Browsing by Author "Wimalasena, S."

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A study of the essential oils of pepper ( Piper nigrum) by combined GC/MS analysis
(Proceedings of Sri Lanka Association of Advancement of Science, 1990) Paranagama, P.A.; Jayathilake, G.S.; Jayawardene, A.L.; Mubarak, A.M.; Senanayeke, U.M.; Wimalasena, S.
A study of the essential oils of nutmeg and mace (Myristica fragrance) by combined GC/MS analysis
(Proceedings of Sri Lanka Association of Advancement of Science, 1989) Paranagama, P.A.; Jayathilake, G.S.; Jayawardene, A.L.; Mubarak, A.M.; Senanayeke, U.M.; Wimalasena, S.
A study of the essential oils of turmeric (Curcuma longa) by combined GC/MS analysis
(Proceedings of Sri Lanka Association of Advancement of Science, 1990) Paranagama, P.A.; Jayathilake, G.S.; Jayawardene, A.L.; Mubarak, A.M.; Senanayeke, U.M.; Wimalasena, S.
A study of the essentials oils of clove bud, stem and leaf (Carryophyllus aromaticus) by combined GC/MS analysis
(Proceedings of Sri Lanka Association of Advancement of Science, 1990) Paranagama, P.A.; Jayathilake, G.S.; Jayawardene, A.L.; Mubarak, A.M.; Senanayeke, U.M.; Wimalasena, S.
Analysis of Volatile Oil inthe Leaves of Murraya koenigii
(Trop. Med. Plants, 2002) Paranagama, P.A.; Wimalasena, S.; Jayatilake, G.S.; Jayawardena, A.L.; Senanayake, U.M.; Mubarak, A.M.
Dietary fibre content of some rice varieties under raw and parboiled conditions
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Adikari, A.C.; Wimalasena, S.
There is a growing demand on foods rich in dietary fibre due to their beneficial health effects. Rice is the staple food for over 50% of the world population including Sri Lanka. This study reports the content of total dietary fibre (TDF), insoluble dietary fibre (IDF) and soluble dietary fibre (SDF) in two varieties of raw rice (RW)(BG 300 and BG 352), and two varieties of parboiled rice (PB)(BG 300 and BG 352) under two levels of bran removal (10% and 7%) obtained from the Institute of Post Harvest Technology, Anuradhapura. IDF was calculated by subtracting the protein and ash content from the weight of the residue obtained after hydrolyzing the sample of rice with Tetramyl enzyme, pepsin enzyme solution and pancreatin solution. The SDF was determined by subtracting the protein and ash content from the residue obtained by incubating the filterate from enzyme hydrolysis with ethanol. Protein content was determined by the Kjeldhal method and the ash content by heating in a muffle furnace at 550 0 C. It was observed that percentage of TDF, SDF and IDF ranged from 56.7% - 44.7%, 16.6 - 12.5% and 40.1 - 30.1% respectively in RW while in PB the values ranged from 63.6 -45.4%, 17.3 -10.8%, 46.2 - 34.61% respectively. For raw rice the highest TDF, SDF and IDF were obtained for BG 300 (10%) while in parboiled rice the highest value was obtained for BG 352 (10%). In all samples except for BG 352 (RW) TDF, SDF and IDF increased with increase in percentage of bran . Parboiled rice had a higher TDF and IDF than raw rice. Except in BG 352 (7%) in other varieties the percentage of SDF was higher in par boiled rice than raw rice. Percentages in parenthesis refer to the percentages of bran removed from rice. Financial assistance from ADB is acknowledged.
Effect of maturity on some chemical constituents of turmeric (Curcuma longa L.)
(Natural Resources, Energy and Science Authority of Sri Lanka, 1988) Cooray, N.F.; Jansz, E.R.; Ranatunga, J.; Wimalasena, S.
Effect of pretreatments on extending the shelf life of minimally processed “Ela Batu” (Solanum surattense)
(Tropical Agricultural Research and Extension, 2007) Dharmabandu, P.T.S.; de Silva, D.S.M.; Wimalasena, S.; Wijesinghe, W.A.J.P.; Sarananda, S.
