Edible composite bi-layer coating based on whey protein isolate, xanthan gum and clove oil for prolonging shelf life of tomatoes

Elsevier, Measurement: Food, Volume 2, 2021, 100005
Ashish Kumar, Charanjiv Singh Saini

Coatings plays an imperative role in increasing shelf life of fruit and have potential to minimize postharvest losses. In this study, impact of coating formulated from whey protein isolate, xanthan gum, clove oil and glycerol monostearate on tomato was evaluated. The tomatoes were divided in six groups and coated by dipping technique. Non-coated and differently treated tomatoes were evaluated under controlled environmental conditions (20 °C and 85% RH). The effectiveness of coatings on different quality attributes was investigated at time interval of 3, 6, 9, 12 and 15 days of storage. Storage life of coated samples exhibited improvement in firmness and color. The titrable acidity, ascorbic acid content, total phenolics content, total sugars and reducing sugars showed better retention in coated samples than non-coated sample. The results depicted that all formulated coatings have potential to maintain quality characteristics and increase the shelf life of tomatoes. The coatings made from whey protein isolate and xanthan gum in equal proportion exhibited best combination among all the coating as maximum quality attributes were retained by this coating because of inhibiting respiration and minimize starch conversion into sugar. Therefore, coatings were proven to be feasible for application due to edible, non-reactive and biodegradable nature.