Bioactive Compounds in Underutilized Fruits and Nuts

The plant wealth of nature is abundant with fruits and nuts which are widely utilized and exploited as supplementary food sources and also for industrial products as well as for extracting medicines. Simultaneously, natural plant products have been in use in healthcare as drugs, antioxidants, flavors, fragrances, dyes, and insecticides. Plentiful of underutilized fruits and nuts (UFNs) are there in the plant kingdom and have remained underexploited for a variety of reasons but contributed significantly in food sustainability, as ample sources of important phytochemicals, and have the potentiality for income generation as well as for maintaining the environmental balance. A wide range of products have been processed from these UFNs which include safe-to-eat fruits, grains, leaves, nuts, roots and tubers, fibers, oils, medicines, spices, stimulants, and derived products. In this chapter we present the importance of UFNs, their nutritional benefits, their bioactive compounds, and other biological activities.

Fruits are a rich source of natural bioactive compounds, which include polyphenols, vitamins, polyunsaturated fatty acids, amino acids, and carotenoids. These compounds are characterized as healthy foods and demonstrated biological activity in human health in both in vitro and in vivo studies. Increasing evidence of these bioactive compounds has shown biological relevant activities including antioxidant, anti-inflammatory, antimicrobial, hypolipidemic, and neuroactive properties. This chapter defines the basic concepts of bioactive compounds in arid and semiarid fruits and identifies the phytochemicals composition of these fruits in addition to their benefits as antioxidant and chronic disease prevention in relation to human health.

Evaluation of phytochemicals from extract of different plant parts has resulted in the identification of numerous important bioactive constituents in various Annona species. The major phytochemical constituents include acetogenins, alkaloids, essential oils, phenolic compounds, cyclopeptides, amino acids, pigments, and vitamins. These phytochemicals contribute toward several pharmacological activities such as antitumoral, antidiabetic, anxiolytic, analgesic, anti-inflammatory, infectious, and parasitic diseases. The aim of this chapter is to discuss the major phytochemicals like acetogenins, alkaloids, and essential oils and their pharmacological in various Annona species including A. squamosa, A. reticulata, A. cherimola, A. glabra, A. senegalensis, A. crassiflora, and A. coriacea.

The fruit of the California fan palm (Washingtonia filifera) is underutilized. Phytochemical analysis of the fruit has demonstrated its high nutritional values. The fruit is a good source of carbohydrates, soluble sugars, and minerals including calcium, phosphorus, potassium, magnesium, and zinc. The fruit has several bioactive compounds having antioxidant, antibacterial, antifungal, and anti-inflammatory properties. Moreover, unlike other palm species, W. filifera tree is resistant to red palm weevil, which encourages its cultivation as a potential widely used food source.

Cape gooseberry (Physalis peruviana L.), also known as goldenberry, is rich in phytochemicals with potential health-promoting impacts. The diversity of novel products obtained from P. peruviana makes this plant of great commercial importance. P. peruviana has been the subject of scientific and commercial interest. P. peruviana is used in different food products including yogurts, beverages, and jams. This chapter summarizes the recent knowledge on active phytoconstituents and the development of P. peruviana products including novel foodstuffs and nutraceutical and pharmaceutical formulations.

Date is the most widely consumed fruit in the world and is considered an essential part of diet in varied cultures. The main nutrients that date fruit provides are the glucose and fructose. Moreover, dates are considered a good source of some essential minerals such as potassium and magnesium. The consumption of about 80 g of dates per day can contribute one-fourth of the recommended daily requirement of non-starch polysaccharides and potassium. Besides the nutritional values, dates contain natural bioactive components of medicinal importance and nutritive bioactive compounds mainly non-starch polysaccharides and selenium. This chapter highlights research progress related to bioactive compounds of date palm fruits’ bioactive compound forms, synthesis, analytical determination, potential functions, and health benefits.

Longkong (L. domesticum) is an economically important tropical fruit that is widely grown in Southeast Asia, and it is very famous because of its bioactive compounds, including phenols, flavonoids, lipids, and triterpene glycosides. These compounds exhibited various biological functions, and longkong fruit pericarp and seeds demonstrated higher level of bioactivities as compared to the flesh. This chapter provides comprehensive and updated information on the biological functions and their association with the bioactive compounds in longkong fruit and its parts.

