Improving Prebiotic Properties of Modified Banana Flour by Spontaneous Fermentation and Autoclaving-Cooling Process

Abstract

Banana flour was a potential prebiotic source due to its resistant starch content. Resistant starch as dietary supplement may stimulate the growth of beneficial bacteria in the human gastrointestinal tract. Banana flour was a potential prebiotic source due to its resistant starch (RS) content. In this study the formation of RS type III (RS3) in banana flour was increased in order to improve the prebiotic properties. Modified banana flour was prepared by fermented the banana slices for 24 h at room temperature followed by autoclaving-cooling process respectively at 121oC for 15 min, 4oC for 24 h. The autoclaving-cooling process was repeated twice cycles. The modification process increased resistant starch content 10.48% to 45.83% db. The prebiotic properties of native banana flour-resistant starch (RS2) and modified banana flour-resistant starch (RS3) were examined including the stability to artificial human gastric juice, the capability modulate he gut bacterial composition using fecal batch culture fermentation, production of short chain fatty acid and prebiotic index (PI) score. The results showed that both RS2 and RS3 were stable to artificial human gastric juice at pH 1, 2, 3, 4 or 5 and they were able to increase the lactobacilfi and bifidobacterial population. The PI score of RS3 was higher (5.14) than RS2 (4.02) and the RS3 also can increase concentration of butyric acid. It can be concluded that modified banana flour-RS showed better prebiotic properties than native banana f1our-RS