10Facultad de Ciencias Veterinarias, Universidad Nacional de Rosario, Casilda, Argentina
11Departamento de Ciencias Básicas, Escuela de Ciencias Agrarias y Naturales, Universidad Nacional del Noroeste de la Provincia de Buenos Aires, Pergamino, Argentina
12Departamento de Nutrición y Bromatología, Facultad de Farmacia, Universidad de Granada, Granada, Spain
13Universidad Autónoma Gabriel René Moreno, Santa Cruz, Bolivia
14Universidad Nacional del Chaco Austral, Presidencia Roque Sáenz Peña, Chaco, Argentina
Abstract
The increasing trend for using natural ingredients for nutraceuticals and phytopharmaceuticals development triggers the study of non-traditional sources for phytopharmaceuticals development, such as underexploited plants and agroindustrial wastes. The extraction, characterization and stabilization of bioactive compounds are intricate due to their low concentrations and their complex interactions in the vegetable matrix. New simple, ecological and efficient technologies are being developed to overcome the disadvantages of traditional extraction procedures, and many strategies should be developed to preserve their bioactivity. Oxidative reactions and protein glycation are two of the main deteriorative reactions affecting biological molecules and functionality loss in vitro and in vivo. Thus, efforts have been extended in search of edible plants with antioxidant or antiglycant properties. This chapter is an outcome of the CYTED Iberoamerican network 415RT0495, which task was to promote the valorization of subvaluated sources of bioactive compounds for food and medical uses.
Keywords: Bioactive natural compounds, edible flowers, industrial by-products and wastes, ultrasound and microwave assisted extractions, analytical antioxidant and anti-glycant assays, microencapsulation techniques
2.1 Introduction
Current trends impulse the use of natural ingredients in food, cosmetic and pharmaceutical industries [1]. Nutraceuticals emerged in the last decade as bioactive herbal formulations with health-promoting capacity, and are employed for the development of functional foods [2]. These trends merge as an answer to consumer demands and require the development of ecofriendly extraction, purification and stabilization techniques.
After the observation of health benefits, symptom relief or disease treatment in different ethnic groups, non-traditional sources of phytopharmaceuticals and nutraceuticals, such as underexploited plants and industrial wastes, are being studied [1–3]. The sustainable use of plant resources, supported by the advances of extraction, stabilization techniques will lead to scientific developments of food ingredients and medicines for the benefit of health. Also, the social and environmental conditions of many regions of the world would be favored through the reduced amount of industrial by-products and losses and the recovery of valuable compounds, relevant for sustainable development.
Once the sources of active biocompounds, or matrix ingredients are identified, extraction procedures are necessary, and the functionality of the extracts has to be confirmed. In the last decades, many improvements of the extraction procedures were developed, and also the analytical methodology for the assessment of their functionality was upgraded.
This review is based in the activities of the CYTED network 415RT0495 composed by members of 8 Ibero-American countries. This network focus in the effective valorization of unexplored plant sources of bioactive compounds for food and medical uses. In this Ibero-American network each member of the eight countries has selected plant materials which they considered under-valuated and/or have been poorly studied, and it was not the aim to analyze an exhaustive number of plants. The tools that the network aims to provide consist of guidelines for sources selection, extraction methodologies, analytical methods, stabilizing procedures and data management.
2.2 Some Unexplored Botanicals From Ibero-America as Potential Sources of Bioactive Compounds
The search of bioactive compounds from Latin-American vegetable sources generally begin after the observation and knowledge exchange among different ethnic groups. Native people intake some of these plants for symptom relief, disease treatment as well as for popular belief. Leaves, flowers, fruits, seeds, stems and roots could be sources of bioactive compounds, anti-oxidant, antitumor, antihypertensive, antidiabetic, antiparasitic, antimicrobial, antihypertensive, cardiodepressive, vasorelaxant, anti-inflammatory, anti-ulcer, antiproliferative, antimalarial, anti-leishmani or antinociceptive properties were reported in the literature [4–6].
2.2.1 South America Regions: Tropical Savanna and Atlantic Forest
The Brazilian Continental Biome (around 8,514,877 km2) includes a large variety of plants. Nevertheless, few of them have been completely studied. Thus, the bioactive compounds or potential carrier materials of many species remain unexplored and need to be characterized [7].
Among the many Brazilian vegetable species from Asteraceae family, Baccharis dracunculifolia (De Candole, D.C.), traditionally named “alecrim do campo”, “alecrim vassoura”, “carqueja”, “chilca”, “cilca”, “erva-de-são-joão-maria”, “suncho”, “thola”, “vassoureira” ou “vassourinha” (Figure 2.1, right) is one of the main plant sources of bioactive compounds present in Brazilian propolis produced in the South East region [8]. This plant that grows mainly in areas of Cerrado, produces essential oil with strong aroma, characteristic of green Brazilian propolis. More than fourteen compounds belonging to the sesquiterpenes and monoterpenes groups have been found in the volatile profile of the extracts obtained from the leaves of B. dracunculifolia. Among them, nerolidol and spathulenol varied seasonally [8], while caffeic acid; 2,2-dimethyl-6-carboxyethenyl-2H-1-benzopyran; drupanin; aromadendrin-4-methylether; artepillin C; p-coumaric acid were also identified [9, 10]. Hydroalcoholic extracts of B. dracunculifolia showed gastroprotective activity (inhibiting ulcers formation in different animal models with decreased of gastric secretion) [11, 16], antinociceptive and anti-inflammatory activities [15] and anticariogenic factors and other antimicrobial activities [10], these latter as so as Brazilian green propolis [12].
Figure 2.1 Left: Jabuticaba fruits (M. cauliflora Berg). Right: Alecrim do campo (B. dracunculifolia).
Source: Falcksbaum, https://es.m.wikipedia.org/wiki/Archivo:Alecrimdocampo.jpg.
Another example of a native plant from the Brazilian Atlantic Forest is Jabuticabeira (Plínia sp.) and also from Santa Cruz area, Bolivia, where it is known as “guapurú”. It belongs to the Myrtaceae family which species Myrciaria cauliflora (DC.) O. Berg and Myrciaria jabuticaba (Vell.) O. Berg are most frequent in the South Central region [14]. The fruits have around 3 cm diameter and barks with dark red to black coloration (Figure 2.1, left), and are consumed fresh or in jellies and liqueurs [18, 19]. They are rich in phenolic compounds such as anthocyanins, flavonoids, tannins, vitamins, fibers and minerals. The bark and seeds, which are usually discarded after pulp consumption, have higher concentrations of these compounds [13]. Cyanidin and delphinidin glucosides were identified in the bark skin from the wastes of these fruits, which are good sources of vitamin C [13], and have been incorporated into foods [16]. The oil extracted from jabuticaba seeds have unsaturated essential fatty acids with predominance of linoleic and linolenic [18], and highly antioxidant compounds are produced by the plant to protect them. Their high antioxidant capacity has been confirmed by electron transfer methods, and they could potentially