Rice bran is known as a good source of fiber that’s added to several food products. It also has the ability to, potentially, be a biocarrier for bioactive compounds, such as tea catechins, which are polyphenols found in tea leaves and popular for their many health benefits (think antioxidants such as epigallocatechin gallate [EGCG]). Trouble is, tea catechins are unstable and their bioavailability may be reduced when going through the digestive tract.
A new study published in The Journal of Food Science, examined defatted rice branwhich has the highest adsorption capacity for tea catechins and the best selectivity for EGCG over total catechinsas a means to enrich tee catechins (Aug. 28, 2015). A total of 400 mg of pretreated rice bran was added to 100 mL of a tea extract solution at 0.75 g/L. The researchers discovered that rice bran as a bioadsorbent has a high selective adsorbility for tea catechins. In addition, the adsorption of total catechins on defatted rice bran was enhanced at high temperatures. They also found that protein was the major component contributing to the adsorption of total catechins on defatted rice bran, with the assistance of cellulose.