**2. Horticultural species with functional properties and their potential use in human health**

The properties and features of some horticultural species that have beneficial effects on human health are mentioned here. It is important to note that the artichoke, leek, hot chili pepper, and coriander are considered in this section, because these species are widely consumed by the human population.

#### **2.1. Artichoke (***Cynara cardunculus* **var. scolymus and** *Cynara scolymus***)**

These species belong to the *Asteraceae* family (**Figure 1**) are native to the Mediterranean region [10] and grow in many parts of the world [11]. *Cynara scolymus* is cultivated due to its large immature flower heads, which have special functional and nutraceutical characteristics, and a high antioxidant capacity, with more than 9000 µmol trolox equivalents (TE) 100 g−1 FW [12]. This antioxidant capacity is due to its high content of total polyphenols like caffeoylquinic acids and flavonoids [7]. These polyphenols are present in flower heads, with values ranging from 4.8 to 29.8 mg g−1 FW in different Italian varieties [7, 13, 14]. It is important to mention that these values are not only dependent on the genetic background, as the interaction genotype-environment also has an influence [7]. Therefore, antioxidant content may be affected by agricultural practices, because in different locations, the same variety may have different antioxidant capacities.

**Figure 1.** Immature flower head of artichoke.

levels of cholesterol, cardiovascular diseases, etc., foods, especially those that are functional,

Despite a wealth of information, there is no universal definition about what constitutes a functional food. However, there is consensus concerning central concepts, which are associated with their benefit for human health beyond their traditional nutrients [2]. Along the same lines, the importance of phytochemicals as a class of biologically active metabolites in plants is accepted [3]. When discussing "potential use for human health" to refer to a particular plant, preliminary evidence on its outstanding phytochemical content must already exist, which means it can be used in the future as a source to investigate more profoundly its beneficial

Some processes such as cooking alter the content and composition of phytochemicals present in vegetables, reducing their concentrations by thermal degradation or augmenting their concentration with respect to the raw material. However, these effects are varying with the cooking method and type of phytochemical [4]. These, together with the growing consumption of fiber, are the principal reasons to recommend the regular intake of fresh vegetables [5]. Functional foods may be plant or animal products, that are fresh, semi-processed or processed, but in this chapter we will refer mainly to fresh plants and their properties beyond their nutritional characteristics. In addition, we will also discuss the existence of several common horticultural and fruit plants that are widely available and consumed by the human population, whose functional properties have yet to be systematized and categorized. Vegetables with high functional interest such as artichoke, leek, hot chili pepper, and coriander, as well as fruit plants such as kiwifruit, sweet orange, and highbush blueberry are considered [6–9]. Within the species discussed in this chapter, only artichokes must be consumed cooked, whilst the

We believe that the updated information about plants with characteristics as functional foods responds to a need of the population and scientists to learn more about healthy habits and

**2. Horticultural species with functional properties and their potential use** 

The properties and features of some horticultural species that have beneficial effects on human health are mentioned here. It is important to note that the artichoke, leek, hot chili pepper, and coriander are considered in this section, because these species are widely consumed by

These species belong to the *Asteraceae* family (**Figure 1**) are native to the Mediterranean region [10] and grow in many parts of the world [11]. *Cynara scolymus* is cultivated due to its large immature flower heads, which have special functional and nutraceutical characteristics, and a

how consumption of natural foods can improve their quality of life.

**2.1. Artichoke (***Cynara cardunculus* **var. scolymus and** *Cynara scolymus***)**

are only a part of the solution [1].

186 Superfood and Functional Food - An Overview of Their Processing and Utilization

implications in human health.

others may be eaten fresh.

**in human health**

the human population.

Choleretic and hypocholesterolemic activities, due to the presence of chlorogenic acid, cynarin, and lutein, have been reported in clinical studies, which demonstrated the effect of leaf extracts on the inhibition of the biosynthesis of cholesterol in rat hepatocytes [15]. Furthermore, these extracts prevented necrosis in rat hepatocytes provoked by hydroperoxides indicated for treatment of dyspepsia, or dyskinesia of the bile ducts, as well as disorders in the assimilation of fats in humans [16–18]. The nutraceutical and therapeutic actions of several metabolites are summarized in **Table 1**. The positive effects of ingesting *C. cardunculus* flower heads have been widely demonstrated; nevertheless, artichoke leaves and external parts of bracts may be used in industrial processes to obtain functional metabolites for use in human health.


