Isothermal Microcalorimetry as A Useful Tool for Fat Determination in Food

Abstract

The catalytic behaviour of lipolytic enzymes coming from Candida cylindracea and porcine pancreas have been studied by means of isothermal microcalorimetry. The obtained calibration curves have been compared in order to find out which enzyme should be better for applications in biotechnology and the food industry. A direct and reliable analytical study of the enzymatic reactions is allowed by the microcalorimetric technique used; moreover, an easy application to real samples is shown, also using non transparent and non homogeneous solutions. The proposed method permits the analysis of samples without pretreatment and without using emulsifying agents or organic solvents. The lipase enzyme chosen to analyse oil, milk and yoghurt samples is the pancreatic one, which has been used to determine total fats contained in food samples. Within each kind of food, the calorimetric responses were significant, so that it was possible to divide the food products under examination into homogeneous classes at different fat contents.

Keywords:

• Fat determination
• Food
• Enzymatic calorimetry