Chapter 9. Antioxidant Vitamin and Phytochemical Content of Fresh and Processed Pepper Fruit (Capsicum annuum)

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II. FRUITS AND VEGETABLES FOR DISEASE PREVENTION

Epidemiological studies indicate that antioxidants present in fruits and vegetables, including βcarotene and vitamins C and E, may be important in prevention of numerous degenerative conditions, including various types of cancer, cardiovascular disease, stroke, atherosclerosis, and cataracts.8–10 Oxidative damage catalyzed by reactive oxygen species (ROS) has been implicated in

over 100 degenerative conditions.11 ROS cause damage to cellular membranes, proteins, and DNA,

which increases the susceptibility of cells to chronic diseases. Oxidative damage in the body is

exacerbated when the balance of ROS exceeds the amount of endogenous antioxidants. The human

body has several enzymatic and nonenzymatic defense systems to regulate ROS in vivo, but these

defense mechanisms are thought to deteriorate with aging. Consumption of fruits and vegetables

that are rich in antioxidant nutrients may afford additional protection against ROS-mediated disorders. Scientists have recently recognized that fruits and vegetables are not only a good source of

antioxidant vitamins but also an excellent source of other essential dietary phytochemicals that can

retard the risk of degenerative diseases.12 The potential health effects of phytochemicals are associated with numerous mechanisms, including prevention of oxidant formation, scavenging of

activated oxidants, reduction of reactive intermediates, induction of repair systems, and promotion

of apoptosis.13

Of interest is how and why fruits and vegetables generate nutraceutical compounds and for

what purpose. With regard to peppers, the presence of different antioxidative enzymes and their

corresponding metabolites in pepper peroxisomes implies that these organelles might be an important pool of antioxidants in fruit cells, where these enzymes could also act as modulators of signal

molecules (O2–, H2O2) during fruit maturation.14 In one study of the peroxisomal fractions of green

and red pepper fruits (Capsicum annuum L., type Lamuyo), the quantity and activity of antioxidant

enzyme systems was generally higher in green than in red fruits.14

In this work, the purification and characterisation of peroxisomes from fruits of a higher plant

was carried out, and their antioxidative enzymatic and nonenzymatic content was investigated.

Green and red pepper fruits (Capsicum annuum L., type Lamuyo) were used in this study. The

analysis by electron microscopy showed that peroxisomes from both types of fruits contained

crystalline cores that varied in shape and size, and the presence of chloroplasts and chromoplasts

in green and red pepper fruits, respectively, was confirmed.



III. ASCORBIC ACID

Capsicum fruit have long been recognized as an excellent source of ascorbic acid, which is a

required nutrient for humans. Svent-Gyorgyi isolated ascorbic acid from paprika fruit in the early

1930s, and subsequently identified the compound in 1933.15 Ascorbic acid has strong reducing

properties due to its enediol structure, which is conjugated with the carbonyl group in a lactone

ring16 (Figure 9.1). In the presence of oxygen, ascorbic acid is degraded to dehydroascorbic acid

(DHA), which still retains vitamin C activity. However, upon further oxidation, the lactone ring of

DHA is destroyed, resulting in formation of 2,3-diketogulonic acid and loss of vitamin activity.

Ascorbic acid is required for collagen formation and prevention of scurvy. Researchers have

postulated a role of ascorbic acid in the prevention of degenerative conditions, including cancer,

heart disease, cataracts, and stimulation of the immune system.17 Prevention of chronic diseases

may be attributed to the ascorbate function as an aqueous reducing agent. Ascorbate can reduce

superoxide, hydroxyl, and other ROS, which may be present in both intracellular and extracellular

matrices. Ascorbate within cells participates as an electron donor, as part of the interaction between

iron and ferritin. Extracellularly, ascorbate may act in concert with tocopherols in lipid membranes,

to quench ROS and prevent lipid peroxidation. Thus, ascorbate may help prevent the oxidation of

low-density lipoprotein (LDL), which is thought to be a major initiating step in the process of

atherosclerosis. The role of ascorbate in cancer prevention may be attributed to its ability to block



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Antioxidant Vitamin and Phytochemical Content of Fresh and Processed Pepper Fruit



O



167



O

OH



O



O



O

OH



O



HO



HO

OH



OH



L-ascorbic acid



L-dehydroascorbic acid



OH



OH

OH



HO



OH



HO



O



O



OH



OH



OH



O

Quercetin



O

Luteolin



HO

O



-tocopherol



HO

O



-tocopherol



FIGURE 9.1 Ascorbic acid, flavonoids, and tocopherols in Capsicum fruit.



the formation of N-nitrosamines and nitrosamides, compounds that induce cancer in experimental

animals, and possibly humans.17

The ascorbic acid content of pepper cultivars from several species is shown in Table 9.1.18–22

All the peppers referenced are excellent sources of ascorbic acid, with many of the cultivars

contributing over 100% of the Recommended Daily Intakes (RDIs) in the U.S. The current RDI

for vitamin C is 90 mg/d for adult men and 75 mg/d for adult women who are not pregnant or

lactating. The only pepper cultivars that fail to meet at least 50% of the RDI for ascorbic acid are

the chile-type cultivars NuMex RNaky, New Mexico, and B-18 at the green stage and the tabascotype called cv tabasco at the green stage.