Due to the cumbersome nature of the cleaning process and high time consumption for the preparation, most Sri Lankan housewives are reluctant to prepare Solunum surattense (Sinh. Elabatu) as a vegetable for their diet. If S. surattense is available in „ready to cook‟ form it would become a popular vegetable among Sri Lankan housewives. Studies were carried out to identify the best conditions for minimal processing of S. surattense. As pre-treatments 2% (w/v) calcium chloride solution, 0.6% (w/v) turmeric solution, 1% (w/v) vinegar solution, 2% (w/v) calcium chloride + 0.6% (w/v) turmeric solution and 2% (w/v) calcium chloride +1% (w/v) vinegar solution were used. Low density polyethylene (LDPE) pouches (gauge 150) were used to pack pre-treated samples and stored them at 8ºC. In all the pre-treated samples stored at 8ºC, Salmonella and E. coli were absent and coliform counts were at acceptable levels. Sensory evaluation of cooked pre-treated samples showed that the sample pre-treated with 2% (w/v) calcium chloride was the best. In addition to shelf life, colour, and degree of browning of the treatments were also acceptable. Treating S. surattense cut fruits with 2% (w/v) calcium chlo-ride solution before packing in LDPE pouches and storing in 8ºC found to be the best method for extending shelf-life of the fruit. The product could be kept for seven days.
Effect of thermal treatments on antioxidant properties of Anacardium occidentale L.
(Sri Lanka Association for the Advancement of Science, 2014) Kopiwatte, A.C.M.; Wimalasena, S.
Effects of different Zinc levels in the sperm culture medium on sperm recovery and quality of sperms in the swims up procedure for sperm processing
(University of Colombo, 2006) Dissanayake, D.M.A.B.; Wijesinghe, P.S.; Rathnasooriya, W.D.; Wimalasena, S.; Palihawadana, T.S.
A controlled in vitro study was carried out to observe the effect of different Zinc (Zn) levels on sperm recovery rate, chromosome integrity, cell membrane integrity and motility in the swim up procedure. Semen samples were obtained from males who underwent seminal fluid analysis at the Infertility Laboratory, Department of Obstetrics and Gynaecology, Faculty of Medicine, Ragama. Twenty normozoospermicm samples were randomly selected for the study and each sample was processed with supplemented Earl's Balanced Salt Solution (EBSS) containing different concentrations of Zn [0.5ml of supplemented EBSS with 25μ1 of solution containing 0.6μmol (group 1) and 1.2 μmol (group 2) of Zn respectively]. One aliquot processed with 25 μl of physiological saline with added EBSS served as the control. Pre and post wash sperm counts and motility were recorded immediately after processing. Post wash sperms from the three groups were observed for chromosome integrity, cell membrane integrity, and motility. Motility changes after four hours of incubation were also observed. The mean sperm concentration showed an increase in group 1 compared to the control sample l21.87 ± 21.61 (SD) millions/ml compared to 18.34 ± 19.73 millions/ml, P<0.05] whereas a reduction was observed in group 2 [16.25 ± 17.73 (SD) millions/ml compared to 18.34 ± 19.73 millions/ml, P>0.05]. The mean differences in sperm concentration compared to the control showed statistically significant differences in both groups where an increase was observed in group 1 [3.52 ± 4.96 (SD) millions/ml] and a reduction in group 2 (- 2.08 ±6.59 millions/ml). The mean differences in sperm recovery rate showed significant differences in group 1 [8.97 ± 14.04 (SD) millions/ml] and group 2 (-4.85 ± 17.92 millions/ml) compared to the control. It was an increase in group 1 and a reduction in the sperm recovery rate in group 2. A significant reduction in mean sperm motility was observed in group 2 [67.33% ± 18.52 (SD) vs. 91.00% ± 9.60, P<0.05] after four hours of incubation. Though a reduction was observed in group 1 it was not statistically significant (83.33% ± 8.72 vs. 93.60% ± 5.01, P>0.05). The motility reduction was significantly greater in group 2 compared to group 1 (26.01% ± 20.24 vs. 10.97% ± -8.35, P<0.05). Chromosome integrity and cell membrane integrity of sperms were not affected by different Zn levels. In conclusion, low levels of Zn in the sperm processing medium (EBSS) have a beneficial effect on sperm recovery in the swim up procedure.
