In vitro bioavailability of phenolic compounds from five cultivars of frozen sweet cherries (Prunus avium L.)

The bioavailability of phenolic compounds from five cultivars of frozen sweet cherries was assessed by a digestion process involving pepsin-HCl digestion (to simulate gastric digestion) and pancreatin digestion with bile salts (to simulate small intestine conditions) and dialyzed to assess serum- and colon-available fractions. After pepsin digestion, the % recovery of total phenolics, relative to the original starting material, increased, whereas the % anthocyanins did not change. Following pancreatic digestion and dialysis, the total phenolics in the IN (serum-available) fraction was about 26-30% and the OUT (colon-available) fraction was about 77-101%. The anthocyanin content in the IN fraction was 15-21%, and in the OUT fraction, it was 52-67%. Skeena, Lapins, and Sweetheart cultivars contained higher levels of total phenolics and anthocyanins, which resulted in higher concentrations of these compounds in the IN and OUT fractions. The potential bioavailability of phenolic compounds was also assessed in Bing and Lapins cultivars at three ripening stages. Immature cherries had higher % total phenolics in the IN fraction than mature or overmature cherries. However, immature cherries had the lowest concentrations of these compounds, making the actual bioavailable amounts of these compounds lower than for mature and overmature fruit. High-performance liquid chromatography analysis of Lapins cherries at three maturity stages confirmed the results obtained using spectrophotometric methods for total phenolics and anthocyanins.     

Different polyphenolic components of soft fruits inhibit alpha-amylase and alpha-glucosidase

Polyphenol-rich extracts from soft fruits were tested for their ability to inhibit alpha-amylase and alpha-glucosidase. All extracts tested caused some inhibition of alpha-amylase, but there was a 10-fold difference between the least and most effective extracts. Strawberry and raspberry extracts were more effective alpha-amylase inhibitors than blueberry, blackcurrant, or red cabbage. Conversely, alpha-glucosidase was more readily inhibited by blueberry and blackcurrant extracts. The extent of inhibition of alpha-glucosidase was related to their anthocyanin content. For example, blueberry and blackcurrant extracts, which have the highest anthocyanin content, were the most effective inhibitors of alpha-glucosidase. The extracts most effective in inhibiting alpha-amylase (strawberry and raspberry) contain appreciable amounts of soluble tannins. Other tannin-rich extracts (red grape, red wine, and green tea) were also effective inhibitors of alpha-amylase. Indeed, removing tannins from strawberry extracts with gelatin also removed inhibition. Fractionation of raspberry extracts on Sephadex LH-20 produced an unbound fraction enriched in anthocyanins and a bound fraction enriched in tannin-like polyphenols. The unbound anthocyanin-enriched fraction was more effective against alpha-glucosidase than the original extract, whereas the alpha-amylase inhibitors were concentrated in the bound fraction. The LH-20 bound sample was separated by preparative HPLC, and fractions were assayed for inhibition of alpha-amylase. The inhibitory components were identified as ellagitannins using LC-MS-MS. This study suggests that different polyphenolic components of fruits may influence different steps in starch digestion in a synergistic manner.     

Anthocyanin transformation in Cabernet Sauvignon wine during aging

Anthocyanins in Cabernet Sauvignon grapes and wines were elucidated by HPLC-MS/MS. Major anthocyanins in Cabernet Sauvignon grape extract are malvidin 3-O-glucoside and malvidin 3-O-acetylglucoside. In matured wine, anthocyanins are transformed to anthocyanin-vinyl derivatives, ethyl bridged anthocyanin-flavanol adducts, and anthocyanin-flavanol adducts. The major anthocyanin pigments are malvidin 3-O-glucoside-pyruvate, malvidin 3-O-acetylglucoside-pyruvate, malvidin 3-O-coumaroylglucoside-pyruvate, malvidin 3-O-glucoside-4-vinylphenol, malvidin 3-O-acetylglucoside-4-vinylphenol, and malvidin 3-O-coumaroylglucoside-4-vinylphenol. The presence of syringetin 3-O-glucoside and syringetin 3-O-acetylglucoside has been established for the first time in grape and wine.     

