Effect of chemical pretreatment on quality attributes of the cashew apple

Cashew apples, tropical pseudo fruit, are rich in bioactive compounds. It is still underutilized due to its high perishability and its astringent flavor. This study aims to extend its shelf life by chemical dip and dry method at the rural level. Inhibition of fruit-spoiling enzymes, such as polyphenol oxidase (PPO), peroxidase (POD), amylase, and cellulase, was a significant response in this method. Enzyme inhibition was carried out using chemicals: NaCl (1-10 mM), CaCl₂ (1-10 mM), and ethylenediamine tetraacetic acid (0.1-1 mM). The effect of chemical concentration and dipping time was studied using a full factorial method at three levels (-1, 0, and 1). The dipping time ranged from 60 to 180 min, and chemical concentrations from 1 to 10 mM were studied. Optimal treatment conditions were obtained as follows: NaCl concentration of 9.45 mM, dipping time of 160 min, and CaCl₂ concentration of 7.8 mM, dipping time of 160 min. NaCl pretreatment showed maximum inhibition of PPO (>80%) and POD (>80%), whereas CaCl₂ pretreatment showed maximum inhibition of amylase (60.58%) and cellulase (80.23%). Hence, to avoid postharvest losses, pretreatment with NaCl and CaCl₂ was adequate to preserve the texture and color of cashew apples. PRACTICAL APPLICATION: Chemical pretreatment can prevent the postharvest losses of cashew apples. Inhibition of PPO, POD, amylase, and cellulase is vital in the shelf-life extension of cashew apples. Sodium chloride dip is a cost-effective method for increasing the storability of cashew apples.