Development and optimization of pectin-based smart coating for fresh guava (Psidium guajava L.)
Loading...
Date
2020
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Punjab Agricultural University, Ludhiana
Abstract
Present study was undertaken with an objective to extract and to develop smart pectin-based
coating from the guava fruit. Selection of guavas for extraction of pectin was done on the
basis of different physio-chemical properties as influenced by harvesting season (rainy,
winter) and maturity stages (immature green, mature, over-ripe yellow and infested). To
develop pectin-based coating, pectin was extracted from mature green guavas and mixed with
different plasticizers (glycerol, sorbitol, polyethylene glycol) with optional anti-microbial
agent (Turmeric powder). The effect of different pectin to cellulose ratio (50:50, 60:40;
70:30), plasticizers with or without addition of turmeric for various coating properties was
investigated and found to be significant (p<0.05). At best combination of pectin to cellulose
ratio (50:50), plasticizer (glycerol) with turmeric, the corresponding values of moisture
content, thickness, weight, color, tensile strength, density, viscosity, surface tension, water
vapor transmission rate were 0.95%, 0.385 mm, 1.7 g, L:48.11, a:19.41, b:33.13, 4.10 MPa,
6.88 g/cc, 0.23 Pa.s, 26.42 N/m, 61.17 gm-2d-1, respectively. On the other hand, pectin coating
without turmeric showed moisture content, thickness, weight, color, tensile strength, density,
viscosity, surface tension, water vapor transmission rate as 0.99%, 0.353 mm, 1.4g, L:73.76,
a:6.34, b:13.46, 4.20MPa, 6.24 g/cc, 0.25 Pa.s, 26.96 N/m, 63.44 gm-2d-1, respectively. The
developed pectin-based coating with and without turmeric had melting point of 134.280C and
138.210C, respectively. The coatings having turmeric exhibited enhanced antimicrobial
properties against E. coli, Yersinia, Salmonella, Shigella, Vibro sp .and campylobacteria sp.
The shelf-life of guavas coated with developed pectin (50:50; glycerol; with and without
turmeric) was assessed under ambient conditions (22OC,78% RH), retail market temperature
(15OC, 85% RH) and low temperature conditions (5OC and 80% RH). Results indicated
significant enhancement in quality with extended shelf-life of guavas upto 15 days and 12
days under low temperature conditions for coating with and without turmeric, respectively.
Description
Keywords
Citation
Japsimran Kaur(2020). Development and optimization of pectin-based smart coating for fresh guava (Psidium guajava L.) (Unpublished M.Tech. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.