“…It should be emphasized that the yeast suspension contained an artifact which was sorbitan monostearate (E491), also known as synthetic wax. This food additive plays a role as an emulsifier and when added to baker's yeast, it helps maintain moisture, consequently increasing the shelf life of the baker's yeast [57]. Therefore, it was assumed that this compound caused irreversible fouling of the membrane, rendering it impossible to clean the membrane using cleaning procedure C. Sorbitan monostearate is insoluble in water; however, it can dissolve in organic solvents, such as ethanol, at temperatures above 57 • C [57].…”