Parameters Optimization of Ultrasound-Assisted Deodorization of Sheep Tail Fat Using Response Surface Technique

Abstract

Sheep tail fat is a common frying oil in Iran due to its good flavor and stability. Deodorization is a high-temperature vacuum purification process for removing the volatile compounds from the edible fats and oils. In this paper, the effects of temperature, time, and ultrasound power on the quality attributes of sheep tail fat during the deodorization process were studied using response surface methodology. Variations of the acid value, peroxide value, iodine value, and saponification value, as well as extinction coefficient, were investigated. The best equations were created for the responses of acid value (R2 = 0.9143, p < 0.0001), peroxide value (R2 = 0.9862, p < 0.0001), iodine value (R2 = 0.9670, p < 0.0001), refractive index (R2 = 0.9816, p < 0.0001), saponification value (R2 = 0.9345, p < 0.0001) and extinction coefficient (R2 = 0.9562, p < 0.0001). Finally, the temperature of 200 ºC, the processing time of 80 min, and the ultrasound power of 307 W were recommended for the optimal conditions of sheep tail fat ultrasound-assisted deodorization.

Keywords

• edible fats
• extinction coefficient
• free fatty acids
• peroxide value
• ultrasound power