Preharvest Applications of Chitosan, Salicylic Acid, and Calcium Chloride Have a Synergistic Effect on Quality and Storability of Date Palm Fruit (Phoenix dactylifera L.)

Abstract

The ‘Khenizi’ date palm is one of the most recognized date palm cultivars. It is commonly consumed at the Bisr, Rutab, and Tamr stages of ripening; however, the fruit has a short shelf/storage life at this stage of maturity even with refrigeration. Preharvest application of a natural elicitor chitosan (Ch) has been reported to have positive influences on quality and shelf life of many fruits; however, synergetic effects of Chand other natural elicitors have not been investigated. Therefore, this study aimed to investigate the synergistic effect of preharvest spray treatments with Ch 1% in combination with calcium chloride (Ca) 3% and salicylic acid (SA) 2 mm on ‘Khenizi’ date fruit quality and storage life. Fruit quality parameters, including physical and physiochemical characteristics, phytochemical content, and bioactive properties, were determined at harvest time and during cold storage at 2 °C for 60 days for 2 months. Our results revealed that a combination of these elicitors had significantly influenced the fruit quality during storage compared with control. For instance, Ch+SA and Ch+Ca+SA treatments improved total phenolic content (TPC), and the antioxidant activity at harvest and at specific times during the postharvest storage period. Furthermore, Ch+SA+Ca treatment significantly delayed senescence in treated fruits during cold storage for 45 days as compared with other treatments and the control. In addition, Ch+Ca-treated fruits had the lowest weight loss after 45 days of cold storage. Ch+SA treatment had the lowest microbial counts as compared with other treatments, including the control. The significance of this study is that it provides evidence that a combination of these elicitors has the potential to improve fruit quality at harvest, as well as during postharvest storage Future studies should be directed to fine tune the concentrations and combinations that may have commercial applications.

Aloe vera/Chitosan-Based Edible Film with Enhanced Antioxidant, Antimicrobial, Thermal, and Barrier Properties for Sustainable Food Preservation

“…The number of colonies was recorded at the end of incubation time and calculated as Log10 colony forming unit per grams of fresh weight (Log 10 CFU g −1 ). This experiment was performed two times in triplicate [ 12 ].…”

“…The structural properties of CH vary according to the degree of deacetylation, molecular weight, and product grade. Due to these variations, the applications of CH have become broader and extended to many different fields such as it is reported as an excellent base material for food packaging, cosmetics, wound dressing, tissue engineering, drug delivery, and adsorbent in wastewater remediation [ 8 , 12 , 13 , 14 , 15 , 16 ].…”

Innovative and Effective Spray Method for Artificial Pollination of Date Palm Using Drone

“…Fifty grams of pitted fruit from each replication was mixed with 100 mL distilled water to extract the juice (1:2 dilution). The Brix value of TSS was measured for each extract using a digital refractometer (DR 6000; A. Kruss Optronic GmbH, Hamburg, Germany) and calculated to the original fruit weight (Ahmed et al, 2022).…”

Mechanism of Peppermint Extract-Induced Delay of ‘Packham’s Triumph’ Pear (Pyrus communis L.) Postharvest Ripening

“…For example, 1-methylcyclopropene is commonly applied to pears to delay fruit ripening by inhibiting the ethylene signalling pathway [ 24 , 25 ]. In addition, the use of plant growth regulators such as salicylic acid and melatonin has been shown to extend the shelf life of fruit by enhancing their antioxidant capacity [ 26 , 27 , 28 ]. However, since these substances are mostly chemical agents, their extraction is difficult, and their broad application is limited by high costs.…”