EFFECT OF HIGH-PRESSURE HOMOGENIZATION (HPH) ON NUTRIENT BIOACCESSIBILITY AND BIOACTIVITY OF TOMATO-BASED EMULSIONS

Bente Kirkhus ¹ Nils Kristian Afseth ¹ Annika Krona ² Grethe Iren Borge ¹ Silje Johansen ¹ Christina Steppeler ¹ Ane Meisland ¹ Sveinung Grimsby ¹ Maud Langton ³

¹Food Science, Nofima, Ås
²Structure and Material Design, SIK, Gothenburg
³Department of Food Science, Swedish University of Agricultural Sciences, Uppsala

Lycopene is a carotenoid mainly found in tomatoes. It is a natural antioxidant with potential health benefits. Previous studies have indicated that mechanical and thermal processing may increase the release of lycopene from the chloroplasts and thereby improve bioaccessibility. Whether processing of tomato also releases other phytochemicals, e.g. natural lipase inhibitors with potential to induce satiety and improve weight control, is unknown. In the present study, tomato-based emulsions with 5% and 10% rapeseed oil were obtained by high pressure homogenization (HPH) at pressures varying from 100 to 1500 bar. Microstructure- and rheological measurements were performed, and the release of carotenoids into the emulsion lipid droplets was analysed by Ultra Performance Liquid Chromatography (UPLC) and Raman spectroscopy. The emulsions were subjected to a static in vitro digestion model simulating the gastric- and duodenal phases using porcine pancreatine and bile. Lipolytic effect was determined by measuring the formation of free fatty acids by solid phase extraction and gas chromatography (GC-FID). The results indicate that compounds in the tomato-based emulsions may influence pancreatic lipase activity. Furthermore, the homogenization pressure significantly affected emulsion microstructure as well as the fraction of lycopene released from the matrix into the lipid droplets, making it available for intestinal absorption. The release could be efficiently and rapidly detected by Raman spectroscopy.

Principal investigator: Dr. Bente Kirkhus bente.kirkhus@nofima.no