PREPARATION OF DIFFERENT ZEIN FILMS FROM CORN GLUTEN MEAL AND THEIR USE IN COATING OF DIFFERENT MODEL FOODS.

In the present study, the zein (10% w/w, dry basis) isolated from corn gluten meal from Bajaura Makka (Zea mays L.) variety of H.P. was solubilised in hot ethanol (90%) using glycerol and fructose as plasticizers. The three types of zein films were prepared, first film preparation was done by mixing zein with absolute ethanol (90%), second film prepared was zein and ethanol added with glycerol 5% (w/w) as plasticizer and third was zein and ethanol added with fructose 4% (w/w). The various physiochemical properties of these three zein films viz. colour, thickness, solubility, water vapour transmission rate were evaluated. The thickness for zein ethanol film was 0.14±0.02 mm and the thickness of films prepared by zein ethanol glycerol mixture and zein ethanol fructose mixture were 0.22±0.04 mm and 0.19±0.07 mm respectively. The water vapour transmission rate of different zein films i.e. zein ethanol mixture, zein ethanol fructose and zein ethanol glycerol was observed as 0.54 × 10^-3, 0.36 × 10^-3 and 0.25 × 10^-3 (g/m²/sec) respectively and solubility of these zein films was 17±0.67%, 25±0.42% and 20±0.80% respectively. The color of zein ethanol film was 1.3 red units, 3.6 yellow units, 4.20 white units and color of zein ethanol fructose film was 1.2 red units, 10 yellow units, 7.4 white units and color of zein ethanol glycerol film was 1 red units, 4.7 yellow units, 4.1 white units as observed in Lovibond Tintometer. The results showed that the film prepared with combination of zein + ethanol + glycerol was having higher film thickness, water vapour transmission rate (WVTR) than other two zein films. These zein films were further used for coating of different model food products viz. Himalayan fig (Ficus palmata) leather, roasted nuts, chocolate cookies and vanilla cookies. [ABSTRACT FROM AUTHOR]