聚乙烯醇活性薄膜对大黄鱼保鲜效果及品质动态监控

为研究智能聚乙烯醇活性薄膜对大黄鱼贮藏品质的影响和由于大黄鱼鱼肉p H改变而引起的薄膜动态色差变化,先以溶液流延法制备含有1%纳米二氧化钛和3%花青素的聚乙烯醇活性薄膜,使用其包装大黄鱼贮藏于4℃,再以感官品质、脂质过氧化值、菌落总数、挥发性盐基氮和pH并结合贮藏过程中薄膜色差变化,作为评定大黄鱼在包装贮藏过程中的鲜度指标。结果表明:在4℃贮藏期间,聚乙烯醇/纳米二氧化钛/花青素薄膜包装处理组的感官品质、脂质过氧化值、菌落总数、挥发性盐基氮和pH均优于空白和使用纯聚乙烯醇薄膜包装处理组,且在贮藏第16 d的菌落总数达到7.11lg cfu/g,其他实验组在贮藏第12 d达到7.14lg和7.03lg cfu/g,其货架期延长了4 d。在20 d贮藏期间过程中,聚乙烯醇/纳米二氧化钛/花青素薄膜表现出灰棕色(0 d)、红棕色(4 d)、淡红棕色(8 d)、肉色(12 d)、灰色(16 d)和深灰色(20 d),通过可见的颜色变化依次响应贮藏过程中大黄鱼鱼肉pH的改变。因此,本研究所制备的智能聚乙烯醇活性薄膜不仅有益于食品的贮藏保鲜,还能够作为颜色指示器在食品贮藏过程中起到动态监控的作用。

Active Poly (vinyl) Alcohol Film on the Fresh-keeping Effect and Quality Dynamic Monitoring of Pseudosciaena crocea

The effect of the intelligent active poly( vinyl) alcohol film on the storage quality of Pseudosciaena crocea was studied,and the visible dynamic color changes of the film due to the change of pH value of Pseudosciaena crocea were also discussed.1% nano-TiO2 and 3% anthocyanin were incorporated into poly( vinyl) alcohol by solution casting method. The indexes of sensory quality,TBA,total bacteria,volatile base nitrogen and pH,which combined with the changes of difference on film color were used to evaluate the freshness of Pseudosciaen acrocea during 4 ℃ storage.The results showed that the sensory quality,TBA,total bacteria,volatile base nitrogen,and pH values of the PVA-nano-TiO2-anthocyanin film packaged group were better than those of the unpackaged and pure PVA film packaged groups stored at 4 ℃.The total number of bacteria on the16 th day of storage reached 7.11 lg cfu/g for PVA-nano-TiO2-anthocyanin film packaged group,compared with 7.14 lg and7.03 lg cfu/g on the 12 th day of storage in other experimental groups.The shelf life was extended 4 d.During the 20 d storage period,the poly( vinyl) alcohol-nano-TiO2-anthranisin film showed gray-brown( 0 d),red-brown( 4 d),light red-brown( 8 d),incarnadine( 12 d),gray( 16 d) and dark gray( 20 d),which could respond well with the changes of p H values of Pseudosciaena crocea by visible color changes. Therefore,the intelligent poly( vinyl) alcohol packaging film prepared in this study could not only have beneficial effects on the preservation of foods,but also serve as a color indicator to achieve intelligent monitoring in the food storage process.