Chilling injury in pineapple fruits: physical quality attributes and antioxidant enzyme activity

Harvested fruit have high metabolic and moisture content which leads to an active biochemical reaction that contributes to decrement of nutritional value such as vitamin, proteins and lipids. The application of low temperature as a single-effective management to prolong shelf-life of fruits is a common practice which applied to keep agriculture commodities at high quality. A matured stage pineapple is very perishable and cold storage chain is crucial in maintaining the chemical and physical quality attributes in order to assure its commercial value for market. The main objective of this study is to evaluate the effect of sub-optimum cold storage scenario on changes of pineapple fruits physical quality attributes, the activity of browning enzyme and antioxidant related enzyme in 2 pineapple cultivars (cv.), Morris (Queen-type) and Josapine (hybrid of Spanish and Smooth Cayeen). Malaysian pineapple fruit cv. with different sensitivity toward CI, Morris (Queen-type) and Josapine (Smooth-Cayenne-type) were stored at sub-optimal storage temperatures (4±2°C) for 28 days to investigate the effects of CI towards physical quality attributes and antioxidant enzyme activity. The result indicated both cv. was affected with CI towards the 28 days of sub-optimum cold storage. Overall physical quality attributes indicated CI was found positively correlated with the increase of EL and TTA and on the contrary decrease its firmness, weight (% w/w), brightness (L*) and redness (A*). Similarly, a positive correlation was also deduced between CI symptoms and the activities of PPO and APX which reflect the incident of oxidative stress. The results derived from this study may serve as a basis for evaluation of better postharvest strategies to control CI during cold chain storage of pineapple fruits and thus assure the quality and nutritional value till it reaches to consumer