3.6. Texture profile analyses
The texture profiles of slated noodles prepared from the blends of
purple yam flour were affected by the composition of the flour blend
as shown in Table 5. The incorporation of yam flour increased the
firmness of salted noodles from 1.49 to 3.06 kg of force with the
increases in the yam flour proportions without many changes to the
cohesiveness of the salted noodles. To compare the viscoelastic
characteristics of wheat dough and salted noodles, the firmness of
salted noodles has the same tendency with the arrival time and
tolerance index of dough as the purple yam flour was added into
dough and noodles. The high correlation coefficient was obtained
between noodles firmness and tolerance index (r= 0.997), and arrival
time of dough (r= 0.841), respectively. The results of this study are in
agreement with the findings of Amudha et al. (2002). They reported
that the force required to compress certain materials increased in
direct proportion to the soy flour in the dough. Yam flour incorporated
into salted noodles significantly increased the gumminess from 0.49
to 1.09 kg of force (pb0.05).