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Phytochemicals and Antioxidant Activity of Fruitsand Leaves of Paprika (Capsicum Annuum L., var.Special) Cultivated in KoreaJi-Sun Kim, Jiyun Ahn, Sung-Joon Lee, BoKyung Moon, Tae-Youl Ha, and Suna Kim

Abstract: The phytochemical composition of carotenoids, tocopherols, free sugars, organic acids, L-ascorbic acid, capsai-cinoids, and flavonoids in green and red paprika (GP and RP), and paprika leaves (PL) cultivated in Korea were analyzed.The ethanolic extracts of GP, RP, and PL were obtained with 80% ethanol, and their antioxidative activities were deter-mined by measuring their ABTS and DPPH radical scavenging activities. RP showed the highest contents of capsanthin(58.33 ± 3.91 mg/100 g dry weight) and L-ascorbic acid (1987.25 ± 19.64 mg/100 g dry weight), and main compoundsof PL were lutein, chlorophyll, and γ -tocopherol (96.91 ± 14.58, 2136.71 ± 21.11, and 723.49 ± 54.10 mg/100 g dryweight, respectively). RP showed the strongest antioxidant activity (IC50 = 55.23 ± 6.77 μg/mL in a 2, 2′-azino-di-[3-ethylbenzthiazoline sulphonate] assay and 150.40 ± 8.07 μg/mL in a 2, 2-diphenyl-2-picrylhydrazyl assay), and theantioxidant activity of PL was higher than β-carotene but lower than RP. The results indicate that the amounts ofcapsanthin and L-ascorbic acid in RP correlate well with antioxidant activity. PL, which has various phytochemicalssuch as lutein, chlorophyll, and γ -tocopherol, might be used in nutraceuticals and pharmaceuticals for improving humanhealth.

Keywords: antioxidant activity, lutein, paprika fruits, paprika leaves, γ -tocopherol

IntroductionPaprika (Capsicum annuum L.) is regarded as a healthy vegetable

that possesses phytochemicals including carotenoids, ascorbic acid,tocopherol, flavonoids, and phenolic compounds, as well as naturalfood colorants (Jeong and others 2006; Al-Duais and others 2009).Traditionally in Korea, pungent red pepper has been only used asa spice, fermented paste, and main ingredient of the fermentedvegetable, kimchi. More recently, consumption of fresh paprikahaving a strong color and little pungency has dramatically increasedabout 6 times for 3 y, with an approximate 3-fold increase incultivation area in 7 y. Fresh paprika, and not pungent red pepper,has become the best export crop in Korea (Jeong and others 2008).

Several studies of red paprika have offered biological evidenceof activities including anti-tumor-promoting activity (Maoka andothers 2001; Maokaa and others 2004) and reduction or pre-vention of chronic diseases such as cardiovascular disease (CVD).These activities involve the improvement of high-density lipopro-tein cholesterol (HDL-C) and hepatic gene regulation (Aizawa andothers 2009; Aizawa and Inakuma 2009). These studies implicated

MS 20100614 Submitted 6/3/2010, Accepted 9/12/2010. Author Kim is withFood and Nutrition in Home Economics, College of Natural Sciences, Korea Natl.Open Univ., 169 Dongsung-Dong, Jongno-Gu, Seoul, 110-791, Republic of Korea.Authors Kim, Ahn, and Ha are with Functional Food Technology Research Group,Emerging Innovative Technology Div., Korea Food Research Inst., Sungnam-Si,Gyeonggi-Do 463-746, Republic of Korea. Authors Kim and Lee are with Div.of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Inst.of Biomedical Sciences and Food Safety, Korea Univ., Seoul 136-713, Republic ofKorea. Author Moon is with Dept. of Food and Nutrition, Chung-Ang Univ., 72-1Nae-ri, Daedeok-myeon, Anseoung-si, Gyeonggi-do 456-756, Republic of Korea.Direct inquiries to author Kim (E-mail: suna7@knou.ac.kr).

carotenoids in red paprika as being key in these beneficial effects.In particular, capsanthin and capsorubin, which are unique to redpaprika, exert antioxidative and anti-tumor activities (Kim andothers 2009). Lutein is already used commercially in nutraceuti-cals and pharmaceuticals to reduce the risk of age-related maculardegeneration (Manchester 2005).

