Chilean Endemic/Native Plant Resources as Functional and Superfoods Chilean Endemic/Native Plant Resources as Functional and Superfoods

The current consumer demand for foods or food supplements with "super properties" is being covered by previously under-exploited ethnic products. The endemic flora from multiple continents serve as source of plant foods such as cereals or tropical fruits. Chile, one of the top five plant biodiversity hotspots on the planet, is a promising source of functional foods with little scientific and commercial research. The aim of this chapter is to summarize the findings related to the antioxidant and antibacterial potential of native/endemic plants and plant-derived compounds from Chile. Resources of these compounds may be found in honey, bee pollen, and berry-like fruits. These products, unknown to many parts outside the country, not only have the advantage of their functional properties but also possess denomination of origin, which gives added value and allows them to be used as food additives such as natural colorants, antioxidants, antibacterials, and antifungals. In the coming years, many of these products will be more commercially known and many of these plant species will be selected and improved, as have happened with products such as tofu or blueberries.


Introduction
The latest food consumer trends point beyond fulfilling the function of providing nutrients to the body. It is intended that foods provide compounds capable of reducing the likelihood of developing diseases, improving or complementing the functions of the body, and even increasing life expectancy. A search for new food sources of these "healthy compounds" is underway to meet the needs of today's consumers. New analytical methods are being used with known foods to demonstrate properties they always had, but properties that had not been properly tested because of technological limitations; new foods or derived food compounds are also being found.
The diversity of food we know is derived from the biodiversity of plant and animal species we know. However, there are still many plant species which have not been explored or whose potential is just beginning to come to light. Many of these plants have been used by aboriginal groups around the world since ancient times. These species, which only grow in specific geographic locations (endemism), are rarely objects of scientific study or for industrial or commercial scaling.
Chile is one of the top five hotspots of plant biodiversity on the planet; here it is possible to find new food and food-derived resources of interesting compounds in the poorly explored flora. In addition, the biodiversity of plant species found in Chile have a high degree of endemism, indicating that they do not grow elsewhere. Leaves, stems, roots, or fruits can be sources of antioxidants and/or antibacterial compounds. Among the plant species with potential are the non-fruiting tree specimens such as quillay and ulmo; within fruit tree species, we may find maqui, murta, calafate, and others that are less known. All these products have high contents of polyphenolics, which have high antioxidant and antibacterial properties.
Polyphenolics are secondary metabolites from plants that have been associated with several healthy benefits such as the prevention of cancer, cardiovascular, inflammatory, and neurodegenerative diseases [1][2][3]; they are also associated with bioactive properties such as antioxidant and antibacterial properties [4][5][6][7].
Each phenolic/flavonoid compound has different antioxidant/antibacterial potency depending on its action mechanism. Phenolic compounds alter the permeability of bacterial cell membranes, which may result in the uncoupling of oxidative phosphorylation, the inhibition of active transport, and the loss of pool metabolites due to cytoplasmic membrane damage [8,9]. Other authors explain the antibacterial activity of phenolics by the presence of more number of hydroxyl groups that may form hydrogen bonds with enzymes, altering their metabolism and also the lipid solubility and the degree of steric hindrance [10,11]. In the case of flavonoids, antibacterial activity has been associated with its capacity to form complex bonds with proteins through non-specific forces such as hydrogen bonding and hydrophobic effects, as well as by covalent bond formation. Thus, it may inactivate microbial adhesins, enzymes, and cell envelope transport proteins. Lipophilic flavonoids may also disrupt microbial membranes [12,13].
properties; and prebiotic capacity [24][25][26][27][28]. Meanwhile, the pollen has also been recognized by health claims. Scientific studies have been shown that bee pollen acts as an anti-anemic, tonic and restorative, hormonal and intestinal regulator, vasoprotector, hepatoprotective and detoxifying agent, and antioxidant and antibacterial [29,30]. All these properties vary with the botanical and geographical origin ( Table 1)

Honeys
Chilean honey has shown biological activity against bacteria and fungi. Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae, and Vibrio cholerae have been inhibited by hydroalcoholic extracts derived from honey [49,50]. Meanwhile, Candida albicans has also shown sensitivity to Chilean honey. Chilean honey even has higher antimicrobial activity than Manuka honey, which has a standard antioxidant and antimicrobial activity potential [51]. The antimicrobial activity of honey is probably the result of the total number of active compounds and not the presence of any one of them (i.e., phenolics and flavonoids). This activity may be the result of synergism between flavonoids and phenolic compounds or between phenolic compounds and terpenes. Some phenolic compounds and flavonoids are present only in certain unifloral honeys. These results have allowed for the identification and certification of these honeys. References [48,52,53] identified chlorogenic, caffeic, coumaric, syringic, p-coumaric, vanillic and salicylic acids, naringenin, quercetin and kaempferol in the unifloral honey of Quillay (Quillaja saponaria). In the same report, [52] found p-coumaric, ferulic, and salicylic acids in the endemic unifloral honey of Ulmo (Eucryphia cordifolia). Pinobanksin and kaempferol are typically identified in Chilean honeys.

