Inhibition of browning via aqueous gel solution of Aloe vera: a new method for preserving fresh fruits as a case study on fresh kernels of Persian walnut.

Aloe Vera (AV) gel is commonly used as a natural, inexpensive, edible coating that can improve the quality and shelf life of fruits. The objective of this study was to evaluate how two methods of applying AV, i.e. as an edible coating (dry environment) and as a gel solution (aqueous environment: a new method), prevent browning and maintain quality characteristics of fresh kernels of Persian walnut for 60 days during cold storage. Distilled water was used as a control group for both environments. In general, AV caused a reduction in the peroxide value (POV) of kernels, while preserving Total Phenolic Compound and Total Antioxidant Activity (TAA). The AV treatment slowed down the process of color change and maintained sensory properties during storage, compared to the control groups of both methods. The AV gel solution performed better than the AV edible coating in terms of POV, color (L* and h°) and microbial growth. In contrast, the AV edible coating was more effective in preserving TPC and TAA. Also, TAA was found to have a significant, positive correlation with L* and, simultaneously, a negative correlation with POV. As far as we know, this is the first instance that the AV gel was used as a formulated solution and as an edible coating on fresh fruits. This innovative method can be used in commercial practice, while being ecofriendly and non-chemical as a treatment for the maintenance of postharvest quality in fruits. © Association of Food Scientists & Technologists (India) 2021.