Quality Evaluation of Cashew Apple Varieties Using Different Drying Methods

Abstract

Background: Cashew apple is packed with lots of bioactive properties. However, it is highly perishable. Quality analysis was determined on sun-dried red cashew (SDRC), sun-dried yellow cashew (SDYC), solar-dried red cashew (SODRC), solar-dried yellow cashew (SODYC), cabinet-dried red cashew (CDRC), cabinet-dried yellow cashew (CDYC), freeze-dried red cashew (FDRC) and freeze-dried yellow cashew (FDYC). Study Design:  Statistical software application SPSS, version 22, with one-way ANOVA    and a post-hoc Duncan test were used to assess the statistical significance of the difference in multiple group comparison. Aims: The study aimed to evaluate two different colour of cashews, in respect to nutrients, phytochemical and antioxidant properties. Methodology: Fresh red and yellow cashew apples was harvested, sliced into 2 mm thickness, pretreated by dipping into sodium metabisulphite and divided into batches. One batch was dried under the sun for 72 h at 28±4° C, the second batch was solar-dried for 48 h at 45-67°C, the third batch was dried in a cabinet at 65 °C for 12 h and the last batch was freeze-dried -65°C for 72 h. All the dried batches was evaluated. Statistical analysis was conducted to determine the result. Results: Higher (2.88; 8.10; 49.55; 20.64; 73.31; 35.87; 23.15; and 11.07) concentration in ash, ºBrix, colour, flavonoid, phenolic, alkaloid, tannin, phytate, DPPH and FRAP contents respectively in the yellow cashew than the red cashew slices, irrespective of their drying methods. However, higher values (8.20; 292.75) of crude fat and ascorbic acid was recorded in the red cashew slices than the yellow samples. Freeze-drying (FD) followed by solar-drying (SOD) and sun-drying (SD) samples had high levels of bioactive components, nutritional and antioxidant capacity in comparison to other drying methods. Conclusion: Higher concentration in the nutrient and bioactive components was recorded in the yellow cashews slices than the red. The application of FD, SOD and SD can reduce post-harvest losses and increase its economic value.