Effects of gamma irradiation on trans fatty acid composition in ground beef

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.

Development of a Functional Dark Chocolate with Baobab Pulp

In recent years, cocoa and dark chocolate have attracted the interest of consumers not only for their sensory characteristics but also for their nutritional properties and positive impact on health. The baobab is a fruit of African origin with a sour and slightly sweet flavour, widely consumed by local communities due to its unique nutritional features. The aim of this work was to evaluate the impact of the concentration of baobab flour in the development of functional dark chocolate, including physical, chemical, nutritional and sensory evaluations. The results presented a positive correlation between the incorporation of baobab flour and the antioxidant activity (up to 2297 mmol TE/100 g), vitamin C content (up to 49.7 mg/100 g), calcium (up to 1052 mg/kg), potassium (up to 10,175 mg/kg), phosphorus (up to 795.9 mg/kg), chlorine (up to 235.4 mg/kg) and sulphur (up to 1158 mg/kg). The sensory evaluation of dark chocolate with 3% baobab presented the highest evaluation on the parameters "texture" and "overall flavour", while the parameter "overall flavour" presented the lowest evaluation on chocolate with 9% baobab. No influence was observed on fatty acid profile, protein, fat and hardness.

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.

Cobalt-60 and electron beam irradiation-induced lipid oxidation in largemouth bass (Micropterus salmoides)

BACKGROUND

Irradiation can cause lipid oxidation of fish. This study aimed to examine the effect of radiation (method, dose and dose rate) on the acid value (AV), peroxide value (PV), thiobarbituric acid reactive substances (TBARS) content and fatty acid profile of fresh and freeze-dried largemouth bass flesh.

RESULTS

AV, PV and TBARS presented a dose-dependent increase in fish meat for both cobalt-60 (⁶⁰ Co) and electron beam (EB) irradiation. With a 6 kGy dose of radiation, all measured indices in the ⁶⁰ Co group were significantly higher than those in the EB group (P < 0.05 or P < 0.01). With a 3 kGy dose of radiation, AV, PV and TBARS in the 200 Gy min^-1 dose rate group were significantly lower than those in the 2 and 80 Gy min^-1 groups (P < 0.05). After ⁶⁰ Co irradiation, AV, PV and TBARS in most fresh samples were significantly higher than those in freeze-dried samples (P < 0.01). And ⁶⁰ Co irradiation decreased the unsaturated fatty acid (UFA) content in fresh samples and increased the UFA content in freeze-dried samples. Our study indicated that ⁶⁰ Co irradiation, particularly at a low dose rate, accelerated lipid oxidation in fish meat. A large amount of muscle moisture enhances the amount of UFA loss in fish meat during ⁶⁰ Co irradiation.

CONCLUSIONS

A low dose (3 kGy) of EB irradiation, a high dose rate (200 Gy min^-1 ) of ⁶⁰ Co irradiation or freeze-drying treatment can alleviate the lipid oxidation of largemouth bass meat. © 2020 Society of Chemical Industry.

Leukoencephalomyelopathy in cats linked to abnormal fatty acid composition of the white matter of the spinal cord and of irradiated dry cat food

Four outbreaks of leukoencephalomyelopathy in colonies of SPF cats on a long‐term diet of irradiated dry cat food were observed in the Netherlands between 1989 and 2001. As a primary defect in myelin formation was suspected to be the cause of the disease and myelin consists mainly of lipids and their fatty acids, we investigated the fatty acid composition of the white matter of the spinal cord of affected and control cats and of irradiated and non‐irradiated food. The irradiated food had low levels of alpha‐linolenic acid compared to linoleic acid as well as a high total omega‐6:omega‐3 ratio of 7:1 in the irradiated and of 2:1 in the non‐irradiated food. The white matter of the spinal cord showed low levels of linoleic acid and absence of alpha‐linolenic acid in affected cats as well as absence of lignoceric and nervonic acid in both affected and control cats. These abnormalities in fatty acid composition of the white matter of the spinal cord may reflect an increased need for alpha‐linolenic acid as a substrate for longer chain omega‐3 fatty acids to compose myelin and thus indicate a particular species sensitivity to dietary deficiency in omega‐3 polyunsaturated fatty acids, particularly alpha‐linolenic acid in cats. Our findings indicate that abnormalities in fatty acid metabolism in myelin play an essential role in the pathogenesis of this acquired form of leukoencephalomyelopathy in cats.

