Indian Journal of Traditional Knowledge Vol. 12(2), April 2013, pp. 195-201 Marketable wild fruits of Sarawak, Borneo: Their mode of consumption, uses and sugar profiles S Muhd Arif Shaffiq 1*, B Japar Sidik 1, Z Muta Harah 2 & R Shiamala Devi 1 1Department of Animal Science and Fisheries, Faculty of Agriculture and Food Sciences, Universiti Putra Malaysia Bintulu Sarawak Campus, 97008 Bintulu, Sarawak, Malaysia 2Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia E-mail: [email protected] Received 21.06.12; revised 28.08.12 Eleven wild plant species documented with fruits mainly used for food and other uses were based on the acquired knowledge passed from elders that has provided local people with wide selection of plants in their diets. Based on the information obtained, 11 wild fruit species were investigated for their sugar concentrations. Taste preference (e.g., mainly sweet, sour, bitter), flavour and ripeness were observed to be important for mode of consumption and uses. HPLC method was used to quantify the major sugars in the fruits. The retention times of sucrose, glucose, and fructose measured were 10.3, 12.7, and 15.1 min, respectively. Artocarpus odaratissimus has significantly high amounts of glucose (39.9 gm kg-1 DW) and fructose (48.5 gm kg-1 DW) whereas Dialium indum and Salacca magnifica had higher sucrose contents in comparison with other wild fruits. Etlingera elatior was found to have the lowest sugar content. Multivariate analysis (PCA) showed 3 groups of fruits species can be separated based on their sugar contents. With respect to glucose/fructose ratio, Artocarpus odoratisimus and Dialium indum have high amounts of fructose, which may induce fructose malabsorption if taken in excessive amount. Information on the wild plant species and their fruit sugar content is essential to determine their potential for further market utilization and human consumption. Keywords: HPLC, Sarawak, Sugar-Pak I, Sugar profile, Wild fruits IPC Int. Cl.8: A61K 36/00, A01G 17/00, B65B 25/01, A01D 46/00, A23B 7/00, A23, C08B, A47G 19/26, A47J 39/02, C07H 5/06, C07H 1/00, C13B 30/14 Borneo, the largest island in the world, has about their fruits determine the selection and mode of 3,000 species of diverse plants of which more than consumption or uses. Wild fruits are usually small in 265 species are dipterocarps and about 155 are size, but are high in fibre content. They often taste endemic to Borneo1. Sarawak, which is a part of sour or even astringent and therefore, are considered Borneo, has a vast tropical rainforest covering an area to have low sugar levels as compared to other of 8,700,000 hectares, which mainly contributes to the cultivated fruits4. Wild fruits are a source of food unique and bizarre plant diversity of Borneo. Forests and income for rural people since they are have always been an indispensable source of food, available in large quantities and are seasonally shelter, and income to the local people residing at its traded in local markets. Wild fruits have reportedly vicinity. Some wild plants and fruits serve as a source high amounts of vitamins and minerals, relatively of food in local community diets. These supplement lower amounts of carbohydrate and calories, and are other food sources, particularly seasonal agricultural free of any synthetic chemicals5. Significant amounts crops and sometimes are even used as emergency of high sugar contents have also been recorded in food supplies, like in conditions of drought and wild cultivars (e.g., in Laurocerasus officinalis) as war 2, 3. Acquired knowledge passed from elders on compared to the cultivated ones, which suggests the wild plants has provided the local people with use of wild fruits as a good source of free sugar wide selection of plants and fruits in their diets. Taste in our diet6. (e.g., sweet, sour, bitter) and flavour of plants and Carbohydrates are a major component and are —————— usually the structural block of plants. They provide *Corresponding author energy and serve as preparatory materials for the 196 INDIAN J TRADITIONAL KNOWLEDGE VOL 12, NO. 2 APRIL 2013 biological synthesis of other constituents in the Willughbeia augustifolia (Miq.), Mangifera pajang human body7. Generally, our food contains two main Kosterm. (embang/embawang), Salacca affinis types of carbohydrates: simple carbohydrates (sugar) Griff. (asam ridan), Salacca magnifica J. P. Mogea and complex carbohydrates8 glucose, fructose, and (remayong), Durio kutejensis (Hassk.) Becc. (durian sucrose are the major constituents of fruit sugars. nyekak), Garcinia parvifolia Benth (asam kundong), Fructose naturally occurs in all fruits as a free Dialium indum L. (keranji), Artocarpus odoratissimus reducing sugar and is considered as the sweetest Blanco (terap), Xanthophyllum escarinatum Chodat