Group B Saponins in Soy Products in the U.S. Department of Agriculture—Iowa State University Isoflavone Database and Their Comparison with Isoflavone Contents

Abstract

Isoflavones in soy protein foods are thought to contribute to the cholesterol-lowering effect observed when these products are fed to humans. The group B saponins are another ethanol-soluble phytochemical fraction associated with soy proteins and isoflavones and have also been associated with cholesterol-lowering abilities. We measured the group B soyasaponin concentrations in a variety of soy foods and ingredients in the U.S. Department of AgricultureIowa State University Isoflavone Database. We compared the isoflavone and soy saponin concentrations and distributions in intact soybeans, soy ingredients, and retail soy foods. Group B saponins occur in six predominant forms. There appears to be no correlation between saponin and isoflavone concentrations in intact soybeans ranging from 5 to 11 mumol isoflavones/g soybean and from 2 to 6 mumol saponin/g soybean. Depending upon the type of processing, soy ingredients have quite different saponins/isoflavones as compared to mature soybeans. In soy foods, the saponin:isoflavone ration ranges from 1:1 to 2:5, whereas in soy protein isolates, the ratio is approximately 5:3. Ethanol-washed ingredients have very low saponins and isoflavones. These very different distributions of saponins and isoflavones in soy products may affect how we view the outcome of feeding trials examining a variety of protective effects associated with soy consumption.

The content of soyasaponin and soyasapogenol in soy foods and their estimated intake in the Japanese

“…Murphy et al. () reported that the average group B soyasaponin content of seven types of tofu was 4.4 μ mol g −1 , on a dry mass basis. Hu et al.…”

Minimizing fishmeal use in juvenile California yellowtail, Seriola lalandi, diets using non-GM soybeans selectively bred for aquafeeds

“…Also, it is important to consider that depending on the amount ingested some compounds classified as ANFs may actually benefit the overall health of the target animal. For instance, saponins display anti-inflammatory effects (Patel and Patil, 2012), cholesterol lowering effects (Murphy et al, 2008) and anti-carcinogenic effects (Anderson and Wolf, 1995) when provided at the appropriate concentration. Because the experimental meals (3011 and 3032) utilized in the present experiment were selected for reduced ANFs levels and due to the fact that saponin levels in these meals were below detection (Table 2), it is unlikely that the use of these non-GM meals would result in saponin-related issues, even at high inclusion levels such as those implemented in the present experiment (32-51% of diet, Table 1).…”

Soy as a Functional Food

“…Soybean flour, soy protein isolate, lecithin, and tofu present reduced content of saponins, 50, 25, 73, and 37%, respectively, compared to that of the whole soybeans (Fenwick & Oakenfull, 1981). Soy-based foods obtained by ethanol processes, such as concentrated proteins, for example, present low content of saponins due to their solubility in alcohol (Murphy et al, 2008). …”