Optimization of processing parameters for preparation of frozen French-fried potatoes

Response surface methodology was applied to analyze the effects of processing conditions including drying temperature and time and pre-frying time on color difference value(ΔE), moisture and oil uptakeing of the product in the preparation of frozen French-fried potatoes. The conditions of preparation were established by means of a central rotatable composite design for drying temperature, drying time and pre-frying time in the range of 74.8～125.2℃, 10～20 min and 35～85 s at 180℃, respectively. The response variables were fitted to predictive models using multiple regression analysis. Results show that drying temperature, drying time and pre-frying time have significant effects(p<0.05) on ΔE, moisture and oil uptakeing of French-frieds potatoes. Applying the approach of desirability function, the parameters of processing were optimized in 108～110℃, 11～12 min for drying, and 38s at 180℃ for pre-frying. After frozen storage at -20℃ and finish frying, the product has less ΔE of 3.99～4.45, moisture of 37.50%～38.50% and oil uptakeing of 14.34%～14.85%, which can meet the requirement of commercial products.