Active compounds that are key to the health benefits of pre-germinated brown rice have been identified by US scientists.
Research leader Robert Yu, an expert at the Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, has revealed that the healthy components are a related set of sterol-like molecules known as acylated steryl-beta-glucosides (ASGs).
Pre-germinated rice is an emerging health food whereby brown rice is soaked in warm water prior to cooking.
The warm bath induces sprouting that, in turn, stimulates rice enzymes to produce more nutrients, including an important brain chemical called GABA.
Animal studies have already shown that a PR-rich diet can improve cognitive function, and act as an anti-diabetic.
Yu and his colleagues claim that they are the first to identify the bioactive compounds behind this effect.
The researchers say that they used mass spectrometry and nuclear magnetic resonance approaches for their study, which unveiled such compounds as ASGs, a diverse family of molecules that consists of a glucose derivative, fatty acids, and sterols.
Since the ASGs were concentrated in rice bran (outer layer) and not the seed, they would not be found in white rice, they add.
The research group also showed that the ASGs had the ability to activate enzymes related to diabetes, and that that activation required the acyl chemical group because regular steryl glucosides (SGs) had no effect.
Though ASGs are found in many plants, soybean derived ASGs did not show any effect on the diabetic enzymes, indicating the ASG complement specific to rice might be unique in its diabetic benefits.