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Quantitative Determination of Piperine. II. Direct Determination with Phosphoric Acid
Author(s) -
GRAHAM HORACE D.
Publication year - 1965
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1965.tb01819.x
Subject(s) - piperine , pepper , phosphoric acid , chemistry , absorbance , reagent , chromatography , chromotropic acid , nuclear chemistry , food science , organic chemistry
SUMMARY Piperine in 85% phosphoric acid forms an unstable yellow color which, when heated for 8 min at l00°C, becomes a stable bluish‐green with absorption maximum at 635 mμ. This reaction was exploited for the direct determination of the piperine content of pepper samples. Pepper, ground to pass a standard U. S. 80‐mesh sieve, was treated 30 min at room temperature (29 ± 1°C) with 85% phosphoric acid. The resulting yellow color was heated 8 min at l00°C, and cooled, and the absorbance was measured against a reagent blank at 635 mμ. Results were comparable to those obtained with the chromotropic acid and H 2 SO 4 –para‐dimethylaminobenzaldehyde methods. Beers' law was obeyed between the levels of 0.04–0.28 PM of piperine per ml of 85% H 3 SPO 4 . The method requires only simple, readily available chemicals and equipment, and is rapid and reproducible with a standard deviation of ± 1.01% of the total amount of piperine as 100%.