However, the increased paprika production has created an eco-nomic and environmental burden that has led to the discarding ofstems and leaves, even with their nutraceutical potential. Youngleaves of pungent red pepper have been used in side dishes to im-part a uniquely pungent flavor in Asian countries such as Koreaand Japan. Paprika leaves display potent biological activities suchas free radical scavenging activity, antimicrobial activity and ty-rosinase inhibitory activity in various solvent fractions (Kim andothers 2003). Also, pepper leaves not only possess antioxidant ac-tivity but also antiproliferative activity against HCT116 humancolorectal carcinoma and MKN 45 gastric adenocarcinoma cell(Jeon and others 2008). However, little information is availableconcerning the specific phytochemicals or their functional value.

The present study was undertaken to identify numerous phy-tochemicals including carotenoids, tocopherols, ascorbic acid, andflavonoids from fruits and leaves of paprika grown in Korea, andto determine their antioxidant activities in different assays. Also,the relationship between each phytochemical and its antioxidantactivity was compared, to identify the principle constituents frompaprika fruits and leaves.

Materials and Methods

Samples and equipmentGreen and red paprika fruits (GP and RP) and its leaves (PL)

(Capsicum annuum L., Var. Special) were harvested on 12 October

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2008. All samples were kindly provided by Nongsan TradingCo. (Kimje, Chonbuk, Korea). Each sample (10 kg) was washed,drained, freeze-dried, ground, and stored at −70 ◦C for subse-quent analysis. All chromatographic analyses were performed us-ing high-performance liquid chromatography (HPLC) apparatusequipped with a PU-2089 pump, auto sampler, and an ultravi-olet and refractive index (RI) detector (Jasco, Tokyo, Japan). AV530 UV/VIS spectrophotometer (Jasco) and VS-5000N cen-trifuge (Vison Scientific, Seoul, Korea) was also used.

Reagents and standardsCapsanthin, capsorubin, violaxanthin, lutein, zeaxanthin, α-

and β-cryptoxanthin, and α- and β-carotene were purchasedfrom ChromaDex (Irvine, Calif., U.S.A.). Capsaicinoids, α-, γ -,and δ-tocopherol, chlorophyll A and B, quercetin, luteolin, L-ascorbic acid, organic acid kit, and sugar kit were purchased fromSigma-Aldrich (St. Louis, Mo., U.S.A.). HPLC-grade acetonitrile,methanol (MeOH), ethanol (EtOH), and water were purchasedfrom Burdick & Jackson (SK Chemicals, Ulsan, Korea). All otherchemicals were purchased from Sigma-Aldrich.

Determination of phytochemicalsCarotenoids and chlorophyll analysis. For carotenoid anal-