Loquat (Eriobotrya japonica (Thunb.) Lindl.) is a subtropical fruit. China and Spain are the major producers of loquat. It is grown in a wide range of climatic conditions from tropical to temperate, and loquat is consumed as whole fruit as well as in the different processed forms. It is nutritionally rich in carbohydrates, vitamins, organic acids, and minerals. Loquat is a prominent source of various bioactive compounds including phenolics, flavonoids, carotenoids, and triterpenoids which exhibit different biological roles such as antioxidant, antiviral, antitumor, hypoglycemic, anti-inflammatory, cytotoxic, antimutagenic, and hypolipidemic activities. In vitro and in vivo studies showed potential health benefits of loquat in mice and several cell lines. However, there is a need of further investigation to correlate the bioactive compounds with the biological activities for better understanding. In this chapter, bioactive compounds of loquat and their biological activities have been summarized.

Rambutan, a widely popular tropical fruit, encompasses rich amount of bioactive compounds. All parts of this plant (leaves, bark, root, fruits, fruit skin, pulp, and seeds) find traditional usage and are linked with high therapeutic values. Rambutan fruit parts like that of peel, pulp, and seeds have been scientifically investigated in depth and is reported to encompass high amounts of bioactive compounds (such as polyphenol, flavonoid, alkaloid, essential mineral, and dietary fiber). These compounds contribute for antioxidant, antimicrobial, anticancer, antidiabetic, and anti-obesity activities. However, literature pertaining toward potential industrial applications (food, cosmetics, pharmaceutical) of rambutan fruits is limited. In the present chapter, it is intended to document some of the interesting research themes published on rambutan fruits and identify the existing gaps to open up arena for future research work.

Solanum betaceum belongs to the Solanaceae family. Its fruit is mainly consumed in South America, but in recent years, it has been distributed to other regions. The different varieties of this fruit are closely linked to its components. Nutritionally, it is an excellent source of vitamin C and also provides vitamins A, B6, and E. However, in this chapter, we will review the nutritional differences according to the region in which S. betaceum is grown in addition to its phytochemical composition and the possible biological activities that have been studied for this fruit.

Soursop (Annona muricata) belongs to the family Annonaceae and is widely distributed and commercially cultivated in tropical and subtropical climates around the world. The stem, leaves, roots, fruits, seeds, peel, and pulp of soursop have been used in traditional medicine for the treatment of diverse ailments. Most of the beneficial activities in human health are attributed to the presence of bioactive compounds (BC) with several in vitro and in vivo biological activities, including anti-inflammatory, antitumoral, and analgesic effects. This chapter focuses on nutritional quality, traditional uses, and the bioactive compounds from A. muricata fruit and their relation with biological activities.

Avocado (Persea americana Mill.) contains a variety of essential nutrients and numerous phytochemicals that play significant roles in disease treatment as well as in management through certain mechanisms. Persea americana consist of long-chain polyunsaturated omega-3 fatty acids (ω-3 PUFAs), which have effects on many human disorders and diseases. Studies suggested that avocado may support cardiovascular health, weight management, and anti-aging. (−)-Epicatechin, a phenolic present in Persea americana fruits, has the ability to directly or indirectly scavenge reactive oxygen species (ROS) by chemically reacting or by modulating the pathways and also acts as an anticancer molecule. All parts of the Persea americana contain secondary metabolites, and their activities against several diseases and metabolic disorders have been discussed in this chapter.

The Bertholletia excelsa Bonpl. seed, Brazil nut, is one of the most important non-timber forest products in the Amazon forest. The commercialization of this nut provides one of the significant sources of income for many indigenous and riverine communities. B. excelsa production is considered organic and environmentally correct. The kernel is an excellent source of protein, energy, and minerals such as selenium (Se), calcium, and magnesium. Selenium is the predominant mineral in B. excelsa, essential in numerous physiological functions. B. excelsa seed has a valuable bioactive composition, including phenolics, flavonoids, tocopherol, and phytosterols, unsaturated fatty acids, proteins, amino acids, and dietary fiber. Intake of phenolic compounds has been associated with potentially beneficial health effects related to anti-inflammatory, antimutagenic, and anticarcinogenic activities. Lipids from B. excelsa are considered as beneficial for health due to the high content of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) and low concentration of saturated fatty acids (SFAs).

