无定形态小分子糖对枣粉水分吸附及玻璃化转变的影响

Effect of Amorphous Small Molecule Sugars on Water Adsorption and Glass Transition of Jujube Powder

无定形态小分子糖的玻璃化转变是导致枣粉吸湿结块,进而影响其品质的重要因素。为明确不同小分子糖组成及含量对枣粉吸湿的贡献程度及玻璃化转变的影响,首先构建去糖枣片基质固态模拟体系(JSS),再经不同比例的果糖、葡萄糖、蔗糖溶液渗透后干燥制粉,分析不同小分子糖含量对JSS体系水分吸附、玻璃化转变温度(T_(g))及粉体基本流动能(BFE)的影响。结果表明:3种小分子糖的比例显著影响JSS的水分吸附、T_(g)与BFE,其中,果糖与T_(g)呈极显著负相关,与BFE呈极显著正相关。a_(w)=0.9时,果糖占比降低25.64%,粉体水分吸附量降低21.68%。3种小分子糖降低枣粉体系T_(g)的能力排序为果糖>葡萄糖>蔗糖,果糖占比降低25.64%,粉体T_(g)升高23.80%,BFE下降21.18%,粉体流动性显著提升。此外,通过降低枣粉中小分子糖总量也可有效降低枣粉体系的水分吸附量,增加T_(g)与提升流动性。综上,通过降低枣粉基质中果糖所占比例或降低枣粉中小分子糖总量均可实现对枣粉基质吸湿特性的有效调控,可为改善枣粉吸湿结块问题提供理论参考。

The glass transition of small-molecule sugars in amorphous forms is an important factor that causes moisture absorption and agglomeration of jujube powder,which affects its quality.In order to clarify the contribution of different small molecular sugar composition and content to the moisture absorption of jujube powder,the jujube slice skeleton(JSS)was first established,which was then infiltrated with different proportions of fructose,glucose,and sucrose solutions.Dried JSS and made powder,analyzed the influence of different small molecule sugar content on the water adsorption,glass transition temperature(T_(g))and basic flow energy(BFE)of the JSS.The results showed that the ratio of the three small molecule sugars significantly affected the water adsorption,T_(g)and BFE of JSS,and there was a very significant negative correlation between fructose and T_(g),and a very significant positive correlation with BFE.When a_(w)=0.9,the proportion of fructose decreased by 25.64%,the water adsorption capacity of the powder decreased by 21.68%.The order of the ability of the three small molecule sugars to reduce the T_(g)of JSS was fructose>glucose>sucrose,and the proportion of fructose decreased by 25.64%,T_(g)increased by 23.80%,BFE decreased by 21.18%,and powder fluidity was significantly improved.In addition,reducing the total amount of small molecule sugars in the jujube powder could also effectively reduce the water adsorption capacity of the jujube powder system,increase T_(g)and improve fluidity.In summary,reducing the proportion of fructose in the jujube powder or reducing the total amount of small molecular sugars in the jujube powder could achieve effective regulation of the moisture absorption characteristics of the jujube powder,which could provide a theoretical reference for improving the problem of moisture absorption and agglomeration of the jujube powder.