Effect of Salicylic Acid and Calcium Nitrate Spraying on Qualitative Properties and Storability of Fresh Jujube Fruit (Ziziphus jujube Mill.)

Abstract

Chinese jujube is among the important medicinal plants grown in Iran. Its valuable fruit have a short post-harvest life. Delaying of quality reduction for few days can help maintaining the shelf life of fresh jujube fruit. The current study was conducted to investigate the possible effects of pre-harvest foliar application of salicylic acid (0, 2 and 4 mM) and calcium nitrate (0, 1 and 2%) on physico-chemical characteristics and shelf life of fresh jujube fruit during storage at 10-days intervals, for 40 days. Results indicated that salicylic acid and calcium nitrate played an important role in maintaining and extending post-harvest quality of fresh jujube fruit, as both substances increased fruit firmness, titrable acidity, total phenolic content, antioxidant activity, ascorbic acid and catalase enzyme, but reducing total soluble solids. The highest total phenolic content (2.38 µg gallic acid/gFW), antioxidant activity (76.73 mmolTrolox/g), ascorbic acid (222.4 mg/100g FW) and catalase enzyme (16.67 U. mg-1 protein), as well as the lowest total soluble solids content (23.11%) were observed when salicylic acid 4 mM was used. Furthermore, maximum fruit firmness (4.22 N) was obtained in the treatment containing calcium nitrate 2%. Treatment containing salicylic acid 2 mM and calcium nitrate 2% had the highest amount of titrable acidity TA (0.45 %). Based on the results, reducing trends of some components like ascorbic acid, antioxidant and phenol, were very fast, even when using salicylic acid and calcium nitrate; their application could cause a delay in these processes, but the quality reduction found could not be compensated. In other characteristics that had a slower quality reducing trend, the application of salicylic acid and calcium nitrate could cause at least a 10-day delay in the reduction of the amounts of these attributes.  In press: Online First articles have been peer reviewed, accepted for publication and published online without pagination. They will receive pagination when the issue will be ready for publishing as a complete number. After the pagination, the articles will be included in Volume 45, Issue 1, 2017. These articles are searchable and citable by they DOI (Digital Object Identifier), but DOI will become active after the articles will be included in the complete issue.