Figure 1 shows the color intensity of 60 MRPs heated
for 3 h. The degree of contribution from the five sugars
to browning was in the order of xylose > arabinose >
glucose > maltose > fructose. Since lysine had the highest
reactivity among the 12 amino acids, the color intensity of
the MRPs from lysine was the highest while reacting with
each kind of sugar (Fig. 1). The color intensity of the