临界熔融协同冻融处理对木薯淀粉/魔芋胶复配物理化及结构特性的影响

Effect of Critical Melting Combined with Freeze-thawing Treatment on Physicochemical and Structural Properties of Cassava Starch/Konjac Gum Composite

以木薯淀粉(cassava starch,CS)和魔芋胶(konjac gum,KGM)为原材料,以“临界熔融-冻融”(critical melting and freeze-thawing,CMFT)为主要手段制备CS/KGM复配物,研究了临界熔融协同冻融处理对CS/KGM复配物理化性质及结构特性的影响。结果表明:CMFT有效促进了可溶性淀粉组分的释放,显著增加了其与KGM相互作用的位点。所制备的复配物耐热加工特性显著提升(溶解度、膨胀度显著降低),其中熔融起始温度从64.13℃(天然)增加至69.73℃(0.7%KGM,P<0.05)。CMFT还显著改善了复配物的糊化特性,其中崩解值从1246.00 mPa·s(天然)显著下降至949.12 mPa·s(0.7%KGM),而最终黏度从2182.00(天然)显著提高至2447.00 mPa·s(0.7%KGM,P<0.05)。此外,CMFT显著增加了复配物的相对结晶度(从22.19%增加到25.50%,P<0.05),表明复配物内部结构相对致密。较高浓度的KGM添加一定程度上促进了CMFT处理中CS与KGM间的协同作用。综上,该研究证明CMFT可通过部分弱化淀粉颗粒结构和释放可溶性淀粉组分增强CS/KGM协同作用,使所制备的复配物具有显著提高的耐热加工特性及糊化特性,并有望作为功能性复配材料应用到食品加工中。

In present study,cassava starch(CS)and konjac gum(KGM)were used as the raw materials,and critical melting combined with freeze-thawing(CMFT)was employed as the main treatment for the preparation of CS/KGM composites.The study aimed to investigate the effects of CMFT on the physicochemical and structural properties of CS/KGM composites.The results demonstrated that CMFT effectively facilitated the release of soluble starches,which significantly increased the interaction sites with KGM.The prepared composite had a significantly increased thermal stability(significantly decreased water solubility and swelling power),in which the onset melting temperature of the CS/KGM composite after CMFT was increased significantly from 64.13℃(native)to 69.73℃(0.7%KGM,P<0.05).CMFT significantly improved the pasting properties of the composite,which decreased the breakdown viscosity from 1246.00(Native)to 949.12 mPa·s(0.7%KGM),and increased the final viscosity from 2182.00(Native)to 2447.00 mPa·s(0.7%KGM,P<0.05).In addition,CMFT contributed to a significant increase in the relative crystallinity of the composite from 22.19%to 25.50%(P<0.05),indicating the formation of a more compacted internal structure of the composite.The higher addition of KGM further promoted the CS/KGM synergistic effect during CMFT.Overall,the study suggested that CMFT enhanced the synergistic interaction of CS/KGM by partially weakening the granular structure and releasing soluble starches.The prepared composite by CMFT had significantly increased thermal stability and improved pasting properties,which are expected to be used as a functional material in food processing.