Changes in Lipid Metabolites and Enzyme Activities of Wheat Flour during Maturation

Abstract

The maturation of wheat flour is a transformative process that elevates its processing and culinary attributes to their peak performance levels. Despite extensive research on starch and gluten protein modifications, the impact of lipid changes has been largely unexplored. This study addresses this gap by examining the maturation of freshly milled wheat flour at 15 °C, 25 °C, and 40 °C over 60 days, focusing on enzymatic activities-lipase, lipoxidase, and catalase-and lipid metabolites, including free fatty acids, conjugated trienes, p-anisidine value, and total oxidation value. The results of this study showed that free fatty acids continued to increase at all temperatures, with the most significant increase of 50% at 15 °C. The p-anisidine value followed a pattern of initial increase followed by a decline, while conjugated trienes were markedly higher at 40 °C, suggesting temperature's significant influence on lipid peroxidation. Notably, total oxidation values became erratic post 30 days, indicating a shift in oxidative dynamics. This study underscores the correlation between lipid metabolites and enzymatic activities, revealing the enzymes' pivotal role in lipid oxidation. The interplay of temperature and time offers valuable insights for optimizing wheat flour maturation, ensuring superior quality for various applications.

Keywords: enzymatic activities; lipid metabolites; oxidative dynamics; wheat flour maturation.

Figure 1

Change in free fatty acid content of wheat flour samples in the maturation process, the lowercase letters indicate significant differences in the same sample at different maturation times at p < 0.05.

Figure 2

Changing the conjugated triene value of wheat flour samples during the maturation process, the lowercase letters denote significant differences between maturation times at the same maturation temperature at p < 0.05.

Figure 3

Changing of p-anisidine value in wheat flour samples during the maturation process, the lowercase letters indicate significant differences between maturation times at the same maturation temperature, and uppercase letters indicate significant differences between maturation temperatures at the same maturation time (p < 0.05).

Figure 4

Changing of total oxidation value of wheat flour samples during the maturation process, the lowercase letters indicate significant differences between maturation times at the same maturation temperature, and uppercase letters indicate significant differences between maturation temperatures at the same maturation time (p < 0.05).

Figure 5

Changing pattern of endogenous lipase activity in wheat flour during maturation, the lowercase letters denote significant differences between maturation times at the same maturation temperature at p < 0.05.

Figure 6

Changing pattern of endogenous lipoxygenase activity in wheat flour during maturation, the lowercase letters denote significant differences between maturation times at the same maturation temperature at p < 0.05.

Figure 7

Changing pattern of endogenous catalase activity in wheat flour during maturation, the lowercase letters indicate significant differences between maturation times at the same maturation temperature, and uppercase letters indicate significant differences between maturation temperatures at the same maturation time (p < 0.05).