Volume 16 Year 2011

Oxalic Acid Content in Green Leafy Vegetables

Sat, 01 Jan 2011 00:00:00 GMT

Oxalic Acid Content in Green Leafy Vegetables Premasiri, H.A.A.; Ekanayake, S. Oxalic acid is toxic in increased quantity due to the promotion of kidney stone formation. inhibition of mineral absorption etc. Oxalic acid is a metabolic end product naturally present in plant materials. Green leafy vegetables being an essential part of a Sri Lankan diet often beneficial with high amount of fiber. ~- carotene and minerals may contain oxalic acid. Thus. the objective of the present study was to determine the oxalic acid content of some green leafy vegetables commonly consumed in Sri Lanka since this data is not currently avai lab Ie. Plant materials were collected mainly from the Western province. The edible portion was homogenized. extracted and titrated with potassium permanganate solution. According to the oxalic acid contents of the plant materials, the plants were categorized in to 3 groups. a) Leaves with high oxalic acid content mukunuwenna white and red stemmed (245-892 I11f'JI00 g). suraia (creeper and plant) 400-1071 mg/IOO g, spinach [326-563 mg/ 100 g]. thatupala red and green stemmed [209-947 mg/l OOg]: b) Leaves with low oxal ic acid (:s 200 mg/ IOOg) content (passion fruit [39-62 mg/I OOg]. man ioc red and wh ite stemmed [75-200 mg/ IOOg]. katurunturunga [46-71 rng/ IOOg), kankun [20-54 mg/ IOOg]. kohila [20-93 mg/ IOOg]. asamodagant [16-78 mg/ IOug], anguua leaves [15-34 mgll OOg] ) 8 and c) Leaves with undetectable amount [<14 mg/I OOg] of oxalic acid tgotukola. lettuce and cabbage). The contribution of oxalic acid to the diet by green leafy vegetables is relatively low when the edible portion is considered in all the leaves analyzed in the present study. However, inclusion of a variety of leaves in the diet will be more beneficial instead of frequent consumption of high oxalic containing leaves which may decrease the absorption of rrdr',':-ra's in the .neal. In addition, people with kidney stone diseases or family history of the kldne, stone diseases should avoid frequent consumption of high oxalic acid containing green leafv vegetables s•.c.•h as nivithi, sarona, mukunuwenno and thampala.

Occurrence of Heterotrophic Bacteria Causing Lysis of M. aerginosa in Beira Lake, Sri Lanka

Sat, 01 Jan 2011 00:00:00 GMT

Occurrence of Heterotrophic Bacteria Causing Lysis of M. aerginosa in Beira Lake, Sri Lanka Manage, P.M.; Prematilake, M.M.S.N. Field and the laboratory studies were carried out to ascertain the potential impact of algicidal bacteria on Microcyctis aeruginosa from June 2005 to March 2007 in Beira Lake, Sri Lanka. M. aeruginosa. and M wesenbergii quantitatively dominated in most sampling dates and constituted >75% of the phytoplankton cell densities when the bloom reached to its peaks. Densities of algicidal bacteria were relatively high with large fluctuations between 2.3 x 102 PFU mli to 0.3 x 102 PFU ml.i. Three algicidal bacteria species were isolated from the lake and identified as Alcaligenes denitrificans, A. xyosoxydans, and Flavobacterium marinotypicum. The algicidal effect of the bacterium was studied and the results suggest that the bacteria did not release extracellular products inhibitory to M aeruqinosa, and that the bacteria kil.ed the algae by direct contact. In the field, rapid decline of Microcystis bloom was detected when algicida. Lar.ter.a were increased. In the laboratory, when the bacterium were inoculated at low densities (104 cells -nl.i) together with Microcvstis, the bacterium proliferated to 107 cells mli and caused tvttcrocvst.s cell lysis. Thus, the result of the present study strongly suggests that algicida' bacteria degrade M.'1eruginosa bloom in natural freshwater environments.

Fat Contents and Fatty Acid Profiles of Indian Scad (Decapterus russelli)

Sat, 01 Jan 2011 00:00:00 GMT

Fat Contents and Fatty Acid Profiles of Indian Scad (Decapterus russelli) Chrishanthi, E.K.I.; Attygalle, M.V.E. Indian Scad iDecapterus russelli. Sinhala: Linna) is one of the less expensive fish varieties in the Sri Lankan market. Total fat contents in white muscle. red muscle and skin: and fatty acid composition in white muscle of the Indian Scad were evaluated. Tile total fat content was relatively high in the skin (3.64%) and red muscle (3.17%)) while the white muscle contained low amount (0.65%). Fatty ac id profi lcs of white muse Ie showed 32.66% saturated fatty ac ids (SFA). 16.07% monounsaturated fatty acids (M UFA) and 39.38% polyunsaturated fatty acids (PUF A). Among SF A. those occurring in the highest proportions were palmitic acid (C 16:0. 18.36%) and stearic acid (C 18:0. 12.21%). Oleic acid (CI8:1 n-9. 10.61%) and palmotoleic acid (CI6:1 n-T, 3.91%) were the main MUFAs. Eicosapentaenoic acid (EPA. C20:5 n-s, 8.83%) and docosahexaenoic acid (DHA, C22:6 n-3. 19.76%) were the main PUFAs. The PUFA/SFA ratio was 1.21and n-6 In-3 ratio was 0.13. Sum of EPA + DHA was 28.59%. Therefore it can be concluded that although the fat content is low the nutritional value of the fat cor.rained in the white muscle of Indian Scad is high.

Sat, 01 Jan 2011 00:00:00 GMT

Contents