介質研磨對纖維素表面性質與巨量礦物元素結合力之影響

Abstract

纖維素是非水溶性膳食纖維的一種，是在自然界中分布最廣、含量最多的多醣，廣泛存在於食品中，且已證實可促進人體健康，例如：促進腸胃蠕動、減重、預防便秘及結腸癌等。然而，許多研究指出膳食纖維會結合巨量礦物元素鈉、鉀、鈣、鎂等離子，且結合力與粒徑大小及保水性有關。 纖維素原料的體積平均粒徑為27.4

Cellulose is an insoluble dietary fiber and is the most abundant polysaccharides in nature. It has been proved that cellulose can improve human health, such as promoting gastrointestinal peristalsis, reducing weight, preventing constipation and colon cancer. It has been reported that macrominerals binding capacity of fiber is related with particle size and water holding capacity. Volume mean diameter of cellulose was significantly reduced by media-milling, resulted in both the reducing particle size and molecular weight. For example, the molecular weight was reduced from 646.29 kDa to 117.1 kDa after 90 min media-milling. Via sediment method, the suspended cellulose yield a zeta potential of -16.6 mV, a negative charge. After media-milling, the absolute value of zeta potential was increased, indicates that nano/submicron cellulose dispersion is more stable, Isoelectric point(IEP) of cellulose raw material is pH 3.03, and dropped to 2.74 after 90 min media-milled, shows that after media-milling, cellulose particles are more negative-charged. Media-milling also improves WHC of cellulosic particles. By centrifugation method, WHC increased 7.9 fold after 30 min media-milling, but decreased after 30 min. Viscosity of cellulose dispersion increased first from 1.71 cp to 25.46 cp and then decrease after 30 min. WHC and viscosity were found correlated. Media-milling can also enhance Mg, Ca, Na, K binding capacity with a relationship with WHC.