ysis, extraction was performed with acetone until the color hadcompletely disappeared. Each sample (2 g) was extracted in 20 mLof acetone at 4 ◦C for 24 h in the dark. The acetone extract(10 mL) was incubated with 2 mL of 30% KOH/MeOH at37 ◦C for 18 h in the dark, and extracted 3 times with diethylether. The combined extract was then washed several times withdistilled water until neutral, and 10 mL of 10% NaCl and 10 mLof 2% Na2SO4 was added to remove the hydrophilic phase. Af-ter evaporating the collected extracts, the residue was dissolved inacetone and stored at −20 ◦C under nitrogen until used. HPLCwas equipped with an XTerra RP C18 column (250 × 4.6 mm,5 μm; Waters, Milford, Mass., U.S.A.) set to 450 nm and 35 ◦C.Mobile phases consisted of 15% water/MeOH (v/v) (A) and 50%acetone/MeOH (v/v) (B) at a flow rate of 1.5 mL/min. The gra-dient system was initially 100% A, 55% A/45% B for 20 min, backto 100% A for 6 min, to 100% B for 7 min, to 100% A for 9 min,and finally to 100% A for 5 min, for a total duration of 47 min.For chlorophyll analysis, each sample (10 mg) was extracted in1 mL of 80% acetone (v/v) for 5 min. Samples were centrifugedfor 2 min, and then filtered using a 0.45 mm polyvinylidene flu-oride (PVDF) syringe filter (Whatman, Clifton, N.J., U.S.A.) andstored at −20 ◦C under nitrogen until HPLC analysis. HPLC wasequipped with an XTerra RP C18 column (250 × 4.6 mm, 5 μm;Waters), and set to 450 nm and 35 ◦C. Mobile phases consisted of15% water/MeOH (v/v) (A) and 50% acetone/MeOH (v/v) (B)at a flow rate of 1.5 mL/min. The gradient system was initially100% A for 19 min, to 55% A/45% B for 1 min, to 100% A for6 min, to 100% B for 7 min, to 100% A for 9 min, to 55% A/45%B for 7 min, for a total duration of 47 min.

Tocopherol and ascorbic acid analysis. Determination oftocopherol was performed using a modification of a previously de-scribed method (Markus and others 1999). Each sample (20 g) wasextracted with 5 mL MeOH and 70 mL dichloroethane/MeOH(6 : 1, v/v) at 4 ◦C for 30 min, and the dichloroethane layer wascollected and removed from the hydrophilic phase by adding 2%Na2SO4. After evaporating, the residue was dissolved in MeOHfor HPLC analysis. HPLC equipped with an YMC-Pack ODS-AM column (4.6 × 250 mm, 5 μm; YMC Co. Ltd., Kyoto, Japan)set at 292 nm and 25 ◦C. The mobile phase was 100% MeOH at a

flow rate of 1.2 mL/min. Ascorbic acid analysis was performedusing the method of Food Code (KFDA 2004). Each sample(25 g) was mixed with 50 mL of 4% metaphosphoric acid. Ascor-bic acid was then extracted by shaking at 4 ◦C for 1 h, followedby centrifugation for 10 min at 4000 rpm. The supernatant wasfiltered using a 0.45-mm PVDF syringe filter (Whatman, Maid-stone, U.K.) and diluted with 4% metaphosphoric acid. HPLCwas conducted using an YMC-Pack Polyamine II column (4.6 ×250 mm, 5 μm; YMC) set at 254 nm and 40 ◦C. The mobilephase consisted of acetonitrile and 40 mM metaphosphoric acid(70 : 30, v/v) at a flow rate of 1 mL/min.

Flavonoid analysis. Flavonoid analysis was performed usingthe slightly modified method of Wach (Wach and others 2007).Each sample (10 g) was mixed with 20 mL of 80% MeOH (v/v)at 90 ◦C for 30 min, followed by centrifugation for 10 min at4000 rpm. Supernatant was hydrolyzed with 2.8 M HCl in 60%MeOH (v/v) at 90 ◦C for 10 min. After removing MeOH byN2, ethyl acetate was added to the residue. Then, ethyl acetatelayer was collected 3 times, dried by N2, and dissolved againin 40% MeOH (v/v) for HPLC analysis. HPLC was done us-ing a ZORBAX Eclipse XDB-C18 column (4.6 × 250 mm,5 μm; Agilent, Palo Alto, Calif., U.S.A.) set to 375 nm and40 ◦C. Mobile phases consisted of 15% H3PO4 in water (v/v) (A)and 70% acetonitrile (v/v) (B). The gradient system was started100% A, to 50% A/50% B for 30 min, to 100% A for 5 min at aflow rate of 1.3 mL/min.

