Functional Foods from Crops on the Northern Region of the South American Andes: The Importance of Blackberry, Yacon, Açai, Yellow Pitahaya and the Application of Its Biocompounds

ABSTRACT

The search for new nutritional alternatives that favor human health is related to one of the world’s tendencies in science and food technology nowadays: research on food with functional properties (antioxidant activity, prebiotic activity, intestinal motility, among others), mainly regions’ autochthonous products, from which the productive sector can benefit thanks to its transformation and added value generation. In this review, the importance of four Andean food items with the potential to be explored and maximized by obtaining functional products is described. Because of the fact that blackberry, yacón, açaí and yellow pitahaya are promissory Andean foods with exceptional qualities for consumers’ health, information was gathered about studies and possible effects in treatment of diseases, and the most used methods for the product and therefore for their biocompounds. It was concluded that this kind of food items represents important alternatives for the transformation and extraction of biocompounds (pigments, antioxidants, fructo-oligosaccharides, fiber, among others), in which non-thermal technologies play a fundamental role in conserving their functional properties, and at the same time, strengthen rural agro-industry and the exploitation of autochthonous products for strengthening region’s and world’s economy.

KEYWORDS:

• Emerging Technologies
• Functional compounds
• Natural Antioxidants
• Properties
• Stability

1. Introduction

In the past few years, the issue of malnutrition has increased, due to the inappropriate eating habits associated with the unbalanced intake of nutrients, caused by the accelerated life style and excessive intake of processed foods with high amounts of additives and artificial preservatives (WHO 2015).

It has been reported that the main causes of death in the world are attributed to non-communicable diseases (NCD) (38 million people a year), from which 75% occur in countries with low – and middle-income (World Health Organization, n.d.) (Plummer et al., 2016). According to the World Health Organization (World Health Organization, n.d.) among the most common NCDs are: cardiovascular and gastrointestinal diseases, irritable bowel syndrome, arthritis, diabetes, hypercholesterolemia and cancer.

Due to the above, the new research trends in food, agriculture and health areas have focused on developing functional foods, to prevent and/or reduce the cases of NCD, in which 30% are due to food and behavioral factors (Plummer et al., 2016).

Currently, there are many food items classified as functional; among them, we can find fruits, vegetables, cereals and tubers, and although there is still no normalized definition of a functional food item, any food can be considered as such, if it is satisfactorily proven that it provides a beneficial action in one or more body functions, beyond its nutritional effects, in a way that it turns out relevant whether to improve health and well-being or to reduce the risk of disease how cardiovascular diseases, cancer and diabetes (Quintin et al., 2019; Roberfroid, 2000).

On the other hand, Andean crops that were historically part of the population’s diet and in many cases used as medicinal plants, they are now being underutilized, losing these foods’ potential to get innovative products with excellent nutritional and sensory properties (Jacobsen et al., 2003). All of this, thanks to their biocompounds, these crops can act as functional foods, that might supply the population’s needs and produce an added value.

The implementation of these crops has positive social and economic effects, since the food and agriculture sector is facing multiple challenges, because it must produce more food for a growing population in order to guarantee food sovereignty; according to The Six Pillars of Food Sovereignty, developed at The Nyeleni International Steering Committee (2007), there are based on six pillars, where Andean crops and agro-industry play a fundamental role, given that the need for food is prioritized, classified as something else than just a commodity. Food Sovereignty respects producers’ work stimulating sustainable development, in a way that, control is established over production and territory, avoiding the privatization of natural resources and promoting both knowledge and traditional skills such as scientific research, with the purpose of developing new technologies to optimize and make the most of these crops’ potentialities in the inclusion of the worlds’ new tendencies, like a competitive advantage for regions. The same way, as the availability of food increases, imports decrease and exports increase, encouraging small and medium-sized producers (Jacobsen et al., 2003).

Additionally, the use of autochthonous crops and wild plants has an environmental impact, because it favors biodiversity, through the preservation of natural resources, avoiding monoculture sowing methods with fewer agrochemicals (Jacobsen et al., 2003), therefore a reduction in the genetic erosion for future Andean generations.

Therefore, this review provides information about the importance of Andean foods (such as blackberry, yacón, açai and yellow pitahaya), and the physicochemical and functional properties of some of them, through the collection of studies on possible effects on the treatment and/or prevention of diseases (Campos et al., 2012; Da Silveira et al., 2019; Diaz et al., 2017; Gowd et al., 2019, 2018; Tibério de Jesus et al., 2019; De Souza et al., 2016; Oliveira-Barbosa et al., 2016; Sousa et al., 2015; Torres et al., 2017; Van de Velde et al., 2018). In addition, it brings together different stabilization techniques for its biocompounds, as well as advances in its application in the food sector.

2. Andean Food, physicochemical and functional properties

The Andean countries in terms of biodiversity have comparative and competitive advantages over other regions, thanks to their geographical location that attributes them ecological factors such as luminosity, temperature and humidity, which are conducive to the growth of native and tropical crops; with essential characteristics, as an alternative to nutrition problems in much of the world (Gordillo and Obed, 2013; Jacobsen et al., 2003).

