Ingredient Levels Optimization and Nutritional Evaluation of a Low‐calorie Blackberry ( Rubus irasuensis Liebm.) Jelly

  Response surface methodology (Box‐Behnken design) was applied to assess and model effects of 3 factors, sweetener, low methoxyl pectin, and calcium content (each at 3 levels), on the overall acceptability of a blackberry ( Rubus irasuensis Liebm.) jelly, as determined by 100 consumers. Jelly was produced using clarified juice, obtained from a cross‐flow microfiltration process. Results showed that the model fit was significant, and there was satisfactory correlation between actual and fitted values ( R  2 = 0.925 and adjusted R  2 = 0.791 ). The model presented no significant lack of fit ( P = 0.096). Sweetener level had a significant effect on overall acceptability ( P ≤ 0.05), but low methoxyl pectin and calcium levels did not. The statistical model was further used to optimize the factor levels for highest acceptability, in order to obtain a jelly that provided less than 8 calories per serving, making it possible to label the product as “low calorie.” The product is a good alternative for consumers who wish to diminish sucrose intake.