[Secondary Contamination by Wheat Allergens across Cooking Bowls through the Use of Sponge Scourers]

After washing the cooking utensils used to prepare liquid batter, flour may remain in the scrubbing sponge. Secondary contamination of cooking devices with wheat allergens is a concern if such scrubbing sponges are used to clean other equipment. Therefore, in this study, bowl washing with detergent, using a scrubbing sponge was evaluated as a cleaning method following liquid batter cooking. Multiple trials revealed that wheat allergens were transferred from a bowl coated with 10 g of liquid batter to an unused bowl via sponge scrubbing with a positive rate of approximately 80%. Residual batter was observed in the scrubbing sponge after cleaning and rinsing procedures, with a residual rate of about 20%. Detailed observation of the residue revealed that proteins such as gluten were attached to the cell skeleton, and between the skeletons of the sponge, and starch granules were attached to the proteins. Even with sponge rinsing conditions added to the protocol, complete removal of wheat allergen was difficult. These studies indicate that particular scrubbing sponges for cleaning the residual wheat on cooking utensils should be dedicated exclusively in cooking facilities that prepare allergy-friendly-foods to avoid risk of allergen contamination.