**Table 1.** Selected plant species and their compounds that are beneficial for human health.

Inositol and inulin are soluble carbohydrates, which are present in external bracts of artichokes. In the case of inositol (chiro-scyllo- and myo-inositol), values fluctuate from 6.7 to 9.3 mg g−1 DW while for inulin they fluctuate from 69.8 to 114.6 mg g−1 DW [16]. These values are higher than the ones reported by Hernández-Hernández et al. [17] in edible bracts of artichoke. Regarding the beneficial properties, inositols have been used in treatments against diabetes mellitus [18]. In this sense, Crawford et al. [19] reported that inositol prevents diabetes mellitus in pregnant women and concluded that myo-inositol shows promising results by preventing the onset of the disease. Furthermore, inulin has been associated with some beneficial functional properties, as it can be a good source of carbohydrates and fiber, associated with positive effects in the prevention of colon cancer [20, 21]. In addition, prebiotic properties and effects on the absorption of calcium have been reported [20, 21]. In this sense, research on mineral absorption of calcium and magnesium concluded that inulin can reduce risk for osteoporosis by increasing their absorption [22].

#### **2.2. Leek (***Allium ampeloprasum* **var. porrum or** *Allium porrum***)**

**Species Molecule Part of plant Specific function for human** 

Inulin Flower head, stem and leaves

Polyphenols White part and green

Ascorbate White part and green

Methanolic extracts White part and green

Hydroalcoholic extracts White part and green

leaves

leaves

leaves

leaves

Fruit and leaves

*Capsicum annuum* L. Polyphenols Fruit Antioxidant capacity [37, 174]

Dietary fiber Fruit Anticarcinogenic, prevents

Essential oils Fruit and leaves Anticancer activity [176, 177] Extracts Seeds Hypocholesterolemic [51] Extracts Seeds Antidiabetic [49]

Ethanolic extract Root Antimicrobial [48] Extracts Aerial parts Antioxidant activity [47] Hydroalcoholic extract Aerial parts Anticonvulsant [15]

Ethanolic extract Seeds Cognitive effects (improves

Fruit, seeds and leaves Anxiolytic, sedatives,

antidepressant

learning in the long term)

Aerial parts Analgesic [55]

Steroidal saponines White part Antiinflammatory,

Caffeoylquinic acids, flavonoids, and cynarin

188 Superfood and Functional Food - An Overview of Their Processing and Utilization

Chlorogenic acid and

Steroidal saponines/ polyphenols

Essential oil, aqueous, methanolic and ethanolic extracts

Diethyl ether and aqueous extracts

Aqueous, ethanolic and chloroformic extracts

**Table 1.** Selected plant species and their compounds that are beneficial for human health.

cynarin

*Cynara cardunculus* L. var. scolymus L. / *Cynara scolymus*

*Allium ampeloprasum* Var. porrum / *Allium porrum*

*Coriandrum sativum* L.

**health**

Luteolin Flower head and leaves Hypocholesterolemic [171]

Flower head and leaves Antioxidant capacity [7, 12–14]

Flower head and leaves Choleretic, hepatoprotective [168, 169,

Stimulates the intestinal flora, hypocholesterolemic

Growth and tissue repair,

gastroprotective and antiulcerogenis

anticancer agent

Hypolipidemic/ hypocholesterolemic

antioxidant

White part Cytotoxic activity: a potential

Antioxidant capacity [28]

Antimicrobial [35]

diabetes, hypocholesterolemic

Prevention of several chronic degenerative disorders

**References**

170]

[170]

[28, 30]

[31, 32]

[33, 35]

[172, 173]

[9, 175]

[8, 44, 48]

[51, 54, 56]

[53]

It has been reported that this species has a substantial nutraceutical and functional properties (see **Table 1**) and is cultivated in Asia, America, and Europe, especially in the Mediterranean region [23, 24]. *A. ampeloprasum*, belongs to subgenus *Allium* section *Allium* (**Figure 2**), is considered a "complex species" due to different ploidy levels and genome constitution, and diploid, tetraploid, and octoploid accessions have been described [25, 26]. In fact, Hirschegger et al. [27] suggested that molecular evidence could be used to consider this species as a tetraploid horticultural group together with other *Allium* genus species. This condition is particularly important in accounting for its nutritional, functional, and nutraceutical characteristics [28].

