Pork liver protein hydrolysates as extenders of pork patties shelf-life

The growing demand for the consumption of more natural products challenges the food industry to meet consumer expectations. In this regard, bioactive peptides obtained from flavourzyme, bromelain and alcalase activity were added to pork patties with the aim of improving their shelf-life. Five treatments were prepared: control (CON, without enzymatic extract), positive control (ASA, with 150 mg kg(-1) of ascorbic acid) and three batches with 250 mg kg(-1) of different porcine liver hydrolysates [flavourzyme (FLA), bromelain (BRO) and alcalase (ALC)]. The analysis of raw burgers included proximate composition (moisture, protein, fat and ash contents), colour parameters (L*, a*, b*), metmyoglobin, lipid oxidation, volatile compounds profile and sensory evaluation. Hydrolysate obtained from bromelain enzyme showed the best a* parameter (5.15), the least lipid oxidation (0.63 mg MDA kg(-1)) and the lowest percentage of metmyoglobin (56.02%). Furthermore, this batch also presented the lowest content of aldehydes and alcohols resulting from lipid oxidation. Our results suggested that the hydrolysates obtained from bromelain activity possessed a good antioxidative activity, and therefore, they could be used as a natural antioxidant to extend the shelf-life of pork burgers.