State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, P. R. China.
Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia.
J Agric Food Chem. 2020 Sep 30;68(39):10884-10892. doi: 10.1021/acs.jafc.0c04287. Epub 2020 Sep 17.
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.
2-三乙基噻唑啉-4-羧酸（TTCA）是在热反应与真空脱水偶联过程中形成木糖-半胱氨酸衍生（Xyl-Cys-derived）美拉德反应中间体（MRIs）时，而不是 Amadori 重排产物（ARP）。为了调节 Xyl-Cys-derived MRIs 的存在形式，本研究提出了一种通过喷雾干燥进行高温瞬时脱水时调节 pH 值的有效方法，以促进 TTCA 向 ARP 的转化。提高喷雾干燥的入口空气温度可以适当促进 MRI 之间化学平衡的转移，促进 TTCA 向 ARP 的转化，同时提高 TA（TTCA+ARP）的总收率。与未喷雾干燥的产物（6.03%）相比，在 190°C 的热风中，向 ARP 的转化率提高到了 20.83%。在 pH 值为 7.5-9.5 的范围内，向 ARP 的转化率进一步提高。当水相反应物的 pH 值调节到 9.5 时，喷雾干燥后的 ARP 平衡转化率提高到 47.23%，占 TA 形成的 59.48%。因此，可以通过喷雾干燥过程中高温瞬时脱水时的储备液 pH 值调节来选择性地获得具有不同 TTCA/ARP 比例的 MRIs。
