“Oil uptake reduction of fried dough by methyl-cellulose coatings application.”

GARCÍA, M.A.; FERRERO, C.; BERTOLA, N.; MARTINO, M.; ZARITZKY, N.

Valencia, España.

Conferencia; Congreso EFFSOT. INTRAFOOD 2005.; 2005

Various hydrocolloids, especially cellulose derivatives can be used to decrease oil content during frying. The excess of fat in the diet has been linked to coronary heart disease, thus coatings applied to food before frying can help in reducing health problems associated to fat consumption. The objectives of the present work were to analyze the oil uptake of coated dough with methylcellulose during deep fat frying, and to study the microstructure of both coating suspensions and fried dough. Aqueous suspensions of 1% Methocel A4M (based on methylcellulose) with and without sorbitol (0.25-1%), as plasticizer, were prepared. The rheological behaviour was analyzed in a Haake RV2 Viscometer and in an Oscillatory Rheometer Haake CV20. Thermal gelation was studied and power law model was applied to characterize the suspensions. Dough discs 3cm in diameter and 0.4cm thick were dipped in the formulations, drained and immediately dipped in sunflower oil at 150°C. Fat content was determined by combining a preliminary batch extraction process with a semi-continuous extraction in Soxhlet. The extracted lipid phases were analyzed by HPLC. Samples were tested by a non-trained sensory panel. Coating-dough interaction was analyzed by SEM, casted suspensions (dried at 60°C) were also observed. Sorbitol presence improved the barrier properties of methylcellulose coatings. Samples with 1% A4M and 0.75% sorbitol formulations reduced up to 35.2% oil uptake and retained 25.7% more water than uncoated samples. No significant differences between coated and uncoated samples were detected by the sensory panel. The lipid phases extracted from coated and uncoated fried samples showed different fatty acid composition. This fact indicated that these coatings acted as a selecting barrier to oil diffusion. SEM micrographs showed a good adhesion between coating and the dough.