Evaluation of the antioxidant ability of hydrazine-purified and untreated commercial carnosine in beef patties

Relationship between Beef Quality and Bull Breed

The beef industry in Poland heavily relies on the Polish Holstein-Friesian (PHF) breed, known for its primary use in dairy production, but which also contributes significantly to the beef supply. In contrast, the Limousine (LM), Hereford (HH), and Charolaise (CH) breeds have gained popularity due to their ideal specialized characteristics for beef production. As PHF continues to dominate the beef market, a thorough comparison of its beef quality and nutritional attributes with the three most popular beef breeds in Poland is essential. This study aims to address this knowledge gap by conducting a rigorous comparison. The experiment was carried out on the beef from 67 bulls kept in a free-stall system with standardized feeding. The highest total antioxidant status (TAS) was found in CH and was 147.5% higher than that in PHF. Also, compared with PHF, a large difference of 70% was observed in LM, while in HH it was only 6.25%. For degree of antioxidant potential (DAP), the highest concentration was found in LM, while CH had a slightly lower score than LM. PHF had the lowest scores for each of the analyzed parameters of protein fraction. For anserine, taurine, creatinine, and creatine content, the highest results were found for LM. For carnosine and coenzyme Q10, the highest values were found for CH. Overall, these results highlight the impact of maturity and breed on carcass composition and quality. Late-maturing breeds, such as LM and CH, tend to exhibit leaner carcasses with superior fatty acid profiles and antioxidant properties. This knowledge is valuable for producers, enabling them to make informed decisions regarding breed selection and production strategies to meet specific market demands for beef with the desired composition and quality.

Environmental microplastics exposure decreases antioxidant ability, perturbs gut microbial homeostasis and metabolism in chicken

The widespread presence and accumulation of microplastics (MPs) in organisms has led to their recognition as a major global ecological issue. There is a lot of data on how MPs affect the physiology and behavior of aquatic species, but the effects of MPs on poultry are less understood. Therefore, we aimed to explore the adverse effects and mechanisms of MPs exposure to chicken health. Results indicated that MPs exposure decreased growth performance and antioxidant ability and impaired chickens' intestine, liver, kidney, and spleen. Additionally, the gut microbiota in chickens exposed to MPs showed a significant decrease in alpha diversity, accompanied by significant alternations in taxonomic compositions. Microbial taxonomic investigation indicated that exposure to MPs resulted in a significant increase in the relative proportions of 11 genera and a distinct decline in the relative percentages of 3 phyla and 52 genera. Among decreased bacterial taxa, 11 genera even couldn't be detected in the gut microbiota of chickens exposed to MPs. Metabolomics analysis indicated that 2561 (1190 up-regulated, 1371 down-regulated) differential metabolites were identified, mainly involved in 5 metabolic pathways, including D-amino acid metabolism, ABC transporters, vitamin digestion and absorption, mineral absorption, and histidine metabolism. Taken together, this study indicated that MPs exposure resulted in adverse health outcomes for chickens by disturbing gut microbial homeostasis and intestinal metabolism. This study also provided motivation for environmental agencies worldwide to regulate the application and disposal of plastic products and decrease environmental contamination.

Dietary supplementation with pioglitazone hydrochloride and l-carnosine improves the growth performance, muscle fatty acid profiles and shelf life of yellow-feathered broiler chickens

The present study aimed to investigate the effects of dietary pioglitazone hydrochloride (PGZ) and l-carnosine (LC) supplementation on the growth performance, meat quality, antioxidant status, and meat shelf life of yellow-feathered broiler chickens. Five hundred broiler chickens were randomly assigned into 4 experimental diets using a 2 × 2 factorial arrangement with 2 PGZ supplemental levels (0 and 15 mg/kg) and 2 LC supplemental levels (0 and 400 mg/kg) in basal diets for 28 d. The feed-to-gain ratio decreased whereas the average daily gain increased with PGZ supplementation. Greater dressing percentages, contents of intramuscular fat (IMF) in breast and thigh muscles, C18:3n-6, C18:1n-9 and monounsaturated fatty acid (MUFA) percentages of thigh muscle were observed with PGZ addition. Additionally, significant synergistic effects between PGZ and LC on the C18:1n-9 and MUFA contents were found. Supplementation with LC decreased drip loss, cooking loss and total volatile basic nitrogen, and increased the redness (a∗) value, the superoxide dismutase and glutathione peroxidase activities in thigh muscles. Moreover, the malondialdehyde content decreased when diets were supplemented with LC, and there was a synergistic effect between PGZ and LC. Additionally, the mRNA abundance of lipogenesis-related genes, such as peroxisome proliferator-activated receptor γ (PPARγ), PPARγ co-activator 1α and fatty acid-binding protein 3, increased with PGZ supplementation, and relevant antioxidation genes, such as nuclear factor erythroid-2-related factor 2 and superoxide dismutase 1, were enhanced with LC supplementation. In conclusion, the results indicated that the supplementation of PGZ and LC could improve the growth performance, antioxidant ability, IMF content, and meat shelf life of yellow-feathered broiler chickens.

