The effect of pre-harvest and post-harvest aloe vera gel treatments on fruit quality and storage performance of table grapes

Abstract

This study investigated the impacts of pre-harvest, post-harvest, and combined pre-harvest+post-harvest Aloe vera gel treatments on various quality parameters of the ‘Red Globe’ grape cultivar during a 150-day storage period. The quality parameters assessed were weight loss, decay ratio, color attributes, firmness, soluble solids content (SSC), titratable acidity (TA), levels of total phenolics and total antioxidant capacity, as these are indicative of bioactive compounds. Post harvest Aloe vera treatment resulted in the lowest weight loss among three treatments, while the combined treatment surprisingly led to the highest weight loss. Pre-harvest treatments resulted in the lowest SSC values, while the combined treatments led to the highest values. Differences in TA value were not statistically significant, neither between treatments nor during the storage period. Storage duration alone significantly affected pH values. The Aloe Vera treatments significantly increased total phenols compared to the control group, and this increase remained consistent throughout the storage period. The combined treatments yielded the highest total phenols (3389.45 µg gallic acid equivalent/g fresh fruit). Similarly, Aloe Vera treatments significantly increased total antioxidant capacity (TAC) throughout the storage period. While the combined treatment yielded the highest TAC on day 150 (6.66 µMol trolox equivalent/g fresh weight), it negatively affected physical and chemical parameters. However, compared to other treatments, this combined approach significant boosted phytochemical levels. These findings suggest that for fresh table grapes, separate pre-harvest or post-harvest Aloe Vera treatments might be preferable. On the other hand, for those prioritizing elevated phytochemical content for health benefits, the combined application offers an option despite its drawbacks.