保质期不是国家统一规定,而是企业自己根据产品保质实验的结果自行界定。不同的产品成分、不同的杀菌条件、不同的包装方式、不同的储藏温度,都会导致不一样的保质期。北京消费者郑先生春节前在超市购买了一袋切片面包,回家后放进冰箱冷藏。后来由于疏忽忘记了这袋面包。前几天他收拾冰箱时发现,面包看起来还和购买时一样。郑先生感到困惑,以前面包存放几天就会变硬或者发霉,而这 Shelf life is not the national unity, but the enterprises themselves based on the results of product quality assurance of self-defined. Different product ingredients, different sterilization conditions, different packaging methods, different storage temperature, can lead to different shelf life. Beijing consumer Zheng before the Spring Festival to buy a bag of sliced ​​bread in the supermarket, go home and put it in the refrigerator. Later, due to neglect, the bag of bread. A few days ago when he packed the refrigerator and found that the same bread and the time of purchase. Mr Cheng was puzzled, past a few days before the bread will be hardened or moldy, and this