Bioavailability and tissue distribution of anthocyanins in bilberry (Vaccinium myrtillus L.) extract in rats

To clarify how structural diversity of anthocyanins relates to their in vivo function, bioavailability was precisely studied in rats using bilberry (Vaccinium myrtillus L.) extract (Bilberon 25) as an anthocyanin source that contains 15 different anthocyanins. The bilberry extract was orally or intravenously administered to rats, and the plasma levels of each anthocyanin were determined by high-performance liquid chromatography. As the result, all anthocyanins except peonidin 3-O-alpha-L-arabinoside were detectable in the blood plasma. The plasma concentration of anthocyanins as a whole reached the maximum level of 1.2 microM at 15 min after oral administration of 400 mg/kg bilberry extract (153.2 mg/kg as anthocyanins) and then decreased with time. Uptake and decay profiles of each anthocyanin in the plasma were almost the same for all anthocyanins except a few with their maximum after 30 min. Among the anthocyanins carrying the same aglycone, the plasma level after 15 min of oral administration was as follows: galactoside > glucoside > arabinoside. Plasma clearance of anthocyanins after intravenous administration clearly showed that arabinoside disappeared more rapidly than glucoside and galactoside. On the other hand, when anthocyanins carrying the same sugar moiety were compared, the half disappearance time of plasma anthocyanins was in the following order: delphinidin > cyanidin > petunidin = peonidin > malvidin. The bioavailability of anthocyanins was in the range of 0.61-1.82% and was 0.93% as the anthocyanin mixture. The bioavailability of anthocyanins carrying the same aglycone was in the following order: Galactoside showed the highest followed by glucoside and arabinoside for cyanidin and delphinidin, but arabinoside and galactoside showed a higher bioavailability than glucoside for petunidin and malvidin. Anthocyanins recovered in urine and bile during the first 4 h after intravenous administration were only 30.8 and 13.4%, respectively. Anthocyanin profiles in tissues were quite different from those in blood plasma. The major anthocyanins distributed in liver and kidney were the O-methyl anthocyanins such as peonidin, malvidin, and other O-methyl anthocyanins derived from delphinidin, cyanidin, and petunidin-glycosides.     

Extraction of polyphenols from processed black currant (Ribes nigrum L.) residues

The total phenol and anthocyanin contents of black currant pomace and black currant press residue (BPR) extracts, extracted with formic acid in methanol or with methanol/water/acetic acid, were studied. Anthocyanins and other phenols were identified by means of reversed phase HPLC, and differences between the two plant materials were monitored. In all BPR extracts, phenol levels, determined by the Folin-Ciocalteu method, were 8-9 times higher than in the pomace extracts. Acid hydrolysis liberated a much higher concentration of phenols from the pomace than from the black currant press residue. HPLC analysis revealed that delphinidin-3-O-glucoside, delphinidin-3-O-rutinoside, cyanidin-3-O-glucoside, and cyanidin-3-O-rutinoside were the major anthocyanins and constituted the main phenol class ( approximately 90%) in both types of black currant tissues tested. However, anthocyanins were present in considerably lower amounts in the pomace than in the BPR. In accordance with the total phenol content, the antioxidant activity determined by scavenging of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation, the ABTS(*)(+) assay, showed that BPR extracts prepared by solvent extraction exhibited significantly higher (7-10 times) radical scavenging activity than the pomace extracts, and BPR anthocyanins contributed significantly (74 and 77%) to the observed high radical scavenging capacity of the corresponding extracts.     

