A Comprehensive Review of Edible Bird Nests and Swiftlet Farming
Total Page:16
File Type:pdf, Size:1020Kb
Journal homepage: www.jcimjournal.com/jim www.elsevier.com/locate/issn/20954964 Available also online at www.sciencedirect.com. Copyright © 2015, Journal of Integrative Medicine Editorial Offi ce. E-edition published by Elsevier (Singapore) Pte Ltd. All rights reserved. ᲒReview "DPNQSFIFOTJWFSFWJFXPGFEJCMFCJSEOFTUTBOE TXJGUMFUGBSNJOH Lee Suan Chua1,2, Siti Najihah Zukefl i1,2 1. Metabolites Profi ling Laboratory, Institute of Bioproduct Development, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor Bahru, Malaysia 2. Department of Bioprocess and Polymer Engineering, Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor Bahru, Malaysia ABSTRACT Edible bird’s nest (EBN) is currently widely consumed by the Chinese community as tonic food and functional food, which is believed to have many medicinal benefi ts. Some studies have reported the biochemical compositions of EBN, graded on the basis of colour, nitrate and nitrite contents. Other studies have shown signifi cant biological effects, while ongoing research is in progress to explore potential pharmacological applications. The high demand for EBNs in the global market has forced the local regulatory bodies to monitor swiftlet farming activities, including the EBN cleaning process. Furthermore, numerous techniques have been developed to authenticate EBN; proteomics is likely to be the most promising of these methods. However, there are limited numbers of relevant protein sequences deposited at the database. More research is needed at the molecular level to explore the mechanisms behind the biological functions, such as bone strength improvement, skin rejuvenation, epidermal growth factor activity and cell proliferation.The current and future prospects of EBN and swiftlet farming are critically reviewed in this article. Keywords: edible bird’s nest; swiftlet farming; proteomics; authentication; Aerodramus Citation: Chua LS, Zukefl i SN. A comprehensive review on edible bird nests and swiftlet farming. J Integr Med. 2016; 14(6): 415–428. *OUSPEVDUJPO the South Eastern part of China[3–5]. Swiftlets are from the Apodidae family. The Greek word apous means “without Swiftlets (Apodidae; Collocaliini) are birds superfi cially feet”, and refers to the swiftlets’ short legs and reluctance similar to swallows (Hirundo rustica, Hirundinidae) and to settle voluntarily on the ground. They perch on the sparrows (Passer domesticus, Passeridae), but they are not surfaces of cave walls or nesting planks where they built closely related. Although swiftlets consume a wide range their nests. Swiftlets are grey brown in appearance and of aerial insects like other species, they can fl y at higher possess a short beak with a wide gape[6]. velocity and have greater maneuverability[1]. There are 24 species of swiftlets recorded in the world. Swiftlets are small in size with body weights between 6 They are divided into four genera, namely Aerodramus to 40 g[2]. They are predominantly found in the South East (echolocating swiftlets), Hydrochous, Schoutedenapus Asian countries from Andaman to Nicobar Island, in the and Collocalia (non-echolocating swiftlets). Indeed, Indian Ocean to the coastal regions of Malaysia, Thailand, the Aerodramus genus is known to be made up of four and Vietnam, Palawan Island in the Philippines and in different species of swiftlets which are A. fuciphagus, A. http://dx.doi.org/10.1016/S2095-4964(16)60282-0 Received July 26, 2016; accepted August 15, 2016. Correspondence: Lee Suan Chua, PhD; E-mail: [email protected] November 2016, Vol 14, No.6 Journal of Integrative Medicine www.jcimjournal.com/jim maximus, A. germani and A. unicolor[7]. The taxonomy, is systematically presented, as well as a review of its morphology and characteristics of swiftlets have been in vivo and in vitro biological effects. The extraction critically reviewed by Looi and Omar[8]. The five most and identification of proteins of EBN and the current common species of swiftlets found in Malaysia and and future prospects of swiftlet farming industry are Borneo Island are Hydrochous gigas, Collocalia esculent also reviewed. Since high demand for EBN provides (white belly swifts), Cypsiurus balasiensis (Asian motivation for falsification of products, here we also palm swift), Aerodramus fuciphagus and Aerodramus review current methods for EBN authentication, including maximus[1,2]. However, most edible bird’s nests (EBNs) their advantages and limitations. produced in South East Asia are builted by three common species of cave swiftlets: A. fuciphagus, A. maximus and &EJCMFCJSEďTOFTU C. esculent. In 