Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University, 1177, Urmia, Iran.
Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Urmia University, 1177, Urmia, Iran.
Int J Biol Macromol. 2019 Sep 1;136:920-926. doi: 10.1016/j.ijbiomac.2019.06.148. Epub 2019 Jun 21.
In this study, the possible use of anthocyanins of black carrot (ABC) as a chemo-responsive dye to fabricate a colorimetric pH indicator in a cellulose-chitosan matrix was investigated in order to the monitoring of spoilage in pasteurized milk. Cellulose paper was impregnated with a chitosan solution prepared by a sol-gel method containing ABC (total anthocyanins content of 10 mg/100 mL) and characterized. The swelling and water solubility increased by incorporation of ABC into the chitosan-cellulose film. The colorimetric pH indicator showed an obvious color variation from pink to khaki at different pH values (pH 2-11). Stability tests revealed that the indicator had acceptable color stability during one-month storage at 20 °C. The results also confirmed the immobilization of ABC into the matrix of the polymeric indicator with no significant effect on the chemical and super-molecular structure of the samples. In food trial, fresh pasteurized milk was entirely discerned through a perceptible color change from blue to violet rose color after 48 h storage at 20 °C, which was comfortably observable by the naked eye. The results proved that the fabricated indicator could be used as food grade biomaterials to monitor freshness/spoilage of milk.
在这项研究中，研究了将黑胡萝卜（ABC）中的花色苷作为化学响应性染料用于在纤维素-壳聚糖基质中制造比色 pH 指示剂的可能性，以便监测巴氏杀菌牛奶的变质情况。纤维素纸用通过溶胶-凝胶法制备的壳聚糖溶液浸渍，该溶液含有 ABC（总花色苷含量为 10mg/100mL）并进行了表征。通过将 ABC 掺入壳聚糖-纤维素膜中，溶胀和水溶性增加。比色 pH 指示剂在不同 pH 值（pH 2-11）下表现出明显的颜色从粉红色到卡其色的变化。稳定性测试表明，该指示剂在 20°C 下储存一个月时具有可接受的颜色稳定性。结果还证实了 ABC 被固定在聚合物指示剂的基质中，对样品的化学和超分子结构没有显著影响。在食品试验中，新鲜巴氏杀菌牛奶在 20°C 下储存 48 小时后，通过从蓝色到紫罗兰玫瑰色的明显颜色变化完全可以辨别，肉眼舒适可见。结果证明，所制备的指示剂可用作食品级生物材料来监测牛奶的新鲜度/变质情况。