Effects of pretreatments on extending the self life of minimally processed Rhisomes of Lasia spinosa
(Institute of Chemistry Ceylon, 2008) Liyanage, S.; Wimalasena, S.; de Silva, D.S.M.
Effects of zinc supplementation on sexual behavior of male rats
(Medknow Publications, 2009) Dissanayake, D.; Wijesinghe, P.S.; Ratnasooriya, W.D.; Wimalasena, S.
CONTEXT: Effects of zinc on male sexual competence are poorly understood. Aim: To study the effects of different doses of zinc on the sexual competence of males using a rat model. MATERIALS AND METHODS: Three subsets (eight in each subset) of sexually experienced adult male rats were supplemented with three different oral doses of zinc sulphate (a daily dose of 1 mg, 5 mg and 10 mg respectively) for two weeks. A subset of eight animals without zinc supplementation was used as the control group Sexual behavior was observed by placing them individually in cages with receptive females. Statistical ANALYSIS : Data analysis was done using SPSS v10 for windows computer software. RESULTS: Supplementation of 5 mg of zinc/day for two weeks led to a prolongation of ejaculatory latency; 711.6 sec. (SEM 85.47) vs. 489.50 sec. (SEM 67.66), P < 0.05 and an increase in number of penile thrusting; 52.80 (SEM 11.28) vs. 26.50 (SEM 6.17), P < 0.05, compared to controls. The same group had elevated prolactin (PRL) and testosterone (T) levels compared to controls at the end of treatment period; PRL- 7.22 ng/dl (SEM 3.68) vs. 2.90 ng/dl (SEM 0.34) and T- 8.21 ng/ml (SEM 6.09) vs. 2.39 ng/ml (SEM 1.79), P < 0.05. In contrast, reduction of libido was evident in the same group, but this effect was not statistically significant ( P > 0.05). However, partner preference index was positive and 5 mg zinc supplementation did not exert a significant adverse effect on the muscle strength and co-ordination. The subset of rats supplemented with 1 mg/day did not show a difference from the control group while supplementation with 10 mg/day led to a reduction of the libido index, number of mounts and intromissions. CONCLUSIONS : Zinc therapy improves sexual competence of male rats; the effect is dose dependent. Increase in the T levels is beneficial in this regard. However, increase in PRL is responsible for the reduced libido index. Further studies on pigs and monkeys are needed to evaluate the therapeutic use of zinc in sexual dysfunction
Evaluation of reproductive hormone profile in relation to semen quality in male partners of subfertile couples
(Sri Lanka Association for the Advancement of Science, 2007) Dissanayake, D.M.A.B.; Palihawadana, T.S.; Wijesinghe, P.S.; Ratnasooriya, W.D.; Wimalasena, S.
The objective of the study was to assess the reproductive hormone profile of a Sri Lankan subfertile male population and to relate it to their semen parameters. Male partners of 152 subfertile couples who sought treatment at the subfertility unit of the department of Obstetrics and Gynaecology at the Faculty of Medicine, Ragama were included in the study. Serum samples were assayed for follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), Estradiol (E2) and testosterone (T) levels, using electrochemiluminescence immunoassay (ECLIA). A semen sample was obtained from each participant on the same day. Seminal fluid analysis was done according to the WHO guidelines. The mean (SEM) of FSH, LH, PRL, E2 and T levels of the males were 5.35 (0.53) mIU/mL, 6.20 (0.33) mIU/mL, 17.53 (0.60) ng/mL, 30.48 (1.80) pg/mL and 523.80 (14.74) ng/dL and the prevalence of abnormalities of these hormones were 9.8% (n=15), 5.9% (n=9), 13.15% (n=20), 0.6% (n=1) and 2.6% (n=4) respectively. Of the study population 20.3% (n=31) men had either single or combination of hormone abnormalities. When the mean hormone levels of the men with normal semen parameters were compared with those of men with abnormal semen parameters, none showed a statistically significant difference; FSH - 4.18 (2. 78) Vs 4.58 (3.15), LH - 5.90 (2.78) Vs 5.70 (2.36), PRL - 28.63 (14.96) Vs 17.59 (7.63) and T -551.39ñ208.17 Vs 515.73 (158.25). Mean (SD), FSH and LH levels were significantly higher among azoospermic participants compared with normozoospermics; 19.69 (9.93) Vs 4.18 (2.78) for FSH, 12.82 (11.82) Vs 5.90 (2.78) for LH, p<0.01). Similarly FSH and LH levels were significantly higher in severe oligospermic participants compared with the normozoospermics; 7.58 (4.34) Vs 4.18 (2.78) for FSH, and 6.96 (2.65) Vs 5.90 (2.78) for LH, p<0.05). The serum FSH level showed an inverse correlation with sperm concentration (r= -0.203, p<0.05) and total sperm count (r= -0.206, p<0.05). In conclusion, an endocrinopathy was present in up to 20% of this population. Abnormalities in Gonadotrophin levels were related with azoospermia and severe oligozoospermia. Serum FSH showed a negative correlation with the sperm concentration and the total sperm count. Other hormones failed to show a significant relationship with the semen parameters in this population. Acknowledgement: National Science Foundation research grant No. RG/2004/M/14
Iron content and availability studies in some Sri Lankan rice varieties
(International Journal of Food Science and Technology, 2011) Herath, H.M.T.; Rajapakse, H.; Wimalasena, S.; Weerasooriya, M.K.B.