The ascorbic acid content of most of the pepper types increases during ripening, with much

higher levels found in mature peppers at the final stage of ripening.23–26 Higher levels of ascorbic

acid observed during ripening may be related to light intensity and greater levels of glucose, the

precursor of ascorbic acid.27 Because total and reducing sugars increase during pepper fruit ripening,

the elevated ascorbic acid levels in mature fruit may reflect greater synthesis due to the higher



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TABLE 9.1

Ascorbic Acid Content of Fresh Capsicum Fruit

Species

C.annuum



Type

Ancho

Bell



Cascabella

Cayenne

Chile



Cultivar



Maturity



mg/100 g

Fresh Weight



San Luis Ancho

Dove

Dove

Ivory

Ivory

Blue Jay

Blue Jay

Lilac

Lilac

Valencia

Valencia

Oriole

Oriole

Black Bird

Black Bird

Chocolate Beauty

Chocolate Beauty

Cardinal

Cardinal

King Arthur

King Arthur

Var. 862R

Var. 862R

Red Bell G

Red Bell G

Red Bell C

Red Bell C

Klondike Bell

Klondike Bell

Canary

Canary

Orobelle

Orobelle

Golden Bell

Golden Bell

Tam Bel-2

Tam Bel-2

Grande Rio-66

Grande Rio-66

Yellow Bell-47

Yellow Bell-47

Peto Cascabella

Peto Cascabella

Mesilla

Mesilla

New Mexico-6

New Mexico-6

New Mexico-6



Green

White

Light Orange

White

Light Yellow

Purple

Orange

Purple

Orange

Green

Orange

Green

Orange

Green

Black

Green

Brown

Green

Brown

Green

Red

Green

Red

Green

Red

Green

Red

Green

Yellow

Green

Yellow

Green

Yellow

Green

Yellow

Green

Red

Green

Red

Green

Orange

Yellow

Red

Green

Red

Green

Red

Green



168

77

103

89

110

95

123

67

104

119

73

91

86

66

62

62

100

102

124

84

87

88

98

95

96

72

107

112

109

112

108

162

95

106

90

109

148

98

149

114

135

172

202

63

102

141

205

130



%RDIa

Male



Female



Ref.



187

86

114

99

122

106

137

74

116

132

81

101

96

73

69

69

111

113

138

93

97

98

109

106

106

80

119

124

121

124

120

180

106

118

100

121

164

109

166

127

150

191

224

70

113

157

228

144



224

103

137

119

147

127

164

89

139

159

97

121

115

88

83

83

133

136

165

112

116

117

131

127

127

96

143

149

145

149

144

216

127

141

120

145

197

131

199

152

180

229

269

84

136

188

273

173



18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

18

20

20

20

20

21

21

21

21

21

21

20

20

18



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169



TABLE 9.1 (Continued)

Ascorbic Acid Content of Fresh Capsicum Fruit

Species



Type



Jalapeno



Serrano

Yellow Wax



C. chinense



Habanero



C. frutescens



Tabasco



a



Cultivar



Maturity



%RDIa



mg/100 g

Fresh Weight



Male



Female



Ref.



