EVALUATION OF GRAPE SEED EXTRACT AS ANTIOXID ANT IN HAMBURGERS

摘要

The aim of this study was to evaluate the capacity of a grape seed extract to delay colour deterioration, h'pid oxidation and microbial spoilage in hamburgers. Five batches of pork patties were manufactured: control (C), control without salt (CS), and meat (identical to the control C) supplemented with 200 mg/kg of BHT, BHA or grape seed extract (G). Hamburgers were stored at 4 °C in two modified atmosphere packages (MAP): Ml [30% O_2-70% CO_2] and M2 [80% O_2-20% CO_2]. pH, colour parameters (L~*, a~*, b~*), lipid oxidation (TBARs formation) and microbial spoilage (lactic acid bacteria (LAB) and Pseudomonas) were determined at 0, 2, 6, 8, 13 and 15 days of storage time. L~*, a~* and b~* decreased in all batches, except L~* values in C and CS patties. The best final values of a~* were found for the grape extract in both packages (M1 and M2). Display time had a significant effect (P<0.001) on TBARs values; hamburgers treated with BHT, BHA and G showed TBARS index means significantly lower than the controls (C and CS) in the final sampling point (0.17, 0.25, 0.34 < 0.51 and 1.36, P<0.05 for BHA, BHT, G, C and CS for M1, respectively). M2 packaged samples showed a higher microbial contamination than Ml samples and the addition of the grape extract reduced the growth of BAL and pseudomonas, respect to the control C, in both MAP evaluated.