Raffinose family oligosaccharides in seed of Glycine max cv. Chiang Mai60 and potential source of prebiotic substances

Raffinose family oligosaccharides (RFOs) content in Glycine max seed of cultivar Chiang Mai60, a local soybean of Thailand, was investigated. RFOs and other low molecular weight sugars were extracted by 50% (v/v) ethanol and quantified by high-performance liquid chromatography (HPLC). The prebiotic property of this extract was subsequently studied by invitro method. The results showed that the concentrations of raffinose, stachyose and verbascose were 6.74 +/- 1.62, 145.32 +/- 18.74 and 1.60 +/- 0.52mgg(-1) dry seed, respectively, while glucose and sucrose were detected at 10.73 +/- 1.35 and 13.28 +/- 2.16mgg(-1) dry seed, respectively. The growth of four Lactobacilli probiotics were increased significantly in a basal liquid medium supplemented with this ethanolic extract as carbon source compared to glucose supplementation. Subsequently, defined mixed culture was studied and it was found that growth stimulation of total Lactobacilli by extracted sugars resulted in the suppression of Escherichia coli and Salmonella enterica serovar Typhimurium growth. It could be concluded that this cultivar showed the RFOs-rich content and a potential to be a source of an effective prebiotic substance for food application.