In the last few decades, the food and pharmaceutical industries have focused on the exploitation of these crops to prevent and/or treat diseases through scientific research, since the market is in search of healthy foods of plant origin that meet the nutritional requirements ideal for human development with the possibility of supplying or fortifying foods that are currently of industrial production (Rojas-Llanes et al., 2014; The Nyéleni, 2007; International Steering Committee, 2007).

The importance of Andean crops in the agri-food sector is that the variety of food is increased through the use of natural resources available in the region, improving the nutritional status of the daily diet with a greater and better contribution of nutrients and/or biocompounds like proteins, carbohydrates, vitamins, minerals, fiber and antioxidants (Quintin et al., 2019); in the case of blackberry, as a Andes berry or “mora de Castilla” is highly consumed in Colombia where annual production surpassing 1000 tonnes (Osorio et al., 2012); the major productor of açaí is Brazil, although the US, Japanese and European markets have an interest in açaí (Neri-Numa et al., 2018). In addition, many of these crops are resistant to adverse environmental conditions, avoiding periods of seasonal scarcity, or pests and diseases, acting as a biological barrier for other plants, helping to conserve the soil and increasing fertility (Rojas et al., 2010).

Based on the above, the Andean foods studied in the review are blackberry, yacon, açaí and yellow pitahaya, which have different potentialities that make them excellent sources of beneficial compounds for the organism.

2.1. Blackberry

Blackberry, a kind of fruit belonging to the genus Rubus (Rosaceae family, Rubus genus) (Gowd et al., 2018) is a worldwide-distributed fruit (Zia-ul-haq et al., 2014); both blackberries’ native species and improved cultivars are harvested (Clark and Finn, 2014). Andean blackberry, or Castilla blackberry (Rubus glaucus Benth.), is native from tropical zones in America, mainly Colombia and Ecuador (Arozarena et al., 2012), the fruits consist of many small drupes on a receptacle about 1–2.5 cm long and is distinguished by its dark reddish color and bitter taste (Figure 1) (Osorio et al., 2012; Rojas-Llanes et al., 2014).

Figure 1. Blackberry

Source: The authors.

Castilla blackberry is a very coveted fruit in the national and international market (Bowen-Forbes et al., 2010; Sánchez, 2012), because it has a high nutritional content of dietary fiber, folic acid, antioxidants, vitamins (vitamin C, vitamin K) and minerals (calcium, iron, potassium) (Kaume et al., 2012; Rodríguez-Barona et al., 2015; Sariburun et al., 2010); Marques et al. (2010) report berries have rich source of an antioxidant such as ascorbate, beta-carotene, glutathione, alpha tocopherol, anthocyanins and phenolic compounds (Marques et al., 2010).

However, it has critical points after its harvest, since it is highly perishable and has a very fragile structure; these factors lead to a shelf life of three to five days in environmental conditions because during the storage and transportation processes a big amount of product is lost (Franceschinis et al., 2014). Blackberries are very complex when it comes to genetic background, growth characteristics, and number of species; and they’re of special interest compared to other fruits, due to the fact that it has been proven that they contain a big amount of antioxidants, such as phenolic components (ellagic acid, tannins, quercetin, gallic acid and anthocyanins) (Dai et al., 2009; Franceschinis et al., 2014; Huang et al., 2012; Kaume et al., 2012); on the other hand, the stability of anthocyanins depends on numerous factors such as temperature, light, oxygen, pH and the presence of co-pigments (Weber et al., 2017). Studies developed by de Souza and others (2014) state that their intake has a positive impact on human health, it would also prevent some diseases as shown in Table 1, which compiles some research done by different authors who evaluated the physicochemical and functional properties of blackberry, as the presence of phenolic compounds with antioxidant capacity.

Table 1. Functional properties of biocompounds found in blackberries

Biocomponent	Functional Effect obtained	Reference
Cyanidin-3-glycoside	Anticarcinogenic effect (it acts in a synergistic way with other components of the extract). In vitro	(Dai et al., 2009)
	Antioxidant capacity (oxidation induced by radicals by intracellular oxidation). In vitro	(Elisia et al., 2007)
Cyanidin-3-glycoside and Cyanidin-3-dioxaneglycoside	Toxicity Protection capacity induced by ethyl carbamate. In vitro	(Chen et al., 2016)
Polyphenolic Compounds	Brain aging lessening. In vivo	(Bickford et al., 2000; Duffy et al., 2008; Shukitt-Hale et al., 2009; Williams et al., 2008)
	Protection against neurodegeneration. In vitro	(Tavares et al., 2012)
	Protection against endothelial dysfunction and vascular insufficiency. In vitro	(Rossi et al., 2003)
	Reduction in the damage caused by an endo-toxic shock induced by LPS. In vivo	(Sautebin et al., 2004)
	Cytotoxic effect in lung and prostate cancer cells. In vivo	(Seeram et al., 2006)
	Cancerous cells’ apoptosis stimulation. In vitro	(Seeram et al., 2006)

There are many authors that studied the effects of blackberry and its biocompounds on models and line cells. Gomes, et al. (2019) evaluated the effects of blackberry juice supplementation on cisplatin-induced renal pathophysiology in mice, and found protection against histopathological alterations through decreased in urea and creatinine levels and modulation of catalase enzyme activity. Meireles, et al. (2015) analyzed the supplementation with blackberry extract in a context of high-fat or standard diet, in Wistar rats; finding a slightly improved glucose metabolism and significantly decreased levels of lactate, independently of diet. Serino et al. (2020) obtained positive Nox1 expression and atherosclerosis results in male mice that were fed low-fat, high-fat or high-fat supplemented with 2% freeze-dried blackberry powder diets for 5 weeks. Regarding behavioral parameters, oxidative stress and inflammatory markers in a model of mania, Chaves et al. (2020) found that the treatment with blackberry extract was able to prevent hyperlocomotion and oxidative damage in the cerebral cortex, hippocampus, and striatum.