Tam Mild Chile

Tam Mild Chile

Green Chile



Green

Red

Green



155

233

122



172

259

136



207

311

163



20

20

18



Sandia

Sandia

Sandia

New Mexico 6-4

New Mexico 6-4

New Mexico 6-4

NuMex RNaky

NuMex RNaky

NuMex RNaky

B-18

B-18

B-18

Jalapeno-M

Jalapeno-M

Tam Veracruz

Tam Veracruz

Tam Veracruz

Tam Mild

Mitla

Jaloro

Sweet Jalapeno

Hidalgo

Hidalgo

Hungarian Yellow

Long Hot Yellow

Gold Spike

Inferno

Inferno

Rio Grande Gold

Sante Fe Grande

Red Savina

Francisca

McIhenny Tabasco

McIhenny Tabasco



Green

Breaker

Red

Green

Breaker

Red

Green

Breaker

Red

Green

Breaker

Red

Green

Red

Green

Red

Green

Green

Green

Yellow

Green

Green

Red

Yellow

Yellow

Yellow

Yellow

Red

Red

Red

Red

Orange

Green

Red



71

220

239

40

122

155

28

145

164

15

91

186

173

179

101

144

72

66

49

131

54

141

263

114

114

115

92

138

243

187

192

203

15

75



79

244

266

44

136

172

31

161

182

17

101

207

192

199

112

160

80

73

54

146

60

157

292

127

127

128

102

153

270

208

213

226

17

83



95

293

319

53

163

207

37

193

219

20

121

248

231

239

135

192

96

88

65

175

72

188

351

152

152

153

123

184

324

249

256

271

20

100



22

22

22

22

22

22

22

22

22

22

22

22

20

20

20

20

18

18

18

18

18

20

20

18

18

18

21

21

20

20

21

21

21

21



Recommended daily intakes, adult males = 90 mg/100 g, adult females = 75 mg/100 g.



levels of sugar precursors.22 In addition to maturation, variation in ascorbic acid content between

pepper types and cultivars may be attributed to differences in genetics, fertilization practices, and

environmental growing conditions. The effects of fertilization on ascorbic acid content of peppers

have been studied. Ascorbic acid content of pepper fruits increased with increasing levels of

phosphorus up to 48 kg/ha, at varying levels of nitrogen (0 to 100 kg/ha),28 and applications

including combinations of organic matter + nitrogen + phosphorus increased ascorbic acid content

of capsicum fruit.29 Application of bioregulators may also affect ascorbic acid content of peppers.



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The ascorbic acid and citric acid contents of “bell” peppers increased with gibberellic acid treatment,30 whereas in another study the ascorbic acid content of bell peppers was not affected by

ethylene treatment.31



A. EFFECTS OF POSTHARVEST HANDLING

ACID CONTENT



AND



PROCESSING



ON



ASCORBIC



The ascorbic acid content of peppers is influenced by postharvest handling, packaging, and processing. Fresh peppers are sensitive to chilling injury, so they should be stored at 8 to 12°C (46 to

54°F), at a relative humidity of 90 to 95%. Under optimum conditions, peppers may be stored for

2 to 3 weeks after harvest. However, the nutritional quality of peppers may change after harvest,

handling, and transportation en route to various markets, especially under abusive handling conditions. The ascorbic acid content of sweet bell peppers from wholesale and retail markets and

simulated consumer storage was reported to be similar, although a wide range of ascorbic acid was

apparent among individual market samples.32 Thus, it appears that the average concentration of

ascorbic acid does not change appreciably from wholesale marketing to consumption. The ascorbic

acid content of bell peppers was influenced by storage temperature but not by packaging in

perforated films.33 Ascorbic acid levels declined 10% after 4 d storage at 10°C (50°F), whereas a

25% loss occurred after 4 d storage at 20°C (68°F). In contrast, the ascorbic acid content of bell

peppers was unaffected by storage temperature 2°C (35°F) and 8°C (46°F), varying levels of carbon

dioxide (5, 10, 20%), or storage time (6, 9, and 12 d).34 In another study, the ascorbic acid content

of bell peppers increased with storage at 13°C (55°F), and with subsequent ripening at 20°C

(68°F).35 Meanwhile, fresh peppers (Capsicum annuum L., variety California) in their green and

red ripe stages were stored at 20°C (68°F) for 7 and 19 d and the ascorbic acid content was noted

to increase as both stages matured during storage.25

The ascorbic acid content of the Morron pepper of “Fresno de la Vega” (Capsicum annuum

L.), a big, sweet variety cultivated in the province of Leon (northwestern Spain) increased as the

peppers ripened.23 For green mature, breaker and red peppers values of 107.3 ± 1.84, 129.6 ± 3.11,

and 154.3 ± 7.56 mg/100 g edible portion were found. The vitamin C content for green mature

and breaker peppers stored at room temperature (20°C, 68°F) increased up to 10 d of storage,

reaching similar values as those obtained for red peppers direct from the plant. However, stored

red ripe peppers showed a significant loss in vitamin C content, around 25%. Refrigeration at 4°C

(39°F) for up to 20 d did not change the ascorbic acid content, except for red peppers, which

showed losses around 15%.

Ascorbic acid content of fresh peppers may also be affected by postharvest chlorinated water

treatments. Green bell peppers dipped in 50, 100, 150, and 200 μg/ml hypochlorite lost 6, 9, 10,

and 18% of their initial total ascorbic acid concentrations, respectively.36 It was recommended that

chlorine concentrations of 50 to 100 μg/ml during a 20-min contact time could be used to control

microbial spoilage without affecting overall quality of bell peppers.

