| The peanut is one of the most important oil-bearing and industrial crops. Aboat 50%~60% of the peanut grown in our country is used for peanut oil. Vegetable oil extraction from peanut and yields partially high temperature peanut meal which is not used totally only used for feed and fertilizer. While the high temperature peanut meal is a protein-rich and dietary fiber-rich, inexpensive and underutilized by-product of the peanut industry that offers the same health and dietary benefits of peanut with less fat. After several propriety disposals, we will gain more from it. The high temperature peanut meal is rich in protein and dietary fiber, so the research will relate to these two aspects.First alkaline extraction and acid precipitation were employed to produce peanut protein isolate. But this protein was denaturalized partially through the extraction, so the enzyme will used to produce polypeptide. The enzymatic hydrolysis of peanut protein use endoenzyme and exopeptidase in order to produce low bitterness polypeptide. The optimum parameters for hydrolysis were established by the single factor and orthogonal test. The optimal processing conditions were as follows: pH 7.0, temperature 50℃,water/protein ratio 25(v/w), the amount of As1398 was 4500U/g protein, the amount of Flavourzyme 500MG was 600U/g protein and the reaction time was 1.5h. Under these conditions, the NR can achieve 82.33% and the bitterness was 1. The power of the peanut polypeptide had a good resolve and various amino acids. Studying on the enzymatic hydrolysis product of the molecular weight distribution, found that molecular mass of peanut peptide distributed mainly in 200~4000.A lot of salts were introduced into peanut polypeptide in the process of peanut protein hydrolysis. This could impact the research of peanut polypeptide activities and its quality. Then the effect of desalination of it was researched. It was simple and available to desalt using DA201-C macro-porous adsorption resin. 20mg/mL peanut polypeptide solution was carried out to desalt using DA201-C column, the outflow was detected by ultraviolet detector in the wavelength of 220nm. Then the column was eluted using water, and peanut polypeptides were adsorbed using 25%, 50% and 75% ethanol. From the stepwise adsorption, there is no fraction by using 75% ethanol. This result was accorded with the optimum parameters for hydrolysis. The fragment of 75% was bitterer than other fragments. The content of ash was reduced from 14.97% to 0.87% and 0.92%. The desalting ratio of peanut polypeptide reached 94.19% and 93.85%. The ant-oxidative activity of peanut polypeptides was better than the hydrolysates undesalted. The fraction by using 50% ethanol has the highest activity, IC50 of which for scavenging DPPH·radical is 0.5mg/mL.After picking up the peanut protein, the dregs were rich in dietary fiber. It could be fully utilized by adding it to cookies. At the same time, it could remedy the lack-ingredient, high-fat and high-sugar shortcomings of traditional cookies and met the demand for health oriented products such as high fiber products. The raw materials on quality of cookies were established by the single factor and orthogonal test. The grind degree is the main factor for the quality of the cookies, followed by the addition of peanut dreg. Again was the addition of butter, and finally factor was the amount of soft white sugar. The best technical of cookies was as following: the amount of the peanut dregs was 5%, the grind degree of peanut dregs was 200 meshes, the amount of butter was 125g and the amount of suger was 105g. The protein content of cookies was 5.09%, and that of dietary fibre was 2.65%.All of these were higher than general cookies, so it had a higher nutritional value. The experiment confirmed that the physicochemical and sanitation index of cookies reached the national standard.
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