Effect of different irradiation dose treatment on the lipid oxidation, instrumental color and volatiles of fresh pork and their changes during storage

This study mainly investigated the effect of different doses irradiation (0, 3, 5 or 7kGy) on the quality changes of pork during 4°C storage by determining the irradiation off-odor intensity, thiobarbituric acid reactive substances (TBARs), fatty acid composition, volatiles and color of the samples during whole storage. The results showed that ≥7kGy irradiation could make the samples produce obvious irradiation off-odor. However, after 7days storage irradiation off-odor was reduced. Lipid oxidation was also promoted by irradiation. Benzyl methyl sulfide was produced newly and significantly increased (P<0.05) by irradiation. Fatty acids in pork samples decreased significantly with irradiation dose increase within the range of <7kGy, but significantly increased (P<0.05) in samples of 7kGy. Irradiation significantly increased the a* values regardless of storage time but had little effects on b* and L* values, and the increase of a* values was dose-dependent.

Comparison of Fatty Acid Composition between Female and Male Japanese Quail Meats

The objective of the present study was to compare the proximate analysis, fatty acids composition, omega fatty acids, trans fatty acids (TFAs), and ratio of the total poly unsaturated fatty acid (ΣPUFA) and total saturated fatty acid (ΣSFA) of female and male quail meats. Significant differences were not observed between pH, crude fat, moisture, and ash content of female and male quail meats (p>0.05). The male quail meat had higher fat and ash contents and lower moisture content than those of the female quail meat. The pHs of male and female quail meat were found to be 6.22 and 6.21, respectively. The results of the fatty acid composition analysis showed that C18:1 (42.14–41.23%), C16:0 (24.31–25.76%), C18:2 (13.82–13.42%), and C18:0 (7.49–7.32%) were found as the major fatty acids in the female and male quail meats. Total TFAs,ΣSFA, monounsaturated fatty acids (ΣMUFA), andΣPUFA content of the female and male quail meats were found to be 2.79–2.82%, 33.22–34.65%, 49.70–48.72%, and 14.29–13.81%, respectively.

Fatty acid profile of gamma-irradiated and cooked African oil bean seed (Pentaclethra macrophylla Benth)

The safety and shelf-life of food products can be, respectively, ensured and extended with important food-processing technologies such as irradiation. The joint effect of cooking and 10 kGy gamma irradiation on the fatty acid composition of the oil of Pentaclethra macrophylla Benth was evaluated. Oils from the raw seed, cooked seeds, irradiated seeds (10 kGy), cooked, and irradiated seeds (10 kGy) were extracted and analyzed for their fatty acid content. An omega-6-fatty acid (linoleic acid) was the principal unsaturated fatty acid in the bean seed oil (24.6%). Cooking significantly (P < 0.05) increased Erucic acid by 3.3% and Linolenic acid by 23.0%. Combined treatment significantly (P < 0.05) increased C18:2, C6:0, C20:2, C18:3, C20:3, C24:0, and C22:6 being linoleic, caproic, eicosadienoic, linolenic, eicosatrienoic, ligoceric, and docosahexaenoic acid, respectively, and this increase made the oil sample to have the highest total fatty acid content (154.9%), unsaturated to saturated fatty acid ratio (109.6), and unsaturated fatty acid content (153.9%). 10 kGy irradiation induces the formation of C20:5 (eicosapentaenoic), while cooking induced the formation of C20:4 (arachidic acid), C22:6 (Heneicosanoic acid), and C22:2 (docosadienoic acid). Combined 10 kGy cooking and irradiation increased the susceptibility of the oil of the African oil bean to rancidity.

