ARS | Publication request: ANALYSIS AND QUANTITATION OF GROUP B SAPONINS IN PROCESSED SOYBEAN PROCUCTS

Submitted to: Phytochemical Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 3, 2001
Publication Date: N/A

Interpretive Summary: Constituents found in the soybean are being examined for their functional role in the prevention of chronic diseases through diet. However, there are not enough pure "phytochemicals" available to fully characterize their activity (both dose and time of intake, for example) in bioassay and nutritional studies. In soybeans, a great deal of interest has been focused on the isoflavones as disease-preventing agents, but these compounds are often found in association with another group of phytochemicals called the saponins. Very little is known about the mode of action of saponins in the human diet, and the saponins are not measured in most foods due to a lack of analytical standards and methodology. This paper describes the preparation of a set of pure saponin standards and a robust analytical method for the determination of their concentrations in agricultural products. This will allow for more nutritional and medical research to proceed.

Technical Abstract: Pure analytical standards for the major saponins present in processed soy products, the five group B saponins (soyasaponins I, II, III, IV, and V), were isolated in milligram quantities by a combination of processing, precipitation/re-solublization, column chromatography, and preparative HPLC. The standards were determined to be pure by liquid chromatography coupled with on- line electrospray ionization mass spectrometry (LC-ESI-MS(N) analysis and NMR. The standards were used to perfect a facile analytical HPLC method using spectrometric detection to determine the percent composition of the group B soyasaponins in various products produced from the processing of the soybean.