Optimization of nutritional beverage developed from radish, sugarcane and herbal extract using response surface methodology

Abstract

PurposeRadish (Raphanus sativus) is valued for its nutritive and medicinal properties, but its juice is not palatable because of the pungent flavor. The purpose of this study is to optimize the blending process of radish juice by using sugarcane juice, herbal extract and salt concentration.Design/methodology/approachThe statistical design provided 20 formulations; where herbal extract concentration varied from 0.5 to 2.5 per cent, sugarcane juice concentration from 20 to 50 per cent and salt concentration from 0 to 1.5 per cent.FindingsThe p = 0.05 was used to designate the statistical significance of all the responses under study. Different product formulations had total soluble solids (TSS) that ranged from 9.7 to 15.0°Brix, titratable acidity from 0.6 to 1.3%, pH from 3.3 to 4.0, reducing sugars from 0.6 to 0.8%, total sugars from 9.4 to 3.1%, total protein from 172.9 to 304.8 mg/100 ml, total phenols from 25.5 to 29.8 mg/100 ml, ascorbic acid from 10.4 to 19.8 mg/100 ml, antioxidant activity from 77.3 to 83.6% and overall acceptability from 5.6 to 7.7. Sugarcane juice concentration of 30%, herbal extract mixture and salt concentrations of 1 and 1.5%, respectively, were the optimized process conditions for the preparation of nutritional radish juice achieved with the best fit of desirability, i.e. 0.88. Cluster analysis revealed that concentration of sugarcane juice had the maximum significant effect on the quality characteristics of nutritional radish beverage as compared to the other two variables under study.Originality/valueThe developed product can help to promote the use of radish as a substrate for the beverage industry.