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The effect of different cooking methods and the influence of the use of chestnuts (Castanea sativa Miller) rather than commercial feed in the pig diet on physicochemical characteristics, oxidative stability and volatile profile of cooked Longissimus thoracis et lumborum Celta pig muscle was investigated. Four treatments were used for cooking meat from both diets: roasting, grilling, frying and microwaving. Analysis of cooked meat included the proximate composition (moisture, protein, fat, and ash contents), colour parameters (L*, a*, b*), cooking loss, shear force, lipid oxidation and volatile compounds. Overall, the cooking technique significantly affected the proximal composition, colour parameters, cooking loss, TBARS and volatile profile of Longissimus thoracis et lumborum, whereas the shear force was not affected by the heat treatment. Frying was the technique that led to a greater presence of fat. Additionally, microwaved and fried samples presented the highest cooking losses. Regarding to the lipid oxidation, grilling and microwaving showed more negative effects on the samples, while frying involved a lower presence of TBARS and hexanal contents. The major volatile compounds were aldehydes for all cooking methods except for the frying technique, which besides presented the lowest amount of total volatiles compounds. With respect to the finishing diet, in general the use of chestnuts did not affect the chemical composition, colour parameters, cooking loss and shear force of cooked Longissimus thoracis et lumborum. Nevertheless, a significant decrease in the TBARS value was found with the inclusion of this fruit in the finishing diet. At the same time, the use of chestnuts also affects the content of some volatile compounds such as heptanal and furan, 2-pentyl., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The effects of guarana seed and pitanga leaf extracts on the physical-chemical and sensory characteristics, and oxidative stability of modified atmosphere-packaged lamb patties with fat replacement during storage (2 °C) were investigated. Four treatments were prepared: control (without antioxidant); with BHT (10 mg/kg); with 250 mg/kg guarana extract (G250); with 250 mg/kg pitanga extract (P250). Analysis included the proximate composition (moisture, protein, fat, and ash) and sensory acceptance (day 0); pH, color (L*, a*, b*), TBARs, carbonyl content, DPPH, and visual sensory assessment (0, 6, 12, and 18 days); fatty acid profile and volatile compounds (0 and 18 days). G250 and P250 did not alter the centesimal composition and the acceptance of the lamb burgers on day 0. The extracts also delayed discoloration of the burgers, endowed the reddest intensity, and retarded lipid and protein oxidation throughout storage time, particularly P250, which presented the lowest TBARs levels (6.92 mg MDA/kg) and carbonyl values (5.59 nmol carbonyl/mg), and the highest antioxidant activity (249.48 μg Trolox/g), at day 18. The MUFA, SFA, and PUFA levels, AI, TI, and h/H ratio were comparable between treatments; only the n-6/n-3 ratio was higher in P250 treatment but within the recommended levels. More volatile compounds were derived from lipid oxidation in the control and BHT treatments than G250 and P250 treatments. As a result, both G250 and P250 groups are effective against color deterioration, and lipid and protein oxidation, without impairing the sensorial characteristics, representing a promising alternative to replace synthetic antioxidants by natural products in lamb burger., (Copyright © 2019 Elsevier Ltd. All rights reserved.)