TOMATO PASTES AND THEIR MOISTURE CONTENT AS DETERMINED VIA THE MEASUREMENTS OF THERMAL EFFUSIVITY BY MEANS OF INFRARED PHOTOTHERMAL RADIOMETRY AND INVERSE PHOTOPYROELECTRIC TECHNIQUE

Dane Bicanic,^a,b Camelia Neamtu,^c Maja Manojlović,^b Dennis van der Linden,^a Dorin Dadarlat,^c Kristijan Posavec,^d Arjan Gijsbertsen,^e and Želimir Kurtanjek^f

^a Laser Laboratory for Photothermal Research, Biophysics Division, Agrotechnology and Food Sciences, Wageningen University, Dreijenlaan 3, Transitorium, 6703 HA Wageningen, The Netherlands

^b Department of Food Chemistry and Nutrition, Faculty of Food Technology and Biotechnology, Zagreb University, Pierottijeva 6, Zagreb, Croatia

^c Institute for Isotopic and Molecular Technology, POB 700, 3400 R Cluj-Napoca 5, Rumania

^d Faculty of Mining, Geology and Petroleum Engineering, Pierottijeva 6, 1000 Zagreb, Croatia

^e Department of Physical and Theoretical Chemistry, Free University, de Boelenlaan 1083, 1081 HV Amsterdam, The Netherlands

^f Laboratory for Automation and Measurements, Faculty of Food Technology and Biotechnology, Zagreb University, Pierottijeva 6, Zagreb, Croatia

Abstract

Infrared photothermal radiometry and inverse photopyroelectric method were used to determine thermal effusivity for tomato pastes characterised by a varying dry matter content. Unlike commonly adapted techniques, the two methods used here are reasonably fast and do not require the application of substantial external heat input; positive correlation between the effusivity and moisture content is high.

Key words: tomato, infrared, photothermal, radiometry