Optimization of recipe for development of Aonla squash- A Response surface methodology approach

Central Composite Design (CCD) was employed for optimizing the recipe for development of Aonla squash with juice content (25 to 40%), acidity (1.00 to 1.10%) as independent variables and adjusting 50% total soluble solids. Thirteen different experimental combinations given by RSM design were used to investigate the effect of independent process variables on four product responses developed squash. RSM evaluated responses of the 13 squash recipes by second order quadratic equations and found that pH ranged from 2.69-3.00, ascorbic acid from 102-212 mg/100ml, browning from 0.428- 0.579 and overall acceptability scores from 6.25-7.75. ANOVA analysis showed that the product responses of beverages were significantly affected (at 5%) by changes in juice and acidity of the squash recipes. Overall acceptability scores of the beverage increased with the increase in proportion of juice content from 25 to 40%. The coefficient of determination i.e., R2 for all responses was higher than 0.95 and nonsignificant lack of fit was observed for all models; which was desirable. Through numerical optimization, standardized recipe selected by RSM for aonla squash was with 40% juice and 1% acidity getting highest desirability of 0.991. The pH, ascorbic acid, browning and overall acceptability for the optimum recipe predicted by the design were 2.96, 197.8 mg/100 ml, 0.557 and 7.7, respectively. Thus, present study was first in its kind to optimize aonla squash recipe by using RSM as a tool which gave advantage of not only selecting best recipe but also provided impression of the influence of ingredients used in squash’s preparation on its physico-chemical profile.