Antioxidant protection of proteins and lipids in processed pork loin chops through feed supplementation with avocado.

This study was conducted to analyze the impact of dietary avocado on the oxidative stability of lipids and proteins during pork processing. Loins from control (fed basic diet) and treated pigs (fed on avocado-supplemented diet) were roasted (102 °C/20 min) and subsequently packed in trays wrapped with oxygen-permeable films and chilled at 4 °C for 12 days. At each processing stage (raw, cooked and cooked & chilled), pork samples from both groups were analyzed for the concentration of TBARS, the loss of tryptophan and free thiols, and the formation of protein carbonyls, disulphide bonds and Schiff bases. Processing led to a depletion of tryptophan and sulfur-containing amino acids and an increase of lipid and protein oxidation products. Dietary avocado was not able to protect against the oxidation of tryptophan and thiols but cooked & chilled loins from treated pigs had significantly lower concentration of lipid and protein carbonyls than control counterparts. Likewise, dietary avocado alleviated the formation of Schiff bases during cooking. These results illustrate the benefits of dietary avocado on the oxidative stability of processed pork loins.

Effect of pre-cooking methods on the chemical and sensory deterioration of ready-to-eat chicken patties during chilled storage and microwave reheating.

The effects of pre-cooking methods, namely, boiling (BL), roasting (RT) and grilling (GR), refrigerated storage (14 days/+4 °C) and microwave reheating on chicken patties were studied. Physical, chemical and sensory parameters were evaluated in order to correlate the chemical deterioration of ready-to-eat chicken patties with the acceptance of the odor. Chemical deterioration was evaluated through the chemical composition, Maillard compounds, Thiobarbituric acid-reactive substances (TBARS) and volatiles. Sensory deterioration (odor liking) was performed by an acceptance test with hedonic scale. According to the TBARS values and volatile compounds generated in the head space during the examined stages, the pre-cooking method and the storage time had a significant effect on lipid oxidation, whereas reheating in a microwave had a negligible impact. At each succeeding processing stage, panelists gave lower odor scores to all samples and no significant differences were found between treatments at any stage. RT and GR patties showed less intense chemical changes and presented higher acceptation scores by the sensory panel than BL patties. Thus, the choice of pre-cooking method and control of storage conditions plays a key role in the inhibition of oxidative changes in ready-to-eat chicken patties.

Antioxidant Extracts from Acorns (Quercus ilex L.) Effectively Protect Ready-to-Eat (RTE) Chicken Patties Irrespective of Packaging Atmosphere.

This study evaluated the impact of a phenolic-rich acorn extract (200 ppm gallic acid equivalents) and the concentration of oxygen in the packaging system (low-oxygen modified atmosphere; 5% vs. normal-oxygen; 21%) on lipid and protein oxidation and consumers acceptance of the ready-to-eat chicken patties. Samples were subjected to cooking (electric oven, 170 °C/16 min), cold storage (14 d at 4 °C), and reheating (microwave, 600 mW/1 min). Samples treated with acorn extract kept thiobarbituric acid-reactive substances numbers and lipid-derived volatiles at basal levels throughout the whole processing irrespective of the oxygen concentration in the packaging atmosphere. Consistently, treated patties had lower protein carbonyls than control ones. The acorn extract also controlled color and texture deterioration during chilled storage and reheating and improved the color and odor acceptance of the products. Formulating with acorn extract is a feasible strategy to inhibit the oxidation-driven changes and preserve the quality of reheated samples as if there were freshly cooked. Compared to the effect of the antioxidant extract, the concentration of oxygen in the packaging system was negligible in terms of quality preservation.

Avocado waste for finishing pigs: Impact on muscle composition and oxidative stability during chilled storage.

The utilization of agricultural waste materials for pig feeding may be an interesting option for reducing production costs and contributing to sustainability and environmental welfare. In the present study, a mixed diet enriched with avocado waste (TREATED) is used for finishing industrial genotype pigs. The muscle longissimus thoracis et lomborum (LTL) from TREATED pigs was analyzed for composition and oxidative and color stability and compared with muscles obtained from pigs fed a CONTROL diet. Dietary avocado had significant impact on the content and composition of intramuscular fat (IMF), reducing the lipid content in LTL muscles and increasing the degree of unsaturation. This did not increase the oxidative instability of samples. On the contrary, muscles from TREATED pigs had significantly lower lipid and protein oxidation rates during chilled storage. The color of the muscles from TREATED pigs was also preserved from oxidation.