Raw and pre-treated greaves and rinds, two meat-processing wastes, were assessed for biochemical methane potential (BMP). Combinations of temperature (25, 55, 70 and 120°C), NaOH (0.3 g g-1 waste volatile solids) and lipase from Candida rugosa (10 U g-1 fat) were applied to promote wastes hydrolysis, and the effect on BMP was evaluated. COD solubilisation was higher (66% for greaves; 55% for rinds) when greaves were pre-treated with NaOH at 55°C and lipase was added to rinds after autoclaving. Maximum fat hydrolysis (52-54%) resulted from NaOH addition, at 55°C for greaves and 25°C for rinds. BMP of raw greaves and rinds was 707±46 and 756±56 L CH4 (at standard temperature and pressure) kg-1 VS, respectively. BMP of rinds improved 25% by exposure to 70ºC; all other strategies tested had no positive effect on BMP of both wastes, and anaerobic biodegradability was even reduced by the combined action of base and temperature.The authors thank Cristiana Goncalves for her help with the enzymatic pre-treatments. The financial support from Portuguese Innovation Agency (ADI), through the project FatValue (QREN no. 3491), is gratefully acknowledged. Professor Giovana Tommaso thanks the EMUNDUS15 - Erasmus Mundus External Cooperation Window (Lot15) that provided financial support for her stay in the University of Minho, Portugal