On the other hand, extracts rich in antioxidants have also been studied by various authors. Feresin, et al. (2016) investigated the role of blackberry polyphenol extracts in attenuating angiotensin II–induced senescence in vascular smooth muscle cells (VSMCs). They observed an increment in superoxide dismutase 1 expression, attenuation of the up-regulation of Nox1 expression and the phosphorylation induced by Ang II, and reduced senescence in response to Nox1 overexpression. Gowd et al. (2019) found that gut metabolites of blackberry anthocyanins improved the glucose consumption and glycogen content significantly in HepG2 cells.

Human research has also been carried out as reported by Solverson et al. (2018). The effects of berry intake on energy substrate use and glucoregulation in volunteers consuming a high-fat diet were evaluated. This treatment resulted in a significant reduction in average 24 h respiratory quotient, indicating increased fat oxidation; and the insulin AUC was significantly lower compared to the control.

2.2. Yacon

Yacon (Smallanthus sonchifolius) is an autochthonous tubber from the Andean region (Castro et al., 2017) (Figure 2), it is studied and under-used, and it belongs to the Compositae family (Caetano et al., 2016). It is a productive crop that grows at a 1000–3200 M.A.S.L. altitude, under heat or cold conditions and it doesn’t have any diseases or plagues-related problems due to the protective effects of its di and sesquiterpenes (Sousa et al., 2015). For these reasons yacon can be considered an interesting and promissory crop with high economic and environmental value (Sousa et al., 2015). Although production has developed in a traditional way since pre-Hispanic cultures, it is in Peru where production takes place in the north and south with approximately 600 ha planting areas and the market has grown in recent years, developing agroindustrial products with added value such as syrup, flakes, flour, chips that generate income of importance to farmers from 2771 kg of gross volume in 2001 to 44217 kg of gross volume in 2012 where the largest item in the destination market is the United States (Comisión CODEX Alimentarius, 2012).

Figure 2. Yacon in fresh

Source: The authors.

It is a new herbaceous evergreen plant that has been expanded to many countries such as Japan, New Zealand, Czech Republic and Brazil (Brites et al., 2016; Oliveira et al., 2013), however, it is native from the Andean region, where its tuberous roots are eaten as food because of its juiciness and sweet taste (Caetano et al., 2016; Habib et al., 2011). Since most of the roots’ biomass is composed of water (86%-90% of fresh weight), the energetic value is low; besides, it contains between 60% and 70% of the dry weight in carbohydrates, mainly β-(2,1) fructo-oligosaccharides (FOS), with a low polymerization (3–10 fructans) (Castro et al., 2017). For this reason, yacon’s root has been considered a functional food item (Brites et al., 2016; Habib et al., 2011). It is also rich in phenolic compounds, especially chlorogenic acid, ferulic acid and some other caffeic acid derivatives (Simonovska et al., 2003); it has a long history of safe use in South America and in other places with possible beneficial properties for health, including prebiotic, antidiabetic, antioxidant and antimicrobial effect (Campos et al., 2016). The former being said, it is highly important to explore its most relevant biological properties in order to encourage the industry to value its richness (Sousa et al., 2015).

FOS are sugars naturally found in many edible plants as onions and garlic, but never in such high concentrations as yacon roots. The rise in the use of FOS as food ingredient has started researches on their possible effects on health (Caetano et al., 2016; Habib et al., 2011).

Due to the previous, it is extremely important to explore its most relevant biological properties in order to encourage the industry to value its richness (Sousa et al., 2015), since yacon’s consumption is related to the promotion of human health benefits (See Table 2), such as hypoglycemic effects, chemopreventive potential agent against colon cancer, and improved gastrointestinal function (Caetano et al., 2016; Genta et al., 2009; Sousa et al., 2015).

Table 2. Functional properties of the parts/biocompounds found in yacon

Part/Biocomponent	Functional effect obtained	Reference
Leaves extract	Hyperglycemia treatment and kidney disorder in traditional medicine. In vivo	(Oliveira et al., 2013)
Leaves extract	Hypoglycemic effect of polar extracts. In vivo	(Aybar et al., 2001; Baroni et al., 2008; Genta et al., 2010)
Fructo-oligosaccharides	Reduction of glucose levels in healthy and hyperglycemic bio models. In vivo	(Aybar et al., 2001; Choque Delgado et al., 2012)
	Prebiotic activity with short-chain fatty acids’ production. In vitro	(Sousa et al., 2015).
	Digestion effects, constipation prevention and lipids and blood glucose reduction. In vivo	(Genta et al., 2009)
	Effect on diabetes and metabolic syndrome. In vivo	(Susana et al., 2005)
Phenolic Compounds	Antioxidant activity and glucose reduction. In vitro e In vivo	(Valentová et al., 2005)
Chlorogenic acid and sesquiterpene lactones	Anti-inflammatory properties. In vivo	(Oliveira et al., 2013)
Yacon’s root flour (FOS)	Triglyceride and lipoproteins reduction. In vivo	(Habib et al., 2011).
Yacon syrup	Weight loss and increase in the defecation frequency and satiety sensation (M. obesas). In vivo	(Genta et al., 2009)

