Oxidative rancidity in avocado purée as affected by α-tocopherol, sorbic acid and storage atmosphere

摘要

Avocado is nutritionally rich in many health-related components and a valuable energy source due to their high quality fat content. The aim of this work was to evaluate the lipid oxidation of refrigerated avocado purée as affected by the addition of α-tocopherol and/or sorbic acid with antioxidant and antimicrobial purposes, respectively. Hence, the formation of hydroperoxides and secondary oxidation products was studied throughout storage under different modified atmosphere packaging conditions. Addition of α-tocopherol clearly reduced rancidity of the lipid fraction. When the antioxidant was added, hydroperoxide formation was inhibited for a period of at least 12 weeks with little effect of the presence of sorbic acid and O2 availability. On the contrary, absence of α-tocopherol in the product formulation preceded the production of secondary oxidative metabolites and a rapid saturation of the fatty acid chains. Sorbic acid was found to have a moderate prooxidant effect (p < 0.05). This detrimental influence on the lipid phase of avocado should be weighted up against the antimicrobial effect in order to evaluate its capability of extending the shelf life of avocado products.