3.5.3. Colour
L*, a*, and b*-values of Som-fug samples during
fermentation are depicted in Fig. 8. Generally, no
differences in L*, a*, and b*-values were observed between
the control and Som-fug inoculated with PA104 at 0 h of
fermentation (p40.05). During fermentation, L*, a*, and
b* values in both samples increased (po0.05). After the
fermentation was accomplished (pHp4.6), similar L* and
b*-values were observed between both Som-fugs (p40.05).
However, fermented Som-fug inoculated with PA104 had
lower a*-value than that naturally fermented Som-fug
(po0.05). The increase in L*-value might be a result of
protein denaturation induced by acids formed. The
increases in a* and b*-values were possibly due to the
non-enzymatic browning reaction as the free amino acid
groups as well as lipid oxidation products increased,
particularly with increasing fermentation time. Maillard
reaction between carbonyl compounds and amino acids is
the major non-enzymatic browning reaction in foods