Comparison of Solvent-Free Microwave Extraction and Conventional Hydro-Distillation of Essential Oils from four Selected Underutilised Citrus sp. Plants

Essential oils (EOs) are widely used in cosmetic, pharmaceutical, fragrance and food industry. Solvent Free Microwave Extraction (SFME) is a green method for the extraction of essential oils from aromatic plants. The aim of the study is to compare SFME with conventional hydro-distillation (HD) technique, for the extraction of EO from four selected underutilised Citrus plant species in the essential oil industry; Citrus medica, C. reticulata, C. madurensis and C. limon in terms of chemical composition, antioxidant activity and energy consumption. The EOs were extracted using SFME (Microwave power: 700 W for 5 minutes and 400 W for 55 minutes) and HD (for 1 hour) and chemically analysed using Gas Chromatography (GC) and Gas Chromatography and Mass Spectrometry (GC-MS). The Antioxidant activity of the EOs were determined using Ferric Reducing Antioxidant Power (FRAP) and Total Polyphenolic Content (TPC) assays. The GC and GCMS identified 4(10)-Thujene (33.82%) as the major compound in C. medica oil, extracted by HD while that was L- terpinene-4-ol (18%) when extracted by SFME technique. The β-Linalool was the major component in C. reticulata (42.98%) and C. madurensis (37.95%) in SFME extracted EOs, however, it has been dropped down to 26.71% and 26.83% respectively during HD extraction. In C. limon, D-Limonene (43.069%) was abundant in HD- extracted EOs while it was (R)-(+)-Citronellal (39.08%) in SFME-extracted EO. SFME yielded EOs with higher amounts of more valuable oxygenated compounds with higher antioxidant capacities over HD. In comparison with HD, the SFME technique presented higher efficiency with reduced extraction times, costs and energy, yielding EOs with excellent chemical profiles and relatively high antioxidant activity.Keywords: Essential oils, Solvent free Microwave extraction, GC, GCMS, Antioxidan

Cardiovascular disease risk assessment and reduction: summary of updated NICE guidance

NICE recommendations are based on systematic reviews of the best available evidence and explicit consideration of cost effectiveness. When minimal evidence is available, recommendations are based on the guideline committee's (GC's) experience and opinion of what constitutes good practice. Evidence levels for the recommendations are given in italic in square brackets. Definitions of evidence certainty are given in box 1

Summaries of papers presented at the IRMU seminar series

Irrigation management / Tank irrigation / Flow control / Cropping systems / Rice / Participatory management / Natural resources / Maintenance / Rehabilitation / Women in development / Legislation / Water management / Participatory rural appraisal / Project planning / Irrigation design / Standards / GIS / Sri Lanka / Canada / Indonesia

Farmer Participation in Planning, Design and Rehabilitation of NIRP Schemes: Current status and needed improvements - Proceedings of a workshop held in Colombo on 14 October 1994

Maintenance / Sustainability / Operations / Irrigation systems / Farmers' associations / Irrigation management / Decision making / Farmer-agency interactions / Farmer participation / Irrigation design / Rehabilitation / Sri Lanka

Santalum album L. (Indian sandalwood) oil content variation of Welimada region, Sri Lanka

Indian sandalwood (Santalum album) has a cultural and economic attraction mainly because of its fragrant oil, known as Santalol, produced in the heartwood. Due to its woody, sweet aroma and fixative properties, Santalol is widely employed in the fragrance industry; in highly priced perfumes and for incenses. The increasing demand and price therefore, have produced a very high market interest.Welimada-Badulla region of Sri Lanka is accepted as the best geographical location for best growth of sandalwood trees with higher oil yields. However, according to the literature, sandalwood oil quantity varies within the same area even for the same size of trees. The present study was therefore initiated to identify the oil quantity variation in Welimada region due to diameter at breast height (dbh) and height of the tree, as well as the percentage of heartwood available.Samples from four different locations of Welimada area were collected for the present study. Core samples were extracted from the selected trees. Oil from each tree was extracted by hydro- distillation method. The dbh, height and the sapwood heartwood percentages were measured for the sample trees. The variations of oil content were then tested with dbh, height and heartwood percentage. Twenty three trees were used for the present study and the oil content of them varied from 0.05% to 4.28%. According to the results, the oil quantity did not significantly vary with diameter at breast height and percentage of heartwood but showed a negative correlation with height. Therefore, it can be concluded that sandalwood oil quantity does not vary with dbh and heartwood percentage. However more samples need to be analyzed to test the relationship between oil content and height of sandalwood trees.

