Roller milling fractionation of green gram (Vigna radiata): optimization of milling conditions and chemical characterization of millstreams.

In the view of recent growing interest in utilization
of grain fractions as food ingredient, present
investigation was carried out to evaluate the roller milling
potential of green gram. The effect of conditioning
moistures on green gram roller milling were studied.
The results showed decrease in flour yield from 85.56
to 58.74 % with increase in conditioning moisture from
10 to 16 %. Higher yield of flour was observed from
the first (C1), second (C2) and third (C3) reduction
passages; whereas, the first (B1), second (B2) and third
(B3) break passages produced less flour. The distribution
of protein, dietary fiber, ash and fat in different
flour streams and by-products from roller milled fractions
of green gram showed wide variation. The protein
content increased with increasing numbers of breaks and
reductions in the flour streams. The highest protein
content of 30.16 % was found in bran duster flour
and lowest (11.32 %) in fine seed coat. The protein
content of break streams was found lower than reduction
streams. The dietary fiber content of coarse seed
coat was highest (71.17 %) followed by the fine seed
coat (57.22 %). The microstructure studies of milled
fractions of green gram showed more deformed and
damaged starch granules in reduction flour streams than
break flour streams.