Enhancement of storage stability of wheat germ oil by encapsulation

Abstract

Wheat germ oil which is a rich source of a-tocopherol is susceptible to oxidation. The main objective of this study was to encapsulate wheat germ oil to enhance its oxidation stability. It was also aimed to investigate the effects of different homogenization methods on physicochemical properties and storage stability of encapsulated wheat germ oil. As homogenization methods, silent crusher (SC), microfluidization (MF) and ultrasonication (US) were used. SC and MF techniques created more stable emulsions than US. The effects of maltodextrin (MD) in combination with sodium caseinate (NaCa), gum arabic (GA), chitosan (CS) or whey protein concentrate (WPC) and also WPC:CS combination at different ratios on encapsulation efficiency of capsules were studied. Sodium caseinate (NaCa) was found to be better coating material than chitosan (CS), whey protein concentrate (WPC) and gum arabic (GA) for the encapsulation of wheat germ oil in terms of encapsulation efficiency. The rate of increase in totox values of fresh oil was apparently higher than that of microcapsules. The loss of alpha-tocopherol in encapsulated oil was found to be lower than that in fresh oil during storage at both 15 degrees C and 45 degrees C for 24 days.