Summaries of papers presented at Irrigation Research Management Unit seminar series during 1994

Irrigation management / Environment / Income generation / Settlement / Privatization / Water resources development / Irrigation systems / Tank irrigation / Water users' associations / Training / Rehabilitation / Farmer participation / Surface water / Conjunctive use / Sri Lanka

Seasonal planning procedures to improve irrigation management performance: How Kirindi Oya experience can be transferred to NIRP schemes. Proceedings of the Workshop on Seasonal Planning Procedures to Improve Irrigation Management Performance: How Kirindi Oya experience of IIMI/ID can be transferred to NIRP schemes, held at the Irrigation Department, Colombo, Sri Lanka, on 16 May 1994

Irrigation managementIrrigation systemsMaintenanceCropsDiversificationSettlementSalinityWater use efficiencyResource managementRehabilitationPerformance

Programmatic use of molecular xenomonitoring at the level of evaluation units to assess persistence of lymphatic filariasis in Sri Lanka

BACKGROUND:Sri Lanka's Anti Filariasis Campaign distributed 5 rounds of mass drug administration (MDA with DEC plus albendazole) to all endemic regions in the country from 2002-2006. Post-MDA surveillance results have generally been encouraging. However, recent studies have documented low level persistence of Wuchereria bancrofti in Galle district based on comprehensive surveys that include molecular xenomonitoring (MX, detection of filarial DNA in mosquitoes) results. The purposes of this study were to demonstrate the use of MX in large evaluation units (EUs) and to field test different mosquito sampling schemes. METHODOLOGY/PRINCIPAL FINDINGS:Galle district (population 1.1 million) was divided into two EUs. These included a coastal EU with known persistent LF and an inland EU with little persistent LF. Mosquitoes were systematically sampled from ~300 trap locations in 30 randomly selected clusters (health administrative units) per EU. Approximately 28,000 Culex quinquefasciatus were collected with gravid traps and tested for filarial DNA by qPCR. 92/625 pools (14.7%) from the coastal EU and 8/583 pools (1.4%) from the inland EU were positive for filarial DNA. Maximum likelihood estimates (MLE) for filarial DNA rates were essentially the same when the same number of mosquito pools were collected and tested from 75, 150, or 300 trap sites (range 0.61-0.78% for the coastal EU and 0.04-0.07% for the inland EU). The ability to use a smaller number of trap sites reduces the cost and time required for mosquito sampling. CONCLUSIONS/SIGNIFICANCE:These results suggest there is widespread persistence of W. bancrofti infection in the coastal Galle EU 8 years after the last round of MDA in 2006, and this is consistent with other data from the district. This study has shown that MX can be used by national programs to assess and map the persistence of W. bancrofti at the level of large EUs in areas with Culex transmission

Sri Lankan Finger Millet (Elucine coracana) Variety ‘Raavana’ as Potential Probiotic Source

This study aims to isolate and identify probiotic potential lactic acid bacteria from fermented Sri Lankan finger millet variety "Raavana" and to investigate the probiotic characteristics, in vitro safety and efficacy. A bacterial isolate with typical lactic acid bacterial phenotypic and biochemical characteristics was isolated and identified. Partial sequence of the 16S rRNA gene of the Sri Lankan strain was deposited in the NCBI gene bank as Lactococcus lactis subsp. lactis FM_19LAB and the accession number MF480428 was obtained. It did not demonstrate hemolysis, DNase, gelatine hydrolysis activity as well as did not acquire complete resistance to any of the antibiotics tested hence indicating the safety. Lactococcus lactis subsp. lactis FM_19LAB had the capacity to tolerate different concentrations of acid, bile, phenol, salt, simulated gastric juices and range of temperatures. Further it exhibited anti-microbial, anticancer and anti-oxidant activities. Further, Lactococcus lactis subsp. lactis FM_19LAB assimilated cholesterol and produced lactic acid during the fermentation