Mesua ferrea L. (family, Clusiaceae), popularly called cobra saffron, is a rare plant traditionally used for the treatment of various ailments and is cultivated as an ornamental plant due to its graceful morphology and beautiful, fragrant large white flowers. Mesua ferrea showed wide range of various phytochemical constituents, which are responsible for different medicinal properties. Specifically it contains alkaloids, glycosides, reducing sugar, tannins, phenolics, coumarins, sterols, xanthones, volatile oil, triterpenoids, resins, and saponins. The plant also consists of various active compounds like α-copaene and germacrene D, β-amyrin, and β-sitosterol and some new compounds named as mesuanic acid; mesuferrols A and B; mesuaxanthones A and B; mesuaferrins A, B, and C; mesuaferrones A and B; mesuarin; and mesuol. The plant has shown various pharmacological activities including anti-inflammatory, anti-hemorrhoid, antiulcer, CNS depressant, α-amylase inhibitory, antioxidant, anticancer, diuretic, hepatoprotective, antivenom, antidiabetic, antibacterial, and immunomodulatory effects.

Amazon region has a greatest biodiversity and social diversity from indigenous and riverine populations. The natives of the Amazon, especially indigenous populations, depend on several palms for obtaining raw material for food, housing, clothing, hunting, and fishing including tucuma fruit (Astrocaryum aculeatum). Tucuma is rich in unsaturated fatty acids, carotenoids, and polyphenols. Despite limited scientific reports, tucuma could present important antioxidant, genoprotective, antitumoral, antimicrobial activities.

The current global food system must adapt to the expected growth of world population. This adaptation will probably include an increased consumption of edible wild foods, due to their richness in micronutrients and bioactive compounds, besides providing a cost-effective and sustainable way of improving caloric food security. Acorns (Quercus nuts) have been presenting an important role on the rural economy. In fact, their nutritional value; high contents in bioactive compounds; biological activity such as antioxidant, anticarcinogenic, and cardioprotective properties; and use in the treatment of specific diseases such as atherosclerosis, diabetes, or Alzheimer’s disease have raised the interest in integrating acorns into the human diet. In the present chapter, we present the chemical constituents of acorns and their biological activities.

The Dipteryx alata Vogel is a native plant from the Cerrado biome found in Brazil known as baru almond and representative of edible seeds and similar to those of true nuts. This almond is a source of minerals and also rich in protein and lipid content. Vitamin E and phenolic compounds present in D. alata almond are associated with their high antioxidant activity. The inclusion of 20 g of D. alata in diet has shown positive effects on the lipid profile (↓LDL-c and ↓TC) in humans. This species is economically devalued mainly by the characteristic of sustainable exploitation and dependence on its seasonal production.

Castanea genus includes several chestnut-producing species with ecological and economical interest. The current industrial processing of chestnut generates great amounts of by-products mostly epicarps and integuments; likewise, there is an immense volume of chestnut flowers, burs, and chestnut leaves that remain in the soil, often contributing to the development of insect larvae, which require effective management strategies. Both materials could be included in extraction processes aimed at recovering high-value bioactive compounds. Herein, the compounds with highest interest, as well as their main bioactivities, are thoroughly characterized in each chestnut component, viz., integuments, pericarps, flowers, bur, leaves, and chestnut tree bark.

Calophyllum inophyllum is a woody tree species that exclusively grows on sandy sea beaches along the Western Ghats of India and other parts of the world such as Tropical Asia, East Africa, Malaysia, Vietnam, Indonesia, Philippines, Australia, and several Pacific islands. C. inophyllum has many therapeutic and traditional uses and has great potential since the plant has been reported to have several medicinally important bioactive principles belonging to xanthones, steroids, triterpenes, coumarins, and benzopyrans. Most significantly, 11 compounds have been isolated from C. inophyllum which are having anti-HIV activity. This chapter describes the importance of this plant with a major emphasis on its phytochemistry and medicinal properties.

