Extraction And Refining Of Oil From Hemp Seed

In order to exploit and develop the hemp seed resource, the main nutritional ingredients and physicochmeical parameter of hemp seed and oil were analyzed, using the Gansu and Ningxia hemp seeds as raw materials. The oil extraction optimizing conditions were studied by aqueous method and ultrasonic assistant method. And then, the process for sodium silicate and activated bleaching clay refining hemp seed oil was developed through simultaneous diacidification and bleaching. Main results follow:The three dimensional size and physicochmeical properties of hemp seeds are not significant different; the oil content of Gansu hemp seed is more than Ningxia's, but the two oils contain 4 kinds of main fatty acid and unsaturated fatty acid is about 88%,which contain more than 20%α-linolenic acid; the protein contain of two hemp seeds is not siguificant different, they have quite simlar amino acid composition and a good proportion; the mineral elements contains is not significant different, but the main elements contains have significant different.Response surface methodology was used to optimize aqueous extraction of oils from Hemp seed oil. The results show that extraction time and its quadratic had significant effect on yield oil rate, the quadratic of water-material ratio significant effect on yield oil rate, the optimum extraction conditions were obtained as follow: water-material ratio 1.98, extraction temperature 78.3℃, extraction time 180min,pH value 7.0, the oil extraction rate reached 81.4%.Response surface methodology was used to optimize aqueous extraction of oils from hemp seeds and then the oils quality parameters were analyzed. The results show that the solid/liquid ratio 8.62ml/g, ultrasonic power 347.2W, extraction time 44.3min, and the rate of oil extraction was 36.2%, its close to the model's value. The model was workable.The process for sodium silicate and activated b leaching clay refining hemp seed oil through simultaneous diacidification and bleaching was developed. Through sing le and orthogonal experiments, using hemp seed crude oil as raw materials. The obtained results show: The total addition amount of excessive alkali and activated clay affects the acid value, color and refining rate significantly (P<0.01).The ratio of excessive alkali and activated clay effect on the color significantly (P<0.01).The total addition amount of excessive alkali, activated bleaching clay and their interaction influence the acid value significantly (P<0.05). With the optimal conditions, the total addition amount of excessive alkali and activated bleaching clay 5.6%, the ratio of excessive alkali and activated bleaching clay 1:3.1, temperature 68℃, reaction time is 20min; the refining rate can reach 86.8%.