Hematian Fahimeh, Baghaei Homa, Mohammadi Nafchi Abdorreza, Bolandi Marzieh
Department of Food Science and Technology, Damghan Branch Islamic Azad University Damghan Iran.
Food Technology Division, School of Industrial Technology Universiti Sains Malaysia Penang Malaysia.
Food Sci Nutr. 2022 Sep 21;11(1):379-389. doi: 10.1002/fsn3.3068. eCollection 2023 Jan.
In this study, a pH-sensitive indicator based on fish gelatin and anthocyanin extract (CSAE) was prepared and characterized. Films were prepared using the solvent casting method and different levels of CSAE, including 10 ml (CSG1), 20 ml (CSG2), and 30 ml (CSG3), and 0 ml (CSG0) as a control sample. The mechanical, optical, and pH sensing of active films and the release of anthocyanins from the films were investigated. The relationship between the total volatile basic nitrogen (TVB-N) of fish fillets and * color index of films was studied. By incorporation of CSAE, the flexibility of films increased, while the tensile strength and UV-Vis light transmittance through the films decreased ( < .05). The films containing the CSAE had a darker, yellowish, and reddish color than the control film. There was a significant relationship between the pH variation and the film color. The films had a purple color at acidic pH, and their color changed to green at an alkaline pH, indicating the sensitivity of the produced films to pH changes. There was a significant relationship between the TVB-N value of fish fillets and the * index of the film during the 16 h storage time. The results showed that by increasing TVB-N values of the fillets, the * color index decreased, and the films' color changed from purple to colorless. In summary, the active films prepared with fish gelatin and CSAE could be used as pH-sensitive intelligent packaging to display the freshness of fishery products.
在本研究中，制备并表征了一种基于鱼明胶和花青素提取物（CSAE）的pH敏感指示剂。采用溶液浇铸法制备薄膜，使用不同含量的CSAE，包括10毫升（CSG1）、20毫升（CSG2）和30毫升（CSG3），并以0毫升（CSG0）作为对照样品。研究了活性薄膜的机械性能、光学性能和pH传感性能以及薄膜中花青素的释放情况。研究了鱼片的总挥发性盐基氮（TVB-N）与薄膜颜色指数之间的关系。通过加入CSAE，薄膜的柔韧性增加，而拉伸强度和透过薄膜的紫外-可见透光率降低（P<0.05）。含有CSAE的薄膜比对照薄膜颜色更深，呈淡黄色和微红色。pH变化与薄膜颜色之间存在显著关系。薄膜在酸性pH值下呈紫色，在碱性pH值下颜色变为绿色，表明所制备的薄膜对pH变化敏感。在16小时的储存时间内，鱼片的TVB-N值与薄膜颜色指数之间存在显著关系。结果表明，随着鱼片TVB-N值的增加，薄膜颜色指数降低，薄膜颜色从紫色变为无色。综上所述，用鱼明胶和CSAE制备的活性薄膜可用作pH敏感型智能包装，以显示渔业产品的新鲜度。