Many preparations of yacon demonstrated effects in many health disruptions with clinical or in vivo trials in yacon syrup, Adriano et al. (2019) founded has a postprandial decreasing effect glucose and insulin concentrations in adult, the study was performed randomized, crossover, double-blind clinical intervention with 40 women, consumed breakfast+ 40 g of yacon syrup with 14 f of fructooligosacharides (FOS), in blood measured postprandial glucose and insulin.

In yacon flour Habib et al. (2011) found beneficial effects on diabetes-associated hyperlipidemia in Wistar rats with the administration of flour yacon was in tablets containing level of FOS (340 or 6800 mg/kg body weight per day); Vaz-Tostes et al. (2014) improved intestinal immune response increased the serum levels of IL-4 and fecal sIgA in preschool children received yacon flour in preparations for 18 week (0.14 g FOS/kg of body per day); Grancieri et al. (2017) observed that beneficial effects on the intestinal health of animals with induced colorectal cancer induced in Wistar rats, the animals that received supplementation with 7.5% FOS of yacon flour for 8 weeks.

In yacon-based product was evaluated for Marcon et al. (2019) improves satiety and mucosal integrity, and possibly favor anti-inflammatory immune responses in the colon with increased the number of regulatory T cells, and regulated the expression of RORγt transcription evaluated in BALB/c male mice supplemented with 6.0% FOS + inulin for 8 weeks.

The leaf, Martinez-Oliveira et al. (2018) mentioned how leaf present effective neuroprotection than the root evaluated in Wistar rats induced neurotoxicity ($\beta$$\beta$- amyloid (A$\beta$$\beta$) and supplemented with extracts of the leaves or roots for 14 days measured memory tests and oxidative stress parameters and biochemical parameters regarding toxicogenetic in leaves, Moreira Szokalo et al. (2020) evaluating the in vitro effect of aqueous extract was prepared to that commonly used in popular medicine, 2 g placed in boiling water and left/20 minutes, the extract was performed in thin layer chromatography and high-performance liquid chromatography to identify the main compounds, other test to determine the range of doses and the cytochalasine B-blocked micronucleus (cytome assay) for geneotoxicity, the results to determine safe consumption as a tea infusion of 2% and the inability of the metabolic system to counteract the genetic instability.

2.3. Açaí

Açaí (Euterpe oleracea Mart.) belongs to the Arecaceae family and is a South America native palm tree especially from the Amazonian plain (El Morsy et al., 2015; Xie et al., 2011; Yamaguchi et al., 2015).

Açaí is an economically significant fruit in the Amazonian region of Brazil and it is exported to other regions worldwide (Figure 3) (Garzón et al., 2017); it is used to make drinks and has been used for years in native Amazon communities in countries such as Brazil, Venezuela, Ecuador, Suriname and Colombia; It is sold fresh in the international market to countries such as the United States, Europe, Japan; Brazil being the largest producer and exporter (Alberto Rojano et al., 2011). It is rounded and weighs 2 grams approximately, 17% is edible because the seed is the remaining 83%, and its color when it’s ripe is dark almost black purple (De Souza et al., 2012). It contains around 13% protein, 48% lipids and 1.5% total sugars; it is rich in phenolic compounds, such as anthocyanins (mainly cyanidin-3-O-glycoside and cyanidin-3-rutinoside), epicatechin, velutina and catechin (Brito et al., 2016; Fernandes de Oliveira et al., 2016), mono and polysaturated fatty acids, phytosterols and dietary fiber, plus it is a good source of potassium, magnesium, calcium, phosphorus, sodium and vitamins E and B1 (De Souza et al., 2012; Lucas et al., 2018; Schauss et al., 2006).

Figure 3. Açaí fruit

Source: image sent by Paulo Pedro Costa.

Açaí’s pulp has gotten plenty of attention in the last few years being one of the new “superfruits”, due to its potential antioxidant and anti-inflammatory properties (Brito et al., 2016; Yamaguchi et al., 2015), and it has gained participation and popularity in the export markets as an ingredient in functional food, because it can be eaten fresh or in a variety of beverage or food preparations with functional contributions to the diet, beyond its basic nutritional composition (Fragoso et al., 2013; Xie et al., 2011), as different authors have reported it (see Table 3).

