Effect of Methyl Cellulose Coating and Pre-Treatment on Oil Uptake, Moisture Retention and
Physical Properties of Deep-Fat Fried Starchy Dough System
American Journal of Agricultural and Biological Science. 2009;4(2)156-166
Jihad M. Quasem, Ayman S. Mazahreh, Khaled Abu-Alruz, Ibrahim A. Afaneh, Alaa H. Al-Muhtaseb, T. R. A. Magee
Problem statement: The influence of edible methyl cellulose coating and blanching pre-treatment in reducing oil uptake and moisture loss during frying of starchy dough system was investigated. Approach: Potato dough cylinder of 60 mm length and 22 mm diameter was used as a model food system. Samples were coated with 0.5% methyl cellulose film-forming solution and uncoated samples were used as control. Compared to the control samples, a reduction of 80% in oil uptake was achieved, with an increase in frying temperature decreasing the oil uptake due to the gel formation of methyl cellulose which was enhanced by higher temperatures. Results: No effect of methyl cellulose coating on the final moisture content was observed. The effect of methyl cellulose coating on structural properties (diameter, length, volume and bulk density) was also examined. The results showed that methyl cellulose coating had a significant effect on dimensional and density changes, as it enhanced the formation of crust, leading to a buildup in pressure within the cylinder, which in turn caused considerable puffing of the sample. Conclusion: Blanching pre-treatment (100°C, 5 min) was found to be effective in reducing the oil content of the potato dough samples.
Key words: Edible coating, methyl cellulose, blanching, deep-fat frying, starch system, physical