ARS | Publication request: Optimisation of Germination Time and Temperature on the Concentration of Bioactive Compounds in Brazilian Soybean Cultivar BRS 133 using Response Surface Methodology

Submitted to: Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 3, 2009
Publication Date: December 15, 2009
Citation: Paucar-Menacho, L.M., Berhow, M.A., Mandarino, J.M., De Mejia, E.G., Chang, Y.K. 2010. Optimisation of Germination Time and Temperature on the Concentration of Bioactive Compounds in Brazilian Soybean Cultivar BRS 133 using Response Surface Methodology. Food Chemistry. 119:636-642.

Interpretive Summary: The objective of this research was to determine the effect of germination time and temperature on the concentration of key nutriceuticals in soybeans. The studies showed that nutriceuticals that have a negative nutritional impact, such as protein degradation inhibitors and lectin, can be reduced in 452 hour germinated soybeans. The studies also indicate that nutriceuticals that have a positive nutritional effect, such as lunasin, isoflavones and saponins are increased after 63 hours of germination time. These studies show that germinated soybeans have modified and enhanced levels of key nutriceuticals and could be used to make new soy flours and products or blended with other flours and products with altyered nutriceutical profiles.

Technical Abstract: The objective was to optimize the effect of germination time and temperature on the concentration of soluble protein, lunasin, BBI, lectin, saponins and isoflavones in soybean seeds from cultivar BRS 133. Isoflavone and saponin concentrations were analysed by HPLC. Lunasin, Bowman-Birk inhibitor and lectin were analysed by ELISA and western blot. The effects of the variations in germination time and temperature on bioactive compounds were analysed using the response surface methodology (RSM), with a 22 central composite rotational design. Germination of soybean for 42 h at 25oC resulted in an increase of 61.7% of lunasin, decrease of 58.7% in lectin and 70.0% in lipoxygenase activity. Optimal increases in the concentrations of isoflavone aglycones were observed in combination of 63 h of germination and 30oC. A significant increase of 32.2% in the concentration of soy saponins was observed in combination of 42 h of germination at 25oC.