Browsing by Author "Wickramasinghe, I."

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Adaptation of hydroponics technology in Matara district –Case study in Beralapanathara
(Sri Lanka Association for the Advancement of Science, 2008) Weerasinghe, K.D.N.; Abeysekara, I.K.; Chandima, H.H.; Wickramasinghe, I.; Liyanage, J.A.
Department of Agric Engineering, Faculty of Agriculture, University of Ruhuna commenced an industrialization program of the Hydroponics technology developed by the Department for farmer groups in Beralapanathara along with SEEDS (Sarvodaya Economic Enterprise Development Services) and ITDG (Intermediate Technology Development Group of Sri Lanka) in 2001. Initially 10 farmers were grouped in to a company and technology was transformed to the members in the company by employing a Graduate for a period of one year, and providing necessary inputs, technology, and know how by the project. Present study was conducted from April to May in 2008 to assess the success of the program after seven years of its existence. The main objective of the study was to assess the economy of the Bell pepper and hydroponically grown Cucumber in Beralapanathara green houses. Survey results revealed that, at present total number of green houses in Beralapanathara were increased up to 16 by grouping 15 farmers. About 76.92 % of farmers have tunnel floor area over 1000 sq.ft; 23.08 % of farmers have floor area less than 1000 sq.ft. Majority of the green houses are dent shape and used the technology innovations for the construction. Bell pepper and Cucumber are the dominating vegetable crops that grown hydroponically in Beralapanathara green houses. 38.46 % of farmers grow only Bell pepper due to its high demand and high market price. Olympus, King Arther, Adino, Golden Bell and Twingo are the commonly grown Bell pepper varieties. Among them, King Arther is better adapted for the area and gives a higher yield compare to other varieties. Cucumber, variety Efdal and variety Sakura have better adoption to this area. Results revealed that, hydroponically grown Cucumber and Bell pepper in a 1000 sq.ft tunnel provides more profit compare to tea. Limiting factor for further expansion of Cucumber appears to be the transport problem, even though profit gain from Cucumber is twice that of the Bell pepper.
Antioxidant activity and physicochemical properties of Flacourtia indica (Uguressa) at different maturity stages
(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Kasunmala, I. G. G.; Navarathne, S. B.; Wickramasinghe, I.
Flacourta indica is an underutilized fruit, which grows wild in bush and its fruits are generally consumed fresh at fully matured and ripe stages. Physicochemical, antioxidant and sensory properties of fruits shows a significant different between each maturity stage. The aim of this study was to analyze the physicochemical and antioxidant properties of fruits at different maturity stages and to identify the best maturity stage for harvesting. Fruits were collected from Galle, Sri Lanka and three maturity stages were selected according to the progressive colour change during fruit development, such as immature – fully green in colour, mature - purple and green in colour and ripen – dark purple in colour. Fruits at each maturity stage were randomly divided into two subgroups for antioxidant analysis and physiochemical testing. Antioxidant analysis was performed on freeze dried fruit samples. Results revealed that weight, volume, length, width, total soluble solids and moisture content of fruits were increased while decreasing pH significantly (P < 0.05) with the maturation and ripening of the fruit. Color of the fruits in terms of lightness (L*) and yellowness (b*) decreased significantly (P < 0.05) while increasing the redness (a*) with maturity. According to antioxidant activity analysis, total phenol content (TPC) value (3.731 ± 0.20 mg gallic acid equivalents/g of dry powder) by Folin-Ciocalteu method showed no significant difference between immature and ripen stages but showed a slight increment in mature stage. 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferric reducing antioxidant power (FRAP) and Oxygen radical absorbance capacity (ORAC) values increased with the maturation and ripening of Flacourtia indica fruit. The study also revealed that dark purple (fully ripen) fruits contained significantly high amount of antioxidant activity in terms of, DPPH, FRAP, ORAC values which were 2280.701 ± 53.05 ppm, 141.775 ± 2.04 mg trolox equivalents/g of dry powder, 31.376 ± 1.35 mg trolox equivalents /g of dry powder respectively. Based on results it can be concluded that fully ripening stage was the best maturity stage for harvesting and can be used as a natural antioxidant in food industry
Effect of dehydration temperature, time and blanching methods on the sensory properties of an herbal tea developed from Moringa oleifera leaves
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Wickramasinghe, W.Y H.,; Wickramasinghe, I.; Ariyasinghe, H. A. E. N.; Wijesekara, I.