Although the effects of modified-atmosphere storage on ascorbic acid retention in whole fresh

bell peppers are conflicting, minimally processed peppers appear to benefit from modified atmosphere storage. Precut jalapeno peppers stored in modified-atmosphere packages (MAP, 5% O2 and

4% CO2) retained 85% of their ascorbic acid after 15 d storage at 13°C (55°F), whereas air-stored

peppers retained only 56%.37 The MAP treatment also retarded the conversion of L-ascorbic to

dehydroascorbic acid. Similar results were reported for sweet blanched bell peppers stored in

reduced-oxygen atmospheres.38 Ascorbic acid levels were better retained in storage atmospheres

of 2% O2 and 4% O2 than were samples stored in air. Conversion of ascorbic acid to dehydroascorbic

acid was also retarded under reduced-oxygen storage.

Due to its water solubility, ascorbic acid is readily leached from pepper fruit during water

blanching and pasteurization in salt–acid brines. The ascorbic acid content of the Morron pepper

of “Fresno de la Vega” showed reductions of 12 and 20–25% during the water blanching and



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171



subsequent canning process.23 Jalapeno peppers that were blanched prior to pasteurization lost 75%

of their ascorbic acid,20 whereas a 40% loss of ascorbic acid occurred during water blanching of

green bell peppers, and a 15% loss occurred during steam blanching.39 In another study, bell peppers

blanched in water lost 24% of their ascorbic acid, though microwave blanched peppers lost only

15%.40 Ascorbic acid content of unblanched “yellow banana” peppers declined substantially during

pasteurization and storage, with only 10% remaining after 124 d.41 Calcium chloride brine treatment

did not affect ascorbic acid retention in pasteurized yellow banana peppers. In contrast, initial

ascorbic acid levels were retained in jalapeno peppers after blanching and pasteurization.42

Blanching may also affect ascorbic acid retention in frozen peppers. Unblanched “padron”

peppers lost 97% of their ascorbic acid within 1 month of freezing, whereas blanching resulted in

a 28% loss, followed by an additional 10% loss after 12 months frozen storage.43 In another study,

average ascorbic acid losses of ten pepper cultivars that were blanched and stored for 12 months

at –12°C (10°F) were 63%, while unblanched cultivars lost 71%.44 Differences in ascorbic acid

losses in these studies may be attributed to differences in pepper genetics, brine composition,

blanching method, and pasteurization time and temperature.

Ascorbic acid content of dehydrated peppers is influenced by blanching and drying methods.

Paprika fruit lost 63% of its ascorbic acid content when naturally dried, whereas losses of 4 to

54% were observed when freshly harvested and overripe fruit were dried using a forced-air

method.45 Other processing parameters may also influence ascorbic acid retention. A 40% loss

of ascorbic acid in paprika powder was noted after centrifugation prior to drying, and a 73%

loss occurred in carmelized paprika.46 In another study, drying time and temperature did not

affect the ascorbic acid content of dehydrated green bell peppers, but after 8 weeks of storage,

blanched peppers dried for 8 h at 60°C (140°F) contained less ascorbic acid than unblanched

peppers.47 Unblanched peppers dried for 12 h at 49°C (120°F) contained more ascorbic acid than

blanched peppers.



IV. FLAVONOIDS

Pepper fruit are particularly rich in flavonoids, a large class of compounds ubiquitous in plants,

that exhibit antioxidant activity, depending on the number and location of hydroxyl groups present.48

In addition to antioxidant function, flavonoids are reported to possess numerous biological, pharmacological, and medicinal properties, including vasodilatory, anticarcinogenic, immune-stimulating, antiallergenic, antiviral, and estrogenic effects, as well as inhibition of various enzymes involved

in carcinogenesis.49 In addition, many epidemiological studies indicate an inverse association

between the intake of flavonols and flavones and the risk of coronary heart disease,50–52 stroke,53

and lung cancer.54–55

Much progress has been made over the past decade in the identification and quantification of

flavonoids and phenolic acids in capsicum fruit due to advancements in HPLC, HPLC-mass

spectrometry, and NMR techniques. Suskrano and Yeoman56 identified three hydroxycinnamic acid

derivatives: p-coumaroyl, caffeoyl, and 3,4-dimethoxycinnamoyl glycosides, and four flavonoid

compounds, although only two were identified: quercetin 3-O-rhamnoside and luteolin 7-O-glucoside. Iorizzi and colleagues57 identified three hydroxycinnamic acids in Capsicum annuum L. var.

acuminatum fruit, cis-p-coumaric acid-β-D-glucoside, trans-sinapoyl β-D-glucoside, and vanilloyl

β-D-glucoside, as well as one flavonoid, quercetin 3-O-rhamnoside. They also identified a unique

lignan glycoside (icariside E5) that possesses antioxidant properties. Materska and colleagues58

identified nine compounds in pericarp tissue of hot pepper fruit (Capsicum annuum L., var.

