Briefly, the addition of extracts (GPI, GPII) did not affect the pH
value or the microbial spoilage in raw pork burgers at the 0.06 g/
100 g concentration tested in the current research. However, the
highest colour stability and the lowest lipid oxidation values were
described in burgers containing extract Type I which showed
a potent antioxidant effect. It seems that the new extraction procedure
[(methanolic extraction þ High-Low Instantaneous Pressure
(HLIP))] permits recovery of a high purity extract which does not
adversely affect the sensorial quality of the meat system (data not
shown). Grape pomace extracts could be a low-cost antioxidant
source, but further researches must be lead in this sense to evaluate
the optimal concentration to obtain a potent antimicrobial activity
without changing the quality attributes of the product.