Capsaicinoid, sugar, and organic acid analysis. Capsai-cinoid was analyzed using a previously described method ofAttuquayefio and Buckle (Attuquayefio and Buckle 1987). Eachsample (4 g) was extracted with 20 mL acetonitrile, followed bycentrifugation at 4000 rpm for 10 min. Extract (10 mL) was ap-plied to a Sep-pak C18 column (Waters), and then extracted with4 mL acetonitrile and 1 mL 1% acetic acid in acetonitrile (v/v). Af-ter evaporating the collected extracts, the residue was dissolved inacetonitrile for HPLC analysis. HPLC was equipped with a ZOR-BAX Eclipse XDB-C18 column (4.6 × 250 mm, 5 μm, Agilent)set to 280 nm and 35 ◦C. The mobile phase was 70% MeOH(v/v) at a flow rate of 0.8 mL/min. Free sugars were analyzed asdescribed previously (Gancedo and Luh 1986). Each sample (1 g)was refluxed with 2 mL 80% EtOH (v/v), and then extracted for1 h. The extracts were filtered with a 0.45-mm PVDF syringe fil-ter. HPLC was equipped with a ZORBAX carbohydrate column(4.6 × 250 mm, 5 μm, Agilent) set to 40 ◦C and RI detec-tor. The mobile phase consisted with 85% acetonitrile (v/v) at aflow rate of 1 mL/min. Organic acids were analyzed by HPLC asdescribed previously (Lopez-Hernandez and others 1996). Eachsample (1 g) was mixed with 10 mL 4.5% metaphosphoric acidat room temperature for 15 min, followed by centrifugation for10 min at 4000 rpm. The extract was filtered with a 0.45-mmPVDF syringe filter. HPLC was conducted using a Waters XTerraRP18 column (4.6 × 250 mm, 5 μm) set to 215 nm and 20 ◦C.The mobile phase was metaphosphoric acid (pH 2.1) at a flow rateof 0.6 mL/min.

Determination of total phenolic contentsTotal phenolic content was determined using Folin–Ciocalteu

reagent (Velioglu and others 1998). Folin–Ciocalteu reagent wasdiluted 2-fold in deionized water. Each sample (1 g) was mixedwith 10 mL of 80% EtOH (v/v) at room temperature for 20 min,followed by centrifugation for 10 min at 4000 rpm.

The extract solution (0.25 mL) was mixed with 0.75 mL di-luted Folin–Ciocalteu reagent and 2 mL of 2% Na2CO3 (v/v), and

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then incubated at 36 ◦C for 30 min. Absorbance was measured at750 nm using a UV-VIS spectrophotometer. Results were ex-pressed as milligrams of catechin equivalent (CE) per gram of dryweight (mg CE/g dw).

Determination of anti-oxidant activityThe 2, 2′-azino-di-(3-ethylbenzthiazoline sulphonate) (ABTS)

and 2, 2-diphenyl-2-picrylhydrazyl (DPPH)-radical scavengingactivities of sample were measured as described previously (Brand-Williams and others 1995; Arnao and others 2001). For the mea-surement of antioxidant activity, each sample (0.3 g) was extractedwith 3 mL of 80% EtOH (v/v) at room temperature for 20 min,and β-carotene was dissolved in acetone (Miller and others 1996;Zanfini and others 2010). All radical solutions were freshly pre-pared each day. The inhibition percentage of ABTS and DPPHradical was calculated as: (1 – [Absorbance of sample/Absorbanceof control]) × 100.

Statistical analysisAll sample measurements were based on dry weight (Davies

and Goodwin 1965) and analyzed in triplicate. Quantitative dataare expressed as mean ± standard deviation (SD) of at least 3measurements. Each experimental set was compared with one-wayanalysis of variance (ANOVA) and Duncan’s multiple-range test (P< 0.05) using SAS version 8.0 for Windows (SAS Inst., Cary, N.C.,U.S.A.). Inhibitory concentration 50% (IC50) value was calculatedby nonlinear regression analysis using SIGMA Plot version 9.0for Windows (Systat Software, San Diego, Calif., U.S.A.). Thedose–response curve was obtained by plotting the percentage ofinhibition compared with concentration.

