Study of thermal properties and heat-induced denaturation and aggregation of soy proteins by modulated differential scanning calorimetry.
Study of thermal properties and heat-induced denaturation and aggregation of soy proteins by modulated differential scanning calorimetry.
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DOI：
10.1016/j.ijbiomac.2006.06.013
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发表时间：
2007-01
影响因子：
8.2
通讯作者：
Chuan-he Tang;Siu-Mei Choi;C. Ma
中科院分区：
文献类型：
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作者：
Chuan-he Tang;Siu-Mei Choi;C. Ma
采用调制差示扫描量热法(MDSC)研究了大豆分离蛋白(SPI)的热性质及其热变性和聚集性。在热谱图中，可逆和不可逆热流信号从总热流信号中分离出来。在不可逆分布中，确定了与残余水损失有关的两个主要吸热峰(分别在100℃和220℃左右)。在可逆分布中，观察到一个与热聚集有关的放热峰。大豆蛋白经不同程度的热处理变性后，表现出不同的不可逆和可逆热流模式，尤其是放热峰。不可逆和可逆信号的吸热或放热转变特性均受样品热历史的影响。在相对湿度(RH)为8%~85%的范围内，放热(聚集)峰的热变随相对湿度(RH)的增加几乎呈线性增加。相反，随着相对湿度的增加，放热开始温度逐渐降低。这些结果表明，MDSC技术可以用来研究低水分下大豆蛋白的热性质和热诱导变性/聚集。还可以评估相关的功能特性，如保水性和水化特性。
The thermal properties and heat-induced denaturation and aggregation of soy protein isolates (SPI) were studied using modulated differential scanning calorimetry (MDSC). Reversible and non-reversible heat flow signals were separated from the total heat flow signals in the thermograms. In the non-reversible profiles, two major endothermic peaks (at around 100 and 220°C, respectively) associated with the loss of residual water were identified. In the reversible profiles, an exothermic peak associated with thermal aggregation was observed. Soy proteins denatured to various extents by heat treatments showed different non-reversible and reversible heat flow patterns, especially the exothermic peak. The endothermic or exothermic transition characteristics in both non-reversible and reversible signals were affected by the thermal history of the samples. The enthalpy change of the exothermic (aggregation) peak increased almost linearly with increase in relative humidity (RH) in the range between 8 and 85%. In contrast, the onset temperature of the exotherm decreased progressively with increase in RH. These results suggest that the MDSC technique could be used to study thermal properties and heat-induced denaturation/aggregation of soy proteins at low moisture contents. Associated functional properties such as water holding and hydration property can also be evaluated.