http://ir.lib.ruh.ac.lk/handle/iruor/19211 2026-04-05T21:02:38Z http://ir.lib.ruh.ac.lk/handle/iruor/19679 Replacement of artificial colourings of a carbonated soft drink with natural colour pigments from red-layered hibiscus. Jayawardana, S.A.S.; Nawarathna, S.B.; Ranaweera, K.K.D.S. A natural red colouring was developed from petals of Red-layered Hibiscus flowers, which are rich in anthocyanins, to replace artificial colourings that are being added to a carbonated soft drink. Boiling distilled water acidified with citric acid (0.8%) was found to be the most suitable solvent to extract the pigments from the petals. Immersing 1 g of petals for 10 minutes in 10 ml of the solvent was identified as the most suitable method to extract the pigments. Natural colouring was prepared in liquid form by concentrating 10 ml of pigment extract down to 1 ml. When storing in a clear glass bottle at 4oC, minimum shelf life of the colouring was 8 weeks. Carbonated soft drink test samples were prepared by adding the developed red colouring to match the colour of the standard beverage. Sensory evaluation, microbial analysis, Brix, pH and Carbonation Level measurements were done, using standard methods, for test samples stored under direct sunlight, indirect sunlight and in a refrigerator. No significant (P>0.05) differences were detected between preferences for standard beverage and test sample, which also contained additional 2% citric acid amount and essence volume. The maximum shelf-life of test samples was limited to 5 days, when storing under direct sunlight. When storing under indirect sunlight or in a refrigerator, their minimum shelf-life was 8 weeks. 2014-07-24T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/19676 An assessment of some growth and yield indices of six varieties of watermelon (citrulus lanatus thumb) in Asaba area of Delta state, Nigeria Enujeke, E.C. Field experiments were conducted in 2011 and 2012 cropping seasons in the Teaching and Research Farm of Delta State University, Asaba Campus, Nigeria to assess some growth and yield indices of six varieties of watermelon (Sugar baby, Charleston gray, Crimson sweet, Green gold, Jubilee, and Ice box) in Asaba area of Delta State, Nigeria. The experiments were carried out in a Randomized Complete Block Design (RCBD) with three replicates. Four parameters were assessed to achieve the objectives of the study-vine length, number of leaves/plant, number of branches /plant, and weight of fruits at 75 days after sowing. The results of the two-year evaluation indicated that Sugar baby variety was superior at 4, 6, and 8 weeks in the parameters tested with mean vine length of 63.4 cm, 133.1 cm, and 181.1 cm, respectively; mean number of leaves/plant of 30.5, 33.5 and 40.4 respectively; mean number of branches/plant of 5.0, 6.0, and 7.0, respectively; and mean weight of fruits of 1315.43 t ha-1 at 75 days after sowing in 2011 and 2012. Based on the findings of this study, it was recommended that farmers in the study area grow Sugar baby variety for increased growth and yield of watermelon. 2014-06-09T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/19672 Haplotype and meristic variations of oreochromis niloticus and its hybrids present in selected reservoirs in Sri Lanka. Samaradivakara, S.P.; Hirimuthugoda, N.Y.; Gunawardana, R.H.A.N.M.; Illeperuma, R.J.; Fernandopulle, N.D.; De Silva, A.D.; Alexander, P.A.B.D. The Nile tilapia, Oreochromis niloticus was introduced from Africa’s to Sri Lanka in the 1970s. Since then tilapia has dominated in most of the reservoir fisheries in Sri Lanka. The genetic and meristic variation of the domesticated tilapia was studied using polymorphisms in mitochondrial DNA (mt-DNA) and by analysis of morphometric and meristic characters. Ninety seven fish from three locations, namely Kurunegala, Anuradhapura, Polonnaruwa and ten control samples from the brood stock of the Udawalwe Tilapia Breeding Centre were collected. The genetic analysis targeted 16Sr region of mitochondrial genome. The Meristic analysis included fourteen meristiccounts, which were subjected to discriminant analysis and cluster analysis. The PCR- SSCP procedure of the mtDNA resolved eight haplotypes that overlapped between the four locations. The meristic and the genetic composition were common within the three domesticated fish populations collected from Kurunegala, Anuradhapura, Polonnaruwa and the brood stock of the Udawalwe Tilapia Breeding Centre. The results of this study will significantly contribute towards new inferences regarding management of the brood stocks and the wild stocks of tilapia aquaculture. 2014-06-17T00:00:00Z http://ir.lib.ruh.ac.lk/handle/iruor/19670 Effects of mycorrhizae as a substitute for inorganic fertilizer on growth and yield of tomato (lycopersicon esculentum l.) and soy bean (glycine max l.), Alawathugoda, C.J.; Dahanayake, N. A greenhouse experiment was conducted to determine the influence of mycorrhizae as a substitute for inorganic fertilizer on growth and yield of Tomato (Lycopersicon esculentum) and Soybean (Glycine max) and soil microbial activity. Four doses of inorganic fertilizers viz recommended dose [Tomato- Urea:TSP:MOP=65:325:65 kg/ha and Soybean Urea:TSP:MOP=35:130:35 kg/ha), 1/2 and 1/4 of recommended dose and 0 dose] were applied to soil with standard dose of mycorrhizae (2 g/5L water). The above four treatments were tested in a Completely Randomized Design (CRD) with five replicates. Results indicated that there was no significant difference in all parameters tested on plants treated with recommended dose and 1/2 of recommended dose of inorganic fertilizer with standard dose of mycorrhizae. The highest fruit wet weight (556 g/plant - 69% higher than the lowest) in tomato plants and the highest pod wet weight (18 g/ plant) in soybean was observed with ½ of the recommended dose of inorganic fertilizer and lowest was observed in plants treated with standard dose of mycorrhizae without inorganic fertilizer (tomato -329 g/plant and soybean 4 g/plant). However the highest pod dry weight (8 g/plant) and seed dry weight (7 g/plant) were observed in 1/2 of recommended dose of inorganic fertilizer with standard dose of mycorrhizae in Soybean. The highest soil microbial activity was recorded in soil treated with standard dose of mycorrhizae without inorganic fertilizer (464 CO2 mg/kg of soil - 61% higher than the recommended dose of inorganic fertilizer) and the lowest was observed in soil treated with recommended dose of inorganic fertilizer (287 CO2 mg/kg of soil). The activities of soil microorganisms were lower in soils treated with inorganic fertilizers considering the growth parameters and soil microbial activity it can be concluded that 1/2 of the recommended dose of inorganic fertilizer with standard dose of mycorrhizae is the best fertilizer mixture for crops, tomato and soybean. Addition of mycorrhizae to the field soil increases the soil microbial activity significantly. 2014-06-09T00:00:00Z