Retention of the B-Vitamins in Rare and Well-Done Beef

Abstract

Right and left 2-rib roasts of beef were cut alike and used as pairs, one being analyzed raw and the other after cooking by a standardized method. The entire meat in each roast was ground and samples used for the determination of thiamine, riboflavin, nicotinic acid, and pantothenic acid. The average vitamin content of the eighteen raw roasts from the Commercial carcasses was in μg./gm.: thiamine 1.3; riboflavin 1.5 and 1.6 by the fluorometric and microbiological methods, respectively; nicotinic acid 49; and pantothenic acid 4.9. Differences in vitamin content between the raw rib roasts within a carcass were not significant for any of the four vitamins but differences between animals were highly significant for thiamine, riboflavin, and nicotinic acid and significant for pantothenic acid. Thiamine and riboflavin values for the Choice carcass were within the range of those from the Commercial carcasses (two grades below Choice) but the Choice carcass was lower than the Commercial carcasses in nicotinic acid and pantothenic acid. Retentions in rib roasts of beef, rare and well done respectively, were: thiamine, 75 and 69%; riboflavin, 83 and 77%; nicotinic acid, 75 and 79%; pantothenic acid 91 and 75%. Retentions of thiamine and pantothenic acid were significantly lower in the well-done than in the rare roast but with riboflavin and nicotinic acid the differences between rare and well-done roasts were not significant. One serving of rib roast of beef was calculated to furnish approximately 7% of the thiamine, 6% of the riboflavin and 37% of the nicotinic acid recommended for a moderately active woman for 1 day.