The Expression of Carnosine and Its Effect on the Antioxidant Capacity of Longissimus dorsi Muscle in Finishing Pigs Exposed to Constant Heat Stress

The objective of this study was to assess the effects of constant high ambient temperatures on meat quality, antioxidant capacity, and carnosine expression in longissimus dorsi muscle of finishing pigs. Castrated 24 male DLY (crossbreeds between Landrace×Yorkshire sows and Duroc boars) pigs were allocated to one of three treatments: constant ambient temperature at 22°C and ad libitum feeding (CON, n = 8); constant high ambient temperature at 30°C and ad libitum feeding (H30, n = 8); and constant ambient temperature at 22°C and pair-fed with H30 (PF, n = 8). Meat quality, malondialdehyde (MDA) content, antioxidant capacity, carnosine content, and carnosine synthetase (CARNS1) mRNA expression in longissimus dorsi muscle were measured after three weeks. The results revealed that H30 had lower pH24 h, redness at 45 min, and yellowness at 24 h post-mortem (p<0.05), and higher drip loss at 48 h and lightness at 24 h post-mortem (p<0.01). Constant heat stress disrupted the pro-oxidant/antioxidant balance in longissimus dorsi muscle with higher MDA content (p<0.01) and lower antioxidant capacity (p<0.01). Carnosine content and CARNS1 mRNA expression in longissimus dorsi muscle of H30 pigs were significantly decreased (p<0.01) after three weeks at 30°C. In conclusion, constant high ambient temperatures affect meat quality and antioxidant capacity negatively, and the reduction of muscle carnosine content is one of the probable reasons.

Dietary supplementation with carnosine improves antioxidant capacity and meat quality of finishing pigs

This study was conducted to determine the effect of dietary carnosine (β-alanyl-L-histidine) supplementation on antioxidant capacity and meat quality of pigs. 72 pigs approximately 60 kg were fed a corn- and soybean meal-based diet supplemented with 0, 25, 50 or 100 mg carnosine per kg diet for 8 weeks. Carnosine supplementation did not affect growth performance and carcass traits of pigs. However, the addition of 100 mg carnosine per kg diet increased pH value of muscle at 45 min, 24 h and 48 h postmortem. It also decreased drip loss at 48 h postmortem and increased redness value of muscle at 45 min postmortem (p < 0.05). The addition of 100 mg carnosine per kg diet enhanced glycogen concentration and Ca-ATPase activity at 24 and 48 h postmortem, and reduced malondialdehyde and carbonyl protein complexes concentrations in muscle at 24 h postmortem (p < 0.05). The addition of 100 mg carnosine per kg diet increased glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) activities in plasma, liver or muscle, as well as SOD and GSH-Px genes expression in muscle (p < 0.05). Taken together, these findings indicate that carnosine supplementation improves antioxidant capacity and meat quality of pigs.

Advances in ingredient and processing systems for meat and meat products

Changes in consumer demand of meat products as well as increased global competition are causing an unprecedented spur in processing and ingredient system developments within the meat manufacturing sector. Consumers demand healthier meat products that are low in salt, fat, cholesterol, nitrites and calories in general and contain in addition health-promoting bioactive components such as for example carotenoids, unsaturated fatty acids, sterols, and fibers. On the other hand, consumers expect these novel meat products with altered formulations to taste, look and smell the same way as their traditionally formulated and processed counterparts. At the same time, competition is forcing the meat processing industry to use the increasingly expensive raw material "meat" more efficiently and produce products at lower costs. With these changes in mind, this article presents a review of novel ingredient systems and processing approaches that are emerging to create high quality, affordable meat products not only in batch mode but also in large-scale continuous processes. Fat replacers, fat profile modification and cholesterol reduction techniques, new texture modifiers and alternative antioxidant and antimicrobial systems are being discussed. Modern processing equipment to establish continuously operating product manufacturing lines and that allow new meat product structures to be created and novel ingredients to be effectively utilized including vacuum fillers, grinders and fine dispersers, and slicers is reviewed in the context of structure creation in meat products. Finally, trends in future developments of ingredient and processing systems for meat products are highlighted.

Effects of Pro-Arg, a novel dipeptide derived from protamine hydrolysate on H2O2-induced oxidative stress in human diploid fibroblasts

Oxidative stress plays an important role in tissue damage associated with many different chronic degenerative diseases, such as cancer and cardiovascular disorders. In our previous study, a novel dipeptide Pro-Arg derived from protamine hydrolysates was found to possess significant antioxidative activity in vitro. In this study, we compared the antioxidant capabilities of purified and synthesized dipeptide (Pro-Arg) and found both of them had very strong hydroxyl-radical scavenging activity in vitro, even at a very low concentration. The protective effect of the dipeptide against oxidative stress was evaluated using H2O2-induced oxidative stress of human diploid fibroblasts MRC-5 cell model. Our results showed the dipeptide attenuated H2O2-induced cellular oxidative damage, and normalized S phase arrest of MRC-5 cells exposed to H2O2. Our findings demonstrate that Pro-Arg can protect against oxidative stress/damage and H2O2-induced human diploid fibroblasts cell death.