Table 3. Functional properties of biocompounds found in açaí

Biocomponent	Functional effect obtained	Reference
Antioxidants	Anemia, diarrhea, malaria, pain, inflammations, hepatitis and kidney diseases treatment.	(Marques et al., 2016)
	Antioxidant and anti-inflammatory properties. In vitro and In vivo	(Ulbricht et al., 2012; Wong et al., 2013)
Acaí powder	Reduction of colon cancer chemically induced. In vivo	(Fragoso et al., 2013)
	Inhibition of osteoclasts’ activity. In vitro	(Brito et al., 2016)
	Acting as adjuvant to lessen the risk of coronary atherosclerosis. In vivo	(Khayat, 2005)
Acaí juice or extract	Atherosclerosis protective effects (Mice having apolipoprotein E deficiency). In vivo	(Xie et al., 2011)
	Hypercholesterolemic effect. In vivo	(De Souza et al., 2012)
	Anti-inflammatory activity. In vitro	(Schauss et al., 2006)
	Kidney attenuation. In vivo	(El Morsy et al., 2015)
	Increase of neuronal cells’ viability in Alzheimer’s diseases. In vivo	(Wong et al., 2013)
Açaí pulp	Intake a Açaí pulp to a hypoenergetic diet for 60 days reduced oxidative stress and inflammation in patients with overweight and dyslipidemic	(Aranha et al., 2019)
Açaí oil	Antidiarrheal action and anti-inflammatory activity and contraceptive. In vivo	(Favacho et al., 2011)
	It doesn’t have a genotoxic effect in cells. In vivo	(Marques et al., 2016)

As mentioned above, the composition of açaí allows it to have some health benefits, classifying it as a functional food. This is why various authors have sought to demonstrate these effects using cell lines or animal models, by ingesting this fruit in different ways. Monge – Fuentes, et al. (2017) used açaí oil in nanoemulsion (NanoA) as a novel photosensitizer for photodynamic therapy (PDT) used to treat melanoma in in vitro and in vivo experimental models. They found that Tumor-bearing C57BL/6 mice treated five times with PDT using açaí oil in nanoemulsion showed tumor volume reduction of 82% in comparison to control/tumor group. Marques et al. (2016) also evaluated the açaí oil, finding that, according to the cytogenetic tests carried out, this product presented no significant genotoxic effects in the analyzed cells, at the three tested doses (30, 100 and 300 mg/kg).

Regarding the extract, more research has been carried out. Machado, et al. (2019) evaluated the anti-inflammatory effect of açaí extract and its mechanism, in macrophages exposed to phytohemagglutinin to induce inflammation; the extract decreased NLRP3 inflammasome levels and reduced pro-inflammatory cytokines, and caused cell cycle arresting and decreased proliferation. Coelho da Mota et al. (2018) demonstrated that the hydroalcoholic extract of açaí seeds treatment had a protective effect against ischemic damage to TRAM flaps in hamsters, improving microvascular blood flow and increasing the survival of flap zones contralateral to the vascular pedicle. Do Carmo et al. (2017) found that the hydroethanolic extracts from six açaí genotypes have a protective effect (13–62%) on SH-SY5Y cells insulted by H₂O₂ at a concentration of 50 ug/mL by DCFH-DA assay.

On the other hand, some authors have investigated the dehydrated fruit. Choi et al. (2017) supplied pellets containing 5% açaí powder, which reduced the incidences of both colonic adenoma and cancer. In the açaí-treated mice, the myeloperoxidase and proinflammatory cytokines levels in the colon were significantly down-regulated. Fragoso et al. (2018) evaluated the possible protective effects of lyophilized açaí pulp in a colitis-associated carcinogenesis rat model, finding a reduction in the total number of aberrant crypt foci (ACF), ACF multiplicity, tumor cell proliferation and incidence of tumors with high-grade dysplasia.

2.4. Yellow pitahaya

Yellow Pitahaya (Selenicereus megalanthus) belongs to the Cactaceae family and it is a crop originating in the tropical and subtropical regions of America (Figure 4) (Ayala-Aponte et al., 2014; Torres Grisales et al., 2017), specifically in the northern part of South America (Nerd and Mizrahi, 1999); nonetheless, it has been harvested in Vietnam for over 100 years after its introduction by the French (Nerd and Mizrahi, 1999); The yellow pitahaya has 20 species (Selenicereusspp). That occur in Bolivia, Peru, Ecuador, Colombia and Venezuela; being the largest producers in Colombia with 43.7% and Israel with approximately 20.8%, exports are made in fresh fruit marketed in specialty delicatessens as well as in hotels in Europe (Montesinos et al., 2015; Mosquera et al., 2011).

Figure 4. Yellow pitahaya fruit

Source: The authors.

The fruit is a medium-sized berry (around 180–250 g), with a yellow skin having nibs and thorns that detach during the ripening process. Its flesh is white, sweet, soft and slightly fibrous and it contains many small digestible black seeds (Nerd and Mizrahi, 1999).

Yellow Pitahaya is an exotic fruit very desired for its consumption in many parts of the world, not only for its delicious taste and lush color and shape, but also for its nutritional content and well-known functional and medicinal properties (Ayala et al., 2010; Baquero et al., 2005; Diaz et al., 2017). It has a high content of phenolic compounds and ascorbic acid and it has also been reported to be a β-carotene, lycopene and vitamin E source, with average concentrations of 1.4, 3.4 and 0.26 µg/100 g of the edible part, respectively (Wichienchot et al., 2010). It can act as a functional food since you can find beneficial properties in it from the skin to its stem (Diaz et al., 2017); however, as observed in Table 4, there are not enough studies about its benefits on health or its impact in reducing chronic diseases (De Mello et al., 2014; Serna-Cock et al., 2013).

