TECHNOLOGY FOCUS - BIOLOGY - Preferred Method: The step (a) involves (i) providing lamb meat that has a low concentration of water, and (ii) flowing supercritical carbon dioxide through the meat to extract lamb fat from the meat and thus provides lamb fat in a supercritical carbon dioxide carrier. The step (b) is carried out at a reaction temperature of 40-50 degrees C. The lipase enzyme is immobilized. The step (a) (i) involves providing lamb meat and reducing the concentration of water in the meat. The reducing process in the step (a) (i) involves freeze-drying or vacuum-drying the meat. The lamb meat has a low concentration of water of 15 wt% or less. The method further involves grinding the meat before step (a) (ii). The method further involves formulating the meat obtained after step (a) (ii) into a food product. The method is carried out in an integrated reactor system comprising (a) a fat extraction unit comprising a first reactor for carrying out the step (a) (ii), which unit comprises unit for supplying lamb meat to the first reactor, unit for adjusting the temperature of the first reactor, unit for supplying supercritical carbon dioxide to the first reactor, and unit for removing from the first reactor lamb fat in a supercritical carbon dioxide carrier, and (b) a biodiesel production unit comprising a second reactor for carrying out the step (b), which comprises unit for adjusting the temperature of the second reactor, unit for supplying to the second reactor lamb fat in a supercritical carbon dioxide carrier that has been removed from the fat extraction unit, unit for supplying 1-5C alcohol or 1-5C ester thereof to the second reactor, and unit for removing biodiesel from the second reactor. The integrated reactor system is adapted such that the first reactor and the second reactor operate at substantially the same temperature and pressure.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The molar ratio of 1-5C alcohol or 1-5C ester to triglycerides in the lamb fat is 3:1 to 5:1. Preferred Components: The 1-5C alcohol or 1-5C ester is chosen from methanol, ethanol, methyl methanoate, methyl ethanoate, ethyl methanoate and ethyl ethanoate, preferably methanol.