The Research Of Key Technologies Of The Comprehensive Utilization Of Bitter Almond

The bitter almond is a traditional Chinese medicine, the dry mature seeds of rosaceae plants of wild apricot, wild apricot, Siberia apricot, the Northeast apricot and apricot.Nutrient-rich bitter almonds which contain amygdalin, bitter almond oil and bitter almond protein have a very high economic value and pratical value.In other, A variety of trace elements and organic matter, such as amino acids, carbohydrates and elements of Calcium and Potassium are contained in the bitter almonds.The amygdalin, about 5% in bitter almond, can be easily hydrolyzed under acidic or enzymatic catalysis. The amygdalin has high medicinal value because of its effect-ion of antitussive and antiasthmatic. HPLC, micellar capillary eletrophoresis et al are reported the derect methods to detect amygdakin, other chemical methods are used to detect amygdalin in a indirect way. Distillation of bitter almond water, Ethanol extraction and ultrasonic extraction are the main methods to extract amygdalin.The bitter almond oil, about 50% in bitter almond, is composed by unsaturated fatty acids which contain linoleic and linolenic. The unsaturated fatty acids in bitter almond oil as a essential fatty acid can lower cholesterol and promote the body’s metabolism. In other way, the bitter almond oil which has high economic value can be added in the industrial lubricants and cosmetics.Compression method and solvent extraction are the main way to extract bitter almond oil, Supercritical carbon dioxide cxtraction as a new extraction method is widely used in the extraction of bitter almond oil.The bitter almond protein, about 20%～30% in bitter almond, is rich in amino acids occupied by essential amino acids. As a high food value protein, the bitter almond protein is contained by low molecular weight protein. Alcohol extraction, alkaline extraction and enzymatic extraction are used to extract bitter almond protein in bitter almond.Although there are some reports about the extraction of the three components, people what to do is to use two of the three components without the comprehensive utilization of bitter almond because of the amygdalase contained in bitter almond. Once broke the bitter almond, there exits hydrolytic reaction between amygdalase and amygdalin. We can use bitter almond oil and amygdalin if we use heat treat bitter almond in order to inactivate enzyme because the bitter almond protein will degenerate. Therefore, how to achieve the full use of amygdalin, bitter almond oil and bitter almond protein will become a urgent problem in the intensive processing and comprehensive utilization.This thesis carried a systematical study on the key technologies of the comprehensive utilization of bitter almond, the process of supercritical fluid extraction of bitter almond oil and the process of separation of amygdalin and bitter almond protein.Experimental results show that:1. While broking bitter almond and extracting the bitter almond oil, amygdalase will be suppressed by controlling water activity in order to prevent the decomposition of amygdalin. Controling the concertration of ethanol and operating temperature are used to inhibite the amygdalase and prevent the denaturation of bitter almond protein. The results show that, controlling the water activity in about 0.67 in broking bitter almond and extracting the bitter almond oil; choosing concertration of ethanol 65% and operating temperature in 50℃in the separation of amygdalin and bitter almond protein.2. This thesis carried a systematical study on the optimum process to extract bitter almond oil by Supercritical carbon dioxide cxtraction. The optimum parameters:extraction pressure 35MPa, extraction temperature 45℃, material grinding dgree 40list and the extraction time 60min. In this way, the extraction rate of bitter almond oil achieves 95.74%.At the same time, some detects about the physical and chemical indicators of bitter almond oil are conducted.The results show that:Peroxide value (meq/kg):2.05; Acid value[(KOH)/(mg/g)]:7.0; Iodine Value (I2g/100g):94.1; Refractive index:1.4056.3. Water bath oscillating extraction and ultrasonic extraction are used to separate amygdalin and bitter almond protein based on the concertration of ethanol 65% and operating temperature in 50℃. The parameters of water bath oscillating extraction is concertration of ethanol 65%, operating temperature 50℃, solid-liquid ratio 1:10, extraction time 60min and extraction of 3 times.The parameters of ultrasonic extraction is concertration of ethanol 65%, operating temperature 50℃, ultrasonic power 300W, extraction time 25 min and extraction of 3 times, in this condition, the amygdalin extraction rate achieves 89.34%.The amygdalin purity achieves 90.01% afer amygdalin’s purity. The Nitrogen solubility index achieves 75.19% in bitter almond crude protein.