Collapse of the endogenous antioxidant enzymes in post-mortem broiler thigh muscles triggers oxidative stress and impairs water-holding capacity

Life after death? Exploring biochemical and molecular changes following organismal death in green turtles, Chelonia mydas (Linnaeus, 1758)

Green turtles, Chelonia mydas, have been included in biomonitoring efforts given its status as an endangered species. Many studies, however, rely on samples from stranded animals, raising the question of how death affects important biochemical and molecular biomarkers. The goal of this study was to investigate post mortem fluctuations in the antioxidant response and metabolism of carbohydrates in the liver of C. mydas. Liver samples were obtained from six green turtles which were submitted to rehabilitation and euthanized due to the impossibility of recovery. Samples were collected immediately after death (t = 0) and at various time intervals (1, 2, 3, 4, 5, 6, 12, 18 and 24 h post mortem), frozen in liquid nitrogen and stored at -80 °C. The activities of catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PDH) were analyzed, as were the levels of lipid peroxidation, glycogen concentration, RNA integrity (RNA IQ) and transcript levels of carbonic anhydrase and pyruvate carboxylase genes. Comparison between post mortem intervals showed a temporal stability for all the biomarkers evaluated, suggesting that changes in biochemical and molecular parameters following green turtle death are not immediate, and metabolism may remain somewhat unaltered up to 24 h after death. Such stability may be associated with the overall lower metabolism of turtles, especially under an oxygen deprivation scenario such as organismal death. Overall, this study supports the use of biomarkers in sea turtles sampled within a period of 24 h post mortem for biomonitoring purposes, though it is recommended that post mortem fluctuations of particular biomarkers be evaluated prior to their application, given that proteins may show varying degrees of susceptibility to proteolysis.

Starch-based composite foam for chicken meat packaging

The development of compostable packages that maintain fresh meat quality, is an important achievement for the poultry industry. The objective of this study was to evaluate the feasibility of using a starch-based composite foam (SCF) in the packaging of fresh chicken meat during refrigerated storage. SCF was prepared using extrusion process. Nisin (2%) was added as antimicrobial agent (SCFN). Commercial expanded polystyrene (EPS) was used as control. Physical characterization, antimicrobial analysis and storage of fresh chicken meat were carried out. No differences were observed in SEM images between SFC and SCFN samples. Water uptake of SCF were higher than SCFN (p < 0.05). SCFN exhibited higher Young´s modulus and flexural strength (p < 0.05), and antimicrobial effect against foodborne pathogens. During the storage of chicken meat, the starch-based composite foam showed a higher capacity to retain liquid than EPS. The color of chicken meat had slight variations at day 4 compared with the raw meat. Nisin did not retard lipid oxidation of chicken meat, however, the aerobic plate count was lower. Therefore, the starch-based composite foam is suitable for fresh meat storage, being improved with the incorporation of nisin as antimicrobial agent.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05538-6.

Protective effects of chlorogenic acid on the meat quality of oxidatively stressed broilers revealed by integrated metabolomics and antioxidant analysis

Oxidation is a major cause of meat quality deterioration during broiler production, which leads to undesirable meat color and impaired water holding capacity (WHC), thereby impacting consumer appeal and satisfaction. Chlorogenic acid (CGA), a natural phenolic acid, is regarded as a potential, safer and healthier antioxidant to improve meat quality. To investigate the protective effects of CGA on the meat quality of oxidatively stressed broilers, 240 one-day-old male Cobb broiler chickens were allocated to four treatments: basal diet (control group), basal diet + dexamethasone (DEX) injection (DEX group), basal diet containing 500 mg kg^-1 CGA (CGA group), and basal diet containing 500 mg kg^-1 CGA + DEX injection (DEX_CGA group). Meat quality, antioxidant capacity, the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, and metabolomic profile were detected in the breast muscle of broilers. Then, correlation analysis between meat quality and antioxidant capacity, antioxidant-related genes, and metabolites was performed. The results indicated that CGA supplementation improved the growth performance and meat quality traits (pH, WHC, and meat color) and enhanced the antioxidant enzyme activity by activating the Nrf2 pathway in the breast muscle of oxidatively stressed broilers. A total of 619 metabolites were identified, among which 93 differential metabolites were found between control and DEX groups, and 65 differential metabolites were observed between DEX and DEX_CGA groups. Breast metabolic profiles were changed by DEX treatment, while CGA supplementation could normalize the metabolic changes in DEX-challenged broilers. Metabolic pathway analysis revealed that most of the differential metabolites between DEX and DEX_CGA groups were involved in pyrimidine/purine, propanoate and phenylalanine metabolism, primary bile acid biosynthesis, and lysine metabolism, which may contribute to explain the protective effects of CGA on meat quality. Moreover, according to the correlation analysis, four metabolites were identified as potential biomarkers to predict the meat quality. In conclusion, our findings demonstrate that CGA is an effective, natural and safe antioxidant to enhance the quality of meat from intensive industrial poultry production.

