Antioxidant and Physical Characteristics of Anthocyanin Extract from Purple Yam (Dioscorea alata L.) Nanoencapsulation: Effect of Maltodextrin and Whey Protein Isolate Ratios

Abstract

Anthocyanins are bioactive compounds with antioxidant, anti-inflammatory, and anti-diabetic activities. This bioactive compound is susceptible to changes in temperature and pH conditions. Its use in food products is also limited. Therefore, protection efforts that can bring anthocyanins into the food system through encapsulation are needed. Encapsulation is a technique for protecting bioactive compounds by coating the mixtures using biomaterials. The spray drying encapsulation process does not require difficult preparation and has good protection capabilities. The goal of this study was to investigate the encapsulating properties of the ratio of whey protein isolate to maltodextrin. This study used maltodextrin : whey protein isolate ratios (MD: WPI) 1:3, 1:1, and 3:1 (w/w). Anthocyanin extract was added 30% (w/w). The mixtures were powdered by drying them with a spray drier. The results showed that MD: WPI = 1:3 can retain more bioactive components than other treatments. The characteristics of nanoencapsulants in antioxidant activity, total phenol content, and anthocyanin were 65.16 + 2.87 %RSA, 776.25 + 45.23 mg GAE/100 g, 60.83 + 1.56 mg/100 g, respectively. The nanoencapsulations had irregular round morphology, particle size and zeta-potential were 301.3 nm and -31.9 mV, respectively. Therefore, anthocyanin encapsulation from purple yam extract was successfully produced with lower-cost material for food and pharmaceutical use.