Cereals processing technology

Asian noodle processing 133
Most mill operations in South East Asia use a mixed grist composition in
their mills to ensure that they can supply the quality requirements of the
noodle manufacturers. There are a few newer mills which do separate runs,
placing their flours in blending bins and preparing customized quality packets
for discriminating customers. However, this is not yet popular due to the
additional costs incurred. Test weight and thousand kernel weight can be used
to predict milling yield while simultaneously indicating the presence of
degrading factors such as damaged, shriveled or frosted grain. Of specific
interest to the millers is the recognized protein loss during milling which can
range from 0.7 to 1.5 percent depending on the type of wheat and its source.
Alkaline noodles are highly dependent upon protein to ensure their unique
textural characteristics while white salted noodles, most notably the Japanese
‘Udon’ noodle are more dependent on the starch characteristics. Falling
number (FN) values are normally included in the wheat’s specifications as it is
an indicator of the enzyme -amylase. It is not uncommon for dry
environments to yield grain with falling numbers above 500 sec 1 . The
enzyme increases tremendously in sprout damaged wheat with minimum
values of 300 sec 1 found in sound wheat. Values below this have sufficient
-amylase activity to degrade the starch to simple sugars causing a loss in
texture and undesirable color. Other enzymes, in particular peroxidase,
associated with noodle discoloration, have been shown to rise thirty-five fold
during severe sprouting. 10 It is of interest to note conflicting research findings
on the impact of severe sprouting on noodle quality. The use of high quality
(60 percent flour yield) patent or straight grade (72 percent yield) flours for
the preparation of yellow alkaline noodles (YAN) did not show significant
differences in brightness (L*) or yellowness (b*) for fresh (2 h) or aged (24 h)
raw noodles prepared from wheat having a falling number between 210–85
sec. 11 Differences from a very sound sample, FN = 485, were, however,
significant. Minimal differences were detected in the cooked noodle’s textural
attributes over the same FN range with the exception of the FN = 485 sample.
Assessment of white salted noodles (WSN), both fresh and dried found no
statistical difference in the noodle’s brightness (L*). Other research 12
suggested that reduced amylograph viscosity values, indicative of sprout
damaged flour, were correlated with reduced noodle color.
In most commercial mill operations it is not unusual for the miller to have
over 50 streams which they can selectively blend to meet the noodle
manufacturer’s requirements. Through proper millstream selection polyphenol
oxidase (PPO) activity can be reduced to less than 4 percent of that found in the
whole grain. 13 In many countries the improved financial situation has allowed
governments to deregulate their wheat imports allowing milling companies new
options for supply. However, in many cases millers limit the availability of flour
with differing quality to only a few specific blends and do not disclose their
actual specifications.