Qin Yuyue, Wang Yurou, Tang Zhenya, Chen Kejun, Wang Zhengxuan, Cheng Guiguang, Chi Hai, Soteyome Thanapop
Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650550, China.
Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, 650550, China.
Food Chem X. 2024 Jul 16;23:101639. doi: 10.1016/j.fochx.2024.101639. eCollection 2024 Oct 30.
As a new type of packaging method, the anthocyanin-based pH-sensitive indicator film has gained much attention owing to low cost, small size, and visually informative property. In this study, an intelligent film based on chitosan/gelatin (CG) matrix with Diels (ZSD) anthocyanin for fish freshness monitoring was developed. The film properties, including thickness, moisture content, color, mechanical properties, UV-vis light barrier property, as well as pH and ammonia sensitivity, were evaluated. The CG-ZSD films exhibited a more compact structure when compared with the CG film. The CG-ZSD20 film showed the highest elongation at break (6.33 ± 0.62%) and lowest tensile strength (20.0 ± 0.58 MPa). FTIR spectra revealed the strong hydrogen bond interactions between ZSD and polymer matrix. Film incorporated with 15% anthocyanin extract has increased melting temperature at 118.9 °C, and a lower weight loss (13.8%) at melting temperature. In pH 1-14 buffer, the color of CG-ZSD films underwent a significant change from red to yellow-green. The CG-ZSD15 film was utilized for monitoring fish freshness and showed visible color changes from deep purple to brown. The total volatile basic nitrogen content and pH value changes of fish were closely related to the visual color changes in film. This demonstrated that the film was a highly pH-sensitive film for quantifying fish freshness in real-time.
作为一种新型包装方法，基于花青素的pH敏感指示膜因其成本低、尺寸小和视觉信息丰富的特性而备受关注。在本研究中，开发了一种基于壳聚糖/明胶（CG）基质并含有二烯丙基二硫（ZSD）花青素的智能膜用于监测鱼的新鲜度。对该膜的性能进行了评估，包括厚度、水分含量、颜色、机械性能、紫外-可见光阻隔性能以及pH和氨敏感性。与CG膜相比，CG-ZSD膜呈现出更致密的结构。CG-ZSD20膜的断裂伸长率最高（6.33±0.62%），拉伸强度最低（20.0±0.58MPa）。傅里叶变换红外光谱（FTIR）显示ZSD与聚合物基质之间存在强烈的氢键相互作用。含有15%花青素提取物的膜在118.9℃时熔点升高，在熔点时失重较低（13.8%）。在pH 1-14缓冲液中，CG-ZSD膜的颜色发生了从红色到黄绿色的显著变化。CG-ZSD15膜用于监测鱼的新鲜度，颜色从深紫色变为棕色。鱼的总挥发性盐基氮含量和pH值变化与膜的视觉颜色变化密切相关。这表明该膜是一种对pH高度敏感的膜，可用于实时定量鱼的新鲜度。
