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Properties of poly(lactide)–whey protein isolate laminated films
Author(s) -
Phupoksakul Thunyaluck,
Leuangsukrerk Manusawee,
Numpiboonmarn Pidsawat,
Somwangthanaroj Agnat,
Janjarasskul Theeranun
Publication year - 2014
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.6775
Subject(s) - whey protein isolate , linear low density polyethylene , oxygen permeability , ultimate tensile strength , materials science , plasticizer , glycerol , composite material , whey protein , chemical engineering , composite number , casting , polyethylene , layer (electronics) , oxygen , chemistry , chromatography , organic chemistry , engineering
BACKGROUND This study aims to examine the feasibility of a novel multi‐layer barrier film made entirely from biopolymers, which can be disposed after use in an economically and ecologically acceptable way, by employing mechanical strength and moisture barrier of poly(lactide) ( PLA ) films and oxygen barrier enhancement of whey protein isolate ( WPI ) films. The effect of glycerol was also determined. The three‐layer films, PLA / WPI / PLA , were compared with those made of linear low‐density polyethylene films ( LLDPE / WPI / LLDPE ). Composite structures of three‐layer films obtained by a simple casting method using denatured WPI solution plasticised with glycerol ( GLY ) at three different ratios of GLY : WPI (1:4, 1:2.5 and 1:1.5). The WPI solution was applied between two base layers of corona‐treated PLA or LLDPE films. RESULT The multi‐layer films showed good appearance with no noticeably visible change and good adhesion of layers. PLA enhanced tensile strength of the composite structure. Oxygen permeability of the multi‐layer films was significantly lower than the base films. The water vapour permeability of the structure relied mainly on the base films. The plasticiser content did not significantly affect the properties of the multi‐layer structures. CONCLUSION Results suggested that WPI could work successfully as an alternative oxygen barrier layer of multi‐layer structures. © 2014 Society of Chemical Industry