STUDY ON THE OPTIMIZATION OF ULTRASONIC-ASSISTED EXTRACTION OF KENAF SEED OIL

Kenaf seeds oil was extracted from kenaf seeds by ultrasonic-assisted solvent extraction in the present study.The extraction process was optimized by response surface methodology on the basis of single factor experiments.Four extraction parameters including ultrasonic time,ultrasonic power,liquid-solid ratio (mL·g^-1) and extraction temperature were selected as independent variables,while kenaf seeds oil yield as response value.The physicochemical indexes and fatty acid compositions of kenaf seeds oil were also analyzed.The results showed that the optimal extraction conditions were obtained as follows,ultrasonic time 40 min,ultrasonic power 250 W,liquid-solid ratio 8:1 and extraction temperature 30℃.Under these conditions,the yield of kenaf seeds oil reached to 93.47%.The effect of factors on the extraction yield was in the order of liquid-solid ratio >ultrasonic time >ultrasonic power >extraction temperature.The kenaf seeds oil obtained by ultrasonic-assisted extraction had better quality with lower acid value and peroxide value.The fatty acid of kenaf seeds oil was mainly unsaturated fatty acid (75.15%),mainly linoleic acid (43.14%) and oleic acid (30.78%).The content of unsaturated fatty acids was up to 75.15%.What's more,kenaf seed oil also had higher content of saturated fatty acids,for example,palmitic acid (21.97%).Ultrasonic-assisted extraction had the characteristics of extraction speed and high extraction efficiency.The best technology conditions of ultrasonic assisted extraction will provide theoretical basis for the development and ultilization of kenaf seed oil.