Collagen content was measured using the Quickzyme Biosciences (UK) kit and performed according to manufacturer conditions. In brief the cartilage specimens were inserted within eppendorf micro-centrifugation tubes. To each sample 6 M HCl was then added and made up to a volume of 100 μl. The specimens were then incubated at a temperature of 95 °C for 20 hours in an oven to commence hydrolysis. They were then allowed to cool at room temperature. Next the samples were centrifuged for 10 minutes at 13000 rpm. The supernatant was then transferred from each tube to fresh ones whilst taking care not to pipette the black particles which represented fat degradation products. These can interfere with the absorption of light. 100 μl of water was added to each one of the samples so as to dilute the hydrolysate. Then 35 μl of the new mixture was used for analysis with a spectrophotometer (Thermo Scientific Fluoroskan Ascent FL Microplate Fluorometer and Luminometer). It contained a Quartz-halogen pump, filters as well as a photomultiplier tube. It had an emission wavelength range of 360 nm to 670 nm. The fluorometric sensitivity was 2 fmol fluorescein/well in a black 96 well plate (n = 3).