Effect of thermal and non-thermal processing on astringency reduction and nutrient retention in cashew apple fruit and its juice

The present study is aimed at evaluating the effect of different processing techniques on astringency reduction, nutrient retention, and sensory attributes in cashew apple fruit and its juice. Astringency attribute was measured by tannin content, while nutrition profile by ascorbic acid, total sugars, and antioxidant activity. Hot water, steaming, and microwave were selected as the source of heat application for treating whole fruit, where the process variables were the temperature and exposure time. The non-thermal technique selected to treat juice was by using bio coagulants, i.e., dried okra pod and drumstick seed powder, where the independent parameters were concentration and settling time. The processes were optimized using a multivariate approach coupled with full factorial design. The obtained results indicated that samples, with 42.6% tannin removal, were rated as being the least astringent. The use of dried okra pod powder under optimal conditions (0.3% concentration, 0.5 h settling time) was found to be the best in reducing astringency while retaining the nutrient and desirable sensory attributes. Maximum tannin removal (48.9 ± 1.6%) with minimum loss of ascorbic acid (8.1 ± 0.9%), total sugar (4.8 ± 0.5%) and antioxidant activity (11.1 ± 1.0) with high sensory score (92.7 ± 1.6%) was achieved with composite desirability of 0.85.