Bronowicka Ostra). The compounds identified included 3 hydroxycinnamic acid derivatives: transp-feruloylalcohol-4-)-(6-(2-methyl-3-hydroxypropionyl) glucoside, trans-p-feruoyl-β-D-glucoside,

and trans-p-sinapoyl-β-D-glucoside, as well as six flavonoids: luteolin-7-O-(2-apiosyl-4-glucosyl6-malonoyl)-glucoside, quercetin 3-O-α-L-rhamnoside-7-O-β-D-glucoside, luteolin 6-C-β-D-glucoside-8-C-α-L-arabinoside, apigenin 6-C-β-D-glucoside-8-C-L-arabinoside, luteolin 7-O-[2-(β-



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D-apiosyl)-β-D-glucoside], and quercetin 3-O-α-L-rhamnoside. In a subsequent study, Materska

and Perucka59 evaluated 4 cultivars of Capsicum annuum L. fruit for phenolic content and antioxidant capacity and reported that sinapoyl and feruoyl glucosides were the predominant components

in red pepper, ranging in concentration from 32 to 42 mg/100 g dry weight, and 15 to 36 mg/100

g dry weight, respectively, whereas quercetin 3-O-L-rhamnoside was the major component in green

pepper, ranging in concentration from 33 to 99 mg/100 g dry weight. The antioxidant capacities

evaluated by the β-carotene-linoleic acid and DPPH systems correlated highly with phenolic content

in the fraction containing phenolic acids and flavonoids. Marin and colleagues24 conducted a detailed

characterization of sweet pepper phenolics (Capsicum annuum L., cv. Vergasa), and reported five

hydroxycinnamic acid derivatives and 25 flavonoids in pericarp tissue. In addition to the hydroxycinnamic acid derivatives and flavonoids, previously identified by Materska and colleagues58 in

hot peppers, they identified several novel compounds including 4 flavonoid O-glycosides: luteolin

7-O-(2-apiosyl-6-acetyl) glucoside, chrysoeriol 7-O-(2-apiosyl-6-acetyl) glucoside, luteolin 7-O(2-apiosyl-di-acetyl) glucoside, and luteolin 7-O-2-apiosyl-6-malonyl) glucoside. Additionally, 12

flavonoid glycosides were identified, which included 2 acylated derivatives, luteolin 6-C-(6-malonyl)-hexoside-8-C-hexoside, and luteolin 6-C-(6-malony)-hexoside-8-C-pentoside. Quercetin 3-Orhamnoside and luteolin 7-O-(2-apiosyl-6-malonyl) glucoside were the predominant flavonoids

present in red fruit, showing concentrations of 0.31 mg/100 g fresh weight and 0.39 mg/100 g fresh

weight, respectively. The concentrations of total hydroxycinnamic acids and total flavonoids in red

fruit were 0.44 mg/100 g fresh weight and 2.54 mg/100 g fresh weight, respectively.

The flavonoid content of different pepper types and cultivars is shown in Table 9.2.60 Peppers

contain both quercetin (a flavonol) and luteolin (a flavone). Quercetin has a hydroxyl group at C-3

in the aromatic ring, while luteolin does not (see Figure 9.1). The structural differences are important

since the presence of a hydroxyl group at C-3 is reported to result in greater free radical-scavenging

efficiency.48 In plant cells, flavonoids occur as glycosides, with sugars bound typically at the C-3

position. Flavonoids are commonly quantified in the aglycone form after acid hydrolysis. Flavonoid

levels vary greatly among pepper types and cultivars with total levels ranging from 1 to 852 mg/kg.

Interestingly, C. annuum cultivars contain higher levels of flavonoids than C. chinense cultivars. Low

levels of flavonoids in the pungent C. chinense peppers may indicate diversion of phenolic precursors

from flavonoid to capsaicinoid synthesis. An exception is the C. frutescens cv. tabasco, which contains

much higher levels of luteolin than the other Capsicum species and cultivars. It appears that fruit

from different Capsicum species vary greatly in their genetic capacity for synthesizing specific

flavonoids. Plant breeders and molecular biologists may take advantage of this genetic variability to

increase the flavonoid content of Capsicum fruit. The exceptionally high flavonoid levels reported

by Lee and colleagues18 may be due to differences in genetics and environmental conditions in which

the peppers were grown. Environmental stress during plant growth has been shown to stimulate the

phenylpropanoid pathway and production of various phenolic compounds.