小叶女贞果实花青素组分鉴定及色谱纯化技术

为提高小叶女贞果实的食用、药用价值,该文系统研究了果实中花青素种类构成及提取物的制备技术。试验采用紫外可见光谱法、高效液相色谱-质谱串联法、酸水解制备苷元等技术对小叶女贞果实花青素含量、单体种类进行了测定,并借助提取、萃取、柱层析等技术研究了花青素提取物的分离纯化过程。研究结果如下:测得每100 g小叶女贞果实中含花青素总量为(499±18.42)mg,从中鉴定出2种花青素单体,分别为矢车菊素-3-O-葡萄糖苷和牵牛花色素-3-O-葡萄糖苷,并以后者为主要存在形式;获得了纯天然、简单易行的花青素提取物制备技术,主要包括酸化乙醇提取、乙酸乙脂萃取、Amberlite XAD-7HP大孔树脂层析分离步骤,最终制得的花青素提取物纯度为35%、得率为0.6%。该研究为后期制备高纯度牵牛花素-3-O-葡萄糖苷单体提供了良好原料基础,为深入研究小叶女贞果实花青素功能活性及其在食品、药品领域潜在应用提供了参考。     

Identification of anthocyanins in the sprouts of buckwheat

The anthocyanin profiles and varieties/breeding line differences of anthocyanin concentrations in common/tartary buckwheat sprouts have been studied. Four anthocyanins, cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside, cyanidin 3-O-galactoside, and cyanidin 3-O-galactopyranosyl-rhamnoside, were isolated from the sprouts of common buckwheat, were separated using high-performance liquid chromatography (HPLC), and were identified using reversed-phase liquid chromatography (LC)/electrospray ionization-mass spectrometry (ESI-MS)/MS techniques. In tartary buckwheat sprouts, two anthocyanins (cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside) were identified. Among 19 common/tartary buckwheat varieties/breeding lines, Hokkai T10 contained the highest amounts of anthocyanins. Cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside concentrations in 6-10 days after seeding sprouts of Hokkai T10 ranged from 0.16 to 0.20 mg/g dry wt and from 5.55 to 6.57 mg/g dry wt, respectively. In addition, dark-grown sprouts of Hokkai T10 accumulated 0.091 and 2.77 mg/g dry wt of cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside whereas other varieties/breeding lines accumulated trace amounts of anthocyanins. Given its anthocyanin-rich red cotyledons, Hokkai T10 is a promising line for use as "Moyashi" type sprouts and is strongly recommended as a new functional food, rich in dietary anthocyanins.     

Anthocyanin metabolism in rats and their distribution to digestive area, kidney, and brain

Anthocyanins are present in human diet due to their wide occurrence in fruits and beverages. They possess antioxidant activities and could be involved in several health effects. The aim of this study was to investigate anthocyanin metabolism and distribution in the digestive area organs (stomach, jejunum and liver) and kidney, as well as a target tissue (brain) in rats fed with a blackberry (Rubus fruticosus L.) anthocyanin-enriched diet for 15 days. Identification and quantification of anthocyanin metabolites was carried out by HPLC-ESI-MS-MS and HPLC-DAD, respectively. The stomach exhibited only native blackberry anthocyanins (cyanidin 3-O-glucoside and cyanidin 3-O-pentose), while in other organs (jejunum, liver, and kidney) native and methylated anthocyanins as well as conjugated anthocyanidins (cyanidin and peonidin monoglucuronides) were identified. Proportions of anthocyanin derivatives differed according to the organ considered, with the liver presenting the highest proportion of methylated forms. Jejunum and plasma also contained aglycone forms. In the brain, total anthocyanin content (blackberry anthocyanins and peonidin 3-O-glucoside) reached 0.25 +/- 0.05 nmol/g of tissue (n = 6). The urinary excretion of total anthocyanins was low (0.19 +/- 0.02% of the ingested amount). Thus, organs of the digestive area indicated a metabolic pathway of anthocyanins with enzymatic conversions (methylation and/or glucurono-conjugation). Moreover, following consumption of an anthocyanin-rich diet, anthocyanins enter the brain.     