Effect of γ irradiation on the fatty acid composition of soybean and soybean oil

Food irradiation is a form of food processing to extend the shelf life and reduce spoilage of food. We examined the effects of γ radiation on the fatty acid composition, lipid peroxidation level, and antioxidative activity of soybean and soybean oil which both contain a large amount of unsaturated fatty acids. Irradiation at 10 to 80 kGy under aerobic conditions did not markedly change the fatty acid composition of soybean. While 10-kGy irradiation did not markedly affect the fatty acid composition of soybean oil under either aerobic or anaerobic conditions, 40-kGy irradiation considerably altered the fatty acid composition of soybean oil under aerobic conditions, but not under anaerobic conditions. Moreover, 40-kGy irradiation produced a significant amount of trans fatty acids under aerobic conditions, but not under anaerobic conditions. Irradiating soybean oil induced lipid peroxidation and reduced the radical scavenging activity under aerobic conditions, but had no effect under anaerobic conditions. These results indicate that the fatty acid composition of soybean was not markedly affected by radiation at 10 kGy, and that anaerobic conditions reduced the degradation of soybean oil that occurred with high doses of γ radiation.

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.

cis-trans isomerization of carbon double bonds in monounsaturated triacylglycerols via generation of free radicals

We investigated the heat-induced cis/trans isomerization of double bonds in monounsaturated lipids. When triolein (9-cis, 18:1) was heated around 180 degrees C, small amounts of isomerization products were obtained depending on the heating period. The heat-induced isomerization of triolein was considerably suppressed by the addition of different antioxidants or under nitrogen stream, and these additives simultaneously inhibited the thermal oxidation of double bonds in triolein. Therefore, an intermediate of the thermal oxidation reaction might be responsible for the heat-induced isomerization of the double bonds in triolein. The thermodynamics of the heat-induced isomerization of triolein (9-cis, 18:1) and trielaidin (9-trans, 18:1) were investigated using Arrhenius plot. The Arrhenius activation energies of cis double bonds in triolein and trans double bonds in trielaidin were 106 kJ/mol and 137 kJ/mol, respectively. The calculated internal rotational barrier heights of these double bonds were similar to those of the double bond of 2-butene radical and significantly lower than those of non-radicalized double bonds in 2-butene. These results suggest that heat-induced cis/trans isomerization of triolein and trielaidin occurs mainly through the formation of radical species, which are the intermediates produced during thermal oxidation. The activation energy difference between the two forms suggests that trans trielaidin radicals are more stable than cis triolein radicals. The high thermodynamic stability of the trans double bonds in lipid radicals would influence the population of cis and trans isomers in edible oils and contribute to slight accumulation of trans-18:1 isomers during heating or industrial processing.

Effects of gamma radiation on microbiological status, fatty acid composition, and color of vacuum-packaged cold-stored fresh pork meat

Pork meat samples were inoculated with high or low levels (10(6) or 10(3) CFU/g) of Salmonella Enteritidis, vacuum packaged, exposed to gamma radiation (1.0, 2.5, and 4.7 kGy), and stored for 1 month at 4 +/- 1 degrees C. In highly contaminated samples, the target strain was completely eliminated only by the 4.7 kGy radiation dose, whereas in samples at the lower contamination level, 2.5 kGy was sufficient to eliminate Salmonella Enteritidis. The highest of the applied radiation doses reduced the aerobic microflora and extended the sample's refrigeration shelf life by at least 2 weeks. The fatty acid profile of pork meat was not significantly affected by any of the applied radiation doses. Irradiation increased the proportion of saturated fatty acids (SFA) and decreased the content of the polyunsaturated fatty acids (P < 0.05). Irradiation also affected negatively the proportions of the nutritional indexes omega-6/omega-3, SFA/monounsaturated fatty acids, and SFA/polyunsaturated fatty acids. The proportion of the trans fatty acids C18:1omega-9 t9 and C18:2 t9,t12 in the total fatty acids was nearly doubled (90 and 86%, respectively) in the samples that had been exposed to 4.7 kGy. None of the applied radiation doses changed the lightness (L* value) of the meat, but redness (a*) and yellowness (b*) increased, particularly for the samples treated with 4.7 kGy.