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WPI Coating (wpi + coating)
Selected AbstractsOxygen Barrier Properties of Whey Protein Isolate Coatings on Polypropylene FilmsJOURNAL OF FOOD SCIENCE, Issue 1 2003S.-I. Hong ABSTRACT Oxygen permeation characteristics of whey protein isolate (WPI) coatings on polypropylene (PP) films were investigated to examine the feasibility of WPI coating as a novel biopolymer oxygen barrier for food packaging applications. Heat-denatured aqueous solutions of WPI with several plasticizers including glycerol, sorbitol, sucrose, propylene glycol, and polyethylene glycol were applied on the surfaces of PP films previously treated with corona discharge. Among plasticizers used, sucrose conferred the best oxygen barrier property to the WPI-coated films. Oxygen permeability (OP) of the resulting WPI-coated films increased significantly with temperature, showing very good agreement with the Arrhenius model. OP of the coated films also increased exponentially with relative humidity. [source] Whey protein isolate coating on LDPE film as a novel oxygen barrier in the composite structurePACKAGING TECHNOLOGY AND SCIENCE, Issue 1 2004Seok-In Hong Abstract To examine the feasibility of whey protein isolate (WPI) coating as an alternative oxygen barrier for food packaging, heat-denatured aqueous solutions of WPI with various levels of glycerol as a plasticizer were applied on corona-discharge-treated low-density polyethylene (LDPE) films. The resulting WPI-coated LDPE films showed good appearance, flexibility and adhesion between the coating and the base film, when an appropriate amount of plasticizer was added to the coating formulations. WPI-coated LDPE films showed significant decrease in oxygen permeability (OP) at low to intermediate relative humidity, with an Arrhenius behaviour and an activation energy of 50.26,kJ/mol. The OP of the coated films increased significantly with increasing relative humidity, showing an exponential function. Although the coated films showed a tendency to have less oxygen barrier and more glossy surfaces with increasing plasticizer content, differences in the OP and gloss values were not significant. Haze index and colour of the coated films were also little influenced by WPI coating and plasticizer content. The results suggest that whey protein isolate coating could work successfully as an oxygen barrier and have potential for replacing synthetic plastic oxygen-barrier layers in many laminated food packaging structures. Copyright © 2004 John Wiley & Sons, Ltd. [source] Color Stability of Edible Coatings During Prolonged StorageJOURNAL OF FOOD SCIENCE, Issue 7 2000T.A. Trezza ABSTRACT: The yellowing rates of edible coatings were determined at 23, 40, and 55 °C at 75% relative humidity (RH). Whey protein isolate (WPI) coatings had lower yellowing rates than whey protein concentrate (WPC) and the same rates as shellac coatings. Hydroxypropyl methylcellulose (HPMC) coatings had the lowest yellowing rates. Zein coatings became less yellow during storage; however, their color was still pronounced. Activation energies and Q10 values for the yellowing of whey protein coatings were similar to those previously reported for the browning of whey powder. The results indicate that WPI coatings can be used in place of shellac coatings when low-color development is desired. WPC coatings can be used to tailor color development of a food. [source] Whey protein isolate coating and concentration effects on egg shelf lifeJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2005Cengiz Caner Abstract The influences of three different concentrations (6, 12 and 18%) of whey protein isolate (WPI) coatings on shelf-life enhancements of the fresh egg quality (weight loss, pH, Haugh unit, yolk index and colors) and the shelf life were evaluated at room temperature. All coated eggs showed lower weight loss than uncoated eggs. Less weight loss (2.46 for 12% WPI and 2.38 for 18% WPI) was observed in WPI-coated eggs. Haugh units (HU) indicated that coated eggs remained in grade ,A' during 3 weeks storage period, whereas uncoated (UC) changed from grade ,A' to ,B' after 1 week of storage. The HU and yolk-index (YI) values of all WPI-coated eggs were significantly higher than those of UC. Among the coated eggs, there were no significant differences in HU, but 12 and 18% WPI coated had higher YI than WPI 6% coated and UC. The albumen pH of the UC eggs was significantly higher than that of coated eggs. Yolk lightness (L*) and (b*); shell (a*) and (b*) of coated eggs were not different from UC after 4 weeks. Performance of WPI coatings depended on the concentration up to 12% but not between 12 and 18%. Results also indicated that WPI coatings served as protective barrier for shelf life of the eggs. Copyright © 2005 Society of Chemical Industry [source] | ||||||||||