Composite edible coatings from commercial pectin, corn flour and beetroot powder minimize post-harvest decay, reduces ripening and improves sensory liking of tomatoes

Abstract

The present study aimed to enhance the shelf life of tomatoes at pink-red stage through pectin (P), corn flour (CF) and beetroot powder (B) based coatings. PCF11 coating was resulted in significant enhancement of shelf life and quality retention of tomato in terms of physiological weight loss (PWL), decay per cent, ripening index, respiration rate, hue angle, firmness and DPPH antioxidant activity. Lower amounts of glucose and fructose quantified through HPLC indicated lesser cell wall components degradation in tomatoes coated with P and PCF11. Edible coatings also protected loss of phenolic acids like gallic and p-coumaric acid in tomato. All three coatings P, PCF11 and PCF11B in tomatoes showed higher retention of gloss and overall flavour scores. Further, the minimum shrinkage (18%) in tomatoes coated with PCF11 on 30th day evinced the uniformity and little hydrophobicity of pectin-corn flour-based coatings as observed through z-average particle size (d.nm)/WVP of coating solutions. Principal component analysis revealed significant correlation of several treatments and storage effects on tomatoes during shelf life study. The least separation among different points of PCF11 in score plot showed least deviation at subsequent storage intervals, revealing retention of quality of tomatoes during storage.

Keywords: Beetroot powder; Commercial pectin; Corn flour; Sensory quality; Shelf life; Tomato.