Presence of β-glucanase activity in wheat and dairy ingredients and use of organic salts as potential enzyme inhibitors

Depolymerization of mixed linkage cereal β-glucans has been observed during the mixing and fermentation of multigrain breads. To maintain the bioactivity of β-glucans in bread and other foods, control of β-glucanase activity during production is needed. β-Glucanase activity in wheat and dairy ingredients was determined by adding them to β-glucan solutions and following the change in the molecular weight of β-glucan at 50 °C for 60 min. The activities in six wheat and six dairy ingredients ranged from undetectable to a 98% reduction in molecular weight. Calcium propionate, potassium sorbate, and sodium benzoate are salts of organic acids commonly used as food preservatives. Low concentrations of these additives (0.1–1.0%) were found to have an inhibitory effect on the β-glucanases found in wheat flour and whey protein isolate. The depolymerization rate of β-glucan was reduced by up to 76% by the three additives.

► Oat and barley β-glucan are frequently degraded by enzyme activity during processing.
► β-Glucanase activity detected in wheat ingredients and also dairy ingredients.
► Size exclusion chromatography used to determine relative depolymerization rates for a standard β-glucan solution.
►  Enzyme activity higher in wheat bran and some dairy ingredients than white wheat flour.
► Calcium propionate potassium sorbate and sodium benzoate inhibited β-glucanase activity by up to 76% near neutral pH.