Increasing luteolin levels in pepper fruit may be important for prevention of coronary heart

disease. A luteolin-rich artichoke extract was recently shown to protect LDL from oxidation in

vitro, which may be due to its antioxidant function or ability to sequester prooxidant metal

ions.61Additionally, luteolin does not complex with copper ions to produce oxidative damage to

DNA, which contrasts with the prooxidant effect observed for quercetin.62

Total flavonoid content of pepper cultivars generally declines as fruit ripens and changes color.

For instance, immature green pepper of sweet peppers (Capsicum annuum L.) cv. Vergasa had a

very high phenolic content, but green, immature red, and red ripe peppers showed a four- to fivefold

reduction.24 Red fruit generally contain higher levels of hydroxycinnamic acids than green fruit,

whereas green fruit contain higher levels of flavonoids than red fruit.21,24,59 However, exceptions to

this rule include the cayenne cv. Mesilla, in which the flavonoid content increased during maturation,

and the “long yellow” cv. Inferno, and tabasco cv. Tabasco, in which no change in flavonoid content

occurred during ripening.21 In terms of antioxidant capacity, red fruit generally have greater radical

scavenging capacity than green fruit, 21,57,59 which may be attributed to higher levels of hydroxy-



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173



TABLE 9.2

Flavonoid Content of Fresh Capsicum Fruit

Total

Species

C. annuum



Type

Ancho

Bell



Cascabella



Cayenne

Chile

Jalapeno



Serrano

Yellow Wax



C. chinense



Habanero



C. frutescens



Tabasco



Cultivar

San Luis Ancho

Yellow Bell

Yellow Bell

Tam B-2

Romanian Sweet

YB 244

YB 126

Peto Cascabella

Peto Cascabella

Tam Cascabella

Mesilla

Mesilla

New Mexico-6

Green Chile

Mitla

Tam Mild

Jaloro

Sweet Jalapeno

TAES Jaloro

Hidalgo

Hungarian Yellow

Long Hot Yellow

Gold Spike

Inferno

Inferno

Short Sweet Yellow

Long Sweet Yellow

Short Hot Yellow

Long Hot Yellow

TAES Hot Yellow

Sweet Banana

Francisca

Red Savina

McIlhenny Tabasco

McIlhenny Tabasco



Maturity

Green

Green

Orange

Green

Yellow

Yellow

Yellow

Yellow

Red

Yellow

Green

Red

Green

Green

Green

Green

Yellow

Green

Yellow

Green

Yellow

Yellow

Yellow

Yellow

Red

Yellow

Yellow

Yellow

Yellow

Yellow

Yellow

Orange

Red

Green

Red



Quercetin

Luteolin

Flavonoids

mg/kg Fresh Weight

276

22

13

44

219

81

112

42

24

67

25

11

126

210

40

18

151

45

52

160

784

447

288

68

65

88

56

62

78

79

43

5

1

2

1



34

11

9

9

26

10

15

16

6

30

17

6

51

52

14

10

38

6

18

41

68

104

37

17

17

18

9

14

15

17

6

1

ND

44

36



310

33

22

53

245

91

127

58

30

97

42

17

177

262

54

28

189

51

70

201

852

551

325

85

82

106

65

76

93

96

49

6

1

46

37



Ref.

18

21

21

60

60

60

60

21

21

60

21

21

18

18

18

18

18

18

60

18

18

18

18

21

21

60

60

60

60

60

60

21

21

21

21



cinnamic acid glycosides and capsaicinoids in the ripe fruit.59 The loss of flavonoids observed during

ripening of most cultivars is consistent with reported flavonoid losses that occur during maturation

of C. frutescens fruit.56 Flavonoid losses during ripening may reflect metabolic conversion of

flavonoids to secondary phenolic compounds.63 The oxidoreductase enzymes polyphenol oxidase64

and peroxidase65,66 may play a role in degradation of flavonols during maturation and senescence.



A. POSTHARVEST HANDLING AND EFFECT OF PROCESSING ON FLAVONOID CONTENT

Little information is available on the effects of postharvest handling and processing on flavonoid

content of pepper fruit. The effect of pasteurization and storage on flavonoid content in yellow

banana peppers has been studied.41 Quercetin and luteolin contents declined 40 to 45% during 4



6409_book.fm Page 174 Saturday, September 16, 2006 9:54 AM



174



Handbook of Nutraceuticals and Functional Foods



months’ storage, whereas calcium chloride brine treatment did not affect flavonoid retention.

Apparently, flavonoids are leached into the salt–acid brine during pasteurization and storage. Future

studies should focus on methods to stabilize flavonoids during postharvest handling and processing.



