Chitosan based coating for extending shelf life of banana

Abstract

The present investigation entitled ‘Chitosan based coating for extending shelf life of banana’ was conducted at Department of Postharvest Management, College of Agriculture, Vellayani during the year 2022-2024 with the objective to evaluate edible coating with chitosan and papaya leaf extract as postharvest treatment for extension of shelf life and quality of nendran and red banana. Nendran banana bunches of uniform size and optimum maturity were dehanded and sanitised with ozonisation (2ppm). The ozonised fruits were dipped in different concentrations of edible coating with chitosan (0.25%, 0.5%. and 1%), papaya leaf extract (PLE 0.25%, 5% and 10%) and combinations of chitosan and papaya leaf extract for 10 minutes along with fruits without any treatment as control. The fruits were kept in CFB boxes and were evaluated for physical, physiological and sensory parameters at an interval of 2 days till the end of shelf life. Among the treatments, Nendran treated with chitosan 1% + PLE 10% recorded 70.28% pulp, 29.71% peel, 2.36 pulp to peel ratio, 22.43 °Brix TSS with the lowest decay percentage (37.50%), PLW (15.20%), highest marketability (74.00%), better colour and texture (5.64 N) with higher sensory scores after 12 days of storage and recorded an extended shelf life of 12.50 days compared to control (6.33 days). In chitosan treatments, nendran banana treated with chitosan 1% recorded 69.68% of pulp, 30.31% peel, pulp to peel ratio of 2.30, 21.46°Brix TSS with least decay percentage (58.20%), PLW (15.36%) highest marketability (41.80%), texture (7.00N), better colour and acceptable sensory scores at the end of shelf life of 10.00 days. Based on physical, physiological, biochemical and sensory qualities chitosan 1% + PLE 10% and chitosan 1% were selected for storage study along with salicylic acid (2mM) as postharvest treatments. The ozonised nendran fruits at optimum maturity were subjected to postharvest treatments as dipping for 10 minutes and were stored in CFB boxes at room temperature (28±2°C) and refrigerated storage (14±1°C) conditions along with untreated fruits as control. The fruits were analysed for physical, physiological, biochemical and 149 sensory qualities at an interval of 3 days in room temperature and 5 days in refrigerated storage respectively. The nendran banana treated with chitosan 1%+ PLE10% + SA 2mM recorded an extended shelf life of 15.16 days and recorded 70.21% of pulp, 29.78% peel, 2.34 pulp to peel ratio, TSS of 23.23°Brix with the lowest decay percentage (39.60%), PLW (15.11%), highest marketability (60.40%), texture (6.43 N), flavonoids (10.11 μg QUE g-1) with acceptable sensory scores under room temperature storage. Under refrigerated storage, nendran banana treated with chitosan 1%+PLE10%+ SA 2mM exhibited pulp % of 70.13, 29.87 % peel, pulp to peel ratio of 1.44, 21.58 °Brix TSS, TSS Acid ratio of 44.95, 13.15% total sugars, 10.58 % reducing sugars, 4.00% starch with least PLW (17.89%), decay percentage (20.23%), titratable acidity (0.48%), highest marketability (79.77 %), texture (5.34N), ascorbic acid (9.75 mg 100g-1) and flavonoids (11.00 μg QUE g-1) and better colour with acceptable sensory scores after 30 days of storage and extended shelf life of 29.50 days The experiment was conducted for Red banana and uniform sized and optimum maturity fruits after ozonisation (2ppm) were dipped for 10 minutes in different concentrations of chitosan (0.25%, 0.5%. and 1%), papaya leaf extract (0.25%, 5% and 10%) and combinations of chitosan and papaya leaf extract along with fruits without any treatment as control. The coated fruits were stored in CFB boxes at room temperature and evaluated for physical, physiological and sensory parameters at 2 days intervals till the end of shelf life. Among the treatments, Red banana treated with chitosan 0.5%+PLE 10% extended shelf life of 11.33 days, as compared to 5.06 days of shelf life in the untreated fruits, with pulp to peel ratio of 2.22, 20.29 °Brix TSS with the least PLW (14.13 %) and highest texture (10.00 N), and better colour with acceptable sensory scores after 10 days of storage. Among chitosan treatments, red banana treated with chitosan 0.5% exhibited TSS (21.13°Brix) with least decay percentage (30.67%), PLW (14.96%), highest marketability (69.33%), better colour and texture (8.83 N) with higher sensory scores with a shelf life of 10.06 days. The chitosan 0.5%+PLE 10% and chitosan 0.5% were selected as the best treatments for storage studies along with salicylic acid (2mM) and the postharvest treated red banana 150 fruits were stored in CFB boxes at room temperature (28±2°C) and refrigerated storage (14±1°C) conditions till the end of shelf life. The effectiveness of the treatments was observed based on physical, physiological, biochemical and sensory qualities at an interval of 3 days at room temperature and 5 days in refrigerated storage, respectively. At room temperature, red banana treated with chitosan 0.5%+PLE10%+ SA 2mM exhibited pulp % of 70.03, 2.34 pulp to peel ratio, 8.28% reducing sugars, 20.42 °Brix TSS with least decay percentage (16.67 %), highest marketability (83.33%), better colour, texture (6.40 N), ascorbic acid (9.43 mg 100g-1) and flavonoids (11.95 μg QUE g-1) with higher sensory scores after 12 days of storage and extended shelf life of 11.66 days compared to control (5.00 days). At refrigerated storage, red banana treated with chitosan 0.5%+PLE10%+ SA 2mM recorded pulp % of 70.48%, 2.38 pulp to peel ratio, 11.24 % reducing sugars, 21.56°Brix TSS with least decay percentage (13.12 %), PLW (9.68%), highest marketability (86.88%), better colour and texture (6.85 N), ascorbic acid (7.68 mg 100g-1) and flavonoids (9.56 μg QUE g-1) with acceptable sensory scores after 35 days of storage with an extended shelf life of 34.66 days compared to untreated fruits which recorded a shelf life of 18.66 days. Based on physical, physiological, biochemical and sensory qualities it is revealed that chitosan based edible coating extended the shelf life and quality of nendran and red banana. The postharvest treatment of chitosan 1%+PLE 10% was the best treatment for extending shelf life and quality of nendran banana whereas chitosan 0.5%+PLE 10% was found as the best concentration for red banana fruits. The postharvest treatment with chitosan 1%+PLE10%+SA 2mM for 10 minutes recorded as the best combination for nendran banana which recorded a shelf life of 15.16 days and 29.50 days under room temperature and refrigerated storage respectively. The red banana fruits treated with chitosan 0.5%+PLE10%+SA 2mM was standardized as the best postharvest treatment which extended the shelf life under room temperature and refrigerated storage conditions as 11.66 days and 34.66 days respectively, with better quality.