Bee pollen
Bee pollen provides important ingredients to the human diet, such as carbohydrates, protein, fat, and other components in lesser amount such as minerals. Carbohydrates are mainly polysaccharides such as starch and sugars and represent between 13 and 55 g per 100 g of sample. With regard to protein content, bee pollen provides all essential amino acids to the human diet and their percentages vary between 10 and 40% of the test sample [55][56][57][58][59][60][61][62][63].
Referring to fats, a study reveals that 3% of the total lipids are free fatty acids and about half of them are omega-3 unsaturated oleic, linoleic (omega-6), and linolenic acids (omega-3) [55].
With reference to the mineral content, bee pollen contains potassium, phosphorus, calcium, magnesium, iron, copper, zinc, and selenium in amounts that satisfy the daily recommended intake per person [64]. However, very few studies have identified the phenolic compounds of Chilean bee pollen. The information on bee pollen production for food applications and some reports concerning their antimicrobial and antioxidant activity [54,66,67].
Phenolic acids, flavonoids, and pigments such as β-carotene are mainly responsible for the healthy properties such as antioxidant and antibacterial properties exhibited by bee pollen [68][69][70]. The phenolic acids and flavonoid glycosides are present in the nectar of flowers visited by bees, which are hydrolyzed and transferred to bee pollen. The number and variety of phenolic acids and flavonoids are highly variable, since beekeepers mix bee pollen with different botanical origins from different plant species [22,71]. A major flavonoid found in bee pollen is rutin [72]. The main group of pigments that compose bee pollen are carotenoids, especially β-carotene, whose concentration also depends on the botanical origin of the sample [63]. The β-carotene content is about 17% of total carotenoids. In some cases, it may contain 20 times less carotenoids that some foods [73]. In Chilean bee pollen, the carotenoid content varies with the botanical origin ( Table 2).
The type and concentration of the polyphenolic compound influence the antibacterial and antioxidant activity exhibited by bee pollen. The most important polyphenolic compounds related to these activities are vanillic acid, protocatechuic acid, gallic acid, p-coumaric acid, hesperidin, rutin, kaempferol, apigenin, luteolin, quercetin, and isorhamnetin [70]. Bee pollen rich in these compounds has shown activity against specific pathogens such as S. aureus, which causes skin infections; E. coli, which causes diarrhea [67,77], Streptococcus pyogenes, which causes acute bacterial pharyngitis [78], P. aeruginosa, which produces tissue damage and affects the immune system [79] and S. pyogenes, which causes skin wounds [16]. Another important study demonstrated the inhibition activity against Salmonella spp., as shown Figure 1 [66].

Endemic/native berries
Chile is the main exporter of berries in the Southern Hemisphere and the fifth berry exporter worldwide because of its comparative advantages: geographic isolation of the country (desert in the north, the Pacific Ocean, the Andes mountains, and the Patagonian ice), which makes it an island from the health point of view, decreasing the incidence of pests and diseases; the Mediterranean climate is beneficial to obtain optimal raw material and production and in a counter-season and phased production [80,81]. Maqui, murta, and others recently explored are included in the list of actual and future production (Figures 2 and 3).

Other berries and berry-like fruits
"Calafate" (taxonomically described as Berberis buxifolia and also Berberis microphylla) fruits are berries that are scarcely studied. However, the available information is very interesting and indicates its potential as an antioxidant, which may be related to its high anthocyanin and hydroxycinnamic acid levels [103,104]. Most recently, exploratory studies have revealed new native/endemic berry-like fruits such as Luma apiculata, Ribes punctatum, Ribes magellanicum, Ribes cucullatum and Ribes tribolum [105,106]. Ribes spp., Rubus spp., Gaultheria spp., and Berberis spp., among others, as promising crops of functional foods or food additives/supplements such as natural colorants ( Table 3). Some other non-scientific studies have been related with functional properties of several non-fruiting plants with anticoagulant, antithrombin, and analgesic properties and related health effects [107]. The fruit is a berry, white or pink. ovoid shaped, 6 mm to 12 mm in diameter [108] Chaura Gaultheria mucronata Antioxidant The fruit is a berry, between 6 and 9 mm in diameter, plum-shaped, passing from white to pink and finally to dark purple when ripe [104,109] Chaura Gaultheria antarctica Antioxidant The fruit is a berry, white or pink, ovoid shaped, 6 mm to 10 mm in diameter [110]

Conclusions and future trends
In spite of the endemism, there are promising bee hive-derived products obtained from Chilean plants, as well as Chilean plant products in general. We are convinced that the main exponents of functional foods and super foods are in nature, which is where we have to explore to find them. However, they should be used and exploited in a sustainable way.