植物乳杆菌素plantaricin Q7在牛乳贮藏保鲜中的应用

植物乳杆菌素plantaricin Q7是由植物乳杆菌Lactobacillus plantarum Q7产生的,其具有广谱抑菌活性的细菌素,有安全、高效、稳定性好等优点.将效价为533 AU·mL~(-1)的植物乳杆菌素Q7添加到牛乳中,探究其在牛乳贮藏过程中的保鲜效果.结果表明:植物乳杆菌素Q7维持了牛乳良好感官,牛乳贮藏第13天时仍没有异味出现,保持乳白色、略带黄色的状态,无分层和沉淀.荧光假单胞菌是牛乳中的优势嗜冷腐败菌.未添加植物乳杆菌素Q7的牛乳中,荧光假单胞菌落数在第7天超出国标规定;添加植物乳杆菌素Q7将延长荧光假单胞菌落数超出国标规定的时间4 d.植物乳杆菌素Q7有效减缓了牛乳酸度的增加速度,降低了牛乳pH值的下降速度.本研究为植物乳杆菌素Q7的开发与应用提供了依据.

Application of plantaricin Q7 in the storage and preservation of milk

Plantaricin Q7 is a bacteriocin produced by Lactobacillus plantarum Q7 with broad-spectrum antibacterial activity.It has the advantages of safety,high efficiency and good stability.In this study,plantaricin Q7 with a titer of 533 AU·mL^-1 was added to milk to explore its preservation effects in the process of milk storage.The result showed that plantaricin Q7 maintained the good sense of milk.There was no peculiar smell on the 13^th day of storage,and the milk remained white and slightly yellow,without stratification and precipitation.Pseudomonas fluorescens was the dominant psychrophilic spoilage bacteria in milk.Without adding plantaricin Q7,the number of P.fluorescens in milk exceeded the national standard on the 7^th day.After adding plantaricin Q7,the time of P. fluorescens exceeding the national standard was postponed for 4 days.Plantaricin Q7 effectively slowed down the increase of milk acidity and the decrease of milk pH value.The results provided a basis for the development and application of plantaricin Q7.