the effect of aloe vera and hot water treatments on maintaining the quality of guava fruit in cold storage

The guava fruit has a relatively short storage life due to its physicochemical properties. despite many studies to maintain the quality and increase the storage life of guava fruits, no optimal method is currently available in this regard. to reduce the chilling injury of guava fruits, this study focused on the postharvest application of aloe vera gel and hot water treatments on guava fruits based on a factorial experiment in a completely randomized design. the applied treatments were storage times at five levels (0, 7, 14, 21, and 28 days), hot water treatments at three levels (no hot water, 40, and 50 °c,) for 10 min, a. vera gel at three levels (0, 5, and 10%), and a control treatment (distilled water, a. vera-free + no hot water). samples were stored at 7±1 °c with 95% relative humidity for 28 days and then at 24 °c for 24 h for adaptation to market conditions. according to the results, the values of the a* color index increased but the values of the l* and b* color indices decreased over storage time. among the experimental treatments, the 5% a. vera gel was more effective for maintaining guava fruit quality by increasing the total sugar content and lowering the ion leakage percentage. the interaction of 40 °c hot water + 10% a. vera gel led to positive effects by reducing the respiration rate and better-preserving fruit firmness. the total chlorophyll values of all treatments in the 4th week were the lowest compared to the same treatments in weeks 1-3. an increase in the storage period resulted in a downward trend in ascorbic acid index. the minimum peel carotenoid and flavonoid content were observed in 40 °c hot water + 10% a. vera gel treatment. treatments with no hot water + 5% a. vera gel, no hot water + 10% a. vera gel, and 40 °c water + 5% a. vera gel resulted in the highest levels of peel antioxidants, ion leakage, and malondialdehyde, respectively. the results of this study demonstrated that the use of a. vera gel and hot water treatments reduces the chilling injury of guava fruits, leading to a better storage life of fruits during the storage time.