The antioxidant content in foods is of great interest, especially for meat products such as sausages. In addition to fat, sausages also contain a lot of water. They have a complex matrix including salts and various natural or added antioxidants and stabilizers.

The Metrohm Rancimat method answers the question of how to measure antioxidants in sausages. Using this method with polyethylene glycol (PEG) as carrier material, the antioxidant measurement in sausages can be determined quickly and reliably. The sample is analyzed without any preparation needed. The induction time can be related directly to the antioxidant capacity—and therefore to the possible shelf life of the sample.

This Application Note describes the determination of the oxidation stability of different sausages with the recommended method from Metrohm using an 892 Professional Rancimat.

First, an appropriate amount of chopped sausage and PEG are weighed into the reaction vessel, and then the analysis is started.

With the Rancimat method, the sample is exposed to an airflow at a constant temperature of 100–180 °C (Figure 1). Highly volatile secondary oxidation products are transferred into the measuring vessel along with the airflow where they are absorbed in the measuring solution.

The conductivity of the measuring solution is continuously registered. The formation of secondary oxidation products leads to an increase in the conductivity. The time until occurrence of this marked conductivity increase is referred to as the «induction time», which is a good indicator for the oxidation stability (Figure 2).