K232 and K270 are measurements from UV spectroscopy. They show how strongly the oil absorbs ultraviolet light of certain wavelengths. K232 indicates early oxidation, K270 later breakdown products and traces of refining.
For extra virgin olive oil, the EU allows at most 2.50 for K232 and 0.22 for K270. Together with acidity, peroxide value and the tasting, they decide the grade. The lower the values, the fresher the oil.
