Effects Of Superfine Grinding On Physical Properties And Protein Function Of Mungbean

Mung bean has high value of nutrition and health care,and it's proteins have the function of detoxification because the proteins can adsorb heavy metal ions.But the development and application of the products are limited because the eating methods of raw materials are inconvenient and the bio-availability is very low.After being superfine ground,particle size of mung bean powder decreased significantly,the specific surface area and surface energy increased greatly due to the small size effect and surface effect,which endowed mung bean powder excellent physical properties.It can also improved the extraction yield and bio-availability of mung bean powder,the detoxification function of mung bean protein was enhanced.Therefore,the study of mungbean's superfine-grinding technology has theoretical and practical significance for the development of new mung bean food.In this paper,mung bean were chosen as raw material,Four kinds of powder were prepared by ordinary grinding and superfine grinding step by step(Coarse powder,Superfine powder ?,Superfine powder ?,Superfine powder?).The effects of superfine grinding on surface morphology,physical and chemical properties,protein extraction rate and protein functional properties of mung bean powder were studied.The experimental results are as follows:1.Scanning electron microscope observation showed that the size and shape of mungbean coarse powder were similar to that of superfine powder,size of some particles of superfine powder II are smaller but irregular,and particles size of superfine powder? decreases obviously and is relatively even.After the powders were dispersed in water and the large particles precipitate,Laser particle size analysis of supension showed that the average particle size decreased gradually from mung bean meal to superfine powder?.With the decreasing of the particle size,the dissolution rate of water-soluble components increased from 10.6%to 26.7%,the expansion force increased from 3.1mL/g to 5.5mL/g and then gradually decreased,the change trend of hydraulic holding force and expansive force is the same,the moisture absorption rate of powder increased rapidly and then increased slowly within 48h.The hygroscopicity increased gradually after being superfine ground step by step,the angle of repose decreased from 58.5° to 36.2°,then it continues increase to 40.2°.The slip Angle decreased from 68.1° to 39.5,and it continued to increase to 42.7 subsequently,which indicating that after being superfine ground,the fluidity of the powders increased first and then decreased later.2.This experiment investigated the effect of extraction temperature,pH and ratio of solid to liquid on protein extraction rate of mung bean powder before and after progressive superfine ground.The results of the univariate study showed that the optimum extraction conditions of the four powders were as follows:temperature 45?,pH 10,solid-liquid ratio 1:90.Based on this condition,response surface method was used to optimize the extraction process of proteins.The optimal extraction conditions were:pH is 11,the ratio of feed to liquid is 1:90,and the temperature is 35?.The protein extraction rate of mung bean powder was 62.75%.The extraction rates of albumin,globulin,glutenin and gluten from mung bean superfine powder?were higher than those from coarse powder,and it increased by 4.00%,7.70%,4.10%and 3.32%,respectively.3.After being superfine ground step by step,the foaming rate and foam stability of mung bean protein gradually increased with the decreasing of the particle size of mung bean powder.The maximum of mung bean superfine powde? was 114.25%and 93.00%,respectively,Compared with 88.5%and 85.30%of coarse powder,it increased by 26.65%and 7.7%,respectively;The emulsification and emulsification stability of the protein gradually increased,Mung bean superfine powder? is the highest,54.8%and 53.30%,respectively.Compared with 52.6%and 51.2%of coarse powder,the increase was 2.2%and 2.1%,respectively.The cation exchange capacity is maximized at pH 11.The cation exchange capacity after superfine grinding was slightly higher than that of coarse powder.The adsorption capacity of mungbean protein to cadmium and lead ions increased first and then remained unchanged.