The Extraction Of Acorn Starch And Analysis On The Main Physicochemical Properties

Aiming at making full use of acorns resources, soaking-alkali cleaning method and starch extraction process of protein hydrolysis through alkali protease were applied to optimize the process conditions of starch extraction and to analyse the main physicochemical properties. The results indicated: the proper process conditions of starch extraction by soaking-alkali cleaning method suppose to be, the pH of bubble lotions is 11, ratio of material to water stands at 1:12, the temperature is 30 centigrade, the content of protein in acorns starch is 7.5%, the content of total starch is 86.34%, yield of starch is 49.58%. When the soaking time is 90 minutes, the mass rate to starch and water is 1:26, the soaking temperature is 55℃, tannic acid occupies the most in the soaking solution, which has a decent removal efficiency against tannic acid in the acorns starch; the optimization of process conditions by enzymolysis using alkali protease is that the pH is 11, the enzymolysis temperature is 45℃, the enzymolysis time is 140 minutes, enzyme dosage is 600 U/g, the content of protein in the starch is 2.32%; the west starch obtained after enzymolysis is soda-wash bleached when the mass rate to starch and water is 1:5, the concentration of aquae hydrogenii dioxide is 1%, the pH is 11, temperature is 45℃and time is 12 hours, protein residues in the final starch is not examined. the content of protein in acorns starch is 26.58%, the starch particle is either ovate or round; compared with maize starch, acorns starch has stronger solubility and expansibility, lower light transmittance of starch paste, stronger anticoagulation, the volume of coagulation is 43.6 mL/100 mL; the starting pasting temperature is74.2℃, the stability of thermal paste viscosity is bad, the stability of cold viscosity is good; acorns starch is more likely to paste and to have large viscosity peak value and bad stability in the alkalic conditions while it has higher starting pasting temperature, unchanged viscosity peak value, worse thermal paste stability and stronger cold viscosity stability; the rigidity of starch gel is 839.2 g, the elastic resilience is 0.4886, the cohesiveness is 0.761 and the properties of gel quality and structure tend to be better . Having applied soaking-alkali wash method to the acorns starch produced, the content of total starch is 85.37%, the starting pasting temperature is low, the viscosity peak value is high as well as starting pasting resistance at constant 93℃,starting pasting resistance during lowing temperature and ending pasting resistance at constant 50℃.The stability of starch paste thermal viscosity is bad, the capacity to forming gel is strong, which is prior to that in Korea.