Quality and shelf life of mango and banana as influenced by chitin nanofiber

The current study was conducted because of the effect of chitin nanofiber on physicochemical properties of mango and banana in ambient condition. The main objective of the study was to identify suitable ecofriendly postharvest treatment for maintaining quality of ‘Nilumbori’ mango and ‘Jin’ banana. The study was conducted at Horticulture Laboratory, Agrotechnology Discipline, Khulna University, Khulna during the period from 25th July 2022 to 6th August 2022. Mango (Nilumbori) was collected from Satkhira and Banana (Jin) was collected from Khulna. The two-factor experiment was conducted in this study following factorial completely randomized design (CRD) with three replications of treatments containing 10 fruits in each replication. The temperature of Horticulture Laboratory ranged from 26℃ to 31℃ with relative humidity 80-90%. The postharvest treatments were applied to randomly selected fruits. Mango (Nilumbori) and banana (Jin) fruits were treated with different concentrations of chitin nanofiber (CNF) as 0.1%, 0.3% and 0.5%. Fruits without treatments were considered as control. Both treated and untreated fruits were kept at ambient temperature. Observations were made during the storage period on various physical (weight loss, firmness, fruit color [subjective and objective], disease incidence, disease severity and shelflife) and chemical (TA, TSS, TA-TSS ratio and vitamin C) parameters of mango and banana fruits. Physical parameters were recorded everyday while chemical parameters on every alternate day. From the experiment of banana, it was observed that cumulative weight loss, firmness and color of T3 (CNF 0.3%) treated fruits performed better than T2 (CNF 0.1%) and T4 (CNF 0.5%). But in case of TA, TSS and vitamin C value, T2 (CNF 0.1%) showed better results. The T3 treated fruits showed lower rate of cumulative weight loss (0.96-part), firmness (0.73-part) and color (0.22-part). However, T2 treated fruits showed better results in vitamin C (0.27-part), TSS (0.75-part) and TA (1.23-times) than the control fruits. The highest shelf life of banana was recorded 5.75 days in T2 (CNF 0.1%) treated fruits while shelf life of control was 4.75 days. Lower concentration of CNF might have the capacity to inhibit ripening process and suitable for banana postharvest. In case of mango, cumulative weight loss, color and TSS of T4 (CNF 0.5%) treated fruits showed better result in comparison to control while T3 (CNF 0.3%) treated fruits performed 51 well in disease incidence and shelf life. Lower rate of cumulative weight loss (0.83-part), color (0.23-part) and TSS (0.64-part) was observed in T4 (CNF 0.5%) treated fruits while CNF 0.3% performed better in firmness (0.90-part) and disease incidence (0.93-part) in comparison to control. The highest shelf life of mango was recorded as 8.5 days in T3 (CNF 0.3%) treated fruits while control fruits exhibited only 7 days. CNF treatment extend shelf life of mango about 1.5 days during postharvest period. This result indicates that moderate concentration of CNF might have the capacity to breakdown the inhibitory effect of higher ambient temperature on ripening process and is suitable for the mango fruits. From the current study, it could be recommended that in banana, lower concentration of CNF (0.1% to 0.3%) and in mango moderate concentration of CNF (0.3% to 0.5%) might be a suitable treatment for maintaining physicochemical properties and shelf life in ambient condition. In this regard, further experiments could be conducted with other varieties of banana by considering lower concentrations and other varieties of mango by considering higher concentrations of CNF. 

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