Influence of the addition of raspberry seed extract on changes in the volatile pattern of stored model breakfast cereal

Laboratory-prepared muesli-type breakfast cereal (mixture of oat flakes, wheat flakes, corn flakes, hazelnuts, raisins, sunflower seeds, and flax seeds) was subjected to accelerated storage test at 60 degrees C with or without the addition of red raspberry seed extract. The oxidative changes in muesli resulting in the formation of secondary oxidation products were evaluated using solid phase microextraction (HS-SPME) and solvent-assisted flavor evaporation (SAFE) to isolate volatiles and GC-MS and chromatography-olfactometry to quantify them and determine the key odorants. During 14 days of storage the total amount of volatile compounds changed from 1.0 mg/kg, in freshly prepared muesli, to 32 mg/kg after storage. The predominant compound was hexanal; its content during storage increased 20-fold, reaching 17 mg/kg. Red raspberry seed extract addition limited the rate of lipid oxidation, and the total amount of volatiles was estimated at 11 mg/kg and that of hexanal at almost 5 mg/kg. An elevated temperature of the storage test also influenced the crucial flavor compounds determined using aroma extract dilution analysis (AEDA). The flavor dilution factor (FD) values for volatile lipid oxidation products were lower in samples with red raspberry seed extract added.     

Anthocyanin composition of Cabernet Sauvignon and Tempranillo grapes at different stages of ripening

Changes in anthocyanins during ripening of Cabernet Sauvignon and Tempranillo grapes were studied over a three year period. The accumulation of anthocyanins showed variations during ripening, especially during the first three weeks after veraison, and the accumulation pattern of those molecules changed only slightly from one year to another. On the other hand, the percentages of the different anthocyanins studied were different for each cultivar, and some changes were observed in both cultivars depending on the weather conditions of the growing season. In warm years the percentages of primitive anthocyanins (delphinidin 3-O-glucoside and petunidin 3-O-glucoside) were slightly lower than in a relatively cool year. Nevertheless, the anthocyanin fingerprints of Cabernet Sauvignon and Tempranillo grapes seem to be rather stable during ripening, despite the sugar content of the grapes.     

effect of dose size on bioavailability of acylated and nonacylated anthocyanins from red cabbage (Brassica oleracea L. Var. capitata)

Recent studies indicate that anthocyanin intake conveys a variety of health benefits, which depend on absorption and metabolic mechanisms that deliver anthocyanins and their bioactive metabolites to responsive tissues. The anthocyanin bioavailability of red cabbage (Brassica oleracea L. var. capitata) was evaluated as reflected by urinary excretion of anthocyanins and anthocyanin metabolites. Twelve volunteers consumed 100, 200, and 300 g of steamed red cabbage (containing 1.38 micromol of anthocyanins/g of cabbage) in a crossover design. Anthocyanin concentration in cabbage extract and urine was measured by HPLC-MS/MS. Six nonacylated and 30 acylated anthocyanins were detected in red cabbage, and 3 nonacylated anthocyanins, 8 acylated anthocyanins, and 4 metabolites were present in urine. Mean 24 h excretion of intact anthocyanins increased linearly from 45 (100 g dose) to 65 nmol (300 g dose) for acylated anthocyanins and from 52 (100 g dose) to 79 nmol (300 g dose) for nonacylated anthocyanins. Urinary recovery of intact anthocyanins (percent of anthocyanin intake) decreased linearly from 0.041% (100 g dose) to 0.020% (300 g dose) for acylated anthocyanins and from 0.18% (100 g dose) to 0.09% (300 g dose) for nonacylated anthocyanins. Anthocyanin metabolites consisted of glucuronidated and methylated anthocyanins. The results show that red cabbage anthocyanins were excreted in both intact and metabolized forms and that recovery of nonacylated anthocyanins in urine was >4-fold that of acylated anthocyanins.     

