Browsing by Author "Peris, C.M."
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Item Determination of Acrylamide Formation with Different Frying Temperatures in Potato (Solanum tuberosum), Cassava (Manihot esculenta) and Sweet Potato (Ipomoea batatas)(Uva Wellassa University of Sri Lanka, 2020) Rangana, M.A.S.; Peris, C.M.; Rambukwella, R.U.W.M.C.B.; Senarathna, K.G.C.Acrylamide is a carcinogenic toxic compound formed during the frying process at high temperatures by the reaction of asparagine and reducing sugars. Due to the high consumption of fried tubers in the world, it is worthwhile to detect and quantify the acrylamide in fried foods to reduce the detrimental effects on human health. This study aimed to analyze the effect of temperature and the available nutrient content on the formation of acrylamide in three selected tuber species named as potato (Solanum tuberosum), cassava (Manihot esculenta) and sweet potato (Ipomoea batatas). Fried tuber samples were prepared by deep frying at 160°C, 180°C and 200°C separately using coconut oil until they reach the standard colour based on the colour chart recommended by the United States Department of Agriculture. Proximate analysis was carried out to determine the nutrient content of raw and fried tubers before analyzing the acrylamide. Gas Chromatography-Mass Spectrometry (GC-MS) was used to detect the acrylamide and quantification was proceeded according to a calibration curve of acrylamide standard (R2 =0.8535). Among the varieties, the potato was recorded the longest frying time and sweet potato was recorded the shortest time duration in all three different temperatures to obtain the recommended colour. Further, the highest amount of protein content was observed in potato and the lowest protein content was observed in sweet potato in raw form and the protein content reduced in all varieties dramatically with the increment of temperature. Similarly, the highest acrylamide concentration was found in potato (1125.65 µgkg-1 ) fried at 200°C and lowest acrylamide concentration was detected in sweet potatoes fried at 180°C which was 84.36 µgkg-1 . Acrylamide was not detected in raw samples. Results revealed that acrylamide formation was increased with the increment of temperature and there is a significant effect of the protein content of tubers on the development of acrylamide (P < 0.05). Keywords: Acrylamide, Frying temperatures, Tubers, GC-MSItem The Effect of Selected Sri Lankan Herbal Plant Crude Extracts Against Spodoptera frugiperda (Fall Armyworm)(Uva Wellassa University of Sri Lanka, 2020) Ranaweera, M.N.; Henegamage, A.P.; Prematilake, M.M.S.N.; Peris, C.M.The fall armyworm (FAW), Spodoptera frugiperda is a recent invasive pest that has successfully established in Sri Lanka where it continues to disrupt agriculture, particularly corn production. Management of fall armyworm using agrochemicals has led to the development of resistance against many insecticides and the accumulation of toxic residues on agricultural products. Therefore, the utilization of plant extracts which are wealthy in bioactive compounds for the control fall armyworm has become a developing pattern. This study was undertaken to screen the effectiveness of Adathoda vassica, Dathura metal, and Tagetes erecta crude extracts against fall armyworm. Shade dried leaves were used for the extraction which was done by the Soxhlet method using methanol and ethyl acetate as solvents. Bioefficacy of crude extracts was studied against third instar larvae of S. frugiperda using 4000, 2000 and 1000 ppm concentrations to test the contact toxicity by topical application method, antifeedant activity by leaf disc no choice assay and repellency effect from the dual choice method. Commercially available insecticide, collagen was used as a positive control. The crude extracts from T. erecta (LD50 - 186.63µg/g) and D. metel (LD50 - 256.44µg/g) showed significantly (p < 0.05) high mortality (100%) rate within twelve hours even compared with the positive control. The results revealed that the methanolic extract of T. erecta showed the highest significant (p < 0.05) antifeedant activity (92.09%) at 4000 ppm compared with other plant extracts. All plant extracts provoked a notable decrease in feeding with the increment of their concentration. Methanolic extract of T. erecta showed the highest significant repellency (66.65%). Therefore, it can be concluded that methanolic extracts of D. metel and T. erecta have the power of damaging fall armyworm and are suitable candidates for the development of bio-insecticide for the local use. Keywords: Fall armyworm, Adathoda vassica, Dathura metel, Tagetes erecta