Study On Extraction And Properties Of Peanut Meal Protein

The protein production prepared from High-Temperature peanut meal (HTPM) was introduced systematically in this paper including extraction of peanut protein isolate (PPI) and process of peanut protein concentrate (PPC) and its functional properties were also studied comprehensively so as to provide effective approaches for PM application and develop high value-added products for human consumption.HTPM of 20μm ~ 50μm was determined as raw material by preliminary test. PPI was extracted by alkaline extraction and acid precipitation. According to the single factor and orthogonal test, the optimum extraction conditions were determined: pH 9.5, temperature 60 "C, solid/solvent ratio 1 I 12, reaction time 2h, under which its protein extraction rate reached 46.51% and purity reached 89.43%. The further process of alcohol washing removed 75% flavonoids of PPI and significantly improved the color whose lightness increased 54% and color values decreased 20%. There were moreα-helical andβ-sheet structures and fewer P-turns and random coil structures after acohol washing. So the secondary structure of PPI became more tightly folded.Taking HTPM of 50μm ~ 100μm as raw material to prepare peanut protein concentrate (PPC) by Mixed Enzymatic Method combined with alcohol washing. Among several common enzymes, cellulase and glucoamylase was selected as the optimum combination and its enzymolysis technology was determined. Through Box-Benhnken center composite design and response surface methodology, the optimum acohol washing conditions were obtained. Combined mixed enzymatic hydrolysis with alcohol washing process whose optimum extraction process of PPC was figured out: solid/solvent ratio 1:10, cellulase addition 250 U/g, glucoamylase addition 300 U/g, pH4.5, temperature 55°C, enzymohydrolysis time 2h. Alcohol washing process was carried out after the centrifugation with its optimize technology: temperature 55°C, alcohol concentration 75%, solid/solvent ratio 1 :1 1(v/w), alcohol washing time 2.5h. Under these conditions, the purity of protein could reach 65.05%, increasing by 23% compared with the raw material and its extraction rate was 61.3%.Peanut protein concentrate (PPC) was added to sausages to replace part of soybean protein concentrate (SPC). Experiments showed that when the addition of PPC was 60% of total vegetable protein, both texture and sensory qualities of sausages were better than those with no PPC.