Preparation and comparative release characteristics of three anthocyanin encapsulation systems

Bilberries (Vaccinium myrtillus L.) and their major polyphenolic constituents, anthocyanins, have preventive activities inter alia against colon cancer and inflammatory bowel diseases. However, anthocyanins are sensitive to environmental conditions; thus their bioavailability in the gastrointestinal tract is an important determinant of their in vivo activity. In the study reported here, the potential benefits of encapsulating an anthocyanin rich bilberry extract (BE) on anthocyanin stability were investigated. Nonencapsulated BE and three different BE loaded microcapsule systems were incubated in simulated gastric fluid (SGF) and fed state simulated intestinal fluid (FeSSIF). After exposure to these media, released anthocyanins were identified and quantified by HPLC with UV/Vis detection. Although a rapid release of anthocyanins was observed within the first 20 min, encapsulation of anthocyanins doubled the amount of available anthocyanins after 150 min of incubation. These results illustrate the ability of encapsulation to inhibit early degradation of anthocyanins in the intestinal system.     

Anthocyanin glycosides from berry fruit are absorbed and excreted unmetabolized by both humans and rats

Anthocyanins, the red/blue pigments found in plants, are polyphenolic compounds consumed by humans and are part of a normal diet. Recent studies have shown that anthocyanins have substantial bioactivity including antioxidant activity and therefore may have beneficial effects on human health. Anthocyanins are a group of over 500 compounds of diverse structures containing different core phenolic aglycons and conjugated with sugars in a variety of glycosylation patterns. In this study, we have investigated the bioabsorption of 15 anthocyanins with structures containing different aglycons and conjugated sugars extracted from blueberry, boysenberry, black raspberry, and blackcurrant in both humans and rats. Intact and unmetabolized anthocyanins were detected in urine of rats and humans following dosing for all molecular structures investigated, thus demonstrating that anthocyanins with diverse molecular structure and from different dietary sources are bioavailable at diet relevant dosage rates. In addition, the relative concentrations of anthocyanins detected in urine following dosing varied, indicating that differences in bioavailability are due to variations in chemical structure. Our results suggest that the nature of the sugar conjugate and the phenolic aglycon are both important determinants of anthocyanin absorption and excretion in rats and humans.     

Structural identification of anthocyanins and analysis of concentrations during growth and flowering in buckwheat (Fagopyrum esculentum Moench) petals

The anthocyanin profiles and variety/breeding-line differences of anthocyanin concentrations in petals of common buckwheat flowers have been studied. Four anthocyanins, cyanidin 3-O-glucoside, cyanidin 3-O-rutinoside, cyanidin 3-O-rhamnoside, and cyanidin 3-O-galactosyl-rhamnoside were isolated from the petals of common buckwheat (Fagopyrum esculentum Moench), separated using high performance liquid chromatography and identified using reversed-phase liquid chromatography-electrospray ionization-tandem mass spectrometry techniques. In every variety/breeding line tested, cyanidin 3-O-rutinoside was detected as the major anthocyanin and the next is cyanidin 3-O-glucoside whereas cyanidin 3-O-rhamnoside and cyanidin 3-O-galactosyl-rhamnoside were trace or not detectable in white and pink flowered buckwheat. Of all the varieties/breeding lines tested, Gan-Chao, a Chinese variety, contained the highest amount of anthocyanins. The largest part of cyanidin moiety was presented as a proanthocyanidin form (PAs-Cy). Anthocyanins and PAs-Cy in petals were increased along with increase of flower development stages. Therefore, fully developed petals of red flowered buckwheat, especially Gan-Chao, are promising as a new anthocyanin-rich material for food processing.     

Urinary excretion of black raspberry (Rubus occidentalis) anthocyanins and their metabolites

Anthocyanins are the most abundant phenolic compounds, widely distributed in fruits and vegetables, and exhibit potent antioxidant capacity. Humans ingest a significant amount of anthocyanins in the daily diet. The objective of the current study was to examine human absorption and metabolism of black raspberry anthocyanins when administered at high doses (2.69 +/- 0.085 g/day). Ten healthy men consumed 45 g of freeze-dried black raspberries daily for 1 week. Urine samples were collected over a 12 h period in 4 h intervals at day 1 and day 7. Urinary anthocyanins were analyzed by high-performance liquid chromatography coupled to a photodiode array detector and a tandem mass spectrometer using precursor ion and product ion analyses. Anthocyanins were excreted in intact forms and metabolized into methylated derivatives in human urine. The urinary excretion of anthocyanins reached a maximum concentration (1091.8 +/- 1081.3 pmol/L, n = 10) during the 4-8 h period after black raspberry ingestion. As compared to the anthocyanin distribution in black raspberries, urinary cyanidin 3-xylosylrutinoside was detected at a higher concentration than that of cyanidin-3-rutinoside.     