V. TOCOPHEROLS

Capsicum fruit, especially in the dried form, are an excellent source of tocopherols. Vitamin E

compounds including tocopherols and tocotrienols are well recognized for their effective inhibition

of lipid oxidation in foods and biological systems.67 The tocopherols are polyisoprenoid derivatives,

which have a saturated C16 side chain (phytol), centers of asymmetry at the 2, 4′, and 8′ positions,

and variable methyl substitution at R1, R2, and R316 (see Figure 9.1). The antioxidant activity of

tocopherols is due to their ability to donate their hydrogen ions to lipid free radicals, thereby

neutralizing the radical and forming the tocopheroxy radical.

Tocopherols have been shown to be effective scavengers of peroxyl and superoxide radicals in

lipid systems. Epidemiological and short-term intervention studies suggest that vitamin E may

reduce the risk of coronary heart disease, some cancers, cataracts, and diabetes, and slow the

progression of neurological diseases. The health effects of vitamin E may be related to numerous

mechanisms, including protection of cells from oxidative damage; protection of LDL from oxidation; enhancement of the immune system; reduction of oxidative damage of specialized tissues

such as the eye lens, nerve tissue, blood vessels, and cartilage; reduction of cholesterol synthesis

by inhibition of the enzyme HMG-Co A reductase; and enhancement of the antioxidant status of

the digesta.68

The α-tocopherol content of pepper types and cultivars is shown in Table 9.3.69,70 γ-Tocopherol

is found in pepper seeds, whereas α-tocopherol is found in pericarp tissue. Dried paprika and “New

Mexico” type peppers used in the spice industry are a fair source of γ-tocopherol, and an excellent

source of α-tocopherol. New Mexico type cultivars contain higher levels of γ-tocopherol in seeds

than paprika cultivars.22 At the red succulent stage, the γ-tocopherol content of seeds from four

New Mexican pepper cultivars ranged from 35.2 to 47.5 mg/100 g.22 These levels of γ-tocopherol

would provide 2.3 to 3.2% of the RDI for adult males and females, per 1-g serving.

The α-tocopherol content of pericarp tissue in both paprika and New Mexico cultivars is

exceptionally high, but the paprika cultivars are a better source of α-tocopherol. Per 100 g serving,

paprika cultivars provide 107 to 1980% of the RDI for adult males and females, whereas the New

Mexico type cultivars provide 13 to 207% of the RDI for adult males and females. Although small

amounts of dried capsicum powders are typically used for food preparation, their exceptionally

high levels of tocopherols may be an important source of vitamin E in the human diet. A 1-g serving

of dried paprika would provide 1 to 20% of the RDI for adult males and females, whereas a similar

serving of dried New Mexican peppers would provide only 0.1 to 2% of the RDI for adult males

and females. Thus, dried peppers, especially paprika type, may be a significant source for vitamin

E as people incorporate greater amounts of ethnic foods containing dried peppers into their diets.

The α- and γ-tocopherol content of pepper fruit is influenced by maturity. γ-Tocopherol content

in seeds generally increases until the red succulent stage and then declines, while α-tocopherol

content in pericarp tissue increases from the mature green to red fully dry stages.22,46,69 The αtocopherol content in pericarp tissue is dependent on lipid content, which varies according to

ripening stage and variety.69 A high correlation exists between oil content and α-tocopherol content

in dry matter. The percentage of oil and α-tocopherol content is highest in red dried paprika fruit

with 80% dry matter.



A. EFFECT



OF



PROCESSING



ON



TOCOPHEROL CONTENT



OF



PEPPERS



Color retention of dried paprika powder may be related to levels of γ-tocopherol in seeds,71 but

conflicting results are reported. Several studies46,72 showed that color retention of paprika was



6409_book.fm Page 175 Saturday, September 16, 2006 9:54 AM



Antioxidant Vitamin and Phytochemical Content of Fresh and Processed Pepper Fruit



175



TABLE 9.3

Tocopherol Content of Fresh Capsicum Fruit

α-Tocopherola

Species

C. annuum



Type

Paprika



New Mexico



Cultivar



Maturity



Pericarp

(mg/100 g DW)



