# Gum tragacanth, a novel edible coating, maintains biochemical quality, antioxidant capacity, and storage life in bell pepper fruits

## TL;DR

This study shows that a 1% gum tragacanth coating helps preserve the quality and extend the storage life of bell peppers by reducing weight loss and maintaining antioxidants.

## Contribution

The study introduces 1% gum tragacanth as a novel edible coating that effectively preserves bell pepper quality during storage.

## Key findings

- 1% gum tragacanth coating reduced weight loss and improved firmness in stored bell peppers.
- Coated fruits showed higher antioxidant enzyme activities and antioxidant capacity compared to uncoated fruits.
- 1% GT coating maintained 75% marketability, significantly better than the 40% in uncoated controls.

## Abstract

Bell pepper fruits (Capsicum annuum L.) are prone to both physiological and pathological deterioration following harvest, primarily due to their high metabolic activity and water content. The storage of bell peppers presents several challenges, including weight loss, softening, alterations in fruit metabolites and color, increased decay, and a decline in marketability. The application of edible coatings (ECs) is one of the environmentally friendly technologies that improves many post‐harvest quantitative and qualitative characteristics of products. This research investigated the impact of different levels of gum tragacanth (GT) coating (0, 0.25, 0.5, 1, and 2%) on the physiological and biochemical traits of stored bell pepper fruits (BPFs) (8 ± 1°C, 90–95% RH) for 28 days. The results showed the positive effect of coating treatments with higher concentrations of GT, up to 1%. Increasing the concentration of GT to 2% decreased the marketability and quality characteristics of fruits compared to 1% GT. After storage, the physiological weight loss of the fruits treated with 1% GT (10.46%) was lower than that of the uncoated fruits (18.92%). Furthermore, the coated fruits (1% GT) had more firmness, total phenol content, ascorbic acid, and titratable acidity content than uncoated fruits during storage. At the end of storage, the coated BPFs with 1% GT showed higher SOD (97.02 U g−1), CAT (24.38 U g−1) and POD (0.11 U g−1) activities and antioxidant capacity (81.74%) as compared to other treatments. Total soluble solids, total carbohydrates, total carotenoids, pH, malondialdehyde, and electrolyte leakage content increased in coated fruit during storage but were significantly lower than in uncoated fruits. Moreover, the samples coated with GT (1%) maintained good marketability (about 75%), while the marketability of the control (about 40%) was unacceptable. The study shows that GT (1%) coating can be a promising novel treatment option for increasing the storage quality of BPFs.

This study investigated the impact of varying levels of gum tragacanth (GT) coating on the quality of stored sweet pepper fruits over 28 days. Results indicated that GT concentrations up to 1% positively influenced fruit quality, while 2% concentrations had negative effects on marketability and overall quality. Fruits coated with 1% GT exhibited lower weight loss, more firmness, and higher levels of phenols, ascorbic acid, titratable acidity, SOD, CAT, POD activities, and antioxidant capacity compared to other treatments.