Bioactive compounds Camu-Camu (Myrciaria dubia (Kunth)) Camu-camu is a shrub native to the Amazon that thrives in areas where flooding is frequent. Genetically, the plant is characterized by a diploid genome and moderate genetic diversity. Several parts of the plant are used in traditional folk medicine to treat a variety of acute and chronic diseases. For over 50 years, the exceptionally high vitamin C content of camu-camu has attracted worldwide attention that continues today because of the recent discovery of several health-promoting phytochemicals with corroborated biological activities (e.g., antioxidant, anti-obesity, antidiabetic). All of these beneficial attributes are well supported by in vitro and in vivo studies as well as human clinical trials. The metabolic precursors of these phytochemicals are synthesized in key metabolic pathways (i.e., the shikimate pathway, the mevalonate pathway). Of these metabolic pathways, we show details for the biosynthesis of betulinic acid, trans-resveratrol, and syringic acid. In conclusion, camu-camu is an exceptional plant for its ability to produce and accumulate significant amounts of a variety of health-promoting phytochemicals. Although several metabolic pathways responsible for the biosynthesis of these phytochemicals have been reconstructed based on fruit and seedling transcriptomes, detailed knowledge of the vast majority of metabolic pathways and their molecular regulatory mechanisms is lacking. Consequently, we must increase our knowledge of the metabolic processes using multi-omic approaches so that we can acquire the skills necessary to develop genetically improved varieties of camu-camu and implement biotechnological applications for the production of these bioactive phytochemicals.

Fig, common fig or edible fig, is the fruit of Ficus carica L. (family: Moraceae) and is one of the most valuable crops in the world. The fruit is edible and is consumed as fresh or in dried forms as well as processed into jams, Fig Newtons, and fig rolls. Ficus carica fruit has incredible medicinal properties and is used for the treatment of different ailments in traditional medicines. Fruits are a rich source of macronutrients and essential micronutrients (i.e., minerals and vitamins) and phytochemicals, such as polyphenols, anthocyanins, and carotenoids. The different phytochemicals in fruits exhibit various bioactivities such as antioxidant, antihypertensive, antimicrobial, hepatoprotective, antispasmodic, antiplatelet, and other health issues. This chapter gives a brief introduction to fig, including nutritional composition, traditional uses, phytochemistry, and bioactivities of fig fruits and clinical trials on dietary supplements of fig extracts.

Semecarpus anacardium Linn. is a tropical plant possessing an extensive range of metabolites which have been isolated and characterized. This chapter gives a critical appraisal of the ethnopharmacological investigations considering the recent findings on this plant. Additionally, it targets to highlight and emphasize the pharmaceutical prospects of this plant which were underestimated but justify a proper scientific analysis for judging the efficacy of this plant for treating health problems and major metabolic disorders.

Pili (Canarium ovatum) is a tropical tree that is indigenous to the Philippines where its center of genetic diversity is located in the Bicol Region. As a nut, Canarium ovatum is considered the priced commodity, and it is often used in the confectionery industry. The pulp, which is totally discarded as waste, contains considerable quantities of bioactive compounds present in the pulp meal as well as in the oil. This chapter describes the characterization of all the parts of Canarium ovatum fruit as source of hydrophilic and lipophilic bioactive compounds with high antioxidant functionality. The exploitation of this underutilized fruit presents a great potential source of phytochemicals with antioxidants functionalities.

Red-jambo is a phenolic compound-rich fruit found in tropical areas of Malaysia and other warm regions of Asia and South America. The phytochemical composition including dietary fibers, phenolic compounds, carotenoids, and volatile compounds of red-jambo fruit has been highlighted along the chapter, as well as antioxidant capacity of its edible parts. The main phenolic compounds in red-jambo are anthocyanins, such as cyanidin-3-O-glucoside, cyanidin-3,5-O-diglucoside, and peonidin-3-O-glucoside concentrated in the peel. Isorhamnetin-3-O-glucoside, quercetin derivatives, catechins, and procyanidins are other flavonoids present mainly in red-jambo fruit peel. The phenolic compounds of the fruit contribute to the majority of the total antioxidant capacity of red-jambo. As potential to functional properties, in vitro studies showed antiproliferative effects of red-jambo fruit extracts against breast and liver tumor cell lines. The bioactive compounds of red-jambo incite investigation on possible relation with in vivo functional properties, mainly with regard to anticancer activity.