Saskatoon and wild blueberries have higher anthocyanin contents than other Manitoba berries

Studies have shown that anthocyanins present in berry fruits have some beneficial health effects such as reducing age-associated oxidative stress and possessing anti-inflammatory properties. Therefore, six Manitoba berries (wild blueberry, Saskatoon berry, raspberry, chokecherry, strawberry, and seabuckthorn) were studied for their anthocyanin compositions (mg/100 g) on dry weight basis. Saskatoon berry and wild blueberry showed a high content of total anthocyanins (562.4 and 558.3 mg/100 g, respectively) that were not significantly (P>0.05) different from each other. The corresponding values for other berries: raspberry (365.2 mg/100 g), chokecherry (177.39 mg/100 g), and strawberry (97.5 mg/100 g) were significantly different from each other (P<0.05), and the total anthocyanin content of seabuckthorn was negligible (0.84 mg/100 g). Fifteen major anthocyanins were isolated from Manitoba berries. Saskatoon berry and wild blueberry contained higher amounts of delphinidin 3-glucoside (Dp-3-glc), malvidin 3-glucoside (Mv-3-glc), and malvidin 3-galactoside (Mv-3-gal). Dp-3-glc was 263.8 (mg/100 g) in Saskatoon berry and 84.4 (mg/100 g) in wild blueberry, whereas the corresponding values for Mv-3-glc in these berries were 47.4 and 139.6 (mg/100 g), respectively. Raspberry, strawberry, and chokecherry contained higher amounts of cyanidin 3-glucoside (Cy-3-glc), cyanidin 3-rutinoside (Cy-3-rut), and pelargonidin 3-glucoside (Pg-3-glc). The total anthocyanin content of Manitoba fruits followed the order: Saskatoon berry and blueberry (high anthocyanin berries), raspberry and chokecherry (medium anthocyanin berries), strawberry (low anthocyanin berries), and seabuckthorn (negligible anthocyanin berries). This study demonstrated that Saskatoon berries and wild blueberries have high potential value for fruit growers as well as the food and nutraceutical manufacturers because of their high anthocyanin contents.     

Plasma and urine responses are lower for acylated vs nonacylated anthocyanins from raw and cooked purple carrots

The bioavailability of acylated vs nonacylated anthocyanins and the effect of cooking and dose on the comparative bioavailability were investigated in a clinical feeding study using purple carrots as the anthocyanin source. Treatments were purple carrots as follows: 250 g raw (463 micromol of anthocyanins: 400 micromol acylated, 63 micromol nonacylated), 250 g cooked (357 micromol of anthocyanins: 308.5 micromol acylated, 48.5 micromol nonacylated), and 500 g cooked (714 micromol of anthocyanins: 617 micromol acylated, 97 micromol nonacylated). Four of the five carrot anthocyanins were found intact in plasma by 30 min after carrot consumption and peaked between 1.5 and 2.5 h. Acylation of anthocyanins resulted in an 11-14-fold decrease in anthocyanin recovery in urine and an 8-10-fold decrease in anthocyanin recovery in plasma. Cooking increased the recovery of nonacylated anthocyanins but not acylated anthocyanins. Large dose size significantly reduced recovery of both acylated and nonacylated anthocyanins, suggesting saturation of absorption mechanisms.     

