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Here we present Positron Annihilation Doppler Broadening Spectroscopy (PADBS) as a powerful method to analyse the origin and development of defect processes in porous silicon structures as a result of alloying with lithium for the use in battery anode applications. Several prepared anodes were lithiated (discharged against Li+/Li) and de-lithiated (charged) with different capacities followed by a distinct treatment procedure and an analysis using the Delft Variable Energy Positron Beam. The results presented here show that we can distinguish two different processes attributed to (1) structural changes in silicon as a result of the alloying process, and (2) the formation of defects that initiate degradation of the material. The limit at which the porous material can be used for at least the first two cycles without the occurrence of damage can thus be accurately determined by using the PADBS technique. [ABSTRACT FROM AUTHOR]

Objective:To determine the effect of folic acid, vitamin B6 and B12 fortified spreads on the blood concentrations of these vitamins and homocysteine.Design and setting:A 6-week randomized, double-blinded, placebo-controlled, parallel trial carried out in a clinical research center.Subjects:One hundred and fifty healthy volunteers (50% males).Interventions:For 6 weeks, the subjects consumed the test spreads (20 g/day): containing per 20 g (1) 200 μg folic acid, 2 μg vitamin B12 and 1 mg vitamin B6, or (2) 400 μg folic acid, 2 μg vitamin B12 and 1 mg vitamin B6 or (3) no B-vitamins (control spread).Results:The B-vitamin status increased on using the test spreads, with the largest effect on the serum folate concentration: 48% in men and 58% in women on spread 1 and 92 and 146%, respectively, on spread 2 (P-values all <0.05). The plasma homocysteine decreased in the groups treated with the fortified spreads as compared to the control group. Average decreases were for males: 0.7±1.5 μmol/l (6.8%) on spread 1 and 1.7±1.7 μmol/l (17.6%) on spread 2 and for females: 1.4±1.2 μmol/l (14.2%) and 2.4±2.0 μmol/l (23.3%), respectively (P-values all <0.05).Conclusions:Consumption of a spread fortified with folic acid, vitamin B6 and vitamin B12 for 6 weeks significantly increases the blood concentrations of these vitamins and significantly decreases the plasma concentration of homocysteine. Fortified staple foods like spreads can contribute to the lowering of homocysteine concentrations.Sponsorship:Unilever Research and Development, Vlaardingen, The Netherlands.European Journal of Clinical Nutrition (2007) 61, 769–778; doi:10.1038/sj.ejcn.1602570; published online 6 December 2006 [ABSTRACT FROM AUTHOR]

In the past decade, the understanding of folate bioavailability, metabolism and related health issues has increased, but several problems remain, including the difficulty of delivering the available knowledge to the populations at risk. Owing to the low compliance of taking folic acid supplements, for example, among women of child-bearing age who could lower the risk of having a baby with a neural tube defect, food-based strategies aimed at increasing the intake of folate and other B-group vitamins should be a priority for future research. These should include the development of a combined strategy of supplemental folate (possibly with vitamin B12), biofortification using engineered plant-derived foods and micro-organisms and food fortification for increasing folate intakes in the general population. Currently, the most effective population-based strategy to reduce NTDs remains folic acid fortification. However, the possible adverse effect of high intakes of folic acid on neurologic functioning among elderly persons with vitamin B12 deficiency needs urgent investigation. The results of ongoing randomized controlled studies aimed at reducing the prevalence of hyperhomocysteinemia and related morbidity must be available before food-based total population approaches for treatment of hyperhomocysteinemia can be recommended. Further research is required on quantitative assessment of folate intake and bioavailability, along with a more thorough understanding of physiological, biochemical and genetic processes involved in folate absorption and metabolism.European Journal of Clinical Nutrition (2006) 60, 287–294. doi:10.1038/sj.ejcn.1602315; published online 26 October 2005 [ABSTRACT FROM AUTHOR]

