College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China.
College of Food Science, Northeast Agricultural University, Harbin, Heilongjiang 150030, China.
Int J Biol Macromol. 2022 Sep 1;216:361-373. doi: 10.1016/j.ijbiomac.2022.06.198. Epub 2022 Jul 5.
A pH-sensitive intelligent indicator film was developed and used for monitoring dynamic changes in chicken freshness at 4 °C and 25 °C by immobilizing 0.2 %-1.0 % purple sweet potato peel extracts (PPE) with sodium alginate (SA). The films presented a wide range of colors from red-pink to green-yellow at 2-13, and the films with less PPE were more sensitive to ammonia. The color of films with 0.6 % PPE changed from pink to blue when used in monitoring chicken freshness at 4 °C (5 d) and 25 °C (60 h), which corresponded to changes in total volatile base nitrogen from 5.35 (5.35) mg/100 g to 16.2 (19.9) mg/100 g. Scanning electron microscopy and X-ray diffraction revealed that PPE improved the compactness and crystallinity of SA films, while Fourier transform infrared spectroscopy revealed hydrogen bonds between SA and PPE. Compared to SA films, the water vapor and light barrier abilities of films with 0.6 % were significantly improved (P < 0.05), there was no significant effect on tensile strength (P > 0.05), and the elongation of 0.6 % PPE films (P < 0.05) was decreased. Thus, PPE can serve as an excellent indicator of intelligent films for monitoring the freshness of meat products.
一种 pH 敏感智能指示膜被开发出来，通过将 0.2%-1.0%的紫薯皮提取物（PPE）固定在海藻酸钠（SA）中，用于监测 4°C 和 25°C 下鸡肉新鲜度的动态变化。该膜在 2-13 范围内呈现出从红粉色到绿黄色的广泛颜色，且 PPE 含量较少的膜对氨更敏感。当用于监测 4°C（5d）和 25°C（60h）下鸡肉新鲜度时，含有 0.6%PPE 的膜从粉红色变为蓝色，这与总挥发性碱基氮从 5.35（5.35）mg/100g 到 16.2（19.9）mg/100g 的变化相对应。扫描电子显微镜和 X 射线衍射表明 PPE 提高了 SA 膜的致密性和结晶度，而傅里叶变换红外光谱表明 SA 和 PPE 之间存在氢键。与 SA 膜相比，含有 0.6%PPE 的膜的水蒸气和光屏障能力显著提高（P<0.05），对拉伸强度没有显著影响（P>0.05），而 0.6%PPE 膜的伸长率（P<0.05）降低。因此，PPE 可以作为监测肉类产品新鲜度的智能膜的优秀指示剂。
