Study On The Mechanism Of Wheat Quality Improvement Induced By Gluten Crosslinking Polymerization During Postharvest Maturation

This study selected 2 different quality wheats(high gluten cultivar Zhoumai 32,medium gluten varieties Huapei No.6)as the experimental materials,the wheat harvest in the simulated four different ecological regions(grain Mengxin ecological area of 15°C 50% RH,North China ecological area of 20°C,65% RH,the ecological region of central China of 28°C,75% RH,Southern China ecological region of 35°C,85% RH),storage.The protein content,wet gluten content,dry gluten content,gluten index,as well as the molecular weight of wheat gluten and the change of the two grade structure were measured at storage for 0 week and 13 weeks.In the process of wheat gluten protein crosslinking polymerization mediated mechanism to improve the quality of the research conclusions are as follows:The variation of wheat gluten protein during storage,the results show that the gliadin content generally decreased,glutenin content increased,the ratio of Glutenin to gliadin increased with the storage time,temperature and humidity of the storage environment,the gluten of glutenin and gliadin content the change is not obvious,while the high temperature and high humidity storage environment,the gluten of glutenin and gliadin content more obvious changes.There was no significant change in wet gluten content and dry gluten content in the Mengxin ecological area,the ecological region of North China and the ecological region of central China,but in Southern China ecological region under the condition of wet gluten content and dry gluten content have significant changes,Zhoumai 32 and Huapei No.6 of the wet gluten content at 21 days than at 0 day were reduced by 2.55% and 2.86%,dry gluten the content of 21 days than 0 day were reduced by 1.09%,1.43%,after 21 days,is not easy to form gluten.Found in SDS-PAGE electrophoresis analysis: Zhoumai 32 and Huapei No.6 in 0-13 weeks during storage,molecular weight of 10.0-60.0KDa spectrum becomes shallow gradually with color,and the relative content is decreased,and the molecular weight of the band color 64.2-117.7KDa has changed deeply,the relative content also increased.In the simulation of Central China ecological region and Southern China ecological region,the spectral bands disappeared,but the total number of bands was not changed during the simulation of the Mengxin ecological area and the ecological region of North China.When the storage conditions were simulated in Southern China ecological region,wheat gluten was not able to be washed inZhoumai 32 and Huapei No.6,respectively,at the end of the fifth week and the fourth week,which was not found in the SDS-PAGE electrophoresis analysis for fifth and fourth weeks.The study found that the relative content of storage in different temperature and humidity changes have a significant impact on wheat gluten,there is a certain correlation between polymerization and crosslinking of wheat gluten in the process of aging.Analysis of fitting infrared spectra and amide I band using the results show that the 2923cm-1 stretching vibration in the region near the C-H absorption band in the 1652cm-1 region showed obvious characteristic peaks,mainly due to the stretching vibration,C=O in addition,in the 950-1185cm-1 band,the absorption peak of a series,mainly due to the stretching vibration of C-C and C-O,CCH,COH and HCO bending vibration.During the storage of two level structure of gluten protein changed,the results are as follows: to reduce the content of ?-helical,because with the extension of storage time of hydrogen bonds to reduce the fracture,the spiral structure is destroyed,the formation of small molecules,increased the content of ?-turn,the ratio of ?-helical / ?-sheet folding decreased,showed that gluten elasticity decreased,the viscosity increased,increased flexibility.