Phytochemicals and Medicinal Properties of Indigenous Tropical Fruits with Potential for Commercial Development

Hindawi Publishing Corporation Evidence-Based Complementary and Alternative Medicine Volume 2016, Article ID 7591951, 20 pages http://dx.doi.org/10.1155/2016/7591951 Review Article Phytochemicals and Medicinal Properties of Indigenous Tropical Fruits with Potential for Commercial Development Hock Eng Khoo,1,2 Azrina Azlan,1,2,3 Kin Weng Kong,4 and Amin Ismail1,2,3 1 Department of Nutrition and Dietetics, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia 2 Research Centre of Excellence for Nutrition and Non-Communicable Diseases, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia 3 Laboratory of Halal Science Research, Halal Products Research Institute, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia 4 Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia Correspondence should be addressed to Azrina Azlan; Received 28 December 2015; Revised 29 April 2016; Accepted 4 May 2016 Academic Editor: Daniela Rigano Copyright © 2016 Hock Eng Khoo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Hundreds of fruit-bearing trees are native to Southeast Asia, but many of them are considered as indigenous or underutilized. These species can be categorized as indigenous tropical fruits with potential for commercial development and those possible for commercial development. Many of these fruits are considered as underutilized unless the commercialization is being realized despite the fact that they have the developmental potential. This review discusses seven indigenous tropical fruits from 15 species that have been identified, in which their fruits are having potential for commercial development. As they are not as popular as the commercially available fruits, limited information is found. This paper is the first initiative to provide information on the phytochemicals and potential medicinal uses of these fruits. Phytochemicals detected in these fruits are mainly the phenolic compounds, carotenoids, and other terpenoids. Most of these phytochemicals are potent antioxidants and have corresponded to the free radical scavenging activities and other biological activities of the fruits. The scientific research that covered a broad range of in vitro to in vivo studies on the medicinal potentials of these fruits is also discussed in detail. The current review is an update for researchers to have a better understanding of the species, which simultaneously can provide awareness to enhance their commercial value and promote their utilization for better biodiversity conservation. 1. Introduction Southeast Asian countries, including Malaysia, have tropical rainforests with a variety of fruit-bearing trees. These trees are evergreen and growing throughout the year. Many of these trees produce edible fruit for animals living within the scrubs and some of these fruits are even used by the local communities in their traditional medicine [1]. Since centuries ago, human started to cultivate different plant species to harvest their edible fruits as food sources. In the ancient days, cultivation of the fruit-bearing trees for their edible fruits was done only by planting them beside the house or around the housing areas. Hence, the fruits can be easily harvested during the fruiting season. Large-scale farming has been introduced and started in the later years for commercialization of these tropical fruits due to increasing in their market demand. Today, many of the tropical fruits have been commercialized. These fruits are banana (Musa spp.), durian (Durio zibethinus L.), jackfruit (Artocarpus heterophyllus Lam.), mangosteen (Garcinia mangostana L.), papaya (Carica papaya L.), pineapple (Ananas comosus [L] Merr.), pitaya (Hylocereus spp.), pomelo (Citrus maxima [Burm.] Merr.), rambutan (Nephelium lappaceum L.), and watermelon (Citrullus lanatus [Thunb.] Matsum. & Nakai). However, in this decade, some indigenous tropical fruits previously unavailable in the market became available in the local markets of Southeast Asia. These include ambarella (Spondias dulcis 2 Evidence-Based Complementary and Alternative Medicine L.), cempedak (Artocarpus integer [Thunb.] Merr.), langsat (Lansium domesticum Corrêa), pulasan (Nephelium mutabile Blume), and salak (Salacca zalacca [Gaertn.] Voss), whereas bambangan (Mangifera pajang Kosterm.), dabai (Canarium odontophyllum Miq.), durian nyekak (Durio kutejensis Hassk. & Becc.), and some wild bananas (Musa spp.) [2] are found mainly in the Borneo market because they are native to Borneo Island. However, some of these fruits are still collected from their wildly grown trees, and their potential medicinal properties are not well understood. This review comprehensively discussed the phytochemicals and medicinal properties for 15 species of indigenous tropical fruits. Their common names, as well as the scientific names, are shown in Table 1. In this review, the 15 species of indigenous tropical fruits are grouped into indigenous tropical fruits with potential for commercial development and indigenous tropical fruits that are possible for commercial development in Southeast Asia, particularly in Malaysia [3]. The indigenous tropical fruit with potential for commercial development are fruits that are frequently consumed by the local communities and readily available in the local markets of Southeast Asia especially during the fruiting season. These fruits, however, are less attractive than the commercially available species. Hence, they are not cultivated in a large-scale plantation or as cash crops. On the other hand, indigenous tropical fruits that are possible for commercial development are those fruits that have lesser popularity than the previous one, and they are only available in part of the tropical regions. Many of these fruits have high nutritive values but their medicinal properties remain unknown [3]. Thus, more effort is needed to research on these fruit species, especially phytochemicals in the fruits which are necessary for future promotion on their use as food and medicine. In this review, phytochemicals of the selected indigenous tropical fruits are categorized into three major groups: (1) phenolics, (2) carotenoids, and (3) terpenes and terpenoids. These phytochemicals are commonly found in many fruits. Anthocyanins are the compounds that contributed to the attractive color of many fruits, ranging from red to purple, whereas carotenoids give yellow to orange colors to fruit. Carotenoids in fruit are divided into carotenes and xanthophylls [4], whereas phenolic compounds in fruits are phenolic acids and flavonoids [5]. Terpenes and other terpenoids in fruits are mainly the volatile compounds, especial (...truncated)