Oil is used to extract pepper flavor, as piperine is relatively non-polar. Its solubility in water (a polar solvent) is only 0.04 grams per liter. It is more soluble in less polar solvents (67 grams per liter in alcohol, for example).
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How to infuse black layer of peppercorn into an oil?
Piperine has amide and benzodioxole functional groups,...