Tendency of lipid radical formation and volatiles in lose or vacuum-packed Brazil nuts stored at room temperature or under refrigeration

Abstract

The Brazil nut is an important product from the Amazonian region and its productive chain is an income source for local communities. The effect of combinations of packaging atmospheres (loose or vacuum-packed) and storage temperatures (4±1 °C or 24±2 °C) on the tendency of lipid radical formation and on volatiles was investigated for the first time in shelled Brazil nut kernels. It was observed that refrigeration, whether combined with lose packing or vacuum packing, was effective to reduce the tendency for lipid radical formation, as detected by spin-trapping electron spin resonance (ESR) spectroscopy, as well as peroxides, conjugated dienes and 3-octen-2-one. However, the combination of refrigeration with vacuum packing, even using low-density polyethylene (LDPE) pouches with a high oxygen transmission rate (OTR), also reduced the formation of hexanal, which is a major off-flavor volatile, and thus should be recommended for the storage of Brazil nut kernels for the studied period.