Protein in Malted Preparations

Abstract

Summary The total nitrogen content of malt extract may range from 0̇2 to 1̇2 per cent. but is usually well above 0̇64 per cent. which corresponds to the B.P. 1948 minimum content of 4 per cent. (total nitrogen x 6̇25). Lower diastatic values are usually associated with lower total nitrogen contents, the tendency being observed with malted barley as well as with malt extract. Of the total nitrogen of malt extract only 12 to 44 per cent. is true protein nitrogen. The greater part represents breakdown products of protein, largely formed during malting and brewing. The “less soluble” nitrogen of malt extract may range from 1̇8 to 10 per cent. of the total nitrogen, and should be reduced to as low a level as possible in malted preparations. In baby foods prepared from malt extract, wheat flour and soya flour sufficient aneurine and nicotinic acid may be derived from the raw materials if care is taken to use malt extract of high vitamin B content. Fortification with riboflavine may be necessary. If the diet is adequately supplemented by vitamins A, C and D the growth-promoting effect on babies may provide a measure of the protein value of the diet. We are indebted to Dr. F. W. Norris for microbiological assays, to Dr. R. G. Booth and to Mr. J. G. Heathcote for checking at the Cereals Research Station some of our protein analyses, to Miss Hazel Williams for fluorimetric estimations of aneurine, to Miss Janet Horsford for technical assistance, and to Dr. H. Chick and her colleagues for advice and generous comments on our work.