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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]

ABSTRACT Toasted rusk rolls with a coarser structure are sensed crispier than those with a fine structure, at the same water activity (aw). The present paper shows that this difference in crispness perception is related to differences in fracture behavior and accompanying acoustic emission. Both sensory and instrumentally determined crispness decreased gradually with increasing aw in roughly the same manner for both coarse and fine products. Nevertheless, the coarse rusk roll was perceived as being crispier than the fine one. Typically, in the coarse structure the measured 'Number of Force Drops' of a relatively large size and the 'Number of Sound Events per cross section area' of relatively large intensity were more numerous than in the fine one. Our data show that relatively large force drops and sound events are related to the more intense crispness perception and stronger sound sensation for the coarse structure toasted rusk roll. We propose the 'Total Sound Energy per cross section area' and the 'Mean Sound Event Intensity' to be primarily responsible for the higher crispness perception of the coarse rusk over the whole aw range. PRACTICAL APPLICATIONS Coarse structured toasted rusk rolls are sensed crispier than fine structured ones (same aw). Difference in crispness is related to fracture behavior and accompanying acoustic emission. Crispness decreased gradually with increasing aw similarly for coarse and fine products. Sound energy cq. Intensity seems primarily responsible for the higher crispness perception. [ABSTRACT FROM AUTHOR]

Crispness is an important sensory quality parameter that strongly influences the acceptability of cellular solid foods such as the crust of many types of breads. Crispness of the bread crust depends particularly on its water content. In this study, the relationship between sensory crispness of crispy rolls and the average water content of the crust was studied for different bread formulations (control, amylase, glucose-oxidase, and protease) and storage conditions (40% and 80% RH). From the different formulations used, only protease treatment increased the crispness of the crust and its retention at both storage conditions. The positive effect of the protease treatment was due to a lower water content of the crust of these breads compared to the other formulations. The relationship between sensory attributes, formulation, and storage conditions was found to be dominated by the dependence on storage conditions. When combining data for low and high humidity storage it showed that crusts with equal water contents could exhibit different scores for crispness. The results led to the hypothesis that a gradient of water content exists within the crust. At high humidity, the crust will take up water from both crumb and environment and a relative smaller gradient of water will exist within the crust. At low humidity on the other hand, the crust will take up water from the crumb only, resulting in a larger gradient of water within the crust. [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]

BACKGROUND: A high plasma concentration of total homocysteine (tHcy) is associated with increased risk of cardiovascular disease. A high protein intake and hence a high intake of methionine-the sole dietary precursor of homocysteine-may raise plasma tHcy concentrations. OBJECTIVES: We studied whether high intake of protein increases plasma concentrations of tHcy in the fasting state and throughout the day. DESIGN: We conducted a randomized, dietary controlled, crossover trial in 20 healthy men aged 18-44 y. For 8 d, men consumed a controlled low-protein diet enriched with either a protein supplement [high-protein diet (21% of energy as protein)] or an isocaloric amount of short-chain glucose polymers [low-protein diet (9% of energy as protein)]. After a 13-d washout period, treatments were reversed. On days 1 and 8 of each treatment period, blood was sampled before breakfast (fasting) and throughout the day. RESULTS: Fasting tHcy concentrations did not differ significantly after the 1-wk high-protein and the 1-wk low-protein diets. The high-protein diet resulted in a significantly higher area under the 24-h homocysteine-by-time curves compared with the low-protein diet, both on day 1 (difference: 45.1 h x mumol/L; 95% CI: 35.3, 54.8 h x mumol/L; P < 0.0001) and on day 8 (difference: 24.7 h x mumol/L; 95% CI: 15.0, 34.5 h x mumol/L; P < 0.0001). CONCLUSIONS: A high-protein diet increases tHcy concentrations throughout the day but does not increase fasting tHcy concentrations. As previously shown, the extent of the tHcy increase is modified by the amino acid composition of the protein diet. The clinical relevance of this finding depends on whether high concentrations of tHcy-particularly postprandially-cause cardiovascular disease. Copyright © 2005 American Society for Clinical Nutrition [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]

Sensory stickiness (sticky mouthfeel) was hypothesized to result from the viscoelastic and adhesive properties of a foodstuff. The objective of the present study was to investigate the relative importance of these two properties. Measurements consisted of compression – decompression cycles on a texture analyzer, with product, type of surface, the presence or absence of saliva and compression regime as variables. Products included commercial mayonnaises, custard desserts and warm sauces, varying in apparent viscosity (at shear rate of 10 s −1 ) between 0.3 and 18.3 Pa.s. Fairly good models were obtained, predicting sensory stickiness with R 2 = 0.85–0.92. The predictive value of the mathematical models did not increase when the surface characteristics approached those of the human tongue (use of porcine lingual mucosa). Different surfaces or the use of saliva resulted in differences in the absolute values of the parameters, but their relative values when comparing different products did not change. The parameters appearing in the predictive models represented product characteristics only. The type of surface was not an important factor in determining differences in sensory stickiness between these samples. For the products used in this study, adhesion was large enough to prevent detachment of the sample from the surfaces, i.e., adhesion was not limiting. Variations in perceived stickiness could be explained with R 2 = 0.86, based on only two product characteristics: consistency and ‘long behavior’ (the extent to which necking occurs during decompression). This was better than the correlation between sensory stickiness and apparent viscosity (R 2 = 0.77), confirming the relevance of ‘long behavior’ for sensory stickiness. [ABSTRACT FROM AUTHOR]

