Effectiveness of enzymatic treatment for reducing dairy fouling at pilot-plant scale under real cleaning conditions

Abstract

Conventional cleaning with chemical products uses a substantial amount of water and energy to clean the fouling related to dairy production, resulting in significant economic costs. We evaluated an enzymatic treatment based on the use of protease and amylase to clean dairy fouling generated in an indirect plate heat exchanger and the spray dryer equipment of a pilot plant, representing real cleaning conditions in the dairy industry. The efficacy of the enzymatic treatment in removing fouling at 50 °C was comparable to that of the clean-in-place method, with alkaline–acid cleaning performed at a maximum temperature of 80 °C. Microbiological analysis showed that the cleaning treatments guaranteed adequate hygienic conditions of the dairy products manufactured. Monitoring fluorescence markers, such as tryptophan, riboflavin, Maillard compounds, and dityrosine could help improve the effectiveness of both alkaline and enzymatic cleaning. The enzymatic treatment fulfills dairy industry objectives, saving water and energy during washing by reducing chemical product use. Considering that enzymatic cleaning is biodegradable after use and that its economic cost is competitive compared to chemical cleaning, it represents a viable alternative to the chemical cleaning of dairy fouling.