Table 4. Functional properties of biocompounds found in the yellow pitahaya

Part/Biocomponent	Beneficial effect obtained	Reference
Fibers and polysaccharides in the skin	Texture agent in the food industry	(De Mello et al., 2014)
Oligosaccharides	Resistance to hydrolysis due to the gastric juice and the α-amylase, and stimulating of lactobacillus and bifidobacterium’s growth. In vitro	(Wichienchot et al., 2010)
Seeds	Presence of essential fatty acids	(Wichienchot et al., 2010)
From the skin to the stem	Benefical properties lessening the risk of chronic diseases	(De Mello et al., 2014; Serna-Cock et al., 2013).

Besides, when in changing temperature storage and in commercialization, it has been found that browning, necrosis and skin’s softening appear as the main factors of damage, which is one of the main causes of post-harvest loss (Baquero et al., 2005; Vásquez et al., 2016), representing approximately 15% of handling inconvenient. Therefore, it is necessary to employ post-harvest techniques to minimize these losses, to extend the product’s shelf life, or extract the biocompounds of interest in the fruit, so as to produce a higher added value to the sector.

As mentioned, in yellow pitahaya there are numerous studies evaluating the content of antioxidants, vitamins, fatty acids, polyphenols and other compounds with functional potential; however, there are few studies on Selenicereus megalanthus, in vivo studies that demonstrate this effectiveness.

Jauregui and Leon (2018) have evaluated the laxative effect and know in which concentration of the hydroalcoholic extract of the exocarp of the fruit (25%, 50% and 75%) in albino mice; the results, show the laxative effect that the higher concentration of extract, the greater the laxative effect and mentioned to this effect by the presence of active metabolites such as anthraquinones, tannins, mucilages and glycosides; in the other hand, Torres Grisales et al. (2017) evaluated the peristalsis acceleration by measuring feces in biomodels (golden hamster) fed with various parts of this fruit (stem, seed, peel and pulp), found to the seed and pulp show increase of feces in 55.13% and 35.01% respectively. Other author mentioned the effect to the dragon fruit species are Hylocereus and Selenicereus in glycemic control on type 2 diabetes, anticancer property, cardiovascular disease, hypocholestrolemic, prebiotic effect and antimicrobial (Choo, Yian Koh and Pick, 2016; Dasaesamoh et al., 2016; Ibrahim, et al., 2018; Kim et al., 2011; Kumar et al., 2018)

3. Biocompounds stabilization

Sensorial perception (appearance/color, texture, and flavor) and bioactive compounds’ deterioration limits the shelf life of commercial products and restrain the use of biocompounds for certain applications (Carocho et al., 2018; Chung et al., 2016). Overall quality and shelf life can be reduced by several factors including microbial growth, water loss, enzymatic browning, lipid oxidation, off-flavor, texture deterioration, rise in respiration rate and senescence process, among others. For this reason, many researches have been carried out to improve their stability to be used thoroughly in food and beverages (Chung et al., 2016; Quirós-Sauceda et al., 2014; Raybaudi-Massilia and Mosqueda-Melgar, 2012). Furthermore, efficacy of functional products in the prevention of diseases depends on the preservation of the bioavailability of active ingredients (Fang and Bhandari, 2010). In addition, as discussed by Weber et al. (2017) in their research on the stability of spray-dried blackberry anthocyanins decreasing and controlling moisture favors the conservation and stability of functional and physico-chemical characteristics; additionally, the physical chemical behavior as to the retention capacity of biocompounds depends on the material being selected. This is how the use of arabic gum and maltodextrin has been reported as materials that in addition to being economical in scale processes favor the protection of biocompounds (Busch et al., 2017; Diaz et al., 2017; Di Battista et al., 2015; Faridi et al., 2016; Gonçalves et al., 2014; Jia et al., 2016; Mazumder and Ranganathan, 2020); as well as spray drying is the technology that is used most because the scaling and energy expenditure can be lower compared to other technologies (Table 5).

