Please use this identifier to cite or link to this item: http://krishikosh.egranth.ac.in/handle/1/5810009926
Authors: K. PRASAD
Advisor: R. R. Sharma
Title: STUDIES ON LENTICELS BROWNING IN MANGO (Mangifera indica L.)
Publisher: DIVISION OF FOOD SCIENCE & POSTHARVEST TECHNOLOGY INDIAN AGRICULTURAL RESEARCH INSTITUTE NEW DELHI
Language: en_US
Type: Thesis
Agrotags: null
Keywords: STUDIES LENTICELS BROWNING MANGO (Mangifera indica L.)
Abstract: Lenticels browning/discolouration (LB/LD) is a serious problem in mango (Mangifera indica L), which hampers export of this valuable fruit. Hence, studies were conducted to know the extent of LB among some indigenous (15) and exotic (3) mango varieties and some measures such as hot water treatment, ascorbic acid and salicylic acid were chosen to see the impact in selected varieties to reduce it. From results, it has been found that fruits harvested at specific gravity <1 had less LB (19.4%) than those harvested at specific gravity >1 (25.7%). Among Indian varieties, maximum incidence of LB (96.1%) was recorded in ‘Langra’ and minimum in ‘H-3-2’ (4.3%). Among exotic varieties, ‘Eldon’ was recorded to be having maximum incidence of LB (41%) and ‘St Alexendrina’ the least (29.3%). Interestingly, most of the hybrids developed by IARI, New Delhi have very low incidence of LB (less than 7%). Among different hot water treatments (HWT), fruits subjected to 50°C for 30 minutes had the lowest incidence (30.6%), whereas untreated (control) fruits had highest incidence of LB (54.3%). This HWT was also effective in reducing fruit decay (21.6%), maintaining highest phenolics (16.80 mg/100 g), PPO, POD and LOX enzyme activity over other HWT treatments or untreated fruits. Similarly, fruits exposed to this treatment exhibited lowest rates of ethylene evolution and respiration rate. All the varieties exhibited significant variability in the studied attributes. Among different concentrations of ascorbic acid, lowest LB (22.2%) was exhibited by fruits subjected to ascorbic acid treatment at 150 ppm concentration. This treatment also reduced fruit decay significantly over control fruits and maintained highest concentrations of total phenolics (12.26mg /100 g), PPO, POD and LOX activity; lowest rates of ethylene evolution (0.607 μl kg-1 h-1), respiration rate (38.96 ml CO2 kg-1 h-1) and minimum colour change (0.82 ΔE) over other treatments of ascorbic acid or untreated fruits. Among different concentrations of salicylic acid, fruits treated with 200 ppm reduced LB (33.7%), postharvest decay (23.3%) and maintained highest concentrations of total phenolics, PPO (0.934 Δ A410O.D min-1mg-1), POD activity (1.267 A410O.D min- 1mg-1) and LOX enzyme activities. This treatment was effective in maintaining lowest rate of ethylene evolution (0.521 μl kg-1 h-1) and respiration. This treatment was effective in maintaining minimum colour change over other treatments or untreated fruits. Further, significant differences were recorded among the varieties for all the studied attributes. The correlation between LB and respiration rate (r2 = +0.872), LB and ethylene evolution rate (r2 = +0.807), LB with polyphenol oxidase activity (r2 = +0.992), LB and lipoxygenase activity (r2 = +0.802) was strongly positive However, the correlation between LB and total phenols (r2 = - 0.755) was strongly negative.
Description: t-9165
Subject: Post Harvest Technology
Theme: STUDIES ON LENTICELS BROWNING IN MANGO (Mangifera indica L.)
These Type: M.Sc
Issue Date: 2015
Appears in Collections:Theses

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