changes in some physicochemical properties and fatty acid composition of irradiated meatballs during storage

Meatball samples were irradiated using a (60)Co irradiation source (with the dose of 1, 3, 5 and 7 kGy) and stored (1, 2 and 3 weeks at 4°C) to appraise some physicochemical properties and the fatty acid composition. The physicochemical results showed no significant differences in moisture, protein, fat and ash content of meatballs because of irradiation. However, total acidity, peroxide and thiobarbituric acid (TBA) values increased significantly as a result of irradiation doses and storage period. The fatty acid profile in meatball samples changed with irradiation. While saturated fatty acids (C16:0, C17:0, C18:0, and C20:0) increased with irradiation, monounsaturated (C14:1, C15:1, C18:1, and C20:1) and polyunsaturated (C18:2, C18:3, and C22:2) fatty acids decreased with irradiation. Trans fatty acids (C16:1trans, C18:1trans, C18:2trans, C18:3trans) increased with increasing irradiation doses. Meatball samples irradiated at 7 kGy had the highest total trans fatty acid content. This research shows that some physicochemical properties and fatty acid composition of meatballs can be changed by gamma irradiation.

Effect of antioxidant application methods on the color, lipid oxidation, and volatiles of irradiated ground beef

Four antioxidant treatments (none, 0.05% ascorbic acid, 0.01%alpha-tocopherol + 0.01% sesamol, and 0.05% ascorbic acid + 0.01%alpha-tocopherol + 0.01% sesamol) were applied to ground beef using either mixing or spraying method. The meat samples were placed on Styrofoam trays, irradiated at 0 or 2.5 kGy, and then stored for 7 d at 4 degrees C. Color, lipid oxidation, volatiles, oxidation-reduction potential (ORP), and carbon monoxide (CO) production were determined at 0, 3, and 7 d of storage. Irradiation increased lipid oxidation of ground beef with control and ascorbic acid treatments after 3 d of storage. alpha-Tocopherol + sesamol and ascorbic acid +alpha-tocopherol + sesamol treatments were effective in slowing down lipid oxidation in ground beef during storage regardless of application methods, but mixing was better than the spraying method. Irradiation lowered L*-value and a*-value of ground beef. Storage had no effect on lightness but redness decreased with storage. Ascorbic acid was the most effective in maintaining redness of ground beef followed by ascorbic acid +alpha-tocopherol + sesamol. Irradiation and storage reduced the b*-value of ground beef. Irradiation lowered ORP of ground beef regardless of antioxidants application methods, but ORP was lower in beef with mixing than spraying method. Beef sprayed with antioxidants produced more hydrocarbons and alcohols than the mixing application, but ascorbic acid +alpha-tocopherol + sesamol treatment was effective in reducing the amount of volatiles produced by irradiation. Therefore, mixing was better than the spraying method in preventing lipid oxidation and maintaining color of irradiated ground beef.

Endogenous factors affecting oxidative stability of beef loin, pork loin, and chicken breast and thigh meats

The susceptibility of meats from different animal species (chicken breast [CB] and thigh [CT], pork [PL and beef [BL]) to lipid oxidation was studied. The amounts of TBARS in raw PL, CB, and CT did not change during a 7-d storage period. TBARS values of raw BL, however, significantly increased during 7-d storage because of high heme iron content, high lipoxygenase-like activities, and low 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities. Ferric ion reducing capacities (FRC) were detected in all raw meats, but their characteristics were different: storage-unstable in CB and CT and storage-stable in PL and BL. Ferric ion reducing capacities in raw CB and CT was higher than those of PL and BL, and could be related to their high oxidative stability. The TBARS values of cooked meat increased significantly with storage. The rates of TBARS increase in cooked CT and BL were significantly higher than those of cooked CB and PL after a 7-d storage. Nonheme iron content in cooked BL was higher than other meats and increased significantly after 7 d. Cooked BL had a higher amount of heat-stable FRC, which acted as a prooxidant in the presence of high free ionic irons, than other meats. Therefore, high heat-stable FRC and increased nonheme iron content in cooked BL were responsible for its high susceptibility to lipid oxidation. Despite relatively low nonheme iron and heat-stable FRC levels, cooked CT showed similar levels of TBARS to cooked BL after a 7-d storage because of its high PUFA content.