An exploitation of the antimicrobial potential of a fruit insoluble fibre by micronization

The potential antimicrobial activity of the insoluble fibre prepared from the pomace of Averrhoa carambola and the effects of micron technology on its antimicrobial activity were investigated. Particle sizes reduction (from > 29 to 14.3 mu m) by micronization significantly increased the levels of measurable condensed tannins and antimicrobial effects. Antimicrobial assays revealed that the micronization treatment could increase the inhibitory and bactericidal activities of the micronized fibre (14.3 mu m) by 2-8-fold and similar to 2-4-fold, respectively. The micronization treatment might therefore provide an opportunity to improve the antimicrobial activity of the fibre sample, particularly against the Bacillus cereus BCRC 10603 and Salmonella choleraesuis BCRC 12948. These results suggested that the supplementation of this micronized fibre, as a natural antimicrobial ingredient, in foods and diets might help inhibit adverse microbial growth in food products (as well as gastrointestinal tract), and hence increase the shelf life or improve the food safety.