title: Using the Scanning Fluid Dynamic Gauging Device to Understand the Cleaning of Baked Lard Soiling Layers.
abstract: Extended or repeated heating of food fats promotes polymerisation reactions that produce difficult-to-remove soil layers. Cleaning of these baked-on/burnt-on fat deposits was investigated using model layers generated by baking lard on 316 stainless steel discs. Rigorous characterisation of the layer material was difficult, as it was insoluble in most solvents. Cleaning was studied using the scanning fluid dynamic gauging technique developed by Gordon et al. (Meas Sci Technol 21:85-103, 2010), which provides non-contact in situ measurement of layer thickness at several sites on a sample in real time. Tests at 50 [Formula: see text]C with alkali (sodium hydroxide, pH 10.4-11) and three surfactant solutions indicated two removal mechanisms, related to the (1) roll-up and (2) dispersion mechanisms reported for oily oils, namely (1) penetration of solvent at the soil-liquid interface, resulting in detachment of the soil layer as a coherent film, observed with linear alkylbenzene sulfonic acid (LAS) and Triton X-100 and aqueous sodium hydroxide at pH 10.4-11; and (2) the breakdown promoted by the agent penetrating through the layer, observed with cetyl trimethyl ammonium bromide (CTAB), in which CTAB antagonised the cleaning action of LAS.
authors.affiliation: Department of Chemical Engineering and Biotechnology, New Museums Site, Pembroke Street, Cambridge, CB2 3RA UK.
authors.forename: Akin
authors.initials: A
authors.lastname: Ali
authors.affiliation: Procter & Gamble Technical Centres Ltd, Whitley Road, Longbenton, Newcastle-upon-Tyne, NE12 9TS UK.
authors.forename: Zayeed
authors.initials: Z
authors.lastname: Alam
authors.affiliation: Procter & Gamble Technical Centres Ltd, Whitley Road, Longbenton, Newcastle-upon-Tyne, NE12 9TS UK.
authors.forename: Glenn
authors.initials: G
authors.lastname: Ward
authors.affiliation: Department of Chemical Engineering and Biotechnology, New Museums Site, Pembroke Street, Cambridge, CB2 3RA UK.
authors.forename: D Ian
authors.initials: DI
authors.lastname: Wilson
keywords: Adhesion; Cleaning; Cohesive strength; Fats; Fouling