This study examined the effects of
soybean beta-conglycinin, from which
phytate was mostly removed, on the plasma
lipids in young and adult rats. Male Wistar young (6 week-old) and adult (21 week-old) rats were fed high
cholesterol diets containing 20%
casein,
soy protein isolate (SPI), or
soybean beta-conglycinin for 10 days. In young rats, although the food intake of the
beta-conglycinin group was higher than those of the
casein and SPI groups, the
weight gain was significantly lower than those of the other groups. However, in adult rats, the
weight gain was not different among the groups. In young and adult rats, relative liver weights of SPI and
beta-conglycinin groups were significantly lower than that of the
casein group, and the degree of the reduction was more marked in the
beta-conglycinin group than in the SPI group. In young rats, the plasma
triglyceride level was significantly lower in the SPI and
beta-conglycinin groups than that in the
casein group. In addition, the plasma
triglyceride level of the
beta-conglycinin group was significantly lower than that of the SPI group. Plasma total
cholesterol levels of the SPI and
beta-conglycinin groups were significantly lower than that of the
casein group. However, there was little difference in the lowering effect between SPI and
beta-conglycinin. These results indicate that
soybean beta-conglycinin may have lowering functions not only on plasma total
cholesterol level, but also on plasma
triglyceride level.