Thirty-eight rice varieties, grown in Low Country Wet Zone, during Yala (2006) and Maha (2006 . 2007) seasons were screened for stable high iron rice varieties and were statistically analysed. Iron contents ranged 1.89.3.73 mg 100 g)1 and varied significantly (P < 0.05) with variety and season. Selected fifteen high iron rice varieties, at degree of polishing 8.10% were analysed for iron, zinc and phytate. High iron contents in endosperm were observed in Suduru Samba (0.47 mg 100 g)1), Basmati 370 (0.37 mg 100 g)1), Kalu Heenati (0.42 mg 100 g)1), Rathu Heenati (0.44 mg 100 g)1) and Sudu Heenati (0.37 mg 100 g)1). Phytate contents of polished rice varieties ranged from 200.300 mg 100 g)1. Large reduction in iron content (84.5.93.6%) was observed in polished rice while the reduction in phytate content (18.9.40.8%) was low. Percentage dialyzability of iron in selected endosperm high iron rice varieties ranged from 1.73 to 8.71. Dialysability of iron in cooked polished rice did not show a relation to the phytate content in raw rice.
Lipid profile of marine and freshwater fish consumed by Sri Lankans
(Sri Lanka Association for the Advancement of Science, 2006) Gunasekara, J.J.; Wimalasena, S.
Minerals in Leafy Vegetables Consumed by Sri Lankans
(University of Kelaniya, 2007) Wimalasena, S.
Minerals are needed for our healthy living and have to be obtained from our diet. Green leafy vegetables are, in general, a good source of vitamins and minerals. Some of these essential minerals are found in trace amounts in our food. Tables used by nutritionists in Sri Lanka contain data obtained from other countries specially India. Except for one study carried out by Athukorala et a! on the copper and zinc content in a few leafy vegetables, mineral contents in leafy vegetables from Sri Lanka have not been reported. In the present day there is growing concerned on the selenium content in food due to its antioxidant properties and this is first repot of the selenium content in the leafy vegetables in Sri Lanka. The present study reports the calcium, potassium, sodium, zinc, iron, manganese, copper molybdenum, nickel, cobalt, chromium and selenium content in the conventional leafy vegetables namely Ipomoea aquatica (Sin. Kankun), Alternanthera sessilis (Sin. Mukunuvenna), Centella asiatica (Sin. Gotu Kola) and the non conventional leafy vegetables Lasia spinosa (Sin. Kohila), Cardiospermum halicacubum (Sin. Penela) and Passiflora edulis (Sin. Passion). Three varieties non conventional leafy vegetables were also analysed as there is a growing interest in consumption of these due to their medicinal properties. The leafy vegetables for the analysis were obtained from the markets of Kiribathgoda. For each determination pooled out fresh leaves from six bundles were used. Each analysis reports the mean of five determinations. The minerals content in each verity of leaves were determined using Atomic Absorption Spectrometer. Except for the determination of selenium where wet ash method was used, the other minerals were determined on the ash obtained by heating the leaves n a muffle furnace at 550 oc to a constant weight . The results were subjected to statistical analysis by one-way /\NOV/\. Contents (mg/100 g DW) of macro minerals (calcium, potassium, sodium, magnesium) and trace minerals (zinc, iron, manganese, copper, molybdenum, nickel, cobalt, chromium and selenium) varied from 1488 (P. edulis) - 284 (C. asiatica), 3410 (A. sessilis)- 237 (C. asiatica), 1427 (! aqatica)- 280 (C. asiatica), 889 (A. sessilis)- 274 (C. asiatica), 75 (L. spinosa)- 12 (C. asaitica), , 117 (P. edulis)- 22 (A. sessilis), 101 (L. spinosa) - 13 (! aqatica), 12 (L. spinosa) - 1.3 (P. edulis), 2 (! aqatica) - 0.5 (C. asiatica), 4 (L spinosa) - 0.3 (C. asiatica), 2 (A. sessilis) - 0.2 (C. asiatica), 15 (L. spinosa)- 0.3 (P. edulis) and 76 (A.sessilis)- 1.2 (C. helicacabum) respectively. Except for iron and selenium L. spinosa had the highest amount of trace metals. In general macro minerals were high in A. sessilis while they were low in C. asiatica. Trace minerals were high in L. spinosa.
