Packing black ripe olives in acid conditions

Abstract

The type of container (airtight and pouches with different O2 permeability) and packing conditions (cover brine, air or N2 atmosphere) has been studied to preserve black ripe olives in acid medium for a year. Unlike the traditional sterilized product, these acidified olives only needed pasteurization to assure its microbial safety, the absence of acrylamide being an additional advantage. Surprisingly, an increase in the oxygen diffusion through the films (i) faded the black color of the olives, (ii) softened the fruit that lost around 33% of its initial firmness in only 6 months, and (iii) produced the lipid́s oxidation forming volatile compounds that transmitted an abnormal flavor which tasters identified as rancid. Therefore, ripe olives in acid medium must be packed in airtight containers such as glass jars, cans o metallic pouches with cover brine or N2 atmosphere. The addition of calcium is recommended to avoid olive softening.