Results and DiscussionAs shown in Table 1, 4, and 7, kinds of carotenoids were iden-

tified from GP and RP, and 3 kinds of carotenoids from PL,respectively. These findings demonstrated that the composition ofcarotenoids were diverse in RP than those in GP and PL. Color

Table 1–Qualitative and quantitative analysis of carotenoid andchlorophyll in paprika fruits and leaves.

Pigments GP RP PL

Capsorubin ND 3.43 ± 0.22 NDViolaxanthin 0.06 ± 0.0 0.01 ± 0.00 1.80 ± 0.35Capsanthin ND 58.33 ± 3.91 NDLutein 6.71 ± 0.70 2.42 ± 0.01 96.91 ± 14.58Zeaxanthin ND 0.18 ± 0.03 NDα-, β-cryptoxanthin 0.28 ± 0.04 0.52 ± 0.10 NDα-, β-carotene 4.19 ± 0.17 4.55 ± 0.11 5.97 ± 0.99Total carotenoid, 11.25 ± 0.88 69.44 ± 4.25 104.68 ± 14.75

mg/100 g dwChlorophyll A 36.53 ± 1.86 ND 1624.97 ± 16.91Chlorophyll B 15.64 ± 0.40 ND 511.74 ± 4.70Total chlorophyll, 52.17 ± 1.69 ND 2136.71 ± 21.11

mg/100 g dw

ND = not detected. Data are expressed as mean ± SD.

property of the “Special” cultivar used in this experiment changedfrom green to red during ripening, with dietary intake with bothcolor stages. Regarding the fruit ripening stage, one study reportedthat the total carotenoid content of RP was 6 times higher than thatof GP due to increased red pigments such as capsanthin and cap-sorubin (Burns and others 2003). Capsanthin content in RP was58.33 ± 3.91 mg/100 g dw, which was approximately twiceas great as that of the “Mesilla” fruit cultivar (20.86 mg/g dw)(Howard and others 2000). Among the carotenoid pigments, cap-santhin and capsorubin are almost unique to Capsicum spp., andare responsible for the final red color (Davies and others 1970).In PL, violaxanthin, lutein, and α, β-carotene were identified, inagreement with another study (Minguez-Mosquera and Hornero-Mendez 1994). Interestingly, the total carotenoid content of PLwas higher than that of GP and RP due to its lutein content. Luteinin PL (96.91 ± 14.58 mg/100 g dw) comprised 92% of total PLcarotenoids, and was approximately 15 times the lutein content inGP (6.71 ± 0.70 mg/100 g dw), and over 40 times the contentin RP (2.42 ± 0.01 mg/100 g dw). Dark green leafy vegetablessuch as spinach, broccoli, kale, and lettuce are lutein-rich dietarysources (Hart and Scott 1995). Another study reported that thelutein content in 11 kinds of leafy vegetables ranged from 45.1to 180 mg/100 g dw (Liu and others 2007). According to Kimand others (2007), lutein contents of leafy vegetables commonlyconsumed in Korea are 4.44 mg/100 g of the edible portion ofsesame leaves and 8.68 mg/100 g of the edible portion of pungentpepper leaves. Presently, PL contained considerable amounts oflutein, consistent with the view that PL might be a potent sourceof dietary lutein.