Buriti (Mauritia flexuosa) is a palm tree from the Amazon rainforest and is in great abundance in flooded forest areas of Brazil, Peru, Colombia, Venezuela, and Bolivia. Its fruits are of a tremendous interest in the food, cosmetic, and pharmaceutical industries. The chemical compositions of this plant play a major role in the biological properties of buriti, among them terpenoids (especially carotenoids), steroids, tocochromanols, organic acids, simple phenolics, and flavonoids. These compounds contribute to the remarkable antioxidant activity of buriti fruits. This chapter reviews botanical aspects, biological activities, nutritional facts, and phytochemistry of M. flexuosa.

Solanum sessiliflorum (cubiu) is an Amazonian fruit full of agro-industrial, biotechnological, and pharmaceutical potentialities. Part of S. sessiliflorum fruit’s richness is related to its abundance in bioactive compounds and nutrients. Some of these substances are fruit pigments and are more apparent during the ripening process. S. sessiliflorum is particularly rich in vitamin C. The purpose of this chapter is to discuss briefly the composition of S. sessiliflorum fruit.

Carissa carandas bears berry-sized fruits which are edible. The acidic pulp is a common ingredient in culinary preparations such as condiments, curries, beverages, and jams. The fruit is pickled in salt solution which is rich in minerals, acids, phenolic compounds, terpenoids, flavonoids, vitamins, peptides, and sugars. The ripe fruit is full of acids and micro- and macronutrients which combine well with sugars and used to prepare a variety of jams. This plant is used as a traditional medicine which has received scientific awareness for its general ethnomedicinal applications. Traditionally, C. carandas plants are used to cure various diseases and are prepared as fresh juices rather than boiling water and decoction of leaves and flowers. In this chapter we present an account of bioactive compounds of karanda and their biological activities.

Bael [Aegle marmelos (L.) Correa] is an important fruit yielding and medicinal tree which is indigenous to Indian subcontinent. Fruits, leaves, stem, stem bark, root, and root bark of Aegle marmelos are utilized in Ayurvedic system of medicine to cure majority of human ailments. Aegle marmelos fruits have dietary and nutraceutical importance and are used in the preparation of jam, squash, toffee, slab, and wine. Extracts of fruits, leaves, stem, stem bark, root, and root bark of Aegle marmelos as well as isolated compounds have been demonstrated to possess several medicinal properties which have been widely employed. In this chapter, we presented the nutritional status of Aegle marmelos fruits, chemical compounds isolated from different parts of the Aegle marmelos plant, and pharmacological properties of Aegle marmelos extracts and their purified compounds.

Different plant parts and water extracts of Salacia have extensively been consumed in many Asian countries as a food supplement to prevent obesity and diabetes. Studies suggest that extracts of Salacia chinensis regulate multiple enzymes in carbohydrate and lipid metabolism, viz., α-glucosidase, aldose reductase, and pancreatic lipase. The major phyto-constituents of S. chinensis are thiosugar sulfonium sulfates such as salacinol, kotalanol, ponkoranol, and salaprinol and their corresponding de-0-sulfonated compounds. In addition, triterpenes, sesquiterpenes, lignans, xanthones, flavanols, flavonoids, and proanthocyanidins have been reported in S. chinensis extracts, which are attributed to other important medicinal properties. Phenolic glycosides, megastigmane glycosides, and certain triterpenes such as foliasalacins and 1,3-diketofriedelane derivatives have not been studied in detail for their pharmaceutical potentials.

Guava (Psidium guajava), a popular fruit which is used as a common dessert, has been found to be rich in nutrients, including vitamins and minerals that are significant for human health. Parts of the guava tree (root, bark, leaves, and fruits) have been used traditionally for treating certain diseases. Guava extracts have the potential to act as powerful antioxidants against hepatic diseases as well as cancer. The vitamins present in guava help the body improve immunity. Other health benefits include the ability to fight against certain diseases like scurvy and thyroid diseases, and it is essential for the brain and eyesight, along with compensating weight loss. The present chapter mainly focuses on the beneficial activities of guava and nutritional contents of the fruit along with health benefits.

