Oct. 1,1921 Biological Analysis of Georgia Velvet Bean 15 



The hull-less seed contained 27.5 per cent protein and therefore furnished 

 16.5 per cent protein when fed at a 60 per cent level ; however, this amount 

 of protein was inadequate for growth even though all the other factors 

 in the diet were rendered satisfactory by the addition of isolated purified 

 food substances. 



Recently Johns and Waterman ^ have isolated two globulins and an 

 albumin from the Georgia velvet bean and have reported analytical data 

 on their composition, using the Van Slyke ^ method of protein analysis. 

 Their results show that, with the exception of the albumin, which is low 

 in histidin, the three proteins of the Georgia velvet bean are quite satis- 

 factory for their diamino-acid content. However, since we have insuffi- 

 cient chemical data on the amino-acid content of the Georgia velvet bean 

 no correlation can be made at present between the chemical composition 

 and the biological response of this seed. The nature of the amino-acid 

 deficiencies is being investigated. 



The velvet-bean seed has also been found to be deficient for growth in 

 the character of its salts ; however, sodium chlorid and calcium carbonate 

 seemed to replace salt mixture No. 32 satisfactorily. 



The concentration of the water-soluble vitamin in the seed has been 

 found to be low. Unpublished data show that the addition of the 

 ground hulls in the same proportions as they occur in the whole seed 

 does not improve the water-soluble vitamin content. It is not apparent 

 from these experiments whether this vitamin was in any way destroyed 

 during the process of autoclaving, since the seed was extremely injurious 

 when fed uncooked. 



SUMMARY 



(i) The Georgia velvet bean seed, Early Speckled variety, when fed 

 raw was found injurious to young rats even when constituting only 40 

 per cent of the total ration. 



(2) Autoclaving the seed for one hour at 15 pounds pressure destroys 

 most of this injury, so that it is possible to include 60 per cent of the 

 bean in a ration. A ration composed of 80 per cent velvet bean cooked 

 still shows some harmful effects. 



(3) This seed, unlike most seeds so far studied biologically, is very 

 abundant in the fat-soluble vitamin. The fat-soluble vitamin as it exists 

 in this seed is quite stable after the seed is autoclaved for one hour at 15 

 pounds pressure. The water-soluble vitamin, however, is of low con- 

 centration in the hulled seed. 



(4) Both the proteins and salts of the velvet bean have been found to 

 be of deficient character for growth. 



1 Johns, Carl O., and Waterman, Henry C. some proteins from the Georgia velvet bean, stizo- 

 LOBIUM deeringianum. In Jour. Biol. Chem., v. 42, no. i, p. 59-69. 



2 Van Slyke, Donald D. the analysis of proteins by determination of the chemical groups 

 CHARACTERISTIC OF THE DIFFERENT AMINO-ACIDS. In Jour. Biol. Chem., V. 10, no. I, p. 15-SS, 2 fig. 1911. 



