| Objected to the dumpling wrappers and wheat glutenin,Sodium Dodecyl Sulfate-Polyacrylamide Gel-Electrophoresis(SDS-PAGE),Fourier Transform Infrared Spectroscopy(FTIR), Ellman’s reagent, ANS (1-aniline-8-naphthalene sulfonic acid) fluorescence probe, Texture Profile Analysis (TPA) were used to study the change mechanism of dumpling wrappers andwheat glutenin were studied systematically in this paper, and explores the dumpling skinschanges associated with the textural properties of the protein mechanism. The main contents are as follows:1.The changes of proteins in dumpling wrappers were studied and the the results showed that the trends of disulfide bonds in dumpling wrappers was different under frozen-t-haw processing and frozen-storage,which increasing of nearly2.2times, respectively, andreducing nearly1.5times;SDS-PAGE results showed that HMW dumpling skins mainlywas around116KDa~97.2KDa,and the changes of HMW and LMW contents were un-regular,however,HMW/LMW ratio showed a obvious increasing trend;During frozen storage,thesecondary structure of dumpling wrappers,β-sheet, random coil, α-helix and β-turn characteristic peaks were located at1617~1631.5cm-1,1644cm-1,1656.9cm-1,1669.8~1683.4cm-1place respectively,and the characteristic peaks of the secondary structure of the sample didnot change under different treatment conditions,but the content of secondary structure changed;Compared with the15d frozen storage, the contents of β-sheet decreased by3.30%and β-turn increased2.37%at the same time, but the contents of random coil and α-helixhad no big changes after90d.2.TPA was used to the dumpling wrappers and the results showed that the elasticity andviscoelasticity decreased with the increasing number of freeze-thaw cycles and hardness reducedyet,whose changes had significant difference (P <0.05),and at the beginning of freeze-thawcycles, the texture of dumpling wrappers changed significantly, while the changes in elasticityand hardness between HMW/LMW ratio and disulfide contents correlation significantly(P<0.05);The hardness, elasticity and cohesiveness of the dumpling wrappers reduced with the increasing ofthe frozen storage,while this change is not obvious in pre-frozen storage.The correlation analysisshowed that hardness, elasticity and cohesiveness were affected by free thiol and disulfide bondcontents and HMW/LMW ratio greatly (P <0.01); The core secondary structure,α+β,had acertain influence on the cohesiveness(P <0.05), while the influence on hardness was not significant.3. The glutenin of dumpling wrappers was objected to study the changes of physicochemicaland functional properties,and the results showed that the contents of disulfide bond increased withincreasing number of freeze-thaw,nearly1.5times than before after five times thawing, on thecontrary, the content of the free thiol decreased by21.60%with the increasing offreeze-thaw;The percentage of high molecular weight glutenin (HMW-GS) decreased from38.93%to20.44%and random coil, α-helix were reduced by8.25%and18.67%, while theβ-sheet and β-turn structure respectively, an increase of21.42%and10.28%after five frozen-thawprocess,and wheat glutenin increased by35.45%on emulsifying, meanwhile foaming increasedby about1times;During frozen storage, with the same results of frozen-thaw, the solubility ofwheat glutenin and the proportion of HMW-GS both reduced,the surface hydrophobicity anddisulfide bond content increased, and the secondary structure changed, while the emulsifying andfoaming properties of wheat glutenin decreased with the frozen storage time increasing. |
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