Corrosion of food grinding discs in gastro-intestinal environment
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Date
2023-09-28
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier Ltd
Abstract
The need for food size reduction before consumption has led to the use of motorized grinding
machine which operates on energized rubbing of two grooved cast-iron discs, and this uninten
tionally results in tribological degradation and corrosion of grinding discs into the ground food.
The objective of this study was to carry out an assessment of corrosion susceptibility of grinding
discs from different manufacturing methods in simulated gastro-intestinal environment. Six
grinding discs from three states in Nigeria were selected for this study, based on manufacturing
methods namely: rotary, cupola, and pit furnaces. Experimental techniques used for the study
included: X-Ray Fluorescence spectroscope for determination of chemical composition and X-Ray
Diffractometer was used for phase identification. Corrosion susceptibility of grinding discs on
interaction with pseudo-body fluid was studied using potentiodynamic polarization scan and
product analysis (gasometric) methods in simulated gastro-intestinal environment, typical of
human stomach, as electrolyte. The electrolyte contained 2 g/L NaCl acidified to pH of 1.7 with
HCl and regulated at 37◦C. Optical microscopy of the electrochemical samples was done for
corrosion damage assessment. The key finding from the study was that all the grinding discs
contain iron and silicon as dominant alloy elements, which existed predominantly as iron carbide
and ferrosilicon phases. Corrosion of the discs in simulated gastric solution was well profound
irrespective of the manufacturing method, though, with varying degree among the discs. The
outcome of this study is applicable to food industries where cognitive measures may have to be
taken on materials selection to minimise the risk of food contamination from materials corrosion.
Description
Keywords
Grinding disc, Corrosion, Potentiodynamic scan, Gasometry, Gastric solution, Food contamination