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.

Automated summary

This study aimed to extend the shelf life of cashew apples, a tropical pseudo fruit, at the rural level by using a chemical dip and dry method. The inhibition of fruit-spoiling enzymes was achieved by applying NaCl, CaCl2, and EDTA. The optimal treatment conditions involved the use of NaCl and CaCl2 to preserve the texture and color of cashew apples, showing significant inhibition of various enzymes.