DISCUSSION 



Simple Correlations Related to the Suitability Factor 



The analyses show that there was less correlation than had been 

 supposed originally between the Suitability Factor and the 10 charac- 

 teristics listed in table 1, Rather unexpectedly, Uie total ash had 

 the highest simple correlation coefficient, namely r « .60"*, signifi- 

 cant at the 0,1-percent level. Ammonia was the only other character- 

 istic which was positively correlated, namely r " ,U0, significant at 

 the 5-percent level, A set of values not charted showed the greatest 

 negative correlation} namely, corrected protein with a value of r •= -."^S, 

 indicating that, when the corrected protein (crude protein corrected for 

 ammonia nitrogen) is high, the solubles usually gave a good dry product. 

 Only one other characteristic, water insoluble matter, had a negative 

 correlation, significant at the 5-percent level. 



These four characteii-stics, that is, a sample having low values for 

 total ash and ammonia, and high values for corrected protein and water- 

 insoluble matter, when taken together, indicate that it should dry on a 

 drum dryer to give a satisfactory dry product. It might be noted that 

 the very high simple correlation coefficient of total ash to specific 

 gravity (r » ,75), which is developed in the first of the multiple cor- 

 relation studies, results in the rather unusual relationship of specific 

 gravity to the Suitability Factor (r « ,32), This value just misses 

 being significant at the 5-percent level. There was almost no relation- 

 ship whatever of dry solids, fat, pH, refractive index, or viscosity to 

 predict whether a sample of condensed solubles will make a satisfactory 

 dry product, (r2 x 100 ■ to U percent). 



Minor Simple Coirelations 



Other simple correlations showed, as expected, a highly significant 

 relationship of fat to separation of oil during drying (r " ,82) and an 

 almost as positive relationship of ammonia to the production of objec- 

 tionable odors noted during the drying operation (r ■ ,62), As was pointed 

 out on page 2k of the Research Report, high values for anmonia resulted 

 from more or less deliberate spoilage of the stickwater before evaporation, 

 which is sometimes used as a means of reducing viscosity of the finished 

 condensed solubles. Ammonia content of the condensed solubles had a barely 

 significant positive correlation to the rather annoying hot plasticity of 

 the dry solubles on. the drums, often observed d\iring the drying process. 



» Note all values of r have been rounded to the nearest hundredth. 



- U - 