Nutritional studies on rice bran incorporated cereal
(Sri Lanka Association for the Advancement of Science, 2008) Bulathsighala, A.T.; Wimalasena, S.; Rajapakse, D.
Rice bran is a highly nutritious by – product of the rice processing industry. In Sri Lanka it is utilized only as an animal feed. The present study reports the utilization of rice bran to produce a consumer acceptable breakfast cereal and the nutritional properties of the product. Three cereals were prepared by mixing rice flour (milled by 2 mm diameter die) with 5%, 10% and 15% stabilized rice bran from Madathawalu. The rice bran was stabilized by steaming in a pressure cooker immediately after milling. The mixture was extruded with a 2 mm die at 140 oC using a twin screw extruder. The cereal prepared was dried at 60 oC for 2 hours and sealed in double layered polythene. The sensory evaluation of the product mixed with slightly warmed milk containing sugar was carried out by 12 trained panellists at ITI using seven point hedonic scale for colour, odour, flavour, appearance. The resulting scores were analysed using the Friedman non-parametric statistical test in the SAS package. The results of sensory evaluation suggest that 10% rice bran incorporated cereal was the best product and the proximate analysis of the product (moisture, protein, fat, ash, fibre and carbohydrates) was also carried out. It was observed that the percentages of moisture, protein, fat, ash, fibre contents of the particular product (dry weight g/g) were 9.3 ± 0.3, 10.9 ± 0.5 , 4.2 ± 0.3, 1.2 ± 0.02, 0.8 ± 0.1 and 82.5 ± 0.9, respectively while those of rice were 14.3 ± 0.3, 8.1 ± 0.5 , 0.96 ± 0.13, 0.7 ± 0.1 , 0.55 ± 0.04 and 89.4 ± 0.6 and of rice bran was 8.53 ± 0.03, 16.8 ± 0.4 , 18.1 ± 0.4, 5.71 ± 0.97, 5.6 ± 0.5 and 53.1 ± 2.5, respectively. The present study reveals that a consumer acceptable cereal that is more nutritious than rice could be obtained by incorporating 10% rice bran with rice. Further, the ash (7 -12%) and crude fibre (8 -12%) content in Madathawalu were lower while moisture (8-12%), protein (12 -16%) and fat (16 -22%) were within the range reported elsewhere.
Potential utilization of Sri Lankan rice varieties to combat iron deficiency anaemia
(Research Symposium 2009 - Faculty of Graduate Studies, University of Kelaniya, 2009) Herath, H.M.T.; Rajapakse, D.; Wimalasena, S.; Weerasooriya, M.K.B.
Rice is the staple food among Sri Lankans. Potential to use rice as a vehicle, to combat population‟s iron deficiency anemia, has been emphasized in present study. Forty two rice varieties were grown in Complete Randomized Block Design (CRBD) at Bombuwala (iron rich soil > 500ppm) and Batalagoda (iron non-rich soil ~ 100 ppm) during Yala and Maha season of year 2006 and 2007. Duplicates were screened for stable high iron rice varieties. The results of pooled analysis including total variation of iron contents in two seasons in two locations showed that the iron contents ranged from 1.75 mg/100g to 3.23 mg/100g. A significant difference (p = 0.05) in iron contents was observed for the varietal, locational and seasonal. Fifteen high iron rice varieties were selected and polished at a degree of polishing 8-10 %. Of them, endorsperm iron rich rice varieties were analysed using ICP-OES. According to results the high iron contents were observed in Suduru samba (4.7 ± 0.58 ppm), Rathu Heenati (4.43 ± 0.75), Kalu Heenati (4.19 ± 0.13), Sudu Heenati (3.71 ± 0.75.) and Basmati 370 (3.71 ± 0.62) on dry weight basis. The bio-availability of five endorsperm iron rich rice varieties, in terms of dialyzability was deduced by in-vitro simulated-gastro intestinal digestion followed by equilibrium dialysis method (Promchan et.al, 2005). Further, the percent bio-availability of some tested rice varieties are given below. Kalu Heenati (8.71 ± 0.94), Suduru samba (7.65 ± 0.18), Basmati 370 (4.78 ± 0.55), Sudu Heenati (2.09 ± 0.49) and Rathu Heenati (1.73 ± 0.03). The present study indicated that Kalu Heenati and Suduru samba are good sources of traditional rice varieties to combat iron deficiency anemia. References Promchan J. and Shiowatana S. (2005). A dynamic continuous-flow dialysis system with on-line electrothermal atomic absorption spectrometric and pH measurements for in-vitro determination of iron bio-availability by simulated gastrointestinal digestion. Anal Bioanal Chem 382: 1360-1367.
Quantification of arsenic and phosphorus in calcium carbide treated mangoes
(Sri Lanka Association for the Advancement of Science, 2004) Haturusinghe, L.S.; de Silva, D.S.M.; Wimalasena, S.
Relationship between seminal plasma zinc and semen quality in a sub fertile population
(Medknow Publications, 2010) Dissanayake, D.M.A.B.; Wijesinghe, P.S.; Ratnasooriya, W.; Wimalasena, S.
RATIONALE: Current knowledge on the relationship between seminal zinc levels and different parameters of human semen is inconsistent. OBJECTIVES: To assess the relationship between seminal plasma zinc and semen quality using two markers; zinc concentration (Zn-C) and total zinc per ejaculate (Zn-T). DESIGN: The study was carried out as a cross-sectional study. SUBJECTS AND METHODS: Semen parameters of 152 healthy men undergoing evaluation for subfertility were assessed. Seminal plasma zinc levels were determined using flame atomic absorption spectrometry. Zn-C, expressed as μg/mL, was multiplied by ejaculated volume to calculate Zn-T. Mann Whitney U test and Chi-square test were used to compare the zinc levels between different seminal groups when appropriate. Correlations were observed with Pearson's correlation of coefficient. Analysis was carried out using SPSS 10.0 for windows software. RESULTS: Zn-C was low in 23 (15%) samples, while in 32 (21%) of the samples Zn-T was abnormal. The number of subnormal samples was high in the low-zinc groups compared with the normal-zinc groups, 15 vs. 8 (P > 0.05) for Zn-C and 28 vs. 4 (P < 0.001) for Zn-T. Zn-C was significantly high in the asthenozoospermics compared with the normal motile group; 138.11 μg/mL (83.92) vs. 110.69 11 μg/mL (54.59) (P < 0.05). Zn-T was significantly low in samples with hyperviscosity compared with samples with normal viscosity; 220.06 μg (144.09) vs. 336.34 μg (236.33) (P < 0.05). Conversely, Zn-T was high in samples with low viability compared with those with normal viability; 437.67 μg (283.88) vs. 305.15 μg (221.19) (P < 0.05). Weak correlations were found between Zn and some semen parameters. However, the correlation was negative between pH and Zn-C (r = -0.193, P < 0.05) as well as Zn-T (r = -0.280, P < 0.01). On the other hand, correlations were positive between Zn-T and sperm count (r = 0.211, P < 0.05). CONCLUSION: Count, motility, viability, pH and viscosity are affected by variations of seminal plasma zinc. Seminal plasma Zn-T is the better marker for assessing the relationship between zinc and semen quality.