Changes of the quality of pure butter under different package conditions

The fresh pure butter made in the laboratory were packaged with vacuum packaging, film packaging and common plastic packing respectively, and they were stored in the 4℃ and room temperature.In order to study the changes of the quality of pure butter during storage, the assessment of moisture content, acid value, peroxide value, the total bacteria count and the sense organ were measured every other day according to the relevant test methods and standards.The result showed that under the 4℃ storage conditions, vacuum packaging could keep the moisture content of the pure butter better than the other two packages.Vacuum packaging could inhibit the increase of the acid value effectively during the storage period, followed by film packaging and common plastic packing.In the aspect of oxidation resistance, the film packaging was similar to the vacuum packaging, and was better under the 4℃ storage condition.Under the film packaging, the total bacteria count of the pure butter was lower compared with the other two packages, according to the sensory evaluation standard, the shelf life of pure butter was 61d under the room temperature, however, that of pure butter was over 76d under the 4℃ storage condition.