Effect of temperature, pressure, sugar, and citric acid content on quality of cashew apple juice produced by vacuum concentration

Cashew apples are a source of by-products in the cashew industry. In the present work, a juice product made from cashew apples was produced through vacuum concentration (VC). During VC, a temperature range of 60 to 90°C, and a pressure range of 500 to 650 mmHg were investigated. Total ascorbic acid (TAA), total tannin content (TTC), and total polyphenol content (TPC) after VC were also evaluated. The variation in VC time was observed when the temperature was investigated. The sensory value of the products after mixing citric acid and sugar was evaluated. The results showed that the nutritional parameters were affected by temperature and pressure. TAA and TPC reached their maximum value at 80°C. The TTC was strongly hydrolysed with increasing VC temperature. Furthermore, negative correlation between vacuum pressure and nutrition was observed. Cashew apple juice after VC diluted with water (1:5), and mixed with sugar (20 g/L) and citric acid (0.2 g/L) was preferred by consumers. TAA, TPC, and TTC were monitored for 42-day storage under two temperature conditions of 35 and 45°C. The shelf life of the product reached 117 d. These results set the platform for the development of beverage products from cashew apple by-products, thereby improving the economy of the cashew industry in Vietnam and the world.