Mechanochemical Effect of Rolling on Mung Bean Starch
Niu Kai;Ji Qingzhu;Li Guixiao;Dai Yangyong;Dong Haizhou;Hou Hanxue;Zhang Hui;Liu Chuanfu;College of Food Science and Engineering,Shandong Agricultural University;Donge Inspection and Testing Center;Engineering and Technology Center for Grain Processing in Shandong Province;
Using mung bean starch as raw materials,the effect of rolling on structure and physicochemical properties of mung bean starch was investigated by scanning electron microscope( SEM),polarizing microscope( PLM),confocal laser scanning microscope( CLSM),X-ray diffraction( XRD),differential scanning calorimeter( DSC),and rapid visco analyser( RVA). The mechanochemical effect of milling on mung bean starch was revealed. The results showed that the amorphous region and part of the crystalline regions of mung bean starch were destroyed by rolling treatment 3 ~ 6 h,which led to the increase of water solution index,welling power,transparency and a significant reduction of gelatinization enthalpy. With the increasing of processing time,recrystallization was happened inside starch granules. After 9 h of rolling treatment,recrystallization occurred in the starch and some bulbous protuberances had formed on the granule surface; swelling capacity,transparency and peak viscosity presented a significant decrease; water solution index,enthalpy and gelatinization temperature of the mung bean starch increased. As the rolling processing time increased to between 12 and 24 h,crystal structure had been severely damaged. Meanwhile,the particle morphology of starch underwent serious change in accompany with water solution index and transparency was increased. But opposite trends were found in enthalpy and welling power. According to the theory of mechanochemistry,loading,aggregation and agglomeration effects occurred successively in the interior of starch granules.