Physicochemical and antioxidant properties of set-type yogurt supplemented by lyophilized water-soluble Melastoma dodecandrum extract-bearded chitosan-coated nutriosomes

Abstract

In this study, the physicochemical and sensorial properties of set-type yogurt (STY)-enriched with water-soluble Melastoma dodecandrum Lour. fruit extract (MDLE) loaded nano-nutriosomes (MDLE-NU) or chitosan-coated nano-nutriosomes (CH-MDLE-NU) powder were investigated during 21 days of cold storage at 4 ± 2 °C. The results showed that MDLE powder has a high amount of phenolics, flavonoids, anthocyanins (59.42, 38.61, and 2.10 g/100g, respectively), and antioxidant activity ranging from 54.12 to 71.37 g/100g. MDLE successfully encapsulated in NU and CH-NU, where encapsulation efficacy reached 96.92% and particle size ranged from 144.57 to 172.30 nm with an acceptable range of PDI (<0.3). However, the commercial food custom of normal NU is still challenging, therefore, freeze-drying of MDLE-NU and CH-MDLE-NU can make their usage applicable. Our results showed that adding MDLE-NU and CH-MDLE-NU powder to STY significantly (p < 0.05) improved the color, water holding capacity, microstructure, texture, and sensory evaluation, as well as reduced whey syneresis, and losing fat globules of STY. Despite MDLE powder-enriched STY showing higher polyphenol content and antioxidant activity than MDLE-NU or CH-MDLE-NU, nutriosomes systems protect bioactive compounds of MDLE against unfavorable conditions in yogurt during cold storage. In which the reduction of total phenolics, total flavonoids, and total anthocyanins from STY-MDLE at the end of storage (21st day) was 2.7, 4.82, and 17.4%, while was 1.02, 2.6, and 3.03%, in STY–CH–MDLE-NU, respectively. This study indicates that MDLE is a promising ingredient to produce functional foods, besides, nutriosomes systems are a promising nanocarrier to encapsulate and protect the bioactive compounds.