Ahmad F B, Williams P A
Centre For Water Soluble Polymers, The North East Wales Institute, Plas Coch, Mold Road, Wrexham LL11 2AW, United Kingdom.
Biopolymers. 1999 Oct 5;50(4):401-12. doi: 10.1002/(SICI)1097-0282(19991005)50:4<401::AID-BIP6>3.0.CO;2-V.
Studies have been undertaken to investigate the effect of sugars on the thermal and rheological properties of sago starch. Sugars were found to increase the gelatinization temperature T(gel), and gelatinization enthalpy DeltaH. T(gel) and DeltaH increased in the following order: control (water alone) < ribose < fructose < glucose < maltose < sucrose. The increase in DeltaH was greater for 50% starch compared to 10% starch samples. The swelling factors in the presence of sugar were higher compared to the control for sugar concentrations below 25% but were lower at sugar concentration greater than 25%. These effects are discussed in terms of the antiplaticizing effect of the sugars compared to water, the influence of sugar-starch interactions and also the effect of the sugars on water structure. The storage modulus G', the rate constant of gelation k, and the gel strength were significantly reduced in the presence of sugars. Generally G' and k decreased in the following order: control (water alone) > hexose > disaccharide > pentoses. This has been attributed to the reduced proportion of amylose leached following gelatinizatison. In the presence of hexoses the freeze-thaw stability of starch gels decreased while in the presence of disaccharides and pentoses the freeze-thaw stability was slightly improved.
已开展多项研究来探究糖类对西米淀粉热性能和流变性能的影响。研究发现，糖类会提高糊化温度T(gel)和糊化焓ΔH。T(gel)和ΔH按以下顺序增加：对照（仅用水）<核糖<果糖<葡萄糖<麦芽糖<蔗糖。与10%淀粉样品相比，50%淀粉样品的ΔH增加幅度更大。对于低于25%的糖浓度，含糖情况下的膨胀因子高于对照，但在糖浓度大于25%时则较低。从糖类与水相比的抗增塑作用、糖-淀粉相互作用的影响以及糖类对水结构的影响等方面对这些效应进行了讨论。在有糖类存在的情况下，储能模量G'、凝胶化速率常数k和凝胶强度均显著降低。一般来说，G'和k按以下顺序降低：对照（仅用水）>己糖>二糖>戊糖。这归因于糊化后直链淀粉浸出比例降低。在有己糖存在的情况下，淀粉凝胶的冻融稳定性降低，而在有二糖和戊糖存在的情况下，冻融稳定性略有提高。
