Leif Horsfelt Skibsted

Professor Emeritus, University of Copenhagen 

Leif Skibsted is Professor Emeritus at University of Copenhagen, Department of Food Science. He is PhD in Pharmacy, and has spent his carrier at universities in Denmark, Brazil and China. Areas of research include: Photochemistry, photophysics, reaction kinetics and thermodynamics of transition metal compounds;  food chemistry and food physics with emphasis on kinetics of oxidative changes and browning; bioavailabilty of iron and calcium. He has since 1992 been responsible for food science in Den Store Danske Encyclopædi, now in the on-line version lex.

Key chemical parameters that determine food shelf life and the methods for effective monitoring.

The shelf life of many foods are determined not by growth of microorganisms, but due to sensory or texture changes in the products. Oxidation is a challenge in most fatty foods, leading to rancid products, but also other food compounds like proteins are subject to oxidative changes. Next to the sensory deterioration there may also be health considerations of oxidized food. In dried products like milk powder and infant formula and in some frozen foods crystallization and browning of components are crucial for nutritive value, formation of toxic compounds and sensory quality.  The presentation gives an overview of the parameters relevant for shelf life and safety and how they can be measured. Process parameters related to their control are also mentioned.