Bifidogenic characteristic and protective effect of saba starch on survival of Lactobacillus plantarum CIF17AN2 during vacuum-drying and storage

Resistant starch (RS) from unripe saba banana (Musa sapientum (Linn)) (Kluai Hin) exhibited high resistance to gastric acid and intestinal amylases. Its bifidogenic effect under competition of human fecal microflora was determined in the simulated proximal region of human colon. In addition, saba RS effectively protected Lactobacillus plantarum CIF17AN2 during drying process. The maximum survival of 85.81% was achieved under vacuum drying operated at 37 °C when saba RS was added. The addition of saba RS to formulate a synbiotic product was able to retain high viability of the vacuum-dried L. plantarum during 8-week storage at ambient temperature. This is because saba RS can stabilize the moisture content of the synbiotic product. In contrast, the dramatic increase of moisture content in the vacuum-dried L. plantarum without saba RS led to significant decrease in cell survival. Moreover, saba RS could potentially protect the vacuum-dried L. plantarum from gastric acid and bile exposures.