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Author: Japsimran Kaur × End date: 2020 × Start date: 2020 × Thesis Type: M.Tech. ×
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    ThesisItemOpen Access
    Development and optimization of pectin-based smart coating for fresh guava (Psidium guajava L.)
    (Punjab Agricultural University, Ludhiana, 2020) Japsimran Kaur; Preetinder Kaur
    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.