Study On Starch Micronized Treatment And Gelatinization

As a macromolecule carbohydrate, starch is a kind of regenerated resource having abundant origin and inferior to cellulose. It is one of the preservation forms of plant energy and is the mainly origin of mankind food. Except food, starch has very widely application in weave, paper making, medicine, petroleum, chemical engineering and agriculture et al.Utilizing ball-milling machine, adopting uniform experimental design method, using ethanol as milling medium, this paper mainly discussed the effect of ball-milling time, speed, starch solution concentration and different species starch to micronized starch granularity. Primary effects of test factors were analyzed through multi-element regression model, and finally the optimum conditions of starch micronization were concluded.It is measured and analyzed the granularity median diameter d50 through mastersizer2000 granular analyzer. The result indicated that ball-milling treatment can effectively reduce starch granularity, which can be approved by granular variate curve, and that there is a dynamic grinding balance. At the initial stages of microzation treatment, the starch granularity gradually reduces with ball-milling time. When the micronized granularity exceeds grinding limit, the starch granularity will be reunited and finally lead to the granularity increase.The micronized starch granular was analyzed and compared through Scan Electron Microscope. The grinding process of starch granularity through the SEM photographs is that: first, there appears fractures on the granularity surface and crack in the granularity interior; with the milling time increasing, the surface fractures flake away and shape innumerable irregular fragment, mingled with bulky starch granularity; finally, plenty of irregular starch granularity become relatively symmetrical.The gelatinization temperature, viscosity, and thermal stability of the milling gelatinized starch were analyzed through NDJ-8S viscosity meter. The results reveal that for maize starch and tapioca starch, after milling treatment, the gelatinization temperature of the micronized starch reduces, the viscosity minishes and the thermal stability fall; for potato starch, gelatinization temperature and granularity size present definite relativity, however, the change of the viscosity and thermal stability is irregular.