Relationships of grain sorghum quality factors (proximate composition
and physical properties) to laboratory wet-milling attributes (fractio
n yields, protein content of fractions and recovery values) of 24 grai
n sorghum commercial hybrids were determined. Initial water absorption
rate was positively correlated with both starch and gluten recoveries
(r>0.45), thus showing the greatest significance among all quality fa
ctors. The need to understand fully protein matrix breakdown relative
to obtaining optimum separation of components was indicated. Positive
correlations of residual protein in search with density and percent ab
raded (r>0.45) were observed. Laboratory wet-milling attributes also w
ere correlated among themselves. The highest positive correlations wer
e observed among yield and recovery of starch and gluten (r>0.6). Thes
e four parameters had strong negative correlations with fiber/germ yie
ld (r<-0.6). Principal component factor analysis identified five facto
rs (named as matrix-breakdown effect, solids-leaching effect, protein-
dispersion effect, protein content of gluten effect, and washing-solid
s effect) that explained 91% of the total variation among wet-milling
attributes. (C) 1998 Academic Press Limited.