Phenolic acids and phytosterols in rice grains and wheat flours consumed in five regions of China.

Abstract

Phenolic acids and phytosterols, the main functional compounds in cereals, could promote wellbeing and reduce the risks of diet-related diseases. This study aimed to demonstrate phenolic acid and phytosterol profiles in rice grains and wheat flours, and estimate their intakes in five geographical regions and among different age groups. Phenolic acids and phytosterols mainly existed in bound form, and the whole rice grain had high amount of 161.39 to 368.74µg/g and 37.50 to 93.31mg/ 100g, respectively. In total, nine phenolic acids and six phytosterols were detected with ferulic and p-coumaric acid, and β-sitosterol the most abundant. The dietary intakes of phenolic acids and phytosterols were calculated combined with the dietary foods intake data of Chinese people. The intakes of total phenolic acids and phytosterols from rice grains and wheat flours varied across different regions with Beijing the highest among the five regions. At the age of 2 to 70 years, the average intakes of phenolic acids and phytosterols from rice and wheat flours were 7.74 to 17.52 and 58.02 to 135.61mg/sp/day, respectively. If 3-ounce of polished rice was replaced by black rice grain, the predicted intakes of total phenolic acids and phytosterols from rice grains and wheat flours would increase by at least 196% and 68%, respectively, especially for free phenolic acids and phytosterols. PRACTICAL APPLICATION: This study would help the consumers know how much phenolic acids and phytosterols they would get from 3 ounces of black rice in a reasonable intake of staple food but shift away other kinds of foods. It could also provide inspirations for food industries to explore the functional cereal foods that are rich in phenolic acids and phytosterols for different regions and different age groups.