Effects of lipase, lipoxygenase, peroxidase, and rutin on quality deteriorations in buckwheat flour.

To investigate the effects of changes in lipase, lipoxygenase, peroxidase (POX), and rutin concentrations on the quality of buckwheat flour, 14 buckwheat varieties were stored for 0, 4, 10, and 30 days at 5 or 20 degrees C. During the storage period, lipase activity correlated to pH (significantly negative) and water-soluble acid (WSA) (significantly positive). The lipoxygenase 1 protein concentration had a negative correlation to WSA (significant at 0 and 4 storage days at 5 degrees C and at 0 and 10 storage days at 20 degrees C). POX had significant correlation to pH and peroxide value (POV) at 5 degrees C, whereas it was not significant at 20 degrees C. The rutin concentration had negative correlations to WSA (significant at 30 days of storage at 5 degrees C and at 4 days of storage at 20 degrees C). Thus, lipase activity plays an important role that relates to lipid degradation in quality deterioration of buckwheat flour.