Variations in fatty acid proportions during desiccation of Telfairia occidentalis seeds harvested at physiological and agronomic maturity

Abstract

The effect of desiccation on lipid content, fatty acid composition and the antioxidative enzymic capacity was investigated in seeds of Telfairia occidentalis, harvested at physiological and agronomic maturity. Seeds were dried at 5 and 28 oC, environments that induced different drying and metabolic rates. Desiccation of seeds was associated with decreased antioxidative enzymic capacity (of peroxidase and polyphenoloxidase), and thus increased likelihood of free radical attack and decreased viability (germinability). Agronomically mature seeds contained predominantly saturated fatty acids (tridecanoic), with very low levels of the major fatty acids of edible oilseeds (palmitic, stearic or the unsaturated C18 fatty acids). There was increased accumulation of the mono-unsaturated (oleic) and polyunsaturated (linoleic) fatty acids when seeds were dried at 28 oC and moisture contents have reduced to about 42 % or lower. In contrast, seeds dried at 5 oC maintained high levels of saturated fatty acids and lower levels of monounsaturated or polyunsaturated fatty acids. Results suggest the need to develop different post-harvest protocols for seed storage, and for processing T. occidentalis to ‘improve' the seed fatty acid profile as an oilseed for human and animal food.


The use of a novel phage-based technology as a practical tool for the diagnosis of tuberculosis in Africa
Tracy Seaman1, Andre Trollip1, Richard Mole2, Heidi Albert1*
1Biotec Laboratories Ltd., c/o National Health Laboratory Service, PO Box 9066, Cape Town 8000, South Africa.
2Biotec Laboratories Ltd., Ipswich, United Kingdom.
*Corresponding ; Tel: +27 (0)21 425 1541 / +27 (0)82 902 8199, Fax: +27 (0)21 425 9857, E-mail: Alberth@mweb.co.za
Sub-Saharan Africa has experienced a significant increase in tuberculosis cases in recent years, fuelled by high rates of TB-HIV co-infection in the region. The diagnosis of tuberculosis is based largely on clinical assessment, sputum smear microscopy and chest radiography. Although smear microscopy is useful for detecting the most infectious cases, a significant portion of cases are negative on sputum smears, making diagnosis more difficult. New tests are urgently needed. The FASTPlaqueTB test, a bacteriophage-based method, has been evaluated in several studies in Africa and elsewhere. Studies in South Africa and Pakistan reported that between half and two-thirds of smear-negative culture-positive TB cases were detected by the FASTPlaqueTB test within 2 days. This suggests a beneficial role for this test in the early diagnosis of clinically suspected smear-negative cases. The same technology has been applied to develop a rapid test to indicate multi-drug resistant TB, FASTPlaqueTB-MDRi. This test gave equivalent results to conventional drug susceptibility methods, but with more rapid results. The tests are simple to perform and require no specialised equipment, making the technology suitable for widespread implementation.


(African Journal of Biotechnology: 2003 2(2): 33-39)