Effect of dihydrocaffeic acid on UV irradiation of human keratinocyte HaCaT cells.

Dihydrocaffeic acid, a dietary constituent and a microbial metabolite of flavonoids, is an antioxidant, but few biological effects have been examined. After its production by microflora in the colon, dihydrocaffeic acid is absorbed and found in plasma as a combination of free and metabolized forms. Excess solar UV radiation provokes damage and initiates immune response and inflammation in skin, sometimes leading to cancer.

Identification of genes associated with the long-gut-persistence phenotype of the probiotic Lactobacillus johnsonii strain NCC533 using a combination of genomics and transcriptome analysis.

Lactobacillus johnsonii strains NCC533 and ATCC 33200 (the type strain of this species) differed significantly in gut residence time (12 versus 5 days) after oral feeding to mice. Genes affecting the long gut residence time of the probiotic strain NCC533 were targeted for analysis. We hypothesized that genes specific for this strain, which are expressed during passage of the bacterium through the gut, affect the phenotype.

Investigation of the metabolic fate of dihydrocaffeic acid.

The antioxidant dihydrocaffeic acid is a dietary constituent and a microbial metabolite of flavonoids. Orally administered to rats, dihydrocaffeic acid was very rapidly absorbed most probably by the gastric or duodenal epithelium and excreted in urine as free and conjugated forms. LC-MS2 analysis of plasma and urine samples allowed confident identification of the dihydrocaffeic acid metabolites.

Determination of the low molecular weight fraction of food-grade carrageenans.

Recently there has been some debate regarding the presence and associated health risk of low molecular weight carrageenan in foodstuffs. Unfortunately measurement of the low molecular weight tail (LMT) of food-grade carrageenans (defined here as the carrageenan having relative molecular mass (Mr) below 50,000) is not trivial, largely due to its low abundance. So far methods employing light scattering have been unsuccessful in producing reproducible results, probably due to the poor detector response at low masses.

Predictive relationship between polyphenol and nonfat cocoa solids content of chocolate.

Chocolate is often labeled with percent cocoa solids content. It is assumed that higher cocoa solids contents are indicative of higher polyphenol concentrations, which have potential health benefits. However, cocoa solids include polyphenol-free cocoa butter and polyphenol-rich nonfat cocoa solids (NFCS).

Study of liquid crystal space groups using controlled tilting with cryogenic transmission electron microscopy.

We developed a method that enables differentiation between liquid crystalline-phase particles corresponding to different space groups. It consists of controlled tilting of the specimen to observe different orientations of the same particle using cryogenic transmission electron microscopy. This leads to the visualization of lattice planes (or reflections) that are present for a given structure and absent for the other one(s) and that give information on liquid crystalline structures and their space groups.

Fast analysis by gas-liquid chromatography. Perspective on the resolution of complex fatty acid compositions.

Separation of fatty acids as methyl ester (FAME) derivatives has been carried out using short and highly polar capillary column developed for fast gas-liquid chromatography (GLC) applications. The GLC parameters have been optimized in order to achieve separation of FAME ranging from 4:0 (butyric acid) to 24:1 in less than 5 min. Milk fat that has by far the most complex fatty acid composition among edible fats and oils has been used to optimize the method.

Limits of suspicion, recognition and confirmation as concepts that account for the confirmation transitions at the detection limit for quantification by liquid chromatography-tandem mass spectrometry.

With the emergence of liquid chromatography coupled to tandem quadrupolar mass spectrometry (LC-QqQ) as a routine technique for quantitative analysis, analytical chemists claimed LC-QqQ to be the gold standard to reach the best compromise between versatility, high throughput, robustness, sensitivity and selectivity. In particular, a high selectivity is ensured when two or more transitions are monitored because not only the retention time and protonated molecule are controlled but also two or more product ions are. With the multiple-transition recording, the transition leading to the most intense signal is used for the quantification (quantifier), while the other one(s) is(are) aimed at confirming the detection of the analyte (qualifiers).

Neonatal dietary supplementation of arachidonic acid increases prostaglandin levels in adipose tissue but does not promote fat mass development in guinea pigs.

The role of arachidonic acid (AA) on the development of adipose tissue is still controversial since its metabolites, i.e., prostaglandins, can either stimulate or inhibit preadipocyte differentiation in vitro.

Chicory increases acetate turnover, but not propionate and butyrate peripheral turnovers in rats.

Chicory roots are rich in inulin that is degraded into SCFA in the caecum and colon. Whole-body SCFA metabolism was investigated in rats during food deprivation and postprandial states. After 22 h of food deprivation, sixteen rats received an IV injection of radioactive 14C-labelled SCFA.

Status of methodology for the determination of fat-soluble vitamins in foods, dietary supplements, and vitamin premixes.

Fat-soluble vitamins (FSVs) include vitamin A, carotenoids, vitamins D, E, and K. New legislation is being introduced in many countries to reinforce regulatory compliance of declared concentrations of vitamins and other micronutrients in food products and dietary supplements. The levels of FSVs are likely to be more closely scrutinized due to their potential health risks associated with overdosing, in particular of vitamin D.

Consumer understanding of nutrition and health claims: sources of evidence.