Chlorophyll A and B contents were 36.53 ± 1.86 and 15.64 ±0.40 mg/100 g dw in GP and 1624.97 ± 16.91 and 511.74 ±4.70 mg/100 g dw in PL, respectively. The total chlorophyll con-tent in PL (2136.71 ± 21.11 mg/100 g dw) was approximately40 times higher than that of GP (52.17 ± 1.69 mg/100 g dw).Xue and Yang (Xue and Yang 2009) reported that the chloro-phyll content of spinach and lettuce ranges from 1.25 to 2.23and 0.42 to 1.14 mg/g fresh weight (fw), respectively. Consider-ing that the moisture level of paprika reached 90%, the chloro-phyll content of PL in the present study was higher than those ofspinach and lettuce. Chlorophyll has been controversial as a pro-oxidant in marine oils (Wanasundara and Shahidi 1998). However,Hoshina and others (1998) reported that chlorophylls were good

Table 3–Qualitative and quantitative analysis of flavonoids andtotal phenolic contents in paprika fruits and leaves.

Total phenolicFlavonoids (μg/g dw) contents (mg

Samples Luteolin Quercetin Total CE/100 g dw)

GP 0.64 ± 0.09b 4.76 ± 0.22ab 5.40 ± 0.13b 691.65 ± 7.62b

RP 0.36 ± 0.06b 3.29 ± 0.58b 3.66 ± 0.57b 731.75 ± 37.25b

PL 14.34 ± 0.27a 5.72 ± 0.95a 20.06 ± 1.11a 1,714.20 ± 47.72a

CE = catechin equivalent.Different letters in the same column indicate significant differences (P < 0.05).

Table 2–Qualitative and quantitative analysis of tocopherol and ascorbic acid in paprika fruits and leaves.

Tocopherol (mg/100 g dw) L-ascorbic acidSamples α γ δ Total (mg/100 g dw)

GP 8.13 ± 1.65c 33.70 ± 1.89b ND 41.84 ± 3.10b 1746.25 ± 1.87b

RP 20.03 ± 0.46b 0.88 ± 0.03b ND 20.92 ± 0.28b 1,987.25 ± 19.64a

PL 58.97 ± 0.39a 723.49 ± 54.10a 3.83 ± 0.96 786.31 ± 53.34a 10.38 ± 2.34c

ND = not detected.Different letters in the same column indicate significant differences (P < 0.05).

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Table 4–Qualitative and quantitative analysis of capsaicinoids, free sugars, and organic acid in paprika fruits and leaves.

Pigments GP RP PL

Capsaicin 6.41 ± 2.12ns 4.59 ± 1.28 2.79 ± 0.16Dihydrocapsaicin 1.18 ± 0.46ns 1.49 ± 0.48 2.30 ± 0.28Total capsaicinoids (μg/g dw) 7.60 ± 1.66ns 6.08 ± 0.81 5.09 ± 0.12Fructose 164.83 ± 1.91b 241.50 ± 8.23a 5.36 ± 0.94c

Glucose 180.88 ± 3.28b 215.26 ± 7.43a 4.27 ± 1.02c

Sucrose 71.61 ± 2.62a 13.89 ± 0.95b 4.97 ± 1.11c

Total free sugars (mg/g dw) 417.32 ± 7.72a 470.66 ± 16.54b 14.59 ± 1.97c

Oxalic acid 5.87 ± 0.16b 303.93 ± 24.31a NDMalic acid 15, 012.88 ± 1490.36b 11, 283.10 ± 62.21c 20, 739.38 ± 118.78a

Citric acid 724.84 ± 17.53b 1, 354.48 ± 55.91a NDFumaric acid 3.01 ± 0.36a 0.39 ± 0.07b NDTotal organic acid (mg/100 g dw) 15, 746.59 ± 1489.58b 12, 941.90 ± 139.58b 20, 739.38 ± 118.78a

ND = not detected; ns = not significant.Different letters in the same row indicate significant differences (P < 0.05).

Table 5–IC50 value of ABTS and DPPH radical scavenging activ-ities from paprika fruits and leaves extracts.

