The Ratio of Ascorbic Acid, Riboflavin and Thiamine in Raw and Pasteurized Milk

Abstract
The ratios to each other of ascorbic acid, riboflavin, and thiamine have been determined for winter milk produced under controlled conditions by the college herd of Ayrshire, Guernsey, Holstein, Jersey, and Shorthorn cows. The vitamin contents of the milk were determined for samples taken just previous to and immediately following pasteurization by the holding process for 30 minutes at 143°–145° F. The ascorbic acid content of the raw milk ranged from 14.0 mg. to 22.5 mg. and averaged 19.7 ± 0.18 mg. per liter; after pasteurization in stainless steel equipment, the extreme values were 7.0 mg. and 19.1 mg., with an average value of 15.9 ± 2.7 mg. per liter. The riboflavin content of the raw milk varied from 1.35 mg. to 1.75 mg. and averaged 1.51 ± 0.09 mg. per liter. The corresponding riboflavin values for the pasteurized milk were 1.19, 2.06, and 1.48 ± 0.01 mg. per liter, respectively. The thiamine content of the raw milk varied from 0.29 to 0.35 mg. and averaged 0.33 ± 0.02 mg. per liter. Corresponding thiamine values for the pasteurized milk were 0.21, 0.34, and 0.30 ± 0.03 mg., respectively. The ratios of riboflavin, ascorbic acid, and thiamine were computed for both the raw and the pasteurized milk. The raw milk contained 4.6 ± 0.3 times as much riboflavin as thiamine, 13.1 ± 1.43 times as much ascorbic acid as riboflavin, and 59.8 ± 6.40 times as much ascorbic acid as thiamine. On the average, the pasteurized milk contained 4.9 ± 0.81 times as much riboflavin as thiamine, 11.0 ± 1.93 times as much ascorbic acid as riboflavin, and 53.8 ± 9.63 times as much ascorbic acid as thiamine.