Agronomic traits and nutritional features of importance in low-raffinose genotypes for added-value soybeans

The presence of anti-nutritional factors (ANF) in legumes is an important challenge towards a higher incorporation of beans in our diet. In soybeans, the oligosaccharides belonging to the raffinose family (RFO), stachyose, raffinose and verbascose, are of interest, as they are resistant to heating treatments and limit the use of soybeans in high value food and feed applications. To overcome these constrains, low RFO-lines have been recently developed. This study, carried out over 2 growing seasons, evaluated new pre-commercial low-RFO cultivars (cvs), with conventional genotypes destined for food use, and other added-value cvs, for agronomic traits, seed composition, with particular focus to oligosaccharides and trypsin inhibitor activity (TIA). The total content of RFO in low-RFO cvs was very low in both growing seasons, with values of less than 0.4 and 0.2 g 100 g -1 in 2022 and 2023, respectively. In comparison to the average concentration present in the other genotypes, the total concentration of RFO in these new cvs was six and eleven times lower in 2022 and 2023, respectively. In both years, the low-RFO cvs reported a yield potential, similar or higher than that of the control genotypes belonging to the same maturity group; furthermore, they showed a good seed dimension and test weight, and a high protein content (>42%). Low-RFO cvs had TIA comparable to those of the conventional genotypes. In conclusion, new low-RFO cvs can provide compositions for high added-value applications with specific requirements, showing also high protein levels and good agronomic performance. • Raffinose and stachyose are the main raffinose family oligosaccharides (RFO) in soybean • Raffinose and stachyose, not digested by intestine, cause flatulence and diarrhea • In pre-commercial low-RFO cultivars raffinose and stachyose were near zero • In control genotypes the RFO content and sugar composition was influenced by year • Pre-commercial low-RFO cultivars reached a high productivity and protein content