Effect of microwave treatment on preparation of stable PUFA enriched vegetable oil powder and its influence on quality parameters

Abstract

Polyunsaturated fatty acids (PUFA) enriched vegetable oil is susceptible to oxidative degradation. Technological advancement in encapsulating such oil has become a new trend to improve stability, preservation, and food application. This paper focuses on the encapsulation through solvent evaporation by optimizing microwave (MW) drying conditions. The oil in water (o/w) emulsion with 50% moisture content (w.b) was dried using different MW power levels (170–200 W), drying time (10–17 min). An increase in MW power level and drying time had a positive impact on the moisture content (3.5–6.4% w.b) of the oil powder and adverse effect on its peroxide value (POV) (9.68–17.4 mEq/kg). The porous powder morphology and passable powder flowability had an influential impact on its wettability (185 ± 0.05) s and physical properties viz. bulk density, true density, angle of repose (AR), water solubility index (WSI), and hygroscopicity. Principle component analysis (PCA) biplot effectively differentiated the effects of drying conditions in the encapsulated oil powder. Rancimat study suggested almost twofold improvement in stability than nonencapsulated oil. Practical applications Due to high unsaturation, PUFA enriched blended vegetable oil is detrimental to lipid oxidation. The present invention aims at the preservation of blended vegetable oil by microencapsulating it through emulsification and converting into oil powder, thus, making it shelf-stable without compromising its antioxidant potential, powder physical properties, and PUFA retention. The microencapsulated oil powder satisfies the PUFA requirements. Hence, the oil powder is endowed with health benefits and can be used by ice-cream and bakery industries.