Psidium guajava L. var. 'Lalit' is a perishable fruit with delicate skin which is prone to damage. The objective of this study was to determine the effect of edible coating made up of hydroxypropyl methyl cellulose and palm oil on ripening of guava. Coating solution was applied over fruits and coated fruits were stored at 24 ± 1 °C and 65 ± 5%RH. Changes in fruit colour, texture softening, respiration rate, weight loss, ascorbic acid content, soluble solids, titrable acidity, chlorophyll content, total reducing sugars, total phenolic content were studied during post-harvest ripening. Fruits coated with 1 % of hydroxypropyl methyl cellulose and 0.3 % of palm oil showed significant delay in weight loss, fruit firmness as well as colour change (p < 0.05). Coating delayed the enzyme activities of peroxidase and polyphenol oxidase of the fruit. Results suggest that overall quality of coated fruit was maintained by edible coating formulation extending the shelf life of fruit up to 12 days with appreciable retention of all quality parameters tested.

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The results suggest that edible coating made up of MC-PO has potential to maintain the quality of sapota fruit. The edible coating extended the shelf-life of sapota fruit by 3 days preserving fruit quality up to 7 days at 24 ± 1 °C and 65 ± 5 %RH. © 2016 Society of Chemical Industry.

Chillies of Pusa jwala variety were coated with composite coating formulation made up of methyl cellulose (MC) and oleic acid (OA) to evaluate the effectiveness of edible coating in extending the shelf‐life of chillies. Edible coating showed good stability, transparency and glossiness when applied on chilli fruit. The coatings when applied on green chillies resulted in restriction in metabolic activities and delayed senescence. MC‐based coating was found to reduce physiological weight loss, textural softening and development of red pigment in the fruit peel. Coated fruit synthesized phenolic compound slower than uncoated fruit bringing about slow changes in capsaicin content as well. MC‐OA based coating could extend the shelf‐life of green chillies to 8 days under ambient storage conditions (24 ± 1C, RH 70 ± 5%) against the 5‐day shelf‐life of uncoated ones. Practical Applications Chilli is considered as one of the most important commercial spice crops and is a widely used universal spice. Preserving fresh chillies with simple, edible coating formulation would reduce the cost of preservation using other expensive and energy consuming techniques such as cold storage and CAP/MAP. As the coating gives each fruit its own micro‐packaging, coated fruits can be well handled as those of uncoated chillies. Being edible and water soluble the coating would not be harmful to consumers compared to use of chemical preservatives.

POD and PPO showed good stability over a wide range of pH and temperature. As reflected by Z and E values, the fruit matrix had no significant influence towards enzyme stability. Designing of thermal process should take into consideration D- and Z-values of the enzymes along with D- and Z-values of microorganisms to obtain a product with better shelf life. © 2017 Society of Chemical Industry.