Optimizing shelf life of pomegranate fruits during traditional storage by Tragacanth gum coating

Abstract

Purpose: One of the primary methods in increasing shelf life and maintaining the horticultural product quality is the application of edible coatings at the product surface. In this regard, this experiment was conducted to investigate the effect of tragacanth gum on some characteristics of pomegranate fruits such as weight loss, appearance quality, decay index, pH, soluble solid contents (SSC), titratable acidity (TA), maturity index, total phenol, vitamin C and anthocyanin content. Research Method: Fruits of two cultivars (‘Malase Yazdi' and ‘Malase Daneh Siah') were harvested and immersed in the tragacanth gum (0, 2.5, 5, 7.5, and 10 g l-1) solution for one minute. After applying treatments, fruits were air-dried, weighed, put in plastic baskets, and kept in the conventional storage in a completely randomized design for three months. Some quantitative and qualitative traits were measured and compared with the non-treated samples. Findings: Results revealed using tragacanth gum had a different effect according to cultivar type. The results also showed that tragacanth gum coatings could control the reduction of fruit appearance quality, and reduce the number of fruit decay in the ‘‘Malase Yazdi''. In ‘‘Malase Daneh Siah'', coating with tragacanth gum could improve pH, SSC, TA, and total anthocyanin content. Phenol content in both cultivars increased at the highest concentration (10 g l-1) of this edible coating. Research limitations: No limitations were founded. Originality/Value: Tragacanth gum coating could improve fruit quality of pomegranate during traditional storage and can be recommended to traditional pomegranate gardeners who still have large-scale traditional pomegranate storage.