Study On Preparation Of Synthesizing Cu(Ⅱ)-Compound Amino Acid Chelate From Rapeseed Meal

Rapeseed meal is a by-product of oil extraction ,which is formed after the squeezing and defatting process. The content of total protein reaches 28%-40% and can be exploited as food additive because of its good quality. However, the meal hasn't been utilized completely. It is only used for animal feed and fertilizer , Its value in use is not high. Therefore,it's significant to work on the value-added process of rapeseed meal.On the basis of alkali-extraction and acid-precipitation combining , the rapeseed protein isolate(RPI) from double-low meal was obtained , Then complex amino acids was obtained from rapeseed protein isolate hydrolyzed by two kinds of enzyme (alcalase and neutral protease) and the optimum conditions were studied . The synthetic couditions of compound amino acid chelated copper from copper and compound amino acid were studied .The optimum conditions for the synthesis were found. The main conclusions of the experiments were as follows:(1) The results showed that the best conditions of alcalase hydrolyze were when pH was 10.5, the liquid:solid ratio was 15:1, the temperature was 50°C, the time of enzymatic hydrolysis was 2 hours , the enzyme concentration were 3250U per gram of substrate. And the best conditions of neutral protease hydrolyze were when pH was 9, the temperature was 45℃, the time of enzymatic hydrolysis was 2 hours the enzyme concentration were 3250U per gram of substrate. In this condition ,the DH of compound amino acid was 45.83% and the nitrogen yield was 82.75%; when the production in pH 3-6, the NSI was in the above of 75.43%. The TCA-NSI of production was 91.71%.(2) The results also showed the content of tannin,glucosinolate and the Inositol hexapHospHoric acid in the enzymatic production were lower than rapeseed meal ,It contains too many kinds of amino acidand the essential amino acid . The mode of the human milk could be approached by increasing some kinds of amino acids. It can be applied to the feedingstuff or food additives. Thus its value in use will be improved.(3)The product was testified by Na₂S chemical method and IR ,It makes out compound amino acid chelated copper was obtained.(4) The experiment indicated that it's main factors were pH and the molar ratio of ligand of compound amino acid to copper cation in the reaction, and the molar ratio of ligand of compound amino acid affect the reaction prominently. Time and temperature of the reaction affected very little. Besides, the optimal condition of synthesizing Cu(II)-compound amino acid chelate was got through theL16(4⁵) experiment:that the optimal temperatureis 50℃,time 50 min, the molar ratio of ligand of compound aminoacid to coppercation 2 : 1 and pH9. In this conditions, the chelation ratio of compound amino acidwith copper was 94.59%, and the content of compound amino reached up to 30.20%.