Preharvest Elicitors as a Tool to Enhance Bioactive Compounds, Quality in Both Peel and Pulp of Yellow Pitahaya (Selenicereus megalanthus Haw) a Harvest and during Postharvest Storage

Yellow pitahaya is a tropical fruit that has gained popularity in recent years. Natural elicitors are compounds that can stimulate the resistance and quality of fruits. The objective of this study was to evaluate the effects of natural elicitors: methyl salicylate (MeSa), methyl jasmonate (JaMe), salicylic acid (SA) and oxalic acid (OA) at concentrations of 0.1 mM (SaMe and JaMe) and 5 mM (SA and OA), applied to the yellow pitahaya fruits, under greenhouse conditions. After full blossom, 4 applications were made with a frequency of 15 days. At time of harvest and after storage, the following variables were evaluated: firmness (whole fruit), total soluble solids (TSS), total acidity (TA), phenolics and carotenoids (in the pulp), while phenolics, carotenoids, macronutrients and micronutrients were determined in the peel. The results showed that JaMe presented a delay of the ripening process, according to TSS, TA, firmness, and total phenolic compounds results, while MeSa advanced the fruit maturation. Regarding the alternative use of the peel as by-product, the application of natural elicitors significantly increased the content of polyphenols, carotenoids, macronutrients and micronutrients in the peel, which can be used as a bioactive compound in the food industry. In conclusion, the results indicate that natural elicitors can be an alternative to improve the quality and shelf life of yellow pitahaya fruits.