The fruit of Bouea microphylla referred as plum mango or gandaria is a popular seasonal fruit, which is widely consumed in the Malay subcontinent. There is ample of traditional knowledge available among the locals on the use of leaves, bark, fruits, and seeds of this plant. However, very limited research information and scientific report is available on their composition, phytochemicals, or on the bioactive compounds. In the present chapter, we have aimed towards comprehensively providing information on nutritional value, functional qualities, health-promoting bioactive compounds, and volatile constituents of this underutilized fruit.

Limonia acidissima L. (common name: Wood apple) is a fruit-yielding tree that belongs to family Rutaceae, and it is native to Indian subcontinent. Wood apple is a nutrient rich fruit, and the pulp is eaten raw with or without sugar. Pulp is used to prepare juice, jam, jelly, and ice cream. Limonia acidissima L. fruits, leaves, stem and stem bark, and roots possess chemical constituents namely coumarins, lignans, flavonoids, phenolic acids, quinones, alkaloids, triterpenoids, sterols, and volatile oils. The solvent extracts and several isolated compounds from various organs of wood apple are reported to have antioxidant, anticancer, antidiabetic, antimicrobial, hepatoprotective, and larvicidal potentials. In this chapter we highlighted the phytochemicals isolated from various parts of Limonia acidissima L. and their biological activities.

Moringa (Moringa oleifera Lam.) is a highly valuable medicinal plant due to its nutritional and pharmaceutical properties. Being an Indian native plant, it is generally grown in the Indian subcontinent and Africa regions. All the plant parts have different bioactive chemical compounds such as phenolics, tannins, flavonoids, isothiocyanates, saponins, alkaloids, glucosinolates, vitamins, and carotenoids. Leaves and pods of this plant are used as vegetables all over India and in other growing countries. Apart from the nutritional values, these plant parts are rich sources of bioactive compounds which are having numerous nutritional and pharmacological potentials. Though the plant is having many applicable values for human benefits, the plant is underused and not much studied in details. Considering the nutritional, medicinal, and socio-ecological aspect of the Moringa, more attention in terms of research point of view is needed.

Cucurbits (gourds and cucumbers) are one of the most economically important plant families for food consumption globally. One specific representative, Momordica cochinchinensis, is geographically restricted to tropical Asia and contains the highest levels of carotenoids of all the known fruits and vegetables and relatively underutilized, with only the aril from the fruit used in private homesteads as well as in foods and beverages. This chapter highlights the bioactive compounds from the fruit ranging from small phytochemicals to larger proteins with diverse functions for improved health. The potentials and recommendations for future development in the nutraceutical and pharmaceutical industry are discussed.

South Africa is a home to many indigenous fruits. The popularity of including plant-based antioxidants in the diet is increasing due to their health benefits. Kei apple, Natal plum, monkey orange, and marula are common Southern African fruits. Although they are found in the wild, they are commercially grown to produce traditional processed products. This chapter describes the fruit morphology; bioactive compounds such as phenolic acids, flavonoids, ascorbic acid, and amino acids; antioxidant properties; and biological activities present in Southern African fruits such as Kei apple, Natal plum, monkey orange, and marula and their health benefits.

In the past, unfortunately, fruit processing wastes and by-products have not been taken seriously. However, in recent era, fruit processing industries have undergone rapid growth globally owing to the awareness of public and scientists. Fruit processing wastes are considered as valuable resource owing to the presence of a broad spectrum of bioactive moieties including polyphenols, antioxidants, proteins, dietary fiber, enzymes, flavoring aromas, organic acids, and minerals. Scientists are trying to recover various bioactive compounds from these wastes through specific extraction techniques, i.e., conventional and novel techniques. Applications of food processing wastes in food, textile, cosmetic, and pharmaceutical industries can be increased through the extraction of bioactive moieties by various methods. This chapter highlights the bioactive profiling of fruit waste material of different processed foods and guides how we can extract these bioactive compounds. Bioactive extraction techniques include conventional extraction and novel technologies are discussed. Utilization of fruit processing wastes in the production of high value-added products has increased the profitability of the fruit processing industry by reducing the cost of disposal of these wastes.