Oligosaccharides composition in eight food legumes species as detected by high-resolution mass spectrometry.

BACKGROUND

As probiotics, soy oligosaccharides have become popular as healthy foods to reduce disease risk. However, comprehensive information about oligosaccharides in different food legumes is limited.

RESULTS

In this study, eight oligosaccharides were well detected and quantified in different varieties of eight legume species using high-resolution mass spectrometry. It was determined that species could be distinguished by total content of oligosaccharides and their distribution modes. Among the studied species, Vigna unguiculata is a better resource of non-digestible oligosaccharides, while Vicia faba and black soybean (Glycine max) are at a disadvantage. Normally, stachyose predominates in non-digestible oligosaccharides, except in mung bean and broad bean, where verbascose predominates. For mung bean and green soybean, the seed coat should be taken into account for oligosaccharide consumption. The developed high-resolution mass spectrometry method greatly simplified the sample preparation process and permitted the identification of oligosaccharides without reference compounds.

CONCLUSIONS

This work involved extensive sample collecting and provided useful information for consumers. The developed method may be useful for rapid quantification of oligosaccharides in related foods.