The present invention is generally directed toward methods of cleaning and descaling surfaces contaminated with food soils, especially clean-in-place systems. More particularly, the methods according to the present invention also provide for sanitizing of surfaces contaminated with food soils. Thus, there is provided a single cleaning cycle that may clean, sanitize, and descale food-soiled surfaces, and in certain embodiments, without the need for a pre-rinse step, using an acidic detergent composition comprising a fatty alkyl-1,3-diaminopropane or salt thereof in the presence of an acid selected from the group consisting of inorganic acids, organic acids, and mixtures thereof.