Evaluating polyphenol and ascorbic acid contents, tannin removal ability, and physical properties during hydrolysis and convective hot-air drying of cashew apple powder

Cashew apple is a source of by-products in the cashew industry. Powder products provide convenience to the process of use, transport, and preservation of nutrients. In this study, the production of soluble powder from cashew apples was developed through the investigation of hydrolysis process (time, temperature, and enzyme tannase) and convective drying conditions (temperature and maltodextrin content). The following indicators are evaluated, such as the total polyphenol content (TPC), total tannin content, total ascorbic acid, solubility, turbidity, and color. The results have shown that TPC increased by 1.67 times, and more than 50% of tannins was removed after the hydrolysis process. At the same time, the efficiency of the process over 30% under all processing conditions was evaluated. These results are the foundation for the development of cashew apple powder and related products, thereby improving the economy of the cashew industry in Vietnam and the world.