29C-9 |
Application of edible coatings in battered and breaded foods: Viscosity of coating solutions |
W. USAWAKESMANEE1, M. S. CHINNAN2, P. Wuttijumnong1, A. Jangchud3, and N. Raksakulthai4. (1) Department of Product Development, Faculty of Agro-Industry, Kasetsart University, 50 Phahonyothin Rd., Chatuchak, Bangkok, 10900, Thailand, (2) Dept. of Food Science & Technology, Univ. of Georgia, 1109 Experiment St., 184 Melton Bldg., Griffin, GA 30223-1797, (3) Dept. of Products Development, Kasetsart Univ., Faculty of Agro-Industry, Bangkok, 10900, Thailand, (4) Department of Fishery Products, Faculty of Fisheries, Kasetsart University, 50 Phahonyothin Rd., Chatuchak, Bangkok, 10900, Thailand Many types of edible coatings have been developed over the years for use in fried food products. However, it has been difficult to compare their efficiency in terms of the barrier properties to moisture and fat in the application. The objective of this study was to determine the viscosity of various coating solutions to establish a criterion for the selection of coating concentration. Solutions were prepared from chitosan (CH), hydroxypropyl methylcellulose (HPMC) and wheat gluten (WG) in five concentrations each with three levels of ethanol in combination with water and/or plasticizer: CH solutions in 0.9, 1.2, 1.5, 1.8 and 2.1% each with 0, 15 and 30 % ethanol; HPMC solutions in 0.6, 0.8, 1.0, 1.2 and 1.4 % each with 0, 15 and 30% ethanol; WG solutions in 4, 5, 6, 7 and 8% each with 30, 40 and 50 % ethanol. Brookfield viscometer with small sample adapter (spindle No. SC4-18, sample volume 8 ml) was used for the viscosity measurements. Regression analysis was performed to obtain the best fit. There was a direct correlation between the viscosity values and the edible coating ingredient with/without ethanol in all treatment combinations. The viscosity of CH, HPMC and WG coating solutions varied from 66.3-918.0 cp, 43.7-932.3 cp and 134.0-773.3 cp, respectively. Linear regressions between log of viscosity and the concentration value yielded an excellent statistical fit (R2>0.94). From these regressions, it was possible to select appropriate solution concentration for each of the edible coating material to provide the same viscosity value in the range of 166.3-472.1 cp. The viscosity range determined in this study will help in obtaining coating solution concentration with the desired viscosity irrespective of the type of coating selected. This information will provide the necessary guidelines in the selection of appropriate coating ingredient to match product application.
Session 29C, Food Engineering: Rheology and texture
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