Moringa oleifera is a highly nutritious plant which can be used as a good source of nutrition and leaves have been found to contain high amounts of vitamins, minerals, proteins and fiber. The main objective of this study is to explore the use of Moringa oleifera leaves, to produce an herbal tea with acceptable sensory properties, by using different dehydration temperatures, time and blanching methods which can be used in the Sri Lankan market. According to AOAC procedures the initial moisture content (%) of fresh leaves was found to be 78.17 ± 1.57 (dry basis). Six sets of samples were prepared where temperature and time combinations were; 600C 4 h 30 min, 650C 3 h, 550C 6 h for unblanched samples and; 600C 5 h 30 min, 650C 4 h and 550C 6 h for the steam blanched samples. The gross yields of the dried leaves to its initial weights were 22.86%, 20.88%, 23.62%, 19.18%, 15.21% and 14.97% respectively. The moisture content of the dried leaves ranged from 2.09±0.17 to 5.36±0.06. The colour values L*, a*, b* ranged from 16.83 ± 3.02 to 30.2 ± 3.32, -1.93 ± 0.46 to - 6.41 ± 0.79 and 5.1 ± 1.29 to 15.49 ± 1.29 respectively. These samples were given to a trained panel of tea tasters for the sensory evaluation and sample 5 (steam blanched, 650C 4 h) was selected as the sample with the best sensory attributes. These samples were evaluated using a 5-point hedonic scale, by a semi-trained panel of 35 assessors and data were analyzed using the MINITAB statistical package using Friedman test. According to the statistical analysis, sample 5 showed the highest score. The brew of unblanched leaves was giving harsh unpleasant characters whereas the steam blanched samples were giving a pleasant taste.
Effect of Tween 20 concentrations on the properties of coriander essential oil incorporated cassava pomace-based films
(Faculty of Science, University of Kelaniya Sri Lanka, 2024) Akmeemana, C.; Somendrika, D.; Wickramasinghe, I.; Wijesekara, I
The global concern about environmental pollution caused by conventional packaging materials has driven governments to restrict certain polythene types. Interest in biodegradable packaging has arisen as a result of its potential to reduce the impacts of pollution. The present study developed packaging materials using cassava pomace, a major waste from cassava starch manufacturing. A major drawback of natural polymer-based packaging is the poor water barrier properties. Researchers incorporate oils to improve these properties, but since oil is not soluble in water-based mixtures, surfactants are needed to create stable emulsions. The objective of this study was to assess the impact of different concentrations of Tween 20 on the physical, mechanical, and microstructure properties of cassava pomace films that were incorporated with coriander essential oil. Three packaging materials were developed, with a different concentration of Tween 20 and a consistent concentration of coriander essential oil. A control film was developed, which contained the oil without Tween 20. The films were evaluated on their thickness, density, solubility, colour, opacity, moisture content, and mechanical qualities, with three replicates. The films' microstructure was assessed using a scanning electron microscope (SEM). The thickness exhibited a 24.24% increase when the concentration of Tween 20 was raised to 0.3%, compared to the control. The density correspondingly increased as the concentration of Tween 20 was increased. Surface colour was measured using L*, a*, and b* parameters. As the Tween 20 concentration increased, L* and a* values decreased slightly. Coriander essential oil gave the packaging a yellow colour, indicating a higher b* value as the Tween 20 concentration increased. The opacity value increased in comparison to the control film and further increased with the increment of Tween 20 concentration. The inclusion of Tween 20 at concentrations ranging from 0.1% to 0.3% resulted in an increase in the moisture content from 8.52 ± 0.06% to 9.77 ± 0.36%, and an increase in solubility from 16.73 ± 0.44 to 21.99 ± 0.85. Compared to the control, the addition of Tween 20 caused an increment in the tensile strength of all the films. Nevertheless, a noticeable decrease in the tensile strength (0.87 ± 0.21 to 0.52 ± 0.09 Mpa) was observed as the concentration of Tween 20 increased from 0.1% to 0.3%. The increment of Tween 20 in cassava pomace-based film increased elongation at break from 15.34 ± 1.94% to 20.09 ± 1.11%. This may be due to the ability of surfactants to behave mechanically as plasticizers. The SEM images revealed a reduction in the size of coriander essential oil droplets detected on the surface of the images without surface defects, such as cracks or bubbles. In conclusion, higher concentrations of tween 20 surfactants negatively affect the important film properties such as tensile strength, water solubility, and moisture content of the coriander essential oil incorporated cassava pomace-based biodegradable films.
