Valorization of Agro-Industrial Residues: Bioprocessing of Animal Fats to Reduce Their Acidity

• Published in: Sustainability
• Main Authors: Martins, António A., Andrade, Soraia, Correia, Daniela, Matos, Elisabete, Caetano, Nídia, Mata, Teresa M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI 2021
• Subjects: Animal fats; Acidity reduction; Circular economy; Lipozyme CALB L; Industrial conditions; Reaction kinetics; Slaughter; Antarc*; Antarctica
• Online Access: http://hdl.handle.net/10400.22/20428; https://doi.org/10.3390/su131910837

Adding value to agro-industrial residues is becoming increasingly important, satisfying needs to promote resources’ use efficiency and a more sustainable and circular economy. This work performs a parametric and kinetic study of enzymatic esterification of lard and tallow with high acidity, obtained by the rendering of slaughter by-products, allowing their use as a feed ingredient and increasing their market value. After an initial analysis of potential enzyme candidates, a Candida antarctica lipase B was selected as a biocatalyst for converting free fatty acids (FFA) to esters, using excess ethanol as the reagent. Results show that the fat acidity can be reduced by at least 67% in up to 3 h of reaction time at 45 °C, using the mass ratios of 3.25 ethanol/FFA and 0.0060 enzyme/fat. Kinetic modelling shows an irreversible second-order rate law, function of FFA, and ethanol concentration better fitting the experimental results. Activation energy is 54.7 kJ/mol and pre-exponential factor is 4.6 × 106 L mol−1 min−1 This work was financially supported by project PP-IJUP2014-SOJA DE PORTUGAL; Base Funding—UIDB/00511/2020 of Laboratory for Process Engineering, Environment, Bio-technology and Energy—LEPABE—funded by National funds through the FCT/MCTES (PIDDAC); Base Funding— UIDB/04730/2020 of Center for Innovation in Engineering and Industrial Technology, CIETI—funded by national funds through the FCT/MCTES (PID-DAC); António Martins thanks FCT (Fundação para a Ciência e Tecnologia) for funding through program DL 57/2016—Norma transitória. info:eu-repo/semantics/publishedVersion