ABTS radical DPPH radicalscavenging activity scavenging activity

Samples IC50 (μg/mL) IC50 (μg/mL)

GP 118.00 ± 0.45b 286.23 ± 3.56c

RP 55.23 ± 6.77c 150.40 ± 8.07d

PL 68.67 ± 19.78c 463.23 ± 58.21b

β-carotene 292.45 ± 0.00a 3318.69 ± 3.93a

ABTS = 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid); DPPH = 2, 2-diphenyl-2-picrylhydrazyl; IC50, inhibitory concentration 50% value.Different letters in the same column indicate significant differences (P < 0.05).

antioxidants in the inhibition of lipid auto-oxidation. Chlorophyllsare regarded as antioxidants (Lanfer-Marquez and others 2005),with a chemopreventive/mutagenesis effect (Dashwood and oth-ers 1998) and anticancer effect (Fahey and others 2005; Hedgesand Lister 2007). Therefore, the high chlorophyll content of PLleaves may increase health benefits.

Tocopherol and ascorbic acid contents of GP, RP, and PL aresummarized in Table 2. α-, γ -Tocopherol was detected in all sam-ples, while δ-tocopherol was only detected in PL. Total tocopherolcontent of PL was approximately 20 times, higher than those of GPand RP. In particular, γ -tocopherol content in PL was 723.49 ±54.10 mg/100 g dw, comprising approximately 92% of the to-tal tocopherol content. This result is noteworthy considering thatinterest in γ -tocopherol is increasing. Tocopherols are a class ofchemical compounds with vitamin E activity, and α-tocopherolhas been regarded as the most important lipid-soluble antioxidantprotecting cell membranes from oxidative damage (Burton andothers 1983). γ -Tocopherol might be important for human health,distinguishing it from α-tocopherol (Jiang and others 2001); anepidemiology study demonstrated that serum concentration ofγ -tocopherol, but not α-tocopherol, was lower in patients withCVD compared with healthy control subjects (Kontush and others1999). Additionally, γ -tocopherol was shown to be protectivelyassociated with colon cancer (Campbell and others 2003) andprostate cancer (Campbell and others 2009) as well as inflammatorydisease such as CVD and myocardial infarction (Kushi and others1996). These results reflect the importance of γ -tocopherol-richfood. Kim and others (2007) reported the γ -tocopherol contentof spinach and lettuce as 2.78 to 4.18 and 0.08 to 0.16 mg/100 g fw, respectively. Surprisingly, γ -tocopherol contents of PLwas 786.31 ± 53.34 mg/100 g dw, meaning that PL is a goodsource of γ -tocopherol.

In contrast, the ascorbic acid content showed the opposite pat-tern (Table 2); ascorbic acid content was 1746.25 ± 1.87 mg/

Figure 1–ABTS and DPPH radical scavenging activity of paprika fruits andleaves. (A) ABTS 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)and (B) DPPH (2, 2-diphenyl-2-picrylhydrazyl) radical scavenging activi-ties of paprika fruits and leaves. Data are expressed as the mean ± SD oftriplicate samples.

100 g dw in GP and 1987.25 ± 19.64 mg/100 g dw in RP, whichwas approximately 180 times higher than that of PL. Thus, PL isa good source of tocopherol, whereas the fruits are a good sourceof ascorbic acid.

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In flavonoids analysis, we identified only luteolin and quercetin(Table 3). Luteolin contents were 0.64 ± 0.09, 0.36 ± 0.06, and14.34 ± 0.27 mg/100 g dw in GP, RP, and PL, respectively, andquercetin contents were 4.76 ± 0.22, 3.29 ± 0.58, and 5.72 ±0.95 mg/100 g dw in GP, RP, and PL, respectively. Total flavonoidcontent of GP and RP was significantly lower than that of PL. Thequercetin levels were higher in GP and RP, while luteolin levelwas higher in PL. These results showed that contents of luteolinand quercetin were smaller than reported in other studies. Also,total flavonoid contents were higher than the sum of luteolin andquercetin; it might be that other unknown flavonoid and phenoliccompounds free of without luteolin and quercetin are present inGP, RP, and PL.

