基于STC-1细胞味觉感知模型对鱼露脯氨酸二肽呈鲜特性的研究

为探究鱼露中脯氨酸二肽的呈鲜特性，本研究以感官评价为基础，建立STC-1小鼠小肠内分泌细胞味觉感知模型，采用钙离子成像方法反映脯氨酸二肽的呈味剂量效应，通过实时荧光定量PCR技术测定二肽对鲜味受体T1R1、T1R3、CaSR、GPRC6a的mRNA表达量的影响，判断介导二肽呈鲜的主要受体。结果表明:13个脯氨酸二肽均无苦味，多呈鲜味和酸味，呈味较强的肽同时具有较低的阈值，其中具有较强味觉活性的肽为Ser-Pro、Ala-Pro、Pro-Ala、Pro-Val、Pro-Ile。脯氨酸二肽的呈味活性越强，其对鲜味受体mRNA表达的促进程度越强，推测T1R1是介导脯氨酸二肽呈鲜的重要受体。本研究提供了一种鱼露脯氨酸二肽呈鲜特性的非人工感官评价方法，同时为深入研究鱼露寡肽呈鲜的定量构效关系打下基础。

Study on Umami Characteristics of Proline Dipeptides in Fish Sauce Based on STC-1 Cells Taste Sensing Model

This paper aimed to explore the umami characteristic of proline dipeptides in fish sauce. The STC-1 cells taste sensing model was established based on sensory evaluation in this study. Calcium imaging was used to reflect the taste dose effect of proline dipeptides. In order to identify the main receptors that mediate umami taste of proline dipeptides, effects on the mRNA expression of umami receptors (T1R1, T1R3, CaSR and GPRC6a) that dipeptides caused were measured by real-time quantitative PCR. The results showed that none of the 13 proline dipeptides had bitter taste, and most of them presented umami and sour taste. The dipeptides with stronger taste also had lower threshold values, among which the peptides with excellent taste activity were Ser-Pro, Ala-Pro, Pro-Ala, Pro-Val and Pro-Ile. The proline dipeptides with stronger taste activity had stronger upregulation effect on expression of umami taste receptors mRNA, and T1R1 was likely to be an important receptor mediating the umami taste of proline dipeptides. This study would provide a non-artificial sensory evaluation method for evaluating umami taste of proline dipeptides in fish sauce, and laid a foundation for further study of quantitative structure-activity relationship of umami oligopeptides in fish sauce.