| 摘要: |
| 研究了一种能够根据包装内猪肉腐败程度而显示不同颜色的指示卡,用于指示猪肉的新鲜度。 将浓度为 0. 2% ,0. 3% ,0. 4% ,0. 5% 的溴甲酚紫乙醇溶液,分别与浓度为 0. 7% 的羟丙基甲基纤维素溶液混合,经流延成膜后再与白色防水纸复合,制得了 4 种新鲜度指示卡,分别用于指示浅盘包装内猪肉的新鲜度。 在贮存期内,测定了猪肉中挥发性盐基氮的含量和对应的新鲜度指示卡颜色的 Lab 值,计算了新鲜度指示卡的色差值。探讨了溴甲酚紫含量对新鲜度指示卡准确显色的影响。 结果表明,新鲜度指示卡色差值与猪肉挥发性盐基氮含量呈线性相关。 在猪肉发生腐败时,溴甲酚紫溶液浓度为 0. 5% 的新鲜度指示卡(A4)由黄色变为绿色,变色点明显;继续腐败时,变为蓝色,变色梯度大;变色不受猪肉质量的影响,起到了指示包装猪肉新鲜度的作用。 |
| 关键词: 溴甲酚紫 新鲜度指示卡 猪肉 腐败 |
| DOI： |
| 分类号:TB487; TS206 |
| 基金项目: |
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| Development of Pork Freshness Indicator Card |
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SUN Yuan-yuan, ZHANG Lei
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Tianjin University of Science and Technology, Tianjin 300222, China
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| Abstract: |
| An indicator showing freshness of pork via discoloration was developed. Bromocresol purple ethanol solution with 0. 2% , 0. 3% , 0. 4% , and 0. 5% concentration was mixed with 0. 7% hydroxypropyl methyl cellulose solution for preparing thin film by tape costing. Four kinds of indicator were made by putting thin film on the white waterproof paper. Indicators were packed with pork (50, 100, 150 g / tray) in the same tray wrapped with PE film to indicate freshness of the pork via discoloration during storage. TVB-N content of pork and the corresponding Lab values of indicators were determined. △E value of the indicators was calculated. The influence of bromocresol purple content on the sensitivity of the indicators was discussed. The results showed that △E value of the indicators and TVB-N content of pork was linear correlation very well; when the pork starts to be spoilage, the indicator with 0. 5% bromocresol purple is discoloration from yellow to green, and the color changing point is obvious; afterwards spoilage of the pork continue,and the indicator's color changes into blue; the discoloration of the indicator in not influenced by weight of the pork;the indicator is effective for indicating the freshness of packed pork. |
| Key words: bromocresol purple indicator pork spoilage |
