2-Threityl-thiazolidine-4-carboxylic acid (TTCA) was found to be the predominant product rather than the Amadori rearrangement product (ARP) during the formation of xylose–cysteine-derived (Xyl–Cys-derived) Maillard reaction intermediates (MRIs) through a thermal reaction coupled with vacuum dehydration. To regulate the existence forms of Xyl–Cys-derived MRIs, an effective method carried out by pH adjustment during high-temperature instantaneous dehydration through spray-drying was proposed in this research to promote the conversion from TTCA to ARP. The increased inlet air temperature of spray-drying could properly facilitate the shift of chemical equilibrium between the MRIs and promote the transformation from TTCA to ARP while raising the total yield of TA (TTCA + ARP). The conversion to ARP was increased to 20.83% at 190 °C of hot blast compared to the product without spray-drying (6.03%). The conversion from TTCA to ARP was further facilitated in the pH range of 7.5–9.5. When the pH of the aqueous reactants was adjusted to 9.5, the equilibrium conversion to ARP was improved to 47.23% after spray-drying, which accounted for 59.48% of the TA formation. Accordingly, MRIs with different TTCA/ARP proportions could be selectively obtained by pH adjustment of the stock solution during high-temperature instantaneous dehydration of spray-drying.

中文翻译：

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在高温瞬时脱水过程中，通过调节pH值调节2-巯基噻唑烷-4-羧酸与木糖半胱氨酸Amadori重排产物之间的转化。

在木糖-半胱氨酸衍生（Xyl-Cys衍生）美拉德反应中间体（MRIs）的形成过程中，发现2-巯基噻唑烷-4-羧酸（TTCA）是主要产物，而不是Amadori重排产物（ARP）。 ）通过热反应加上真空脱水。为了调节Xyl–Cys衍生的MRI的存在形式，本研究提出了通过喷雾干燥在高温瞬时脱水过程中通过调节pH值进行的有效方法，以促进TTCA向ARP的转化。喷雾干燥的进口空气温度的升高可以适当地促进MRI之间化学平衡的转变，并促进从TTCA向ARP的转化，同时提高TA的总产量（TTCA + ARP）。转换为ARP的次数增加到20。与未经喷雾干燥的产品（6.03％）相比，在190°C的热风下为83％。在7.5–9.5的pH范围内，从TTCA到ARP的转化进一步得到促进。当将含水反应物的pH调节至9.5时，喷雾干燥后向ARP的平衡转化率提高至47.23％，占TA形成的59.48％。因此，在喷雾干燥的高温瞬时脱水过程中，通过调节储备溶液的pH值可以选择性地获得具有不同TTCA / ARP比例的MRI。