SENESCENCE REGULATION AND VALUE ADDITION IN SWEET PEPPER (Capsicum annuum L.)
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Date
2019
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POST HARVEST TECHNOLOGY ICAR - INDIAN AGRICULTURAL RESEARCH INSTITUTE NEW DELHI
Abstract
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
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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).
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Description
T-10085
Keywords
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