Microencapsulation of muscadine grape extracts to produce shelf stable nutraceutical powder and storage studies

Abstract

Phenolic compounds found in muscadine pomace were extracted using enzyme treatment, bladder press and microfiltration operation. These extracts were microencapsulated using coating materials of gum arabic and whey protein and spray drying operation. The microcapsules were characterized using Scanning electron microscopy and particle size distribution. Microencapsulation yield of particles was 99.17% and 88.15% for particles coated with whey protein and gum arabic respectively. Microencapsulated and uncoated samples were kept at controlled environmental conditions. Uncoated powder samples changed color from purple to black while appearance changed from free flowing to rubbery. In coated samples, the color changed and appearance changed from free flowing to caking. Half lives were obtained from the storage of samples over 8 weeks and indicate that microencapsulation helps in protecting the antioxidants at 4 °C as compared to 25 °C. It was that found maximum degradation was found in following order pure compound>whey protein>gum arabic.