Use of beta-carotene encapsulated with whey protein and casein and its effects on the shelf life of canola oil during storage

Microencapsulation is a suitable technology for incorporating active agents into a carrier. In the present study, the weight ratios of two solutions of casein and whey protein in the ratios of 70:30, 50:50 and 30:70, containing 5% by weight of beta-carotene per 100g of wall material for microencapsulation were studied by spray drying method. The results indicated that samples containing 70% whey protein and 30% casein showed the best physical and chemical parameters. The results showed the efficiency of microencapsulation (70.44%), phenolic compounds (4.11 μg/mg), free radical scavenging (36.86%), dye stability of beta-carotene (75.18%) and FRAP (304.15 μmol of iron/gr).  The samples revealed an upward trend during the increase in whey protein concentration. However, the particle size (11.09 nm) showed a decreasing trend with increasing whey protein concentration. In the following, the ratio of 30% casein to 70% whey protein was introduced as the best treatment and then added to the canola oil sample in three concentrations (200, 700 and 1200 ppm). The results indicated that the amount of polar compounds, acidic, peroxide in the oil samples during the upward trend time and the stability index has decreased. With increasing the concentration of microcapsules up to 1200 ppm, the polar content, peroxide and acid numbers were significantly lower compared to their lower concentrations. As a result, the acid number, peroxide and polar number of oil containing 1200 ppm in the lowest amount were 1.13%, 7.46 mA/kg of oil and 42.41%, respectively. In general, the results of this study showed that whey protein/casein is one of the important sources that can be used to coat bioactive compounds.