Effect of Germination On the Protein Content and On the Level of Specific Activity of Lipoxygenase

Effect of germination on the protein content and on the level of specific activity of lipoxygenase-1 in seedlings of three soybean cultivars.
Arch Latinoam Nutr 1995 Sep;45(3):222-6
Bordingnon JR, Ida EL, Oliveira MC, Mandarino JM.

EMBRAPA-CNPSo, Londrina, PR, Brazil.

The effect of germination on the protein content and in the level of specific activity of lipoxygenase-1 on seedlings of Santa Rosa, FT-2 and Davis soybean cultivars were studied. Soybean seeds of the three cultivars were germinated from 0 to 72 hours in a seed germinator at 30 degrees C temperature, 100% relative humidity, and absence of light. The seeds were then frozen in liquid nitrogen, freeze-dried and milled. The lipoxygenase-1 was extracted with 0.02M thris-HCI buffer at pH = 8.2 and 13% saccharose for 30 minutes at 4 degrees C without shaking. The highest levels of specific activity of lipoxygenase-1 per milligram of flour (dry basis) in the Santa Rosa, FT-2 and Davis cultivars were observed between 18 and 36, 18 and 24, and 0 and 12 hours, respectively. The polinomial quadratic model best fits the regression analysis of the variable levels of specific lipoxygenase activity for cultivar Davis (R2 = 0.9197). Although for cultivars Santa Rosa (R2 = 0.9041)., and FT-2 (R2 = 0.7486) the 4th degree polynomial model has shown the best fit. The protein content in the three cultivars studied reached the maximum values at 48h germination. The germination induced a relative increase of the protein content but caused a reduction of the level of specific lipoxygenase-1 activity.