Abstract
This contribution presents a novel optical method to determine the pH-value during the high pressure treatment of foods. Up to date an appropriate online measurement device does not exist. The present study makes use of a multivariate approach, using the optical properties of pH indicators. An indicator mix of 16 different pH-sensitive substances is applied. The calibration of the system is performed taking five different buffer substances (TRIS, CAPS, citric, phosphoric and acetic acid buffers), applying thermodynamical considerations, to calculate the pH-value at high pressure. The corresponding spectra of the indicator mix is measured and fed to a multivariate data model together with calculated pH values. Different chemometric models have been constructed to estimate the pH value based upon the spectrum of the indicator mix. The calibration device covers a pH range from 2 to 8. After calibration it was possible to determine the pH value at pressures up to 450 MPa with an accuracy of 0.02 pH units in 9 different test media.
| Original language | English |
|---|---|
| Pages (from-to) | 757-761 |
| Number of pages | 5 |
| Journal | High Pressure Research |
| Volume | 22 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - Jun 2002 |
Keywords
- Chemometrics
- Food technology
- High pressure treatment
- In-situ measurement
- Spectroscopy
- pH-value