**Figure 2.** Green leaves and white part of leek.

The principal beneficial properties of the *Allium* genus are mainly due to the presence of many sulfur compounds containing bioactive constituents, including: dimethyl disulfide, methyl propenyl disulfide, propyl propenyl disulfide, dimethyl trisulfide, methyl propyl trisulfide, methyl propenyltrisulfide, S-methyl cysteine sulfoxide, S-propyl cysteine sulfoxide, S-propenyl cysteine sulfoxide, and N-(*γ*-glutamyl)-S-(E-1-propenyl) cysteine [6].

In the evaluation of 30 leek cultivars, the content of total phenols varied from 5 to 15 mg gallic acid equivalents (GAE) g−1 DW for whole plants [28]. Other studies reported values of 5.5–6.0 mg GAE g−1 DW in whole leeks [29]. These differences in the total phenolic content could be attributed to the genetic variability of this species and agricultural systems [28]. Moreover, in the same study, the oxygen radical absorbance capacity (ORAC) was evaluated, where the green leaves possessed 82–135 µmol TE g−1 DW, whereas the white part contained just 27–88 µmol TE g−1 DW. Additionally, Vandekinderen et al. [30] determined the total vitamin C content (ascorbic acid + dehydroascorbic acid) whose values reached 9.65 mg 100 g−1 FW in whole leeks. Bernaert et al. [28] reported 5.54 mg ascorbic acid (AA) g−1 DW in whole leeks and higher values in green leaves than in white parts (2.77–8.52 mg AA g−1 DW and 0.89–3.55 mg AA g−1 DW, respectively). Values of polyphenols, AA, and antioxidant activity may be influenced by the season of year, genetic characteristics, and biotic and abiotic factors during vegetative growth, as well as agricultural practices.

The antiinflammatory, gastroprotective, and cytotoxic activities of organosulfate compounds, saponins, particularly steroidal saponines, have been well documented in *A. ampeloprasum* var. porrum [31–33].

Another property that is exclusive to the *Allium* genus is their antimicrobial activity (see **Table 1**). This has been reported since ancient times, and leeks have been used to treat wounds and respiratory diseases, as well as acting as an antibacterial agent due to the presence of alliin-containing structures [34, 35]. Polyphenols of methanolic extracts of green leaves and white parts of *A. porrum* are potent against Gram-positive (*Staphylococcys aureus* ATCC 25923 and *Bacillus subtilis* ATCC 6633) and Gram-negative (*Klebsiella pneumoniae* ATCC 13883, *E. coli* ATCC 25922, *Proteus vulgaris* ATCC 13315 and *Proteus mirabilis* ATCC 14153) bacteria, as well as fungal species (*Candida albicans* ATCC 10231 and *Aspergillus niger* ATCC 16404) [28]. These authors affirm a negative effect of methanolic extracts of *A. porrumon* Hep2c, L2OB, and RD cell cultures. This cytotoxic activity could indicate a future use of these natural biological compounds in human health.

#### **2.3. Hot chili pepper (***Capsicum annuum* **L. var. longum)**

The fruit of this species (**Figure 3**), immature or mature and leaves, contains at least two groups of bioactive compounds of significance for human health, polyphenols and carotenoids. The polyphenol content is variable but reaches over 20 mg GAE g−1 DW in mature and dried fruits [36], and 40 mg GAE g−1 DW in leaves [37]. The polyphenols of fruits have a total antioxidant capacity of 26.6–44.4 µmol TE g−1 DW, depending on the variety [36]. According to Serrano et al. [38], the small intestine has around 25% of bioavailability of total polyphenols.

**Figure 3.** Immature fruit of red hot chili pepper.

The principal beneficial properties of the *Allium* genus are mainly due to the presence of many sulfur compounds containing bioactive constituents, including: dimethyl disulfide, methyl propenyl disulfide, propyl propenyl disulfide, dimethyl trisulfide, methyl propyl trisulfide, methyl propenyltrisulfide, S-methyl cysteine sulfoxide, S-propyl cysteine sulfoxide,

