Particle size reduction effectively enhances the cholesterol-lowering activities of carrot insoluble fiber and cellulose.

This study investigated and compared the effects of particle size reduction on the cholesterol-lowering activities of carrot insoluble fiber-rich fraction (IFF) and plant cellulose. Our results demonstrated that micronization treatment effectively pulverized the particle sizes of these insoluble fibers to different microsizes. Feeding the micronized insoluble fibers, particularly the micronized carrot IFF, significantly (p < 0.05) improved their abilities in lowering the concentrations of serum triglyceride (18.6-20.0%), serum total cholesterol (15.5-19.5%), and liver lipids (16.7-20.3%) to different extents by means of enhancing (p < 0.05) the excretion of lipids (124-131%), cholesterol (120-135%), and bile acids (130-141%) in feces. These results suggested that particle size was one of the crucial factors in affecting the characteristics and physiological functions of insoluble fibers. Therefore, particle size reduction by micronization might offer the industry an opportunity to improve the physiological functions of insoluble fibers, particularly the carrot IFF, in health food applications.