Quality Preservation and Shelf Life Extension of Broccoli Florets Using Tragacanth Gum Coating

Broccoli (Brassica oleracea L. var. italica) as an important vegetable has a high postharvest respiration rate, so, it loses its quality rapidly. The use of edible films and coatings as protective layers to create a covering on the surface of fruits and vegetables plays a key role in maintaining the quality of this product. The present research investigated the qualitative and biochemical traits of broccoli coated with tragacanth gum (0, 0.1, 0.2, and 0.4%) and cellophane and uncoated ones (as control) weekly during three-weeks cold storage. Based on the results, coating influenced all measured traits (except flavonoid content, vitamin C and antioxidant activity) and storage time influenced all recorded traits significantly (P 0.01). The results revealed that over the storage period, the physicochemical and biochemical parameters and visual quality of the broccoli decreased. Tragacanth gum 0.2% led to less weight loss, however, appropriate soluble solids content, and higher titratable acidity and organoleptic properties were recorded for 0.4% coated florets. Cellophane was effective in retaining some physicochemical characteristics, weight, and marketability, but it reduced phenolics. Tragacanth gum coating can be used as a biomaterial, as a substitute for synthetic cellophane film to preserve broccoli.