Research The Influence Of Processing Methods On Polyphenols Of Buckwheat

In this paper, the buckwheat was used as raw material, the five processing methods of bread processing, noodle processing, micronization, extrusion and High Hydrostatic Pressure were used for buckwheat.The influence of different processing on antioxidant activity, polyphenols content and the form of buckwheat was studied.The results are as follows:1、During buckwheat bread processing, the flavonoids, rutin content and antioxidant capacity were increased after fermentation and knead dough, however, had declined after being steamed, but the decline is small; The flavonoids, rutin content and antioxidant activity of buckwheat bread dough was not affected significantly by fermentation time.2、During buckwheat noodles processing,the flavonoids, rutin content and antioxidant capacity were increased after knead dough, however, had a little influence after Proofed, producted wet noodles and drying process.The flavonoids, rutin content,DPPH · and ABTS+ · scavenging activity of buckwheat bread dough was not affected significantly by proofed time,the TAA was increased with longer time.3、The contents of phenols, flavonoids and rutin, and antioxidant activity were all first decreased and then increased with the increase of degree of micronization, and weakened to a lesser extent, a higher degree of micronization could better retain and increase the content of polyphenols and antioxidant activity.,but the bound rutin was not affected by micronization.4、The free and total polyphenols content and antioxidant activity of buckwheat was significantly decreased, bound polyphenols content and antioxidant activity was increased and higher than the free state after extrusion. With the increase of extrusion temperature, polyphenols and antioxidant activity was most rised, polyphenols content and antioxidant activity of buckwheat has been relatively good retention at 160～180℃.There is a certain influence on buckwheat of the screw speed and material moisture,but no significant change in the trend.Screw speed of 320r/min and the material moisture content of 21%, the buckwheat had higher levels of polyphenols, and antioxidant activity is strong.5、 High Hydrostatic Pressure treatment can significantly improve flavonoids, phenols, rutin content and DPPH·, ABTS+ · scavenging activity of buckwheat, while TAA was reduced; with increasing pressure, all indicators showed a downward trend.6、The free,bound and total flavonoids, phenols, rutin content and antioxidant activity of buckwheat have a good correlation during the different processing conditions of micronization and extrusion.In bread processing, noodle processing and High Hydrostatic Pressure,flavonoids, phenols, rutin content in buckwheat had significant correlation with DPPH · ABTS+ · scavenging activity (P<0.01 or 0.05),TAA was not.