Important physiochemical properties of selected underutilized yams and development of cup-cakes using “Raja ala” (Dioscorea alata) flour
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Gunasekara, G. D. M.; Wickramasinghe, I.; Wijesekara, I.
Sri Lanka has many underutilized yams with high nutritional potential. Most of these underutilized species have lost their significance among the present generation due to many reasons such as urbanization and changing food habits. The objective of this study was to evaluate the nutrient composition, and physiochemical properties of five selected underutilized yam varieties in Sri Lanka; “Raja ala”, “Kidaramala”, Aralog-green, Aralog- red, and “Katu ala”. In addition, cup-cakes were developed using “Raja ala” flour with food gums including pectin 0.3% (w/w based on flour). Yams were collected, peeled, dried, ground, and sieved to obtain fine flour powder. The proximate analysis was carried out to calculate the moisture content, crude protein, total fat, total carbohydrate, and total ash. Then, the texture profile of cupcakes including hardness, deformation, adhesiveness, cohesiveness and springiness were analyzed. The moisture content of both flesh and peel from each five varieties varied between 6.20% and 7.82% (dry weight, w/w). All five varieties were low in fat content and highest was recorded in “Raja ala” (1.10 ± 0.01%), whereas the lowest was recorded in “Katu ala” (0.27 ± 0.16%). The crude protein content of “Raja ala” and Aralog-green were 4.62 ± 0.59% and 3.89 ± 0.57%, respectively. The highest ash content was recorded in “Kidaram ala” (5.88 ± 1.30%) and the lowest was recorded in Aralog-red (1.65 ± 0.04%). By incorporating pectin, gluten free cupcakes were prepared with “Raja ala” flour. According to the results, the hardness at cycle 1 and cycle 2 were 6065.00 g and 4335.00 g respectively. Also, the stringiness length, cohesiveness, adhesiveness and springiness were 14.63 mm, 0.31, 11.30 mJ and 36.46 mm respectively. Furthermore, the analysis of antioxidant potential and total phenolic content of both peel and flesh of the above selected yams, flour properties, and sensory qualities of developed cup cakes are in progress.
Preliminary investigation of polycyclic aromatic hydrocarbon levels in smoked fish produced by fisher community in Sri Lanka
(Sri Lanka Association for Fisheries and Aquatic Resources, 2016) Dehikumbura, G.A.M.D.K.; Ganegama Arachchi, G.J.; Senevirathne, K.N.; Prasadani, W.C.; Paththuwe Arachchi, M.; Perera, R.; Wickramasinghe, I.
Preliminary study on starch extraction ratio and nutritional composition of two cassava cultivars
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Weerasinghe, R. K. L.; Wickramasinghe, I.; Somendrika, M. A. D.
