Almond (Prunus dulcis (Mill.) D.A. Webb) skins as a potential source of bioactive polyphenols.
An exhaustive study of the phenolic composition of almond ( Prunus dulcis (Mill.) D.A. Webb) skins was carried out in order to evaluate their potential application as a functional food ingredient. Using the HPLC-DAD/ESI-MS technique, a total of 33 compounds corresponding to flavanols, flavonols, dihydroflavonols and flavanones, and other nonflavonoid compounds were identified. Peaks corresponding to another 23 structure-related compounds were also detected. MALDI-TOF MS was applied to characterize almond skin proanthocyanidins, revealing the existence of a series of A- and B-type procyanidins and propelargonidins up to heptamers, and A- and B-type prodelphinidins up to hexamers. Flavanols and flavonol glycosides were the most abundant phenolic compounds in almond skins, representing up to 38-57% and 14-35% of the total quantified phenolics, respectively. Due to their antioxidant properties, measured as oxygen-radical absorbance capacity (ORAC) at 0.398-0.500 mmol Trolox/g, almond skins can be considered as a value-added byproduct for elaborating dietary antioxidant ingredients.
Monagas
Maria
M
Instituto de Fermentaciones Industriales (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain.
Garrido
Ignacio
I
Lebrón-Aguilar
Rosa
R
Bartolome
Begoña
B
Gómez-Cordovés
Carmen
C
D000975:Antioxidants / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis*; D010636:Phenols / Q000032:analysis*; D010936:Plant Extracts / Q000494:pharmacology; D059808:Polyphenols; D044945:Proanthocyanidins / Q000032:analysis; D027861:Prunus / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D044945:Proanthocyanidins