Abstract: Objective:To study the effects of amylose levels in corn starch on intestinal fermentation of rats. Methods:42 female Wistar rats were stochastic divided into 7 groups, and fed respectively on diets containing 300g/kg cornstarch with 0, 26.8%, 53.8%, 61.6%,75.7%, 78.9%,85.8% for 3 weeks. Body weight gain, feed efficiency, starch digestion efficiency, the weight of cecal tissue and the amount of short chain fatty acids(SCFA)in cecal contents were determined. Results:the apparent digestion of starch in rats fed 61.6% AS, 75.7% AS, 78.9%AS and 85.8%AS diets were significantly lower than that fed 0% AS or 26.8% AS diets. High amylose cornstarch(HACS) significantly increased the contents weight in small intestine and cecum compared with 0%AS and 26.8% AS. The dry weight of cecal contents in 75.7%AS groups was the highest among all groups. The amounts of acetic, propionic and total SCFA in cecum were significantly higher in rats fed HACS diets than that fed 0%AS and 26.8%AS diets. The content of propionic in 53.8% AS group, the content of butyric and total SCFA in 61.6%AS groups and the contents of acetic, acetic and succinic in 75.7%AS group were the highest in all groups, while the amount of SCFA in 78.9% AS group was the lowest in HACS groups. Conclusion:HACS might reduce the digestion of starch, and increased the weight of intestinal indigested residues and the amount of SCFA in cecum, however, these effects did not correlated with amylose contents of cornstarch.

Key words: amylose starch, resistant starch, intestinal fermentation, short chain fatty acids