{
  "url": "https://openlegislation.uk/eu-regulation-2016-1227/annex-I",
  "json_url": "https://openlegislation.uk/eu-regulation-2016-1227/annex-I.json",
  "legislation": "eur/2016/1227",
  "legislation_title": "Commission Implementing Regulation (EU) 2016/1227 of 27 July 2016 amending Regulation (EEC) No 2568/91 on the characteristics of olive oil and olive-residue oil and on the relevant methods of analysis",
  "legislation_url": "https://openlegislation.uk/eu-regulation-2016-1227",
  "path": "annex/I",
  "kind": "annex",
  "number": "I",
  "heading": null,
  "text": "ANNEX II\nDETERMINATION OF FREE FATTY ACIDS, COLD METHOD\n1.\nSCOPE AND FIELD OF APPLICATION\nThis method describes the determination of free fatty acids in olive oils and olive pomace oils. The content of free fatty acids is expressed as acidity calculated as the percentage of oleic acid.\n2.\nPRINCIPLE\nA sample is dissolved in a mixture of solvents and the free fatty acids present titrated using a potassium hydroxide or sodium hydroxide solution.\n3.\nREAGENTS\nAll the reagents should be of recognized analytical quality and the water used either distilled or of equivalent purity.\n3.1\nDiethyl ether; 95 % ethanol (v/v), mixture of equal parts by volume.\nNeutralize precisely at the moment of use with the potassium hydroxide solution (3.2), with the addition of 0,3 ml of the phenolphthalein solution (3.3) per 100 ml of mixture.\nNote 1:\nDiethyl ether is highly inflammable and may form explosive peroxides. Special care should be taken in its use.\nNote 2:\nIf it is not possible to use diethyl ether, a mixture of solvents containing ethanol and toluene may be used. If necessary, ethanol may be replaced by propanol-2.\n3.2\nPotassium hydroxide or sodium hydroxide, titrated ethanolic or aqueous solution, c(KOH) [or c(NaOH)] about 0,1 mol/l or, if necessary, c(KOH) [or c(NaOH)] about 0,5 mol/l. Commercial solutions are available.\nThe exact concentration of potassium hydroxide solution (or sodium hydroxide solution) must be known and checked prior to use. Use a solution prepared at least five days before use and decanted into a brown glass bottle with a rubber stopper. The solution should be colourless or straw coloured.\nIf phase separation is observed when using aqueous solution of potassium hydroxide (or sodium hydroxide), replace the aqueous solution by an ethanolic solution.\nNote 3:\nA stable colourless solution of potassium hydroxide (or sodium hydroxide) may be prepared as follows. Bring to the boil 1 000 ml of ethanol or water with 8 g of potassium hydroxide (or sodium hydroxide) and 0,5 g of aluminium shavings and continue boiling under reflux for one hour. Distil immediately. Dissolve in the distillate the required quantity of potassium hydroxide (or sodium hydroxide). Leave for several days and decant the clear supernatant liquid from the precipitate of potassium carbonate (or sodium carbonate).\nThe solution may also be prepared without distillation as follows: to 1 000 ml of ethanol (or water) add 4 ml of aluminium butylate and leave the mixture for several days. Decant the supernatant liquid and dissolve the required quantity of potassium hydroxide (or sodium hydroxide). The solution is ready for use.\n3.3\nPhenolphthalein, 10 g/l solution in 95 to 96 % ethanol (v/v) or alkali blue 6B or thymolphthalein, 20 g/l solution in 95 to 96 % ethanol (v/v). In the case of strongly coloured oils, alkali blue or thymolphthalein shall be used.\n4.\nAPPARATUS\nUsual laboratory equipment including:\n4.1 Analytical balance;\n4.2 250 ml conical flask;\n4.3 10 ml burette class A, graduated in 0,05 ml, or equivalent automatic burette.\n5.\nPROCEDURE\n5.1\nPreparation of the test sample\nWhen the sample is cloudy, it should be filtered.\n5.2\nTest portion\nTake a sample depending on the presumed acidity in accordance with the following table:\nExpected acidity(oleic acidity g/100 g)\nMass of sample (g)\nWeighing accuracy (g)\n0 to 2\n10\n0,02\n> 2 to 7,5\n2,5\n0,01\n> 7,5\n0,5\n0,001\nWeigh the sample in the conical flask (4.2).\n5.3\nDetermination\nDissolve the sample (5.2) in 50 to 100 ml of the previously neutralized mixture of diethyl ether and ethanol (3.1).\nTitrate while stirring with the 0,1 mol/l solution of potassium hydroxide (or sodium hydroxide) (3.2) (see Note 4) until the indicator changes (the colour of the coloured indicator persists for at least 10 seconds).\nNote 4:\nIf the quantity of 0,1 mol/l potassium hydroxide (or sodium hydroxide) solution required exceeds 10 ml, use the 0,5 mol/l solution or change the sample mass according to the expected free acidity and the proposed table.\nNote 5:\nIf the solution becomes cloudy during titration, add enough of the solvents (3.1) to give a clear solution.\nCarry out a second determination only if the first result is higher than the specified limit for the category of the oil.\n6.\nEXPRESSION OF RESULTS\nAcidity as a percentage of oleic acid by weight is equal to:\nV × c × M 1000 × 100 m = V × c × M 10 × m\nwhere:\nV the volume of titrated potassium hydroxide solution (or sodium hydroxide) used, in millilitres;\nc the exact concentration in moles per litre of the titrated solution of potassium hydroxide (or sodium hydroxide) used;\nM 282 g/mol, the molar mass in grams per mole of oleic acid;\nm the mass of the sample, in grams.\nOleic acidity is reported as follows:\n(a) to two decimal places for values from 0 up to and including 1;\n(b) to one decimal place for values from 1 up to and including 100.",
  "extent": "E+W+S+N.I.",
  "status": null,
  "version": "current",
  "annotations": [],
  "outstanding_effects": [],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/eur/2016/1227/annex/I",
    "retrieved_at": "2026-11-01T14:45:40.245469+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}