In the evaluation of 30 leek cultivars, the content of total phenols varied from 5 to 15 mg gallic acid equivalents (GAE) g−1 DW for whole plants [28]. Other studies reported values of 5.5–6.0 mg GAE g−1 DW in whole leeks [29]. These differences in the total phenolic content could be attributed to the genetic variability of this species and agricultural systems [28]. Moreover, in the same study, the oxygen radical absorbance capacity (ORAC) was evaluated, where the green leaves possessed 82–135 µmol TE g−1 DW, whereas the white part contained just 27–88 µmol TE g−1 DW. Additionally, Vandekinderen et al. [30] determined the total vitamin C content (ascorbic acid + dehydroascorbic acid) whose values reached 9.65 mg 100 g−1 FW in whole leeks. Bernaert et al. [28] reported 5.54 mg ascorbic acid (AA) g−1 DW in whole leeks and higher values in green leaves than in white parts (2.77–8.52 mg AA g−1 DW and 0.89–3.55 mg AA g−1 DW, respectively). Values of polyphenols, AA, and antioxidant activity may be influenced by the season of year, genetic characteristics, and biotic and abiotic factors during vegetative growth, as well as agricultural

The antiinflammatory, gastroprotective, and cytotoxic activities of organosulfate compounds, saponins, particularly steroidal saponines, have been well documented in *A. ampeloprasum*

Another property that is exclusive to the *Allium* genus is their antimicrobial activity (see **Table 1**). This has been reported since ancient times, and leeks have been used to treat wounds and respiratory diseases, as well as acting as an antibacterial agent due to the presence of alliin-containing structures [34, 35]. Polyphenols of methanolic extracts of green leaves and white parts of *A. porrum* are potent against Gram-positive (*Staphylococcys aureus* ATCC 25923 and *Bacillus subtilis* ATCC 6633) and Gram-negative (*Klebsiella pneumoniae* ATCC 13883, *E. coli* ATCC 25922, *Proteus vulgaris* ATCC 13315 and *Proteus mirabilis* ATCC 14153) bacteria, as well as fungal species (*Candida albicans* ATCC 10231 and *Aspergillus niger* ATCC 16404) [28]. These authors affirm a negative effect of methanolic extracts of *A. porrumon* Hep2c, L2OB, and RD cell cultures. This cytotoxic activity could indicate a future use of these natural biological

The fruit of this species (**Figure 3**), immature or mature and leaves, contains at least two groups of bioactive compounds of significance for human health, polyphenols and carotenoids. The polyphenol content is variable but reaches over 20 mg GAE g−1 DW in mature and dried fruits [36], and 40 mg GAE g−1 DW in leaves [37]. The polyphenols of fruits have a total antioxidant capacity of 26.6–44.4 µmol TE g−1 DW, depending on the variety [36].

S-propenyl cysteine sulfoxide, and N-(*γ*-glutamyl)-S-(E-1-propenyl) cysteine [6].

190 Superfood and Functional Food - An Overview of Their Processing and Utilization

practices.

var. porrum [31–33].

compounds in human health.

**2.3. Hot chili pepper (***Capsicum annuum* **L. var. longum)**

Regarding the total carotenoids present in different varieties of red hot chili peppers, Hervert-Hernández et al. [36] indicated values from 87.6 to 373.3 mg 100 g−1 DW. In addition, the same authors determined that the bioavailability of chili carotenoids in the small intestine ranges from 20 to 50% of the total content, depending on the variety [36]. In addition, *C. annuum* is also a good source of vitamin C (up to 26.5 mg g−1 DW) [39]. Minerals, mainly potassium and magnesium, as well as dietary fiber, reducing sugars (around 20% DW), and antimicrobial activity useful for functional food production are also characteristic of this species [9]. Regarding the antimicrobial activity, De et al. [40] identified three pathogens that are susceptible to ethyl alcohol extracts of chili: *Bacillus subtilis* ATCC6633 (minimum inhibitory concentration (MIC) 10–25 mg mL−1), *Escherichia coli* ATCC10536 (MIC 25–50% mg mL−1), and *Saccharomyces cerevisiae* ATCC 9763 (MIC 2–5% mg mL−1). In addition, an antimicrobial activity in *Staphylococcus aureus* ATCC14154, *Escherichia coli* ATCC-1698, *Pseudomonas aeruginosa* ATCC-23993, *Candida albicans* ATCC-14053, and *Sarcina lutea* (Collection of Microbiology Laboratory of Chemical Engineering Department, Institut Teknologi Bandung) has also been reported using ethanolic extracts of chili [41]. These authors indicate that capsaicin may be one of the main responsibles of microorganism inhibition. Likewise, Huang et al. [42] affirm that developments of *Staphylococcus aureus, Saccharomyces cerevisiae*, and *Aspergillus niger* were negatively affected by capsaicin.

