Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Center, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
J Agric Food Chem. 2010 May 26;58(10):6465-71. doi: 10.1021/jf100340j.
This study investigates the impact of the oxidants potassium bromate and potassium iodate (8, 16, 32, 64, and 128 micromol/g dry matter of egg white protein) on pound cake making. The impact of the oxidants on egg white characteristics was studied in a model system. Differential scanning calorimetry showed that the oxidants caused egg white to denature later. During heating in a rapid visco analyzer, the oxidants caused the free sulfhydryl (SH) group levels to decrease more intensively and over a smaller temperature range. The oxidants made the proteins more resistant to decreases in protein extractability in sodium dodecyl sulfate containing buffer during cake recipe mixing and less resistant to such decreases during cake baking. We assume that, during baking, the degree to which SH/disulfide exchange and SH oxidation can occur depends on the properties of the protein at the onset of the process. In our view, the prevention of extractability loss during mixing increased the availability of SH groups and caused more such loss during baking. During cooling, all cakes baked with added oxidants showed less collapse. On the basis of the presented data, we put forward that only those protein reactions that occur during baking contribute to the formation of a network that supports final cake structure and prevents collapse.
本研究探讨了氧化剂溴酸钾和碘酸钾（8、16、32、64 和 128 微摩尔/克蛋清蛋白干物质）对磅蛋糕制作的影响。在模型体系中研究了氧化剂对蛋清特性的影响。差示扫描量热法表明，氧化剂使蛋清变性的时间更晚。在快速黏度分析仪中加热时，氧化剂使游离巯基（SH）基团水平更剧烈地降低，且降低范围更小。氧化剂使蛋白质在蛋糕配方混合过程中在含十二烷基硫酸钠的缓冲液中的蛋白质提取率降低的程度更不易降低，而在蛋糕烘焙过程中则更不易降低。我们假设，在烘焙过程中，SH/二硫键交换和 SH 氧化的程度取决于过程开始时蛋白质的性质。在我们看来，混合过程中可提取性损失的预防增加了 SH 基团的可用性，并导致烘焙过程中更多的损失。在冷却过程中，添加了氧化剂的所有蛋糕的坍塌程度都较小。基于所提供的数据，我们提出只有在烘焙过程中发生的那些蛋白质反应有助于形成支撑最终蛋糕结构和防止坍塌的网络。