Table 5. Technologies applied to the biocompounds found in Andean food

Food	Biocomponent	Applied Technology	Optimal temperature employed in the process	Results	Reference
Açaí	Anthocyanins	Drying in fluidized bed using maltodextrin	Drying air temperature at 66 °C; 295 airflow rate of 1.24× Qms and maltodextrin concentration of 20.5 % w/w	The result was a nutritious energetic powder with low humidity content, high anthocyanins content, excellent fluidity and a heterogeneous porous surface	(Costa et al., 2015)
		Spray drying with maltodextrin 10DE as coating material	Inlet air temperature at 170 °C; feed flow rate of 15 g/min and maltodextrin concentration of 20%	Powder with high retention of anthocyanins, with influence in the dried temperature	(Tonon et al., 2008)
		Spray drying	The inlet and outlet air temperatures were 140 ± 2 °C and 78 ± 2 °C, respectively. Maltodextrin 10DE, Maltodextrin 20DE or Gum arabic as carrier agent	Powder with high pigment protection and high antioxidant capacity, with influence of the drying temperature and the coating material	(Tonon et al., 2010)
		Lyophilization and Pasteurization	The pulp was pasteurized at 90 °C for 30 seconds	The pasteurization process can improve the anthocyanins preservation and increases their shelf life	(Albarici and Pessoa, 2012)
	Polyphenols	Cross-flow microfiltration with enzymatic treatment (pectinase)	The enzymatic treatment was conducted for 30 min at 35 °C. The microfiltration unit was operated in batch mode for 120 min at 25 °C	Alternative process of flesh clarification, to stabilize the physicochemical properties and functions of açaí	(Machado et al., 2012)
		Lyophilization		Antioxidants and vitamins are preserved. It exhibits an antioxidant value extremely higher than other fruits	(Miao and Wu, 2014)
			Temperature = −20 °C	High content of anthocyanins, proanthocyanidins and other flavonoids	(Schauss et al., 2006)
Blackberry	Anthocyanins	Spray drying	The inlet air temperature was 145 °C and the concentration of carrier agent was 7% (w/w)	Stable powders rich in anthocyanins with high antioxidant capacity, extending their shelf life	(Ferrari et al., 2013; Mahdavi et al., 2014)
		Spray drying with co-pigments	The inlet and outlet temperature was set at 150 °C and 90 °C. The applied coating material was maltodextrin 19 (DE value 18–20)	The presence of co-pigments improved greatly the anthocyanins’ stability of spray dried blackberries	(Weber et al., 2017)
		Ultrasound	Treatment conditions of 100% amplitude level for 10 min at a frequency of 20 kHz	Appropriate preservation technique in the processing of blackberry juice with high anthocyanin retention	(Tiwari et al., 2009b)
	Phenolic compounds	Lyophilization	The solution was frozen at −80 °C for 24 h, with subsequent lyophilization by LIOBRAS L101	High efficiency of compounds’ encapsulation and antioxidant capacity, using B-cyclodextrin and xanthan	(Gonçalves et al., 2014)
	Phenolic compounds and anthocyanins	Freeze-drying with sugars addition and chlorogenic acid	Addition of chlorogenic acid and sugars like glucose and trehalose	Higher anthocyanins and total phenols retention, and high antioxidant capacity, with the addition of glucose and trehalose. Higher anthocyanin content with chlorogenic acid	(Kopjar et al., 2012; Kopjar et al., 2009)
	Phenolic Compounds, anthocyanins and ascorbic acid	Thermo-ultrasound	The optimal conditions were: 50 ± 1 °C at 17 ± 1 min	Alternative to pasteurization for high quality healthy juices’ production with a rise in bioactive compounds and antioxidant capacity	(Cervantes-Elizarrarás et al., 2017)
		High pressure processing	High pressure treatment at pressures from 400–600 MPa for 15 min at ambient temperature (≈20 °C)	Efficient method to preserve compounds and their antioxidant capacity in fresh and nutritious purées, with superior properties than those thermally processed	(Patras et al., 2009)
Yellow Pitahaya		Osmotic deshydration	Osmotic dehydration at atmospheric pressure using sucrose (65 ° Brix) for 4 h at 30 °C	Appropriate preservation technique and/or pretreatment for agroindustrialization of fruit	(Ayala Aponte et al., 2010)
		Lyophilization	The fresh pitahaya slices were frozen at −35 °C and a vacuum pressure of 8 Pa was applied to the sublimation process. The process time was 12 h	Appropriate method to preserve the physical and physicochemical properties of fruit slices	(Ayala et al., 2010)
		Application of 1-methylcyclopropene	application of 200 mg L^−1 aqueous solution of 1-methylcyclopropene (1-MCP) on preharvest yellow pitahaya	Significant beneficial effects on physicochemical and sensorial properties, extending their shelf life	(Serna-Cock et al., 2013; Serna et al., 2012)
Yacon	Fructans	Pulsed vacuum osmotic dehydration	The optimum condition with sorbitol was concentration of 38 °Brix, temperature of 35 °C and vacuum pressure of 74 mmHg	Appropriate pretreatment to get dehydrated yacon with high fructans retention and minor color changes	(Fernandes et al., 2016)
		Ultrasound-assisted osmotic dehydration	The optimum condition was: solution concentration of 60° Brix for both solutions and tus of 2.67 min for xylitol samples and 0 min for sorbitol samples	Appropriate technique for the fruit’s shelf life extension, with good fructans retention under short ultrasound times	(De Mendonça et al., 2015)
	Fructo-oligosaccharides	Scalding and drying	Blanching treatments that included ascorbic acid/CaCl2 and the use of 80 °C as drying temperature	Yacon flour rich in fructo-oligosaccharides with potential for the production of prebiotic functional food items	(Campos et al., 2016)
		Ultrasound	US at 600–1200 W L^−1 for 5 min	Non-thermal technologies appropriate for the processing of fructo-oligosaccharides, without creating significant changes in their concentration or the degree of polymerization	(Alves Filho et al., 2016)
		High pressure processing	HPP at 450 MPa for 5 min
		Cold atmospheric plasma	ACP at 70 kV for 15–60 s
	Phenolic compounds and Fructo-oligosaccharides	Spray drying	Inlet drying air temperature of 140 °C and outlet drying air of 90 °C. Polydextrose were used in concentrations of 10 and 15% (w/v)	This technique showed bioactive compounds’ retention with high antioxidant capacity, and fructo-oligosaccharides suffered less de-polimerization in simple sugars	(Carvalho Lago and Zapata Noreña, 2016)
		Foam mat drying	Yacon juice added of egg albumin as foaming agent were subjected to foam mat drying using a temperature of 70 °C and thicknesses of the foam layer of 0.5 cm	Efficient alternative for processing yacon, through the extraction of high quality, low water activity and satisfactory physicochemical characteristics powdered juices	(Szlapak Franco et al., 2016)
		Vacuum drying	High-drying temperature (65 °C), low slice thickness (0.2 cm) and high acid concentration (1.0 g/100 g solution)	Appropriate technique to dry yacon at low temperatures, increasing its shelf life while keeping its functional and sensorial characteristics	(Reis et al., 2012)

