A novel, non-invasive method of monitoring dough development using a d
iode array near infrared spectrometer has been developed. The variatio
n in two specific absorbance wavelengths in the second derivative spec
trum (1160 nm and 1200 nm) as the dough is mixed is shown to follow th
e same trend as mixer power consumption. Both absorbance features show
a reduction in peal; area as dough mixing progresses, reaching a mini
mum at optimum dough development, and an increase as the dough mixing
continues past peak mixer power consumption. Consistent results were o
btained for un-yeasted and Full formula doughs made from flours of dif
ferent strengths using three different laboratory mixers of different
mixing action (spiral, z-arm and pin). In the case of the z-arm and pi
n mixers, the NIR mixing curves predicted longer mixing times than the
power consumption curves, and both methods differentiated between flo
urs of different strength. The spiral mixer showed no statistical diff
erence between the mixing times measured by each method, and further,
there was no statistical difference between the mixing times for each
flour when measured using either method. These differences may be due
to mixer design or mixing intensity. The data presented shows tile pot
ential of the technique for providing information on the chemical proc
esses that occur during dough development in relation to flour strengt
h and mixing action and intensity. (C) 1998 Academic Press Limited.