Produce Color and Appearance 209
of compounds. The HPLC-DAD analysis of the methanol extract of the pepper
pericarp showed peaks of numerous polyphenols and UV spectra typical for hydrox-
ycinnamic acids, flavonols, flavons, and C-glycosylflavones. The combination of
DAD and ESI-MS detectors provided information necessary for structural identifi-
cation. Five hydroxycinnamic derivatives and 23 flavonoids were characterized and
quantified. Some of these compounds were not previously reported. Significant
differences in the qualitative and quantitative content of phenolic compounds were
found among different maturity stages. The number and amount of phenolics was
very high in the immature green pepper while green, whereas immature red and red
peppers showed four- to fivefold reductions in these compounds.
The chemical composition of different apple cultivars determines their usefulness
for various products. The classification of cider apple varieties is based on total
content of polyphenols. These compounds are considered responsible for color and
for balance of bitterness and astringency in ciders. Five technological groups are
recognized: sweet, bittersweet, semiacid, semiacid-bitter, and acid-bitter. Alonso-
Salces et al. (2004) determined the polyphenolic composition of 31 Basque cider
apple cultivars in pulp, peel, and juice. The concentration of these compounds
differed widely depending on the cultivars. A higher concentration of total polyphe-
nols was found in peel than in pulp in all varieties. Depending on the cultivar, the
peel:pulp ratio ranged from 1.5 to 5.4. The authors recommend that ciders be made
using mixtures of different apple cultivars in order to obtain balanced composition
for proper fermentation, flavor, color, and stability.
Characterization of flavonols in cranberry (Vaccinium macrocarpon) powder was
reported by Vvedenskaya et al. (2004). Freeze-dried cranberry powder was extracted
twice with 80% acetone/water, partially evaporated, defatted with hexane, and further
extracted with ethyl acetate. The ethyl acetate extract was evaporated and separated
further using Sephadex LH-20 column chromatography. The fraction containing
flavonols was further separated by a developed HPLC procedure. Twenty-two distinct
peaks were observed that were determined by UV-vis and mass spectra to correspond
to flavonol glycoside conjugates. The following six compounds previously not
reported in cranberry and cranberry products were identified: myricetin-3-beta-
xylopyranoside, quercetin-3-beta-glucoside, quercetin-3-alpha-arabinopyranoside,
3-methoxyquercetin-3-alpha-xylopyranoside, quercetin-3-O-6-p-coumaroyl)-beta-
galactoside, and quercetin-3-O-(6-benzoyl)-beta-galactoside. This work represents an
important contribution to the identification of new flavonoid compounds in cranberries.
Olsson et al. (2004) studied selected antioxidants, low-molecular-weight carbo-
hydrates, and total antioxidant capacity in four cultivars of strawberries at three
ripening stages, unripe (white green), ripe (red), and fully ripe (dark red), over two
seasons. For the measured content of antioxidants and total antioxidant capacity
there was a two- to fivefold variation among cultivars. Lower concentrations of
chlorogenic acid, p-coumaric acid, quercetin, and kaempferol were found in unripe
berries than in riper berries.
Kosar et al. (2004) investigated phenolic components of strawberry cultivars
Camarosa, Dorit, Chandler, and Osmanli and their hybrids. The effects of maturation
were analyzed at three stages (green, pink, and ripe). The authors presented quan-
titative data on acids (p-hydroxybenzoic, p-coumaric, and ellagic), anthocyanins