Department of Food Science and Technology, Faculty of Agriculture, Urmia University, Urmia, Iran.
Department of Food Science and Technology, Faculty of Agriculture, Urmia University, Urmia, Iran.
Int J Biol Macromol. 2023 Dec 31;253(Pt 4):127035. doi: 10.1016/j.ijbiomac.2023.127035. Epub 2023 Sep 22.
In this research, a color sensor based on nanofiber cellulose film modified with ninhydrin was designed to measure amino acids and formalin index in fruit juice. For this purpose, three types of cellulose films with porosity of 5, 30 and 125 μm were used. These films were treated with standard solution of ninhydrin. The characteristics of modified films were investigated using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and X-ray Diffraction (XRD) tests. The color factors of the sensors (a and b) changed in the presence of amino acids and juice with different levels of formalin index. Therefore, the modified films with ninhydrin as a colorimetric sensor were calibrated using 7 types of amino acids and based on the formalin index of 4 types of juice. Then the sensors were used to measure the formalin index in 4 types of juice. The results showed that the sensors have relative selectivity towards methionine amino acid. The formalin index values calculated in the juices by the sensor were compared with the titration method as a reference method. All three types of sensors were able to detect formalin index. The results of the sensor performance verification showed that the sensors can measure formalin index in different juices with 95-98 % accuracy. These sensors showed fast sensitivity and selectivity to the amino acids in juice, also these sensors are safe and the measurement method is fast and simple.
在这项研究中，设计了一种基于修饰有邻苯二醛的纳米纤维纤维素膜的颜色传感器，用于测量果汁中的氨基酸和甲醛指数。为此，使用了三种具有 5、30 和 125μm 孔隙率的纤维素膜。这些膜用邻苯二醛的标准溶液处理。使用傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和 X 射线衍射（XRD）测试研究了改性膜的特性。传感器的颜色因子（a 和 b）在存在氨基酸和不同甲醛指数的果汁时发生变化。因此，使用 7 种氨基酸对带有邻苯二醛的改性膜进行校准，并根据 4 种果汁的甲醛指数进行校准。然后，使用传感器测量 4 种果汁中的甲醛指数。结果表明，传感器对蛋氨酸氨基酸具有相对选择性。通过传感器计算出的果汁中的甲醛指数值与滴定法（参考方法）进行了比较。所有三种类型的传感器都能够检测甲醛指数。传感器性能验证的结果表明，传感器可以以 95-98%的准确度测量不同果汁中的甲醛指数。这些传感器对果汁中的氨基酸具有快速的灵敏度和选择性，并且这些传感器是安全的，测量方法快速简单。
