Background: Edible coatings are useful method that applied to preserve postharvest quality of production. The coatings can extend the shelf life of products and inhibit microbial growth. Chitosan based coatings are one of the best methods to prolong fruit and vegetable shelf life. The antimicrobial and other properties of chitosan are developed when it is combined with other functional ingredients.
Methods: The effectiveness of chitosan, ethanolic extract of liquorice (LE) and complex of chitosan-liquorice extract (CHLE) was evaluated for controlling blue mold and extending shelf life in apples. The fruits were coated with chitosan(1.0%), LE (62.5 mg/ml) and CHLE coating, and stored at 25 °C. Quality properties of fruit (such as weight loss, firmness, total soluble solid content(TSS), titrable acidity and pH) and decay incidence were assessed on 0,1,4,7 and 14 days of incubation, respectively.
Results: The results of experiments indicated that minimum of water loss(3.8%), TSS(14.53) and firmness(5.6 kg/cm2 ) were in CHLE coated apples. In addition, this coating significantly inhibited penicillium expansum during the storage and the lowest decay incidence was for apples coated with CHLE(29 mm). Chitosan and LE coating retarded undesirable changes during postharvest storage and inhibited decay incidence compared with uncoated samples. There was no significant difference (p ≤ 0/05) between treatments and control overtime in terms of titrable acidity and pH levels.
Conclusions: The results reported here indicate importance and efficacy of CHLE coating in extending shelflife and reduction of postharvest losses of apple in storage time.
Keywords: Chitosan; Edible coating; Liquorice extract; Postharvest losses.