the handbook of food engineering practice crc press chapter 10 ...

Other phase change phenomena are also important. Carbohydrates in the
amorphous state may crystallize at lower temperatures, creating more free water for other
reactions but reducing the amount of available sugars for reaction (Kim et al., 1981). A
characteristic case is the phenomenon of staling of bread (Zobel, 1973). Retrogradation of
the amylopectin and a redistribution of moisture between starch and gluten have been
implicated in staling. Staling shows a negative temperature effect between 4°C and 40°C,
having the maximum rate at 4°C. A number of studies, using a variety of textural indices,
were reviewed by Labuza (1982). A typical bread staling Arrhenius plot is shown in
Figure 4 with an average "negative E A " of - 9 kcal/mol.
Figure 4.
Anomalies in Arrhenius behavior. Effect of temperature on rate
of bread staling.
28