Instrumentation to Estimate the Moisture Content in Bread Using Electrical Impedance Spectroscopy

• Main Authors: Chintan M. BHATT, J. NAGARAJU
• Format: Article
• Language: English
• Published: IFSA Publishing, S.L. 2008-10-01
• Series: Sensors & Transducers
• Subjects: Bread; Impedance spectroscopy; Multi channel ring electrodes; Moisture migration
• Online Access: http://www.sensorsportal.com/HTML/DIGEST/october_08/P_340.pdf

Bread undergoes several physicochemical, sensory and microbial changes during storage that results in a rapid loss of freshness. These changes depend on the moisture content present in the bread product. An instrument based on impedance spectroscopy technique has been designed to estimate moisture content in bread during storage. It is a portable low cost instrument with multichannel ring electrodes suitable for simultaneous measurement of impedance at different zones of bread loaf. A dedicated AT89S52 microcontroller and associated peripherals are employed for the hardware. A constant current is applied across the bread loaf through central pair of electrodes and the voltages across different zones of bread loaf are measured using the remaining four ring electrode pairs. These measured values of voltage and current are used to measure the impedance of Bread loaf. A linear relationship is observed between the measured impedance and residual moisture content in bread during storage of 120 hours.