ObjectiveThe aim of this study was to investigate whether milk fortified with folic acid enhances the folate status of humans and whether the presence of folate-binding proteins (FBP) in pasteurised milk affects the bioavailability of folic acid from fortified milk. In untreated and pasteurised milk, folate occurs bound to FBP, while FBP is (partly) denatured in ultra-high-temperature (UHT)-treated milk. The effect of FBP on folate bioavailability is still unclear.Design, subjects and settingHealthy, free-living subjects (n=69) aged 18–49 y participated in a 4-week double-blind, placebo-controlled dietary intervention study.InterventionIn addition to a fully controlled diet, the subjects consumed each day 500 ml of pasteurised or UHT milk, either fortified or not with 200 μg folic acid.ResultsConsumption of fortified milk increased folate concentrations in serum and in red blood cells (RBC) by 6.6–7.0 nmol/l (P<0.001) and 32–36 nmol/l (P<0.01), respectively. Similarly, plasma homocysteine concentrations were lowered 0.88–0.89 μmol/l (P=0.001) in subjects who consumed fortified milk. The bioavailability of folic acid from pasteurised milk relative to that of folic acid from UHT milk was 74–94% (NS), depending on the parameter used.ConclusionsMilk fortified to supply an additional 200 μg of folic acid/s substantially increased folate status, and decreased plasma total homocysteine concentrations in young, healthy subjects. Milk is therefore a suitable matrix for fortification to enhance the folate status in humans. No significant effect of endogenous FBP was found on the bioavailability of folic acid from milk.European Journal of Clinical Nutrition (2005) 59, 906–913. doi:10.1038/sj.ejcn.1602159; published online 1 June 2005 [ABSTRACT FROM AUTHOR]

Objective: To investigate the dose-response relationship between cholesterol lowering and three different, relatively low intake levels of plant sterols (0.83, 1.61, 3.24 g/d) from spreads. To investigate the effects on lipid-soluble (pro)vitamins.Design: A randomized double-blind placebo controlled balanced incomplete Latin square design using five spreads and four periods. The five study spreads included butter, a commercially available spread and three experimental spreads fortified with three different concentrations of plant sterols.Subjects: One hundred apparently healthy normocholesterolaemic and mildly hypercholesterolaemic volunteers participated.Interventions: Each subject consumed four spreads, each for a period of 3.5 week.Results: Compared to the control spread, total cholesterol decreased by 0.26 (CI: 0.15-0.36), 0.31 (CI: 0.20-0.41) and 0.35 (CI: 0.25-0.46) mmol/L, for daily consumption of 0.83, 1.61 and 3.24 g plant sterols, respectively. For LDL-cholesterol these decreases were 0.20 (CI: 0.10-0.31), 0.26 (CI: 0.15-0.36) and 0.30 (CI: 0.20-0.41). Decreases in the LDL/HDL ratio were 0.13 (CI: 0.04-0.22), 0.16 (CI: 0.07-0.24) and 0.16 (CI: 0.07-0.24) units, respectively. Differences in cholesterol reductions between the plant sterol doses consumed were not statistically significant. Plasma vitamin K1 and 25-OH-vitamin D and lipid standardized plasma lycopene and alpha-tocopherol were not affected by consumption of plant sterol enriched spreads, but lipid standardized plasma (alpha + beta)-carotene concentrations were decreased by about 11 and 19% by daily consumption of 0.83 and 3.24 g plant sterols in spread, respectively.Conclusions: The three relatively low dosages of plant sterols had a significant cholesterol lowering effect ranging from 4.9-6.8%, 6.7-9.9% and 6.5-7.9%, for total, LDL-cholesterol and the LDL/HDL cholesterol ratio, respectively, without substantially affecting lipid soluble (pro)vitamins. No significant differences in cholesterol lowering effect between the three dosages of plant sterols could be detected. This study would support that consumption of about 1.6 g of plant sterols per day will beneficially affect plasma cholesterol concentrations without seriously affecting plasma carotenoid concentrations. [ABSTRACT FROM AUTHOR]

With the view of preparing semi-liquid weaning foods of high energy content, the influence of roasting (stationary hot air treatment) and fermentation (with natural and pure culture inocula) on the viscosity of maize-sorghum-soya porridges was investigated. Roasting resulted in porridges of significantly higher viscosity (cooked porridge cooled to 40 degrees C). Porridges made from the individual ingredients (maize, sorghum, soya) did not show this behaviour. Natural fermentation of mixed ingredients resulted in lower porridge viscosities (cooked porridge cooled to 40 degrees C, as well as hot-paste peak viscosity) when pH was 5.0-5.5. At lower pH the viscosity of the final porridges increased. Fermentation experiments of individual ingredients inoculated with pure cultures of Lactobacillus plantarum and Candida famata lead to the conclusion that various factors contribute to the effect of fermentation on porridge viscosity. Porridges of minimum viscosity are obtained at pH 5.0-5.5 corresponding with a moderate extent of fermentation. From a consumer safety point of view, it would be preferable to acidify to lower pH values (pH < 4.5). If necessary, viscosity adjustments could be made using malted cereals. [ABSTRACT FROM AUTHOR]