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SENESCENCE REGULATION AND VALUE ADDITION IN SWEET PEPPER (Capsicum annuum L.)
V.R. Sagar
2019
Ph.D
An experiment was carried out to developreliable management strategies for shelf life extension of sweet pepper at ICAR – Indian Agricultural Research Institute, New Delhi in 2015-2016. The fruits of sweet pepper varieties viz. Swarna (Yellow), California Wonder (Green) and Indra (Red) were harvested from centre for protected cultivation (CPCT) and brought to the division of food science and post harvest technology to carry out the research. The fruits from all the three varieties were divided into three size lots for conducting the experiment. Salicylic acid (SA), a plant hormone, has been reported to regulate a number of processes in plants. Therefore, in the first experiment, derivatives of salicylic were applied in sweet pepper to assess their suitability for shelf life extension. Accordingly, sweet pepper varieties viz. Swarna, California Wonder and Indra were treated with derivatives of salicylic acid viz. Acetyl salicylic acid (ASA), 5 Sulpho salicylic acid (5 SSA) and Gentisic acid (GA) at 0.5 mM and 1 mM concentrations under ambient condition (18-32°C and 80±10% RH) and analyzed the change in physical and biochemical profile at 3 days interval for 9 days. Fruits treated with 1 mM ASA and GA significantly delayed the senescence process by delaying the changes of weight, and firmness. Application of SA derivatives also resulted in more retention of TSS (3.96 0Brix), total phenols (10.0 mg GAE/g), total antioxidants (20.27 mM Trolox/g), more firmness (22.95 N) and less decay (8.69% decay). Thus the derivatives of salicylic acid may be effective in delaying the senescence process in sweet pepper. Surface coating encompasses use of thin wax film, carbohydrates etc. applied on the fruit surface. Accordingly, in the second experiment, chitsoan and carrageenan coatings were studied to find out their suitability in sweet pepper. Sweet peppers were treated with chitosan and carrageenan (0.5 and 1.0%), stored at ambient condition for 9 days and recorded their physical and biochemical changes. Application of 1.5% chitosan extended the shelf life of sweet pepper by maintaining higher firmness (27.69 N) and lower PLW (9.98%). Higher retention of antioxidant activity (20.27mMTrolox/g), total phenolics (10.25 mg GAE/g), ascorbic acid (105.17 mg/100g) and low decay incidence (9.75% decay) were recorded. Carrageenan coating 111 was found less effective compared to chitosan. Therefore 1.5% chitosan effectively enhanced the shelf life of sweet pepper. Lastly, value addition in the form of dehydrated sweet pepper slices was developed for retention of functional quality and their storability was studied.Pre treatments using hot water, steam blanching and microwave followed by drying in cabinet dryer, microwave and vacuum dryer revealed that steam blanching with vacuum dehydration resulted in more retention of total antioxidants (96.49 mM trolox/g), ascorbic acid (56.34 mg/100g) and total phenols (73.42 mg GAE/g). Storage studies revealed that HDPE packaging retained better functional qualities than LDPE in terms of moisture content (6.13%), ascorbic acid (52.10 mg/100g), total carotenoids (4.88 mg/100g), total phenols (64.78 mg GAE/100g), and rehydration ratio (5.58). 112
T-10085
sweet pepper, shelf life, post harvest, salicylic acid, surface coating,
en_US
POST HARVEST TECHNOLOGY ICAR - INDIAN AGRICULTURAL RESEARCH INSTITUTE NEW DELHI
Post Harvest Technology
SENESCENCE REGULATION AND VALUE ADDITION IN SWEET PEPPER (Capsicum annuum L.)
Thesis

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