Hair sheep lamb meat ageing-an instrumental odour analysis

Abstract

Background: The electronic nose is a system of sensors which is far from a real nose’s sensitivity, it is a device based on chemical, biological and electro chemical responses from the compounds present in food products known as the aromatic footprint which might discriminate different food states. Objective: The aim of this work was to evaluate the effect of feeding system and ageing times in meat samples taken from Doper X Colombian lambs by electronic nose analysis Methods: Fiftyfour 10-week-old Dorper X Colombian lambs were used in 2 feeding systems: grazing and semifeedlot (n=27). Samples were analyzed in 3 ageing conditions (0, 7 and 15 days). 10 g of sample was weighed, vacuum-packed and cooked until reaching 72°C internal temperature and stored at 4°C. The samples were placed in 40 mL vials closed with 22 mm PTFE-silicone septa to start the analysis and then placed at 16°C for 10 minutes. Afterwards, they were incubated at 35.5°C for 20 minutes, a 100 mL/min flow was selected to avoid presenting low responses in the sensors. 40°C was established to prevent water condensate formation that could have interfered in the sensors’ response. Results: The obtained results showed that discrimination was possible between PC1 with 90.6% and PC2 with 72.6% (data variability) in feeding systems with 88.89% (correct discriminating function) due to the volatile compounds forming the aromatic profile of cooked lamb meat, especially sulphur aromatic ones. Conclusions: A greater number of sensors were necessary for discriminating between different ageing times on account of the multiple aroma-producing reactions.