The effect of natural elicitors and cold storage period on quality improvement of UAE date palm fruits
Date palm (Phoenix dactylifera L.) is a widely cultivated agricultural crop in most Arab countries. ‘Barhi’ is very popular among the date palm cultivars grown in the United Arab Emirates and is often consumed at the Bisr stage (crunchy apple-like texture fruit). After harvest and during marketing, the major challenge of this fruit (Bisr stage) is to retain its long-term quality. Several studies have reported different spray treatments with elicitors or edible coating to improve the marketability of fresh fruit. The main objective of our study was to investigate the effect of preharvest spraying of natural elicitors such as chitosan (Ch), calcium chloride (Ca), and salicylic acid (SA) on the shelf life, quality, and phytochemicals content of ‘Barhi’ dates stored under cold storage for two months. These elicitor treatments were prepared as single treatment or in combination with other elicitors. The preharvest spray treatments were applied on the fruit 5, 15 and 18 weeks after pollination. The results revealed that all treatments significantly delayed the rapid ripening and deterioration of date fruit. The least weight loss was observed in treatment Ch followed by Ch+SA and Ch+SA+Ca. When compared to control fruits, treatments Ch+Ca, Ch+SA+Ca and Ch+SA had significantly lower levels of total soluble solids. After 60 days of cold storage, the treatments Ch+Ca and Ch+Ca+SA did not show any decayed fruit. The treatment with Ca followed by Ch+Ca+SA had the highest levels of total phenols, flavonoids, and tannins at the end of the storage period. The antioxidant and antimicrobial activities were significantly higher in Ch+SA+Ca, Ch+SA and Ch treatments compared to the control. As a result, these three treatments are recommended for extending the shelf life of ‘Barhi’ date fruit. These are promising strategies to sustain the quality of fruit and decrease postharvest pathogen damage during cold storage.
Fatima Y.Y. Al Shaibani won the ISHS Young Minds Award for the best oral presentation at the VII International Date Palm Conference in the United Arab Emirates in March 2022.
Fatima Y.Y. Al Shaibani, Integrative Agriculture Department, College of Agriculture and Veterinary Medicine, United Arab Emirates University, Al Ain 15551, United Arab Emirates, e-mail: firstname.lastname@example.org
The article is available in Chronica Horticulturae