Sprouts of genetic soybean lines: evaluation of chemical-physical properties

Summary Soybean sprouts are vegetables for direct consumption obtained from germinated grains, which have been used for centuries in Eastern countries. Their nutritional characteristics and ease of production have attracted the attention of consumers from Western countries. Small seeds with high germinating power and vigour are inherent qualities for shoot production. At the Brazilian Agricultural Research Corporation - Embrapa, these characteristics have been considered in the genetic breeding program to obtain special soybean cultivars for human consumption. The aim of this study was to produce and characterize the quality of soybean sprouts from the genetic lines BRM09-10505, BRM10-60599 and PF133002, in comparison with the cultivar BRS 216, which was developed for use as sprouts and natto. Trays placed in a growth chamber (25 °C and 99% relative humidity) were used for produce the sprouts. The protein, lipid, ash, isoflavones, Kunitz trypsin inhibitor and phytic acid contents were analysed in the seeds and sprouts. The length and weight of the sprouts were also determined. Seeds of the line BRM09-10505 showed 95% germinating power followed by BRS 216 (93%) and the other lines (88% on average). Germination, by mobilizing chemical compounds, increased the protein (8.96%) and isoflavone (56.00%) contents, and reduced the concentrations of the Kunitz trypsin inhibitor (26.91%) and phytic acid (13.78%). The cultivar BRS 216 presented the highest protein content in the seeds (41.96 g.100 g-1) and sprouts (47.70 g.100 g-1). The line BRM09-10505 had the highest trypsin inhibitor content in the seeds (27.56 mg IT g-1) and in the sprouts (19.62 mg IT g-1); the highest total isoflavone contents in the seeds (340.10 mg.100g -1) and in the sprouts (406.38 mg.100 g-1); and the lowest phytic acid content in the sprouts (1.13 g. 100 g-1). After four days of germination, the length and weight of the sprouts were, respectively, 8.03 cm and 214.36 g for line BRM09-10505 and 7.31 cm and 140.93 g for BRS 216. Of the lines tested, BRM09-10505 showed good potential for sprout production.