The objectives of the present study were to compare the bioavailability of vitamin A from liver paste and from a vitamin A supplement at three nutritionally relevant levels of intake, and to estimate levels of "safe" intake based on concentrations of retinoic acid and its metabolites in plasma after a single dose of vitamin A from liver paste. Women (n = 35; 19-47 y of age) consumed 3.0, 7.5 or 15 mg vitamin A as liver paste or as a vitamin A supplement with a test meal in a randomized design, with a combined crossover (two sources) and parallel approach (three dosages). Retinyl esters and retinoic acid (RA) metabolites were quantified in blood samples at 2-24 h after dosing. The areas under the time-response curves (AUC) were calculated to evaluate responses in plasma vitamin A after intake of liver paste and the vitamin A supplements. For retinyl esters, the AUC was significantly affected by the dosage, but not by the source. The formation of 13-cis-RA, 13-cis-4-oxo-RA, and to a lesser extent all-trans-RA was significantly higher after consumption of liver paste compared with the supplement, especially at higher dosages. Long-term baseline concentrations of retinol were not affected by a single intake of vitamin A. In conclusion, the bioavailability of vitamin A from single doses of liver paste and a vitamin A supplement does not differ, but the plasma concentrations of RA metabolites are higher after intake of liver paste. Thus, pregnant women should indeed limit the intake of vitamin A from liver products. [ABSTRACT FROM AUTHOR]

The potential benefits of a high fruit and vegetable intake on the antioxidant status and on relevant biomarkers of oxidative damage to lipids, proteins and DNA and on (functional) markers of oxidative stress were evaluated. A randomized, free living, open placebo-controlled cross-over trial of 3 wk, with a 2-wk washout period between treatments, was performed in a group of 22 male smokers with a relatively low vegetable and fruit intake using a vegetable burger and fruit drink. The vegetable burger and fruit drink increased serum levels of vitamin C, alpha-carotene, beta-carotene, beta-cryptoxanthin and zeaxanthin and plasma total antioxidant capacity. However, no effects were demonstrated on any marker of oxidative damage to lipids (malondialdehyde F(2)-isoprostane) proteins (carbonyls) and DNA (Comet assay) and (functional) markers of oxidative stress (reduced/oxidized glutathione ratio, glutathione-S-transferase alpha, glutathione-S-transferase pi and nuclear transcription factor-kappaB). Apparently, these increased levels of antioxidants in serum were not sufficiently high to show beneficial changes with the selected biomarkers. Alternatively, oxidative stress in male smokers with a relatively low fruit and vegetable intake might have been still too low to demonstrate a beneficial effect of antioxidants. [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]

The effects of lutein and lycopene on beta-carotene absorption and cleavage were investigated in 12 male subjects. Responses of carotenoids and retinyl palmitate in the triacylglycerol-rich lipoprotein (TRL) fraction after a separate 15-mg beta-carotene dose were compared with those after a dose of 15 mg beta-carotene combined with 15 mg lycopene or lutein (given as natural concentrates or extracts). After combined dosing with lutein, the areas under the curve (AUCs) of beta-carotene and retinyl palmitate in the TRL fraction, adjusted for the triacylglycerol response, were 66% (P = 0.019) and 74% (P < 0.059), respectively, compared with 100% after dosing with beta-carotene alone. After combined dosing with lycopene these percentages were 90% and 101%, respectively (NS). Beta-carotene conversion, estimated from the ratio between the AUC for retinyl esters and beta-carotene, assuming eccentric cleavage, was 69%, 71%, and 72% for treatment with only beta-carotene, beta-carotene combined with lycopene, and beta-carotene combined with lutein, respectively. In addition, a pilot study was performed to evaluate application of TRL response curves to measure absorption of carotenoids from vegetable sources (15 mg carotenoid as carrots, spinach, and tomato paste). As compared with the carotenoid concentrates, responses were considerably lower or hardly measurable (beta-carotene and retinyl palmitate after carrots, lutein after spinach), except for lycopene and retinyl palmitate after a single dose of tomato paste. In conclusion, this study showed that lutein, but not lycopene, negatively affected beta-carotene absorption when given simultaneously with beta-carotene but apparently had no effect on beta-carotene cleavage. Copyright (c) 1998 American Society for Clinical Nutrition [ABSTRACT FROM AUTHOR]

Presents a study intended to determine the particle size distribution of a tomato concentrate by wet sieving. Methodology of study; Results and conclusions of study.