29C-10 |
Rheological properties of wheat flour batters containing cellulose ethers (methylcellulose and hydroxypropyl methylcellulose) during gelatinization |
S. NARUENARTWONGSAKUL1, M. S. CHINNAN2, S. Bhumiratana1, and T. Yoovidhya1. (1) Dept. of Food Engineering, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand, (2) Department of Food Science and Technology, University of Georgia, 1109 Experiment St., Melton Bldg., Griffin, GA 30223-1797 Cellulose ethers (methylcellulose and hydroxypropyl methylcellulose) have been used for providing viscosity and lowering oil uptake in batter-coated fried products. The gelation temperature and gel firmness of these hydrocolloids depend on their type, molecular weight, and concentration. It is hypothesized that these factors may also affect the rheological properties of batters and influence the oil absorption of fried products. The objectives were to explore the effects of type, number average molecular weight (Mn), and concentration of cellulose ethers on apparent viscosity of batters and their rheological properties during gelatinization. Batters were prepared by mixing wheat flour with stock solution of cellulose ether in four concentrations each with five levels of water to flour ratio. Three cellulose ethers (A4M, E4M, and K4M) were tested to determine the effect of type and the special emphasis on Type A with three different Mn [A15 (Mn=14,000), A4C (Mn=41,000), and A4M (Mn=86,000)] were considered to investigate the effect of varying Mn on apparent viscosity of batters. Rheological properties [temperature at G crossover point (TG) and maximum storage modulus (G¢max)] of batters, with 1,200 cp in each treatment combination, were analyzed during gelatinization. While the effect of cellulose ether type was similar on apparent viscosity, Mn and level of concentration showed direct correlation. However, apparent viscosity of batters decreased with increase in water to flour ratio. Type, Mn, and concentration of cellulose ethers affected the TG and G¢max values of gelled batters. Batters containing K4M exhibited the highest TG and lowest G¢max values. Increase in cellulose ether concentration with simultaneous increase in water content resulted in higher TG (except batters containing A15) and lower G¢max values of gelled batters. Type, Mn, and concentration of cellulose ethers had a significant effect on the rheological properties with potential to favorably affect the oil absorption of fried products.
Session 29C, Food Engineering: Rheology and texture
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