Functional Tinospora cordifolia (giloy) based pasteurized goat milk beverage: Impact of milk protein-polyphenol interaction on bioactive compounds, anti-oxidant activity and microstructure

Abstract

Tinospora cordifolia (giloy), a medicinal plant widely used in Indian system of medicine, is known to cure various ailments owing to its therapeutic values. Milk is considered as an ideal/delivery carrier system for its bioactive molecules. Therefore, in view of ‘green milk’ concept, and to potentiate the therapeutic benefits of goat milk and giloy juice, pasteurized functional giloy-goat milk beverage was developed using goat milk and debittered giloy juice (90 : 10) and evaluated for its' storage stability at refrigeration temperature (4 ± 1°C). Results revealed that functional beverage prepared with herbal extract treated giloy juice had highest (p < 0.05) total solids, bioactive compounds and anti-oxidant activity as compared to goat milk alone. HMF content showed retardation of browning reaction upon herbal extract application. Viscosity of the beverages was observed to be increasing with increasing shear rate. Fluorescent microscopy indicated polyphenol-milk protein interaction which was well confirmed with FTIR analysis and SEM, thus, supporting the compatibility of giloy juice with goat milk system. Three main principal components were identified for sensory evaluation data using Principal Component Analysis and results revealed beverage acceptability even over the 5 days of storage.