Effect of glass transition on the hardness of a thermally compressed soup solid
Effect of glass transition on the hardness of a thermally compressed soup solid
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DOI：
10.1016/j.jfoodeng.2018.11.019
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发表时间：
2019-04-01
影响因子：
5.5
通讯作者：
Kawai, Kiyoshi
中科院分区：
文献类型：
--
作者：
Mochizuki, Takumi;Sogabe, Tomochika;Kawai, Kiyoshi
这项研究描述了水含量对汤粉玻璃化转变温度 (T-g) 以及在高于和低于 T-g 的不同温度下压缩的汤固体硬度的影响。尽管差示扫描量热法显示出模糊的玻璃化转变，但热流变分析显示出清晰的机械玻璃化转变。由于水塑化作用，机械 T-g 随着水活度（或水含量）的增加而降低。由于 X 射线衍射显示出反映结晶氯化钠、乳糖和蔗糖的峰，因此汤粉中的无定形区域可能主要由蔬菜、酵母、牛肉和鸡肉提取物组成。热压缩汤固体的断裂应力随着样品的水分活度、压缩高度（密度）和温度而增加。结果表明，当汤固体在高于机械 T-g 的温度下压缩时，其断裂应力急剧增加。
This study described the effect of water content on the glass transition temperature (T-g) of a soup powder and the hardness of a soup solid compressed at various temperatures above and below the T-g. Although differential scanning calorimetry showed indistinct glass transition, thermal rheological analysis revealed a clear mechanical glass transition. The mechanical T-g decreased as water activity (or water content) increased because of a water-plasticizing effect. Since X-ray diffraction showed peaks reflecting crystalline NaCl, lactose, and sucrose, the amorphous region in the soup powder likely consisted mainly of vegetable, yeast, beef, and chicken extracts. The fractural stress of the thermally compressed soup solid increased with water activity of the samples, compressed height (density), and temperature. The results showed that the fractural stress of the soup solid increased dramatically when it was compressed at a temperature above the mechanical T-g.