The optimization of the deep-fat frying process of coated zucchini pieces by response surface methodology

Abstract

The effect of Carboxymethyl cellulose (CMC) gum in three concentrations of 0.5, 1, and 1.5% (w/v) was investigated on the oil uptake and qualitative properties (moisture content, color, and overall acceptance) of zucchini during frying at 150, 165, and 180°C for 1, 3.5, and 6 min. To determine optimum conditions of frying operation, the response surface methodology (RSM) was used. Based on the modeling performed, the lowest oil uptake (1.93%) was determined for the coated samples with concentrations of higher than 0.75% of CMC gum and fried at temperatures less than 157.5°C for 2.25 min. The optimization results of RSM showed that oil uptake of zucchini coated with CMC gum during frying is decreased significantly (p < 0.05) with the reduction of operation time and temperature, and concentration of CMC gum. Optimum conditions for decreasing oil uptake of coated zucchini pieces were 153.46°C, 0.5%, 1.03 min for temperature, concentration and time, respectively.