The conventional thermal processing used in the food industry is still the most taken technology for the extension of the shelf life and products’ preservation (Tiwari et al., 2009a); nevertheless, thermal processing particularly under severe conditions can induce many chemical and physical changes which damage the organoleptic properties and can reduce the content or bioavailability of some bioactive compounds (Qin et al., 2019; Rawson et al., 2011) and sensory parameters such as color consistency and flavor (Laura Tibério et al., 2019). Al-juhaimi et al. (2018) in their study collected different investigations where they show that heat treatments can cause various changes in their physicochemical properties, specifically in the activity of the bioactive compounds present in different fruits and vegetables, like strawberry, tomatoes, spinach, shallots, kale, swamp cabbage, and cabbage; Tembo et al. (2017) mentioned degradation ascorbic acid includes dehydroascorbic acid, 2-furoic acid, 2-furaldehyde, 2,3-diketogulonic acid, 3-deoxypentosone, and low molecular weight compounds; dehydroascorbic acid formation is reversible and compounds have no vitamin C activity and may contribute to change in flavor and odor and is possible to form colored compounds including 5-hydroxymethylfurfural in anaerobic conditions.

The thermal and kinetic characteristics of various types of fruits have been conducted to understand the phenomena that occur during thermal degradation how to mentioned Rueda-Ordóñez et al. (2019) the thermal decomposition to exposure biomass can be divided into three stages: moisture evaporation, volatile release and carbonization, thus, depend on the temperature and time (Laura Qin et al., 2019; Rueda-Ordóñez et al., 2019; Tibério et al., 2019). However, some authors report in particular cooking methods (boiling, microwaving) in mushrooms, bitter melon, broccoli, bitter gourd and water convolvulus preserve or improve the nutritional quality like antioxidant activity, L-ascorbic acid ((NG et al., 2011; Ng et al., 2019; NG and Rosman, 2019; Ng and Tan, 2017). Likewise, authors such as Tembo et al. (2017), showed that thermal pasteurization (72 °C, 15 s) retained vitamin C which further showed extended half-life under refrigeration temperature (6 °C).

Hence, consumers’ demand for food and nutritious beverages, that are minimally and naturally treated, has led to the interest in non-thermal technologies. Non-thermal technologies are preservation treatments are effective at environmental or sub lethal temperatures, this way minimizing the negative thermal effects in nutritional parameters and food quality (Qin et al., 2019; Tiwari et al., 2009). The growing interest in these technologies is not only with the purpose of getting high-quality food with “fresh” characteristics, but also to provide food items with improved functionalities (Rawson et al., 2011), as evidenced in the results reported from the use of different technologies by different authors in Table 5.

In the region, research has been carried out with the incorporation of different technologies for both extraction and stabilization of these biocompounds in order to generate products with high added value that may have a market in the food, cosmetic, pharmaceutical industries; either as type products raw material or finished products; being spray drying and the use of encapsulation materials such as gum arabic and maltodextrin the most used raw materials for stabilization of biocompounds.

4. Conclusions

Nowadays the demand for natural products has increased due to the interest in nutritious, safe and environmentally responsible foods. Therefore, we can see that Andean foods and tropical fruits represent a potential source of natural food ingredients, creating a great opportunity for the agroindustry where consumers are looking for exotic characteristics and the presence of compounds able to prevent non-communicable chronic diseases, such as antioxidants, fructo-oligosaccharides and pectins; so the blackberry, the yacon, the açaí and the yellow pitahaya, are within the trend of functional foods. However, the short shelf life of these foods has limited their consumption making their inclusion within the new trends not completely explored yet. Nonetheless, these could have a greater application in the food industry by increasing their stability and that of their biocompounds. This way, the use of non-thermal processing and preservation technologies, as well as studies focused on bioactive compounds such as polyphenols and sugars, will probably grow exponentially, due to the higher consumers’ demand of healthy minimally processed food items. Moreover, the use of encapsulated biocompounds, can lead to improvements both on stability and on bioavailability in vivo and in vitro, and optimize paths for their management and exploitation; in the region, spray drying has been implemented and can continue to be implemented, because it is an economic technology of easy scaling and standardization compared to technologies such as lyophilization and freeze drying that involve high energy expenditure as well as expensive equipment in industrial applications that are difficult for agribusiness companies to access.