A Validated Solid-Liquid Extraction for the Determination of Polyphenols in Apple Tissues

ALONSO-SALCES, R. M.; BARRANCO, A.; CORTA, E.; BERRUETA, L. A.; GALLO, B.; VICENTE, F.

TALANTA

ELSEVIER SCIENCE BV

Año: 2005 vol. 65 p. 654 - 662

0039-9140

A solid–liquid extraction procedure followed by reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with a photodiode array detector (DAD) for the determination of polyphenols in freeze-dried apple peel and pulp is reported. The extraction step consists in sonicating 0.5 g of freeze-dried apple tissue with 30 mL of methanol–water–acetic acid (30:69:1, v/v/v) containing 2 g of ascorbic acid/L, for 10 min in an ultrasonic bath. The whole method was validated, concluding that it is a robust method that presents high extraction efficiencies (peel: >91%, pulp: >95%) and appropriate precisions (within day: R.S.D. (n = 5) <5%, and between days: R.S.D. (n = 5) <7%) at the different concentration levels of polyphenols that can be found in apple samples. The method was compared with one previously published, consisting in a pressurized liquid extraction (PLE) followed by RP-HPLC-DAD determination. The advantages and disadvantages of both methods are discussed.