Development of free and encapsulated Arjuna herb extract added vanilla chocolate dairy drink by using response surface methodology (RSM) software

Abstract

Two functional vanilla chocolate milk drinks i.e. Drink 1 (containing free herb) and drink 2 (containing encapsulated herb) were optimized by incorporating alcoholic extract of Terminalia arjuna (free and encapsulated forms), cocoa powder and sugar into milk with the help of Central Composite Rotatable Design (CCRD) of response surface methodology (RSM). During the optimization of Drinks, the products were evaluated for sensory (namely colour and appearance, flavour, mouthfeel, sedimentation and overall acceptability) and physico-chemical (i.e. pH, colour, sedimentation and viscosity) characteristics. In addition, the flavour score was aimed to be maximized while the other responses were kept in range in order to arrive at optimized solutions. The result revealed that the desirability of Drink 1 and Drink 2 were 1.0 and 0.93, respectively, representing herb extract (free form: 0.3% and encapsulated form: 1.8%, respectively), cocoa powder (0.75 and 0.97%, respectively) and sugar (6.85 and 7.00%, respectively) into milk and had corresponding sensory attribute such as sweetness score (7.34 and 7.36, respectively), flavour score (7.00 and 7.20, respectively), overall acceptability score (6.96 and 7.34, respectively) and physicochemical properties such as L* (50.29 and 49.41, respectively), a* (10.27 and 11.25, respectively), sedimentation value (3.44 and 3.84, respectively) and viscosity (9.74 and 10.63cp respectively). All the examined model solutions had significant influence on the different parameters indicating that the statistical model designed for these attributes fitted well in all the aspects of model efficiency check (R2>85%). Further, the sensory qualities of optimized Drinks formulations were improved by addition of vanilla essence (0.05%) and stabilizer (0.03%).