sugar. Sucrose is prevalent in almost all plant (langgir), Vitis triloba Roth (lakum/lakom), and kingdoms whereas glucose is synthesized during Etilengera eliator (Jack.) R.M. Smith (kantan, kechala). photosynthesis and is stored in the form of starch in The study samples for sugar content analysis consisted plants9. Wild forest fruits are a free source of sugar of ripe fruits of 11 species of plants that are found in and energy to the local people. Moreover, their the forests of Sarawak, Borneo. availability in the market with affordable prices makes them cheap sources of energy for the rural Sample preparation people. The demand for wild fruits is limited in the All fruits were washed under the running tap water urban area due to their seasonal availability and to remove the dirt and soil. The edible parts of fruits limited commercialization of indigenous fruits10. were sliced and were dried in an air circulating oven Investigations on the sugar profiles of 19 Thai wild at 60ºC for 24 hrs. The dried fruit slices were then fruits in the Asian regions suggest that these fruits are separately ground into fine powders and were kept in a good source of free sugar11. Despite the potential of airtight containers and desiccators for further analysis. wild fruits, yet no studies have been conducted that Determination of sugar content by HPLC provide composition trends or content on the sugar, Extraction and separation of the samples were especially glucose, fructose, and sucrose levels, of carried out based on the Johansen et al.15 and Xiaoli et wild fruits found in Sarawak. al.16 method. One gram of each dried fruits were Wild plants species and their other components extracted in 10 ml of 80% ethanol (80 ml absolute such as fruits, leaves, twigs, flowers, barks and roots ethanol: 20 ml water) at 80ºC in a water bath for were consumed, traded and used for other purposes 60 min. The extracted solutions were centrifuged for such as medicine and household needs. It is hard to 20 min at 2500 x g. The supernatants were then distinguish the plant function either for food or evaporated till dryness in a water bath at 80ºC. The medicine and has been reflected in several studies that residues were then mixed with 0.5 ml of 0.001 M plants were consumed as food and also used for Ca-EDTA17. The prepared samples were then filtered medicine 12, 13, 14. Thus, the main objective of this through a 0.45 µm membrane filter (Advantec-mixed study was to record the mode of consumption of cellulose ester). selected marketable wild fruits available in local The calibration curves were obtained by preparing markets of Sarawak and estimate their sugar standard solutions of D (+) glucose, D (-) fructose, composition. A more detailed knowledge on the and D (+) sucrose (Sigma Chemical Co.) in 50 ppm variability of sugar contents of fruits could be a Ca-EDTA and ultra pure water. Concentrations of the desirable feature for breeding wild fruit selections standard solutions used in this study ranged from 0.05 with improved nutritional quality. Methodology Survey, study sites and sample collection Surveys pertaining to the local produce mainly wild fruits were recorded from the local markets of Sarawak, mainly from Bintulu, Sibu, Sarikei, and Lundu (Fig. 1). The surveys obtained from local traders and suppliers provided information on 11 species in 10 families of diverse wild plants, components utilized and, their mode of consumption Fig. 1—Map of Sarawak showing location of native markets and uses. The wild fruits belonged to the species surveyed. MUHD ARIF SHAFFIQ et al. : MARKETABLE WILD FRUITS OF SARAWAK, BORNEO 197 to 1.00 mg ml-1. Soluble sugars were then analyzed by (sucrose) were found in the fruits (Table 2). Results the high-performance liquid chromatography (HPLC) indicated that the sugars commonly found in all fruits method (Waters Alliance 2695). The HPLC was fitted were glucose and fructose ranged from 2.1 to 39.8 gm with a controller (Waters Delta 600 pump) and an kg-1 dry weight (DW) and 1.9 to 48.5 gm kg-1 DW, inline degasser-AF (Waters) connected with a respectively. Previously published literatures also refractive index (RI) detector (Waters 2414) using a indicate that glucose and fructose are higher as Sugar-Pak I column (Waters). The mobile phase compared to sucrose in Thai wild fruits11. Some reports (0.001 M Ca-EDTA in ultra pure water) was pumped have recorded high amount of fructose and glucose in through the column at a flow rate of 0.4 ml per min. wild fruits. In the 13 sweet cherry cultivars of Slovenia, The temperature of the column was set at 70ºC and of glucose is predominant followed by sucrose21. As ripe the RI detector at 40ºC. The amounts of soluble fruits were used in this study (except V. triloba), the sugars were identified based on their retention times.