Ergothioneine: a potential antioxidative and anti-melanosis agent for food quality preservation

The global population increase has increased the demand for food products. However, post-harvest deterioration due to oxidation and discoloration results in a drastic loss of food quality and supply. Thus, research has focused on developing strategies to minimize such losses. One of those strategies includes the application of ergothioneine (ET), a potent hydrophilic antioxidant, to several food products so as to overcome their short shelf-life. ET can be synthetic or derived from several species of edible mushrooms and their extracts, which are known sources of natural ET. Given the reported potential of ET in food quality preservation, this review compiles the recent applications of ET as a preservative for maintaining the quality of food commodities.

Priming of intestinal cytoprotective genes and antioxidant capacity by dietary phytogenic inclusion in broilers

The potential of a phytogenic premix (PP) based on ginger, lemon balm, oregano and thyme to stimulate the expression of cytoprotective genes at the broiler gut level was evaluated in this study. In particular, the effects of PP inclusion levels on a selection of genes related to host protection against oxidation (catalase [CAT], superoxide dismutase 1 [SOD1], glutathione peroxidase 2 [GPX2], heme oxygenase 1 [HMOX1], NAD(P)H quinone dehydrogenase 1 [NQO1], nuclear factor (erythroid-derived 2)-like 2 [Nrf2] and kelch like ECH associated protein 1 [Keap1]), stress (heat shock 70 kDa protein 2 [HSP70] and heat shock protein 90 alpha family class A member 1 [HSP90]) and inflammation (nuclear factor kappa B subunit 1 [NF-κB1], Toll-like receptor 2 family member B (TLR2B) and Toll-like receptor 4 [TLR4]) were profiled along the broiler intestine. In addition, broiler intestinal segments were assayed for their total antioxidant capacity (TAC). Depending on PP inclusion level (i.e. 0, 750, 1,000 and 2,000 mg/kg diet) in the basal diets, 1-d-old Cobb broiler chickens (n = 500) were assigned into the following 4 treatments: CON, PP-750, PP-1000 and PP-2000. Each treatment had 5 replicates of 25 chickens with ad libitum access to feed and water. Data were analyzed by ANOVA and means compared using Tukey's honest significant difference (HSD) test. Polynomial contrasts tested the linear and quadratic effect of PP inclusion levels. Inclusion of PP increased (P ≤ 0.05) the expression of cytoprotective genes against oxidation, except CAT. In particular, the cytoprotective against oxidation genes were up-regulated primarily in the duodenum and the ceca and secondarily in the jejunum. Most of the genes were up-regulated in a quadratic manner with increasing PP inclusion level with the highest expression levels noted in treatments PP-750 and PP-1000 compared to CON. Similarly, intestinal TAC was higher in PP-1000 in the duodenum (P = 0.011) and the ceca (P = 0.050) compared to CON. Finally, increasing PP inclusion level resulted in linearly reduced (P ≤ 0.05) expression of NF-κB1, TLR4 and HSP70, the former in the duodenum and the latter 2 in the ceca. Overall, PP inclusion consistently up-regulated cytoprotective genes and down-regulated stress and inflammation related ones. The effect is dependent on PP inclusion level and the intestinal site. The potential of PP to beneficially prime bird cytoprotective responses merit further investigation under stress-challenge conditions.

Dietary vitamin E regulates the activity of antioxidant enzymes through Wnt10b signaling in the muscle of zebrafish

Vitamin E (VE) regulates the activity of antioxidant enzymes through Wnt10b signaling in zebrafish.