Study On The Preparation Conditions And Influencing Factors Of Buckwheat Pesistant Starch

Buckwheat is a new starch resource, it contains high rate of natural resistant starch. Buckwheat resistant starch was prepared by acid-modification and hydrothermal treatment methods, using the yield of resistant starch as evaluation index, studying the effects of different starch concentration, dosage of hydrochloric acid, acid-modification time, boiling water bath time, cold storage temperature and time and other technology condition on the yield of resistant starch, at the same time, combining single and hierarchy extraction methods to analyze lipid, albumin, globulin, gliadin, glutelin and other components on the yield of resistant starch, preliminary ascertaining the best technology for preparing buckwheat resistant starch.The results showed that:(1) During the process of preparing buckwheat resistant starch by acid-modification and hydrothermal treatment methods, the effects of hydrochloric acid dosage on the yield of resistant starch was most significant, after that was the ratio of starch to water, the influence of cold storage time in 4℃was small; Under the condition of ratio of starch to water (1:9), hydrochloric acid dosage 2.5%, acid-modification time 0.5 h, boiling water bath time 4 h, cold storage in 4℃for 42 h, the yield of buckwheat resistant starch can be highly improved. Buckwheat resistant starch had a high paste temperature, good stability in cold and heat paste, high quality of freeze-thaw stability. It had a similar function compare with dietary fiber and can be used as low energy, high dietary fiber functional food component.(2) The main component of buckwheat flour had a centain effect on the formation of resistant starch, the existence of lipid went against the formation of resistant starch, it was due to the fact that amylase in the buckwheat flour combined with lipid would no longer participate in the formation of amylase double helix, so its existence would greatly decreased the yield of resistant starch, and most lipid would form complex when combining with different protein molecular in the buckwheat flour, which would indirectly influence the effect of protein in the formation of resistant starch. The existence of albumin was beneficial to the formation of resistant starch, after doffing albumin alone, the yield of resistant starch decreased significantly comparing with raw flour. Gliadin had a negative effect on the formation of resistant starch, and its influce became bigger after degreasing. Glutelin had a posive effect on the formation of resistant starch, and similar to gliadin, its influce became bigger after degreasing. Residue protein was of little impact.