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Continuous monitoring of yoghurt fermentation using a noble metal electrode array
Author(s) -
Bjorklund Robert B.,
Magnusson Christian,
Mårtensson Per,
Winquist Fredrik,
KrantzRülcker Christina
Publication year - 2009
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.2008.01886.x
Subject(s) - fermentation , partial least squares regression , platinum , electrode , working electrode , noble metal , electrochemistry , voltammetry , cyclic voltammetry , rhodium , analytical chemistry (journal) , reference electrode , chemistry , food science , materials science , metal , mathematics , chromatography , biochemistry , catalysis , statistics , organic chemistry
Summary An electrochemical probe containing gold, platinum and rhodium working electrodes was used to monitor yoghurt production in a pilot facility. Three commercial starting cultures at 40, 42 and 44 °C transformed milk having 1.5% fat content to mild yoghurt products. The electrochemical changes in the broth during fermentation were recorded as current responses from pulse voltammetry over the electrodes. Principal component analysis of the responses generated two‐dimensional score plots describing the qualitative fermentation progressions. Two distinct fermentation pathways were observed leading to similar final products. The pH was recorded during the fermentations and the data was used as reference values for creating a partial least squares model for prediction of pH as an example of a quantitative application for the sensor. The relative mean squared error for validation of the model using four probes interchangeably was about 2%. The probe was constructed of materials approved for use in the food industry and did not require a standard glass reference electrode.