The seed oils of some species of the family Cruciferae
SummaryThe physicochemical properties of the oils of the seeds of seven plants of the family Cruciferae —Cakile maritima, Sisymbrium altissimum, Sisymbrium Loeselii, Descurainia Sophia, Erysimum cheiranthoides, Brassica amoracioides andCrambe pontica — have been studied and their fatty acid compositions have been determined. The results obtained showed no marked differences from those given in the literature.
Importance of minor components to the oxidative stability of camelina, chia, and sophia seed oils
Camelina, chia, and sophia seed oils were evaluated for their fatty acid composition, triacylglycerol (TAG) profile, oxidative stability, and tocol contents, before and after the removal of their minor components. Samples were stripped of their minor components by using column chromatography or stripped by silicic acid-charcoal (stationary phase; 2h). All tested samples contained significant levels of α-linolenic acid and total tocol content. However, all stripped oils were devoid of any tocopherol or pigment. The oxidative state of the oils indicated that stripped oils were significantly less stable than their unstripped counterparts. Meanwhile, the photooxidative stability of oils indicated that stripped oils were more stable than their original counterparts. Involvement of chlorophylls as photosensitizers appears to be exerting a dominant effect. Therefore, these oils, similar to extra virgin olive oil, must be protected from light by using tin containers or dark bottles in order to retain their health promoting effect and prevent off-flavour development.
Experimental study of water fluxes in a residential area: 2. Road infiltration, runoff and evaporation
Lack of accurate data has led some hydrologists and city planners to assume that urban infiltration is zero and runoff is 100% of the rainfall. These assumptions lead to an over estimation of road runoff volume and an underestimation of direct recharge to groundwater, which is already rising under some UK cities. This study investigates infiltration and runoff processes and quantifies the percentage of rainfall that contributes to storm drainage, and that which infiltrates through different types of road surface. Access tubes were installed for measuring soil water content using a neutron probe in three car parks, a road and a grass site at the Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford. Storm drainage was recorded at the exit of the Thamesmead Estate in Crowmarsh Gifford, just before the drain joins the River Thames at Wallingford. Rainfall and water table depth were also recorded. Weekly measurements of soil moisture content indicated that the top 40 cm layer is not influenced by water‐table fluctuations and, therefore, positive changes in soil moisture could be attributed to infiltration of rainfall through the surface. Depending on the nature of the surface, subsurface layers, level of traffic, etc., between 6 and 9% of rainfall was found to infiltrate through the road surfaces studied. The storm drainage generated by road runoff revealed a flow pattern similar to that of the receiving watercourse (River Thames) and increased with the increase of infiltration and soil water content below the road surface. The ratio of runoff to rainfall was 0·7, 0·9 and 0·5 for annual, winter (October–March) and summer (April–September) respectively. As the results of the infiltration indicated that 6 to 9% of annual rainfall infiltrates through the road surface, this means that evaporation represents, 21–24% of annual rainfall, with more evaporation taking place during summer than winter. Copyright © 2003 John Wiley & Sons, Ltd.