#### **2.4. Coriander (***Coriandrum sativum* **L.)**

This species of the *Apiaceae* family (**Figure 4**) is usually cultivated throughout the year in diverse edafoclimatic areas [43]. It is native to Italy and is currently propagated in several Mediterranean regions of Europe, as well as in America and Asia [44]. It is consumed principally fresh, either alone or in salads. This species has multiple human health benefits and has considerable potential as a functional horticulture species (see **Table 1**). *C. sativum* contains essential oils in seeds and in the pericarp whose content and composition appear to be dependent on biological and geographical traits [35]. The oil content is approximately 1% of seed weight of which linalool is the major component (73%) [44–46]. In the stem and immature leaves, the most important compounds are essential oils, flavonoids (quercetin, kaempferol, and acacetin), phenolic acids (vanillic acid, p-coumaric acid, syringic acid, p-OH benzoic acid, cis-ferulic acid, and trans-ferulic acid), and polyphenols [8]. The principal phytochemicals are *β*-carotene (5.1 mg g−1 DW), AA (1.16 mg 100 g−1 FW), total phenolics (2.05 mg GAE 100 g−1 DW), and antioxidants (1.12 mg GAE 100 g−1 DW) [47].

**Figure 4.** Stem and immature leaves of coriander.

According to Kumar et al. [48], ethanolic extracts of fresh coriander roots contain alkaloids, flavonoids, terpenoids, sterols, carbohydrates, saponins, and phenolic compounds. This extract and its fractions possess significant antibiotic activity against *Staphylococcus aureus, Bacillus cereus, Salmonella typhi*, and *Klebsiella*.

The antihyperglycemic (antidiabetic) activity of coriander has been studied by several authors. Deepa and Anuradha [49] analyzed the effects of coriander seed extracts in rats, which showed decreases by 44% in blood glucose and by 58% in glycosylated hemoglobin levels with respect to untreated rats. At the same time, the insulin level in plasma increased to 40%. They also reported beneficial effects in kidney and pancreas. Moreover, *C. sativum* seeds have hypocholesterolemic properties in rats, increasing hydroxymethyl glutaryl CoA (HMG-CoA) reductase and plasma lecithin cholesterol acyl transferase activities [50, 51].

**2.4. Coriander (***Coriandrum sativum* **L.)**

192 Superfood and Functional Food - An Overview of Their Processing and Utilization

and antioxidants (1.12 mg GAE 100 g−1 DW) [47].

*Bacillus cereus, Salmonella typhi*, and *Klebsiella*.

**Figure 4.** Stem and immature leaves of coriander.

This species of the *Apiaceae* family (**Figure 4**) is usually cultivated throughout the year in diverse edafoclimatic areas [43]. It is native to Italy and is currently propagated in several Mediterranean regions of Europe, as well as in America and Asia [44]. It is consumed principally fresh, either alone or in salads. This species has multiple human health benefits and has considerable potential as a functional horticulture species (see **Table 1**). *C. sativum* contains essential oils in seeds and in the pericarp whose content and composition appear to be dependent on biological and geographical traits [35]. The oil content is approximately 1% of seed weight of which linalool is the major component (73%) [44–46]. In the stem and immature leaves, the most important compounds are essential oils, flavonoids (quercetin, kaempferol, and acacetin), phenolic acids (vanillic acid, p-coumaric acid, syringic acid, p-OH benzoic acid, cis-ferulic acid, and trans-ferulic acid), and polyphenols [8]. The principal phytochemicals are *β*-carotene (5.1 mg g−1 DW), AA (1.16 mg 100 g−1 FW), total phenolics (2.05 mg GAE 100 g−1 DW),

According to Kumar et al. [48], ethanolic extracts of fresh coriander roots contain alkaloids, flavonoids, terpenoids, sterols, carbohydrates, saponins, and phenolic compounds. This extract and its fractions possess significant antibiotic activity against *Staphylococcus aureus,*  Additional properties such as analgesic, anticonvulsive, anxiolytic, sedative, antidepressant, and cognitive effects of coriander have been tested *in vivo* in mice. In many cases, its effect was comparable with equivalent standardized doses of the typical drugs used to treat these diseases, elegantly demonstrating the beneficial properties of coriander in human health [15, 52–56].