1937, Ernst regarded the classification of swiftlets Edible bird’s nest, or “Yan Wo”, is a great delicacy and as the most difficult task in the taxonomy of birds[1]. a traditional medicine, which is also considered to be a Swiftlets are diffi cult to be distinguished physically, and beauty enhancer. Currently, it is widely used as healthy are best identified by their nests, which may include food due to its high nutritional values and therapeutic feathers and impurities. For example, 85%–90% of the benefits. The market value of EBN ranges from $1 000 nests from A. maximus are comprised of feathers, while to $10 000 per kilogram depending on its grade, type and the remaining 10%–15% are edible; whereas the nests origin[8]. of C. esculenta are comprised of 95%–98% feathers and EBN is composed of secretions from the swiftlet’s other impurities, and the remaining 1%–2% are edible[1,9]. sublingual salivary glands, which is used as a cement in Because of the high impurity content of A. maximus the nest. The secretions are produced at the greatest rate and C. esculenta nests, they are not ideal for human during nesting and breeding season. The sublingual consumption. However, the nests of A. fuciphagus are salivary glands may increase their weights from 2.5 preferred, more valuable, and heavily exploited, as they to 160 mg[13]. This sticky secretion is regurgitated and are mainly composed of salivary secretion (70%–80%) hardens once it is exposed to air, forming the bird’s nest. with relatively small amounts of impurities (20%–30%), The nests are built into the walls of inland or sea-side such as feathers and droppings[10]. caves, over a period of approximately 35 days, and mainly Swiftlets exhibit colonial behaviour, and are usually builted by male swiftlets[14,15]. The glutinous secretions present inlarge numbers at their nesting or hunting sites. form a part of the nest, and bind together other materials, They are able to produce echolocation calls which aid such as feathers, seaweed or mosses[15]. them in hunting insects and navigating in total darkness[11]. EBNs are built in a half-bowl shape; their curvature is One of the most intriguing features of the birds is that they made up of fi ne strands of solidifi ed saliva and numerous secrete a viscous mucus from their salivary glands and feathers, while the ends are formed from thick and use it as construction material for the nests that protect compact solidifi ed secretions. Such structure enables the their eggs and hatchlings[12]. Furthermore, swiftlets are nest to withstand the weight of their eggs and hatchlings, observed to be faithful to their nesting sites, and rebuild and remain firmly attached to the walls throughout the their nests in the same site even after their nests are course of a breeding season[16]. The unprocessed EBN removed. has an approximate length of 5.0–10.0 cm and breadth of The most famous swiftlet nesting sites are Niah Cave 3.5–6.0 cm. The thickness of the nest at the curvature is and Gomantong Cave, which are located in Sarawak about 0.5–1.0 cm, while its thickness at the ends is around and Sabah, respectively, in Malaysia. There are also 1.0–2.5 cm, and approximately 4.0–8.0 g per piece in many nesting sites at the southern tip of Borneo Island weight. in Indonesia. The caves come in various shapes and There are three different colours, white, orange and red, sizes, but they share a similarity of being dimly lit or in that are found in EBN in the market. The difference in total darkness. The poor lighting conditions create an colour is not known. One of the most popular hypotheses environment exclusive to swiftlets, providing a natural is that the red coloration is produced by swiftlets’ blood form of protection against their predators. The caves of which is released during the construction of the nests. swiftlets are also well-known for strong ammonia smell, Some people believe that red nests are produced from generated from the massive amount of swiftlet droppings natural fermentation in the bird house or cave. The colour that accumulate on the ground. Although the droppings of nests may change from white to yellow, and then are a major deterrent to most creatures including human, slowly become orange or red[17]. Other theories suggest they are a main source of nutrients for insects. that the colour is related to the food source of the swiftlets, Here, a review on EBN and its biochemical composition which is mainly insects, and may have high mineral or Journal of Integrative Medicine November 2016, Vol 14, No.6 Download English Version: https://daneshyari.com/en/article/8693328 Download Persian Version: https://daneshyari.com/article/8693328 Daneshyari.com.