To Compare Phenolic Profilees Of Tartary And Common Buckwheat And To Analaze Their Steamed Food By Simulated Gasintesinal Tests

Modern epideological studies suggested that buckwheat had antioxidant, antiathero- scloresis, antidiabetics and antitumor properties, which mainly depended on flavonoid of buckwheat phenolics. And the flavonoid content of tartary buckwheat was much higher than that of common buckwheat. However, little studies has compared free and bound phenolic content and profiles and gasintesinal characteristics between tartary and common buckwheat. To investigate the effects of different solvent systems on phenolic contents and antioxidant activities in bran extract of tartary buckwheat, Folin-ciocalteu's methods and three different antioxidant bioassays were used, respectively. In order to provide the basis for the full use of buckwheat bran resources, this paper compared phenolic contents and profiles of tartary and common buckwheat by high performance liquid chromatography (HPLC). Meanwhile, this paper studied phenolic decomposition of buckwheat flour products in simulated gastrointestinal test in vitro.The main result of this paper:⑴The TPC and TFC decreased in the following order: tattary buckwheat bran>tartary buckwheat flour>common buckwheat bran>common buckwheat four, and had significant differences (p<0.05). The rutin contents in flour and bran of tattary buckwheat were higher than those of common buckwheat, being 223-299 times, while no significant differences between flour and bran in same type buckwheat. In addition, the most buckwheat phenolics were in free form.⑵In solvent system, 80% acetone extracts exhibited highest total flavonoids content, phenolic content and antioxidant activities. Antioxidant activities of ultrasound 30 min extract was higher than others in the terms of ABTS·+, DPPH·scavenging assays and inhibition usingβ-carotene-linoleic acid assay. ⑶The contents of phenolics acids and flavones in tartary buckwheat all were higher than that of common buckwheats, so were the contents of bound phenolics and flavonoids. Meanwhile, common and tartary buckwheat contained gallic acid, protocatechuic acid, vanillic acid, caffeic acid, p-cumaric acid, ferulic acid, catechin, rutin, quercetin, in addition, tartary buckwheat contained abundant p-hydroxybenzoic acid. Result also showed that a significant difference in contents of phenolic compounds was observed between common and tartary buckwheat cultivated in same geographical regions.⑷After steaming, the contents of free phenolics and free flavonoid and antioxidant activities in tartary buckwheat bun has increased, while existing decrease in common buckwheat. It showed that both contents and activities of antioxidants of different steamed food in three simulating gastrointestinal tests were significantly different. The proportion of the phenolic contents of bun and common buckwheat steamed food in simulated saliva step was highest, 42.50% and 37.92%, respectively, while that of tartary buckwheat steamed food in all steps were similar, being 29.91%, 30.23% and 27.85%.