花青素纳米纤维智能标签对羊肉新鲜度的无损检测

为实现羊肉新鲜度的无损、实时、可视化检测,及建立可靠的预测模型,将花青素纳米纤维智能标签应用于市售温度(10±2)℃储藏下的羊肉,并测定了智能标签的微观结构和胺敏感性,以及羊肉储藏过程中的新鲜度指标(感官品质、挥发性盐基总氮含量(Total Volatile Basic Nitrogen,TVB-N)、pH值、菌落总数、酸度/氧化力系数)和纤维膜的色差。结果表明:花青素纳米纤维膜呈淡粉色,由250 nm左右的均匀纤维丝组成,具有胺敏感性;羊肉的各新鲜度指标指示其在储藏72 h时已腐败变质,同时纤维膜由粉色变为白色;相关性分析表明纤维膜色差与各新鲜度指标具有显著相关性(P0.05),并建立了准确率为88.2%的色差对TVB-N的预测模型(R2=0.967)。综上所述,羊肉新鲜度的无损、可视化和实时检测可通过花青素纳米纤维智能标签实现,且根据标签颜色即可初步预测羊肉新鲜度级别,为解决肉类安全问题提供了新思路。

Non-destructive detection of mutton freshness using anthocyanin nanofiber smart label

Abstract: A high demand has been growing for non-destructive, cost-saving, and online visual detection on the lamb freshness. In this study, a prepared smart label was used to detect the freshness of mutton stored at a commercially available temperature (10±2°C). A reliable prediction model was then established. This smart label was made of a nanofiber membrane fabricated by electrospinning, which was loaded with pH-sensitive anthocyanin and biodegradable polylactic acid. A scanning electron microscope (SEM) and UV-2450 spectroscopy were used to observe and detect the microstructure and amine sensitivity of the fiber membrane. Some parameters were measured during the storage of mutton, including the sensory quality, total volatile base nitrogen (TVB-N), pH value, the total number of colonies, acidity/oxidation capacity coefficient of meat, and fiber membrane color difference. The freshness of mutton was accurately graded, thereby preliminarily evaluating the accuracy of the fiber membrane for the detection. The results showed that the fiber membrane was amine sensitive in the light pink with uniform fiber filaments of about 250nm. The freshness indicators of mutton demonstrated that the membrane had been putrefied and deteriorated after 72h storage, where the fiber membrane changed from pink to colorless. Correlation analysis showed that the color difference of the fiber membrane had a significant correlation with each freshness index. A prediction model was successfully established for the TVB-N with an accuracy rate of 88.7% was successfully established(R2=0.966 5). Thus, the smart label of anthocyanin nanofiber could be applied to the detection of mutton freshness, where the freshness could be accurately graded according to the color of the label. The reason was that the amines were produced during meat spoilage, some of which evaporated into the packaging environment, thereby changing the pH value of the environment, whereas, the anthocyanins were color responsive to pH, which caused the label color to change in turn. The price of the label was relatively low and the overall price was only 0.0027 Yuan, indicating a great advantage in market applications. The anthocyanin smart label can be used to realize the non-destructive, visual, and real-time detection of mutton freshness, providing a new idea to solve meat safety.