Differentiation of Vitis vinifera L. and hybrid red grapes by matrix-assisted laser desorption/ionization mass spectrometry analysis of berry skin anthocyanins

Among the methods that have been developed for anthocyanin characterization, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) offers several analytical advantages in terms of speed, minimal sample handling, specificity, and reliability, without requiring any previous chromatographic separation. This study used MALDI-TOF MS to profile the anthocyanins from the berry skins of 23 red grape varieties clustered as (i) authentic Vitis vinifera grapes, (ii) American hybrid cultivars, and (iii) Casavecchia cultivars, previously characterized as functional crosses of V. vinifera with nondefined hybrid grapevines. Anthocyanin profiling demonstrated evidence of several varietal traits that enabled the differentiation of authentic V. vinifera from hybrid cultivars on a molecular basis. In particular, acyl 3,5-O-diglucoside anthocyanins were established as easily monitored molecular markers of the hybrid varieties. It was also demonstrated that MALDI-post source decay MS is a powerful tool to differentiate isobaric 3,5-O-diglucosides and their derivatives, which prevail in hybrid cultivars, from acylated 3-O-glucoside anthocyanins.     

Anthocyanin absorption and antioxidant status in pigs

The effect of a simultaneous intake of food or flavonoids on anthocyanins absorption and antioxidant status in pigs was investigated. Twelve male pigs at 27.1 +/- 0.7 kg BW fitted with jugular venous cannulae were maintained in individual metabolic crates. The animals were each given one of three dietary treatments in random order: blackcurrant powder (BC) to give a dose of 100 mg total ACNs/kg BW mixed either with water and sugar (Diet A), cereal (Weet-Bix), milk, and sugar (Diet B), or cereal, milk, sugar, and an additional flavonol (rutin, approximately 100 mg/kg BW) (Diet C). The four major anthocyanins of BC, delphinidin-3-glucoside, delphinidin-3-rutinoside, cyanidin-3-glucoside, and cyanidin-3-rutinoside, were identified and quantified by HPLC-PDA in all three diets. In the pig plasma, four peaks with a reversed pattern to those of anthocyanins in the BC extract were detected. The total amount of anthocyanins absorbed was not significantly different between the three diets, but the rate of absorption and subsequent decline was slower following administration of diet B and C than diet A. All three diets increased antioxidant capacity when measured by the FRAP assay but not when measured by the ORAC and non-protein ORAC assay. However, the increase was delayed and did not appear until 4 h after ingestion, at a time when plasma anthocyanin levels had returned to baseline. The present study demonstrates that the simultaneous intake of food or other flavonoids delays the absorption profile for anthocyanins. Our results also suggest that the increase in antioxidant capacity is not due to dietary anthocyanins but may be due to metabolites that result from anthocyanin consumption.     

Pigments in the fruit of red-fleshed kiwifruit (Actinidia chinensis and Actinidia deliciosa)

Kiwifruit cultivars (Actinidia chinensis and A. deliciosa) generally have fruit with yellow or green flesh when ripe. A small number of genotypes also have red pigments, usually restricted to the inner pericarp but varying in intensity and in distribution within the fruit. Carotenoids, chorophylls, and anthocyanins were extracted from the fruit pericarp of such red-fleshed kiwifruit selections. Pigments were analyzed by HPLC and identified by comparison with authentic standards and by liquid chromatography-mass spectroscopy to obtain a tentative identification of the major anthocyanins in red-fleshed kiwifruit. The yellow and green colors of the outer fruit pericarp are due to different concentrations and proportions of carotenoids and chlorophylls. The red color found mainly in the inner pericarp is due to anthocyanins. In the A. chinensis genotypes tested the major anthocyanin was cyanidin 3-O-xylo(1-2)-galactoside, with smaller amounts of cyanidin 3-O-galactoside. In the A. deliciosa genotypes analyzed, cyanidin 3-O-xylo(1-2)-galactoside was not detected; instead, the major anthocyanins identified were cyanidin 3-O-galactoside and cyanidin 3-O-glucoside. However, the two species did not differ consistently in anthocyanin composition.