乙基纤维素/蓝莓花青素浸泡型标签对牛奶新鲜度的指示

Indication of Milk Freshness by Ethyl Cellulose/Blueberry Anthocyanin Immersion Label

中文关键词: 乙基纤维素  浸泡  新鲜度  指示标签  牛奶

英文关键词: ethyl cellulose  soak  freshness  indication labels  milk

中文摘要:

      目的 旨在研发一款可浸泡在液体中的食品级牛奶新鲜度指示标签，让消费者简单方便且直观地了解牛奶的实时品质。方法 以乙基纤维素为聚合物基材，蓝莓花青素为pH敏感染料，吐温80和甘油为增塑剂制备出标签。通过比色分析、溶胀率、迁移测试、接触角、傅里叶变换红外光谱分析、扫描电镜(SEM)对指示标签进行表征，再将标签用于牛奶新鲜度监测，探究牛奶菌落总数、pH与指示标签总色差的关系。结果 花青素添加量为乙基纤维素质量分数10%的指示标签在pH缓冲液中的指示效果最佳;乙基纤维素和花青素通过氢键较好地结合使标签耐水性较好，可浸泡于液体中;迁移测试证明标签与牛奶接触不会造成安全问题;牛奶菌落总数、pH值与指示标签总色差存在相关性。结论 花青素添加量为乙基纤维素质量分数10%的指示标签在新鲜牛奶中显示为浅紫色，在变质牛奶中显示为粉色。该浸泡型指示标签在指示牛奶新鲜度上有良好应用价值和开发前景。

英文摘要:

      The work aims to develop a food grade milk freshness indication label that can be immersed in liquid so that consumers can learn the real time quality of the milk directly. With ethyl cellulose as a polymer substrate, blueberry anthocyanin as a pH sensitive dye, Tween 80 and glycerol as plasticizers, a freshness indication label was prepared. The indication label was characterized by colorimetric analysis, swelling rate, migration test, contact angle, Fourier transform infrared spectroscopy analysis, scanning electron microscopy (SEM), and then the label was used for milk freshness monitoring to explore the relationship between the total colonies and pH of the milk and the total color difference of the indication label. The results showed that when the anthocyanin content was 10% (mass fraction) that of the ethyl cellulose, the indication effect of the indication label was the best, and the ethyl cellulose and the anthocyanin made the label have better water resistance through the combination of hydrogen bonds, and can be soaked in liquid. The migration testing proved that contact with milk would not pose a safety issue. The total colonies and pH of milk were significantly correlated with the total color difference of the label. The conclusion is that an indication label with anthocyanin content of 10% (mass fraction) that of ethylcellulose appears light purple in fresh milk and pink in spoiled milk. It can be predicted that the label has good application value and development prospects in indication of milk freshness.