Retention of color and volatile compounds of Spanish-style green table olives pasteurized and stored in plastic containers under conditions of constant temperature

Abstract

Spanish-style green table olives pasteurized and stored in two types of pasteurizable plastic pouches and glass bottles were analyzed for color parameters and volatile components after 6.5 months of storage at 30 °C. Color parameters in pouches made of aluminium oxide coating on polyethylene terephthalate + medium-density polyethylene (AlOx-coated PET + MDPE) were acceptable and, in general, did not significantly differ from those in glass, but unacceptable values corresponding to dark visual colors of both olives and brine were found in pouches made of polyethylene terephthalate + medium-density polyethylene/ethylene vinyl alcohol (PET + MDPE/EVOH). Forty-three volatile compounds were identified and quantified in olive pulp by solid phase micro-extraction (SPME) and gas chromatography coupled to mass spectrometry (GC-MS), 36 of these compounds being significantly different between the plastic and glass treatments. The type of plastic container had an impact on the volatile composition of product. Oxidation and scalping were considered to be the most probable causes for the differences in volatile components between PET + MDPE/EVOH pouches and glass containers, but in AlOx-coated PET + MDPE pouches no oxidation process was apparent.