CHEMICAL ENGINEERING TRANSACTIONS VOL. 75, 2019 A publication of The Italian Association of Chemical Engineering Online at www.cetjournal.it Guest Editors: Sauro Pierucci, Laura Piazza Copyright © 2019, AIDIC Servizi S.r.l. I SBN 978-88-95608-72-3; I SSN 2283-9216 Characterization of Mixed Fatty-Starchy Soils for Cleaning Studies in Food Industry Mireya Serrano-Haro, Manuel Tirado-Delgado, Otilia Herrera-Márquez*, José M. Vicaria, Encarnación Jurado-Alameda Department of Chemical Engineering, University of Granada. Avda. Fuentenueva, s/n, 18071. Granada (Spain) oherrera@ugr.es A protocol for the preparation of mixtures of fat (pork lard) and soluble potato starch have been developed in order to standardized model soils for detergency studies. Different mixtures have been prepared and used as a soiling agent of stainless steel fibres. Cleaning tests have been carried out in a laboratory device reproducing a Cleaning-In-Place system, using phosphate buffer pH 7.0 as a cleaning solution. Individual detergencies referred to the fat and starch have been obtained analytically, as well as total detergency measured by weighing. Analytical and weighed detergencies have coincident results. Cleaning results constitute a first step for the development of a cleaning map for different grades of fat-starch mixed soils. 1. Introduction Quality and hygiene standards in food industry require that special attention be paid to cleaning and disinfection processes, assuring the surfaces in food equipment are physically and microbiologically clean (Liu et al., 2002). CIP (Cleaning-In-Place) systems are commonly applied to clean effectively without the need for any disassembly and reassembly (Moerman et al., 2014). Nevertheless, these procedures are generally standardized and do not take into account the differences in the type and composition of the different soils (Fryer et al., 2006). On the other hand, cleaning operations are expensive and entails a high environmental impact. Efforts to minimise the use of time, water, chemicals and energy are currently made in order to improve plant sustainability (Fryer et al., 2011). The development of specific and precise cleaning formulations for different soils and substrates can contribute significantly to this objective, besides optimizing the performance of cleaning processes (Suárez et al., 2012). While CIP protocols for protein-based fouling deposits has been thoroughly studied in the literature (Xin et al., 2002; Christian and Fryer, 2006), carbohydrate-based deposits have received little attention so far (Khalid et al., 2016). Cleaning protocols specifically designed for starchy soils have been tested on Jurado-Alameda et al. (2015) and Jurado-Alameda et al. (2016) using microparticles and ozone, respectively. On the other hand, fatty soils pose a particular challenge because of their hydrophobicity and tendency to wet hard surfaces preferentially to water (Magens et al., 2017; Detry et al., 2007). In this work different mixtures of fat (pork lard) and soluble potato starch have been prepared in order to standardize model soils for its later use on washing assays. Stainless steel fibres have been used as a substrate. Total detergency have been determined by weighing and analytical tests have been carried out for separate determination of carbohydrates and fat in the remaining soil, obtaining separate detergency figures that can help in the study of the cleaning mechanisms of complex soils. DOI: 10.3303/CET1975037 Paper Received: 20 July 2018; Revised: 18 December 2018; Accepted: 18 April 2019 Please cite this article as: Serrano-Haro M., Tirado-Delgado M., Herrera Marquez O., Vicaria J.M., Jurado Alameda E., 2019, Characterization of Mixed Fatty-starchy Soils for Cleaning Studies in Food Industry, Chemical Engineering Transactions, 75, 217-222 DOI:10.3303/CET1975037 217