Encapsulation of flaxseed oil enriched in carotenoid by microwave technique using innovative wall materials

In this study, flaxseed oil enriched in carotenoid by microwave technique was encapsulated using innovative wall materials. In the first part of the study, the effect of microwave technology and the use of flaxseed oil as the solvent on the yield of carotenoid extraction from carrot juice processing waste were investigated. Response surface methodology was employed to optimize the effect of microwave power (50-200 W), extraction time (1-12 min) and oil to solid ratio (5:1-20:1 g/g) on percentage recovery of carotenoid. Optimum conditions obtained for microwave-assisted carotenoid extraction were 165 W, 9.39 min and 8.06:1 g/g of oil to solid ratio which gave carotenoid recovery of 77.48%. Selected physical and chemical properties of flaxseed oil and carotenoid enriched flaxseed oil were investigated in terms of fatty acid composition, acid value, peroxide value, p-anisidine value, colour parameters (Hunterlab L*, a* and b* values), β-carotene content, total phenolic content and antioxidant activity (DPPH). Encapsulation of the enriched flaxseed oil was performed by spray freeze drying by using different emulsion formulations. Emulsions which contain various concentrations of carotenoid enriched flaxseed oil (6, 9, 12 and 15% w/w) and ratios of maltodextrin/(pectin+wax) proportions (3:1, 6:1, 9:1 and 12:1 g/g) were encapsulated by spray freeze drying to determine the emulsion formulation with the highest encapsulation efficiency. Spray freeze drying and spray drying techniques were compared in terms of the encapsulation efficiency, moisture content, particle size, flowing properties, morphological properties and oxidative stability.