Abstract
This study investigated the effects of different storage conditions, temperatures of -20, 10, room temperature (RT), 40 and 63 degrees C for up to 12 months in the presence or absence of air and light, on the stability of an encapsulated gac (Momordica cochinchinensis) oil powder. A stability trial of the encapsulated oil powder incorporated into yoghurt, pasteurised milk and cake mix stored at 4 +/- 0.5 degrees C and RT for different storage times was also carried out. The results showed that a progressive degradation of colour, beta-carotene and lycopene, and a progressive increase in surface oil content and peroxide value (PV) occurred in the encapsulated powders with increasing storage temperatures and storage times. However, the degradation was much less when the encapsulated powder was stored at low temperature in the absence of air and light. The degradation of beta-carotene and lycopene in all samples during storage fitted a first-order reaction. The sorption curves of the encapsulated powders at 10, 30 and 40 degrees C were fitted with BET and GAB models. The results also showed that the encapsulated gac oil powder could be successfully incorporated into food products in terms of retention of colour, p-carotene and lycopene, and low PV. (C) 2015 The Institution of Chemical Engineers.