We also analyzed capsaicinoids, free sugars and organic acids,which are nutritional factors as well as taste-related factors(Table 4). GP, RP, and PL had similar capsaicinoid contents, al-though the ratio of capsaicin to dihydrocapsaicin differed slightly.Capsaicinoid contents were 7.60 ± 1.66 μg/g dw in GP, 6.08 ±0.81 μg/g dw in RP, and 5.09 ± 0.12 μg/g dw in PL. In free sugaranalysis, we identified fructose, glucose, and sucrose. The total freesugar contents of GP and RP were 417.32 ± 7.72 mg/g dw and470.66 ± 16.54 mg/g dw, respectively, which were approximately30 times higher than that of PL (14.59 ± 1.97 mg/g dw). Organicacids were determined to be oxalic acid, malic acid, citric acid, andfumaric acid in GP and RP, and only malic acid was detected inPL. Malic acid was the most abundant acid regardless of plant partas 15012.9 ± 1490.4 mg/100 g dw in GP, 11283.1 ± 62.2 mg/100 g dw in RP, and 20739.4 ± 118.8 mg/100 g dw in PL.

GP, RP, and PL exerted ABTS and DPPH radical scavengingeffects in a dose-dependent manner (62.5, 125, 250, 500, and 1000μg/mL in ABTS assay and 125, 250, 500, 1000, and 2000 μg/mL in DPPH assay) (Figure 1). We already showed that β-carotenecontent of all samples was much the same (Table 1). Also, β-carotene is known to possess antioxidant properties (Miller andothers 1996). Therefore, we compared all samples to β-carotenefor antioxidant activities. All samples showed higher antioxidantactivities than β-carotene in both assays. Especially, RP showed thehighest activity at all concentration in DPPH assay. Interestingly,the activity of PL in ABTS assay was similar to that of RP, and alittle higher than that of GP. As shown in Table 5, the IC50 valueof RP was 55.23 ± 6.77 μg/mL and 150.40 ± 8.07 μg/mL inABTS and DPPH assay, respectively. It was significantly lower thanGP and PL as well as β-carotene. Moreover, the IC50 value of PLwas considerably lower than that of β-carotene. This value wassimilar with the 4 medicinal plants (Subhasree and others 2009)and a little lower than 11 edible leafy vegetables (Dasgupta and De2007).

Additionally, we compared antioxidant activities with eachcomponent shown in Figure 2. RP may be a good source ofL-ascorbic acid and capsanthin. Even though PL possesses phyto-chemicals such as lutein, γ -tocopherol, and total phenolic com-pounds, RP showed the strongest antioxidant activity. The highcontent of capsanthin and L-ascorbic acid in RP correlated wellwith antioxidant activity. The antioxidant activity of PL appearedto be considerable compared with β-carotene, and this mightbe due to the combined activities of several phytochemicals,

Figure 2–Antioxidant activity compared with (A) carotenoid, (B) tocopherol, (C) L-ascorbic acid, and (D) total phenolic content of paprika fruits andleaves. Concentrations of ABTS and DPPH were 125 and 250 μg/mL, respectively. Data are expressed as mean ± SD of triplicate samples.

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especially lutein and γ -tocopherol, even in the absence of L-ascorbic acid.

ConclusionsThis study provides basic evidence that dietary intake of GP,

RP, and PL is beneficial to improve human health. Furthermore,PL, which has been discarded until now, can be used for novel nu-traceutical and pharmaceutical resources of bioactive compoundssuch as lutein and γ -tocopherol.

AcknowledgmentsThis Study was supported by a grant of Rural Development Ad-

ministration and by Agricultural R&D Promotion Center, Min-istry of Food, Agriculture, Forestry and Fisheries, and by KoreaFood Research Inst., Ministry of Knowledge Economy, Republicof Korea.

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