Vandel

Vandel

Gamba

Gamba

Mild

Mild

Mild

Mild

SZ-20

Mihalytelki

SZ-80

F-03

SZ-178

Km-622c

Km-622c

Km-622c

Km-622c

Km-622c

Km-622d

Km-622d

Km-662d

Km-622d

Km-622d

Mihalyteleki

Mihalyteleki

Mihalyteleki

Mihalyteleki

Mihalyteleki

K-50

Km-622

K-801

Semi-Determ. 7/92

SZ-80

K-V2

K-90

Strain-100

Mihalyteleki

SZ-20

Bibor

Napfeny

Negral

Sandia

Sandia

Sandia

Sandia

Sandia



Green

Red

Green

Red

Green

Green-red

Red

Red-dried

Ripe

Ripe

Ripe

Ripe

Ripe

Green

Breaker-1

Breaker-2

Faint red

Deep red

Green

Breaker-1

Breaker-2

Faint red

Deep red

Green

Breaker-1

Breaker-2

Faint red

Deep red

Deep red

Deep red

Deep red

Deep red

Deep red

Deep red

Deep red

Deep red

Deep red

Deep red

Deep red

Deep red

Deep red

Green

Breaker

Red

Red-partially dry

Red-dried



16

28

17

33

26

46

65

68

47

33

38

61

56

17

48

85

92

109

34

35

43

48

115

43

39

42

38

40

180

192

161

297

139

205

265

141

133

152

95

90

87

5

9

17

10

19



%RDIb

M

107

187

113

220

173

307

433

453

313

220

253

407

380

113

320

567

613

727

227

233

287

320

767

287

260

280

253

267

1200

1280

1073

1980

927

1367

1767

940

887

1013

633

600

580

33

60

113

67

127



F



Ref.



200

69

350

69

410

69

410

69

330

69

580

69

810

69

850

69

590

70

410

70

480

70

760

70

710

70

210

46

606

46

1,060

46

1,150

46

1,360

46

430

46

440

46

540

46

606

46

1,440

46

540

45

490

45

530

45

480

45

500

45

2,250

45

2,400

45

2,010

45

3,710

45

1,740

45

2,560

45

3,310

45

1,760

45

1,660

45

1,900

45

1,190

45

1,130

45

1,090

45

60

22

110

22

210

22

130

22

240

22

Continued.



6409_book.fm Page 176 Saturday, September 16, 2006 9:54 AM



176



Handbook of Nutraceuticals and Functional Foods



TABLE 9.3 (Continued)

Tocopherol Content of Fresh Capsicum Fruit

α-Tocopherola

Species



Type



Cultivar

New Mexico 6-4

New Mexico 6-4

New Mexico 6-4

New Mexico 6-4

New Mexico 6-4

Nu-Mex R-Naky

Nu-Mex R-Naky

Nu-Mex R-Naky

Nu-Mex R-Naky

Nu-Mex R-Naky

B-18

B-18

B-18

B-18

B-18



a

b

c

d



Maturity



Pericarp

(mg/100 g DW)



Green

Breaker

Red succulent

Red-partially dry

Red-dried

Green

Breaker

Red succulent

Red-partially dry

Red-dried

Green

Breaker

Red succulent

Red-partially dry

Red-dried



6

6

16

12

7

3

8

13

11

21

2

8

24

15

31



%RDIb

M



F



40

40

107

80

47

20

53

87

73

140

13

53

160

100

207



80

80

200

150

90

40

100

160

140

260

30

100

300

190

390



Ref.

22

22

22

22

22

22

22

22

22

22

22

22

22

22

22



α-Tocopherol = 1.0 mg αTE.

Recommended daily intakes, adult males and females = 15 mg αTE.

Fruit harvested and analyzed in 1994.

Fruit harvested and analyzed in 1995.



improved with the addition of seeds, though other studies71,72 found that the color stability of paprika

was unaffected by addition of seeds. Conflicting results obtained between the studies may be related

to varying levels of α-tocopherol in the peppers studied. Tocopherol content of dried paprika powder

may also be influenced by cultivar, maturity, and drying method.45 Tocopherol retention was lower

in naturally dried samples than in forced-air-dried paprika. The α-tocopherol content increased

during natural drying, reaching a maximum concentration when the dry matter of the fruit was

between 53 and 68%, whereas a decrease in tocopherol content was observed with fully dry fruits

having a dry matter content of 89%. For forced-air-dried fruit, utilization of fresh fruit as the starting

material resulted in substantial losses of α-tocopherol. The best retention of α-tocopherol was

obtained by drying overripe fruit having 53 to 68% dry matter. Two cultivars evaluated (Km-622

and V-2) lost 12.4 and 41.2% of α-tocopherol, respectively, when their overripe fruits were dried

by the forced-air method. Thus, genetic variation should be taken into account when investigating

the processing quality of new paprika cultivars.

Tocopherol content is affected by additional processing parameters, including predrying centrifugation and carmelization during drying.46 The α-tocopherol content of “paprika” fruit was

highest in carmelized samples, indicating that carmelization of sugar afforded protection against

tocopherol degradation during drying. The α-tocopherol content of centrifuged paprika was lower

than values from noncentrifuged samples, indicating that it was removed from paprika fruit during

the centrifugation step.



VI. CAROTENOIDS

Varying composition and concentration of carotenoids in capsicum are responsible for diversely

colored fruit. Common carotenoids in capsicum fruits are shown in Figure 9.2. Capsicum species