The relation of the oxidizability value and the amino and ammonia nitrogen content to the quality of cream and butter

Abstract

Summary Representative samples of cream and butter from thirteen different creameries were examined and it was found that the second grade cream contained a greater percentage of the total nitrogen present as amino nitrogen and ammonia than the first grade cream from the corresponding plants. This value averaged from 1.6 to 9.6 on cream producing first grade butter and 8.1 to 12.6 on cream that produced second grade butter. The results on the corresponding butters varied from 0.8 to 6.3 for the first grade and from 4.7 to 6.7 for the second grade samples. The butter from the cream containing the smaller amounts of amino nitrogen and ammonia as per cent of the total nitrogen scored from 93 to 94, while there was a general decrease in score on the butters from the cream having the higher value. The oxidizability value varied from 0.4 to 6.7 on the first grade butter and from 3.4 to 8.8 on the second grade butter, being higher, in general, on samples having the lower scores. Eleven authentic samples of fresh milk from individual cows gave values for amino nitrogen and ammonia as per cent of the total nitrogen varying from 2.2 to 3.6.