Cassava (Manihot esculanta) is one of the most important food crop among tropical countries. Cassava has higher carbohydrate content and its tapioca starch and modified tapioca starch is highly used as an ingredient of many food products. The objective of this preliminary study was to compare the starch yields and analyze the moisture, fat and protein contents of the extracted starch of two cassava cultivars (Kirikawadi and Muthukawadi variety). Cassava starch was extracted using good quality mature cassava roots. They were cleaned to remove mud, peeled, washed and grated. Those grated roots were milled with tap water mixing in 1:4 ratio by using laboratory scale blender at low speed and filtered through a muslin cloth. Residue was repeatedly milled and filtered again. The suspension was kept to sediment the starch for overnight. The supernatant was decanted and the settled residue was collected into a drying tray and was dried at 600C for 5 hr, dried sample was ground using laboratory blender, sieved through a 300 µm sieve, packed in airtight pouch, sealed in airtight container and stored in cold room (<50C). Cassava starch yield was calculated. Moisture content, fat content and protein contents were analyzed by AOAC (2012) methods. The average extraction ratio of Kirikawadi variety and Muthukawadi variety were 0.13 and 0.11. The average starch yield of Cassava Kirikawadi and Muthukawadi varieties were 12.8% and 11.05%. The flesh of the roots of Kirikawadi and Muthukawadi varieties contained average moisture content of 51.77% and 53.08% respectively. The average range of moisture content of starch of Kirikawadi variety ranged from 16.08% to 16.97% and Muthukawadi variety ranged from 6.99% to 8.43%. The crude fat content of starch of Kirikawadi variety ranged from 0.31% to 0.36% and Muthukawadi variety ranged from 2.14% to 3.29%. The average crude protein content of starch of Kirikawadi variety ranged between; from 2.37% to 3.35% and it ranged from 2.46% to 2.53% in Muthukawadi variety starch. There was a significant difference (p<0.05) between the average moisture content of starch extracted from Kirikawadi and Muthukawadi. Furthemore, there was a significant difference (p<0.05) between the average fat content and there was no significant difference (p>0.05) between average protein content of starch extracted from Kirikawadi and Muthukawadi.
Textural profile analysis of granulated cassava pearls of two cultivars treated with conventional and microwave heating
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Bulathgama, B. E. A. U.; Wickramasinghe, I.; Wijesekara, I.; Somendrika, M. A. D.
Cassava (Manihot esculenta Crantz) is an important food source in tropical countries, and it is a readily available root crop variety in Sri Lanka as well. Yet processed cassava (flour) is underutilized. The objective of this study was to identify the effect of conventional and microwave heating on two selected cassava cultivars namely; Kirikawadi and Muthukawadi granulated flour pearls. The granulated cassava pearls were made by the moistening and mechanical shaping of the flour by adding 50% water by weight. Then the pearls of both cultivars were subjected to conventional heating in normal cooking oven at 1000C for 20 minutes, and microwave heating in mid power for 5 minutes. The obtained pearls were then analyzed for the texture profile analysis. The morphology of flour granules were observed by microscopic image projection, where the two cultivars showed no observable difference in their granular shapes. The two cultivars; Kirikawadi and Muthukawadi flour had an initial moisture content of 8.23% and 9.00% respectively and after moistening the moisture contents were 41.95% and 38.59% respectively. After the heat treatments, the texture profiles including hardness, deformation, adhesiveness, cohesiveness and springiness were analyzed for all the samples. According to the results, the highest hardness was obtained by microwave heating method for both cultivars. The hardness of conventionally heated varieties were 200.00 g for Kirikawadi and 235.00 g for Muthukawadi, and microwave heated varieties were 19780.00 g and 10390.00 g respectively. The deformation has changed with the heating method, where the deformation of both conventionally heated varieties varied, between 0.64 - 0.66 mm and microwave heated varieties showed 1.38 mm (Kirikawadi) and 1.90 mm (Muthukawadi). Other texture properties; adhesiveness, cohesiveness and springiness showed no significant variation (P>0.05) either with cultivar or heating method. According to the results of the study, the microwave heating is suggested to be more preferable over the conventional heating method, as modified forms of this type of starches have higher demand in the novel processed food industry.