Optimization of process temperature and time of vacuum drying for production of cashew apple (Anacardium occidentale L.) powder using response surface methodology

Abstract

Cashew apple is a waste from cashew nut processing industry that is high in antioxidants. The cashew apple powder was dried using a vacuum dryer that aimed to create a functional product containing high antioxidant compounds. The objective of this study was to optimize vacuum drying conditions for the production of cashew apple powder using Response Surface Methodology (RSM). The effect of process temperature (55-65°C) and time (9-15 h) on some characteristics (vitamin C content, antioxidant activity, water content, and color changes) of cashew apple powder were analyzed. A Central Composite Design was used to develop models for the responses. The optimum condition of the vacuum drying process was obtained at a drying temperature of 60.1°C and drying time of 11.4 hours. The optimum combination resulted in cashew apple powder with vitamin C content of 118.5 mg/100g, antioxidant activity (IC50) of 70.6 ppm, water content of 11.4%, and total color difference (ΔE) of 8.8. A validation experiment was conducted at the obtained optimum condition and the results showed that no significant difference between the actual and predicted values based on paired t-test (p > 0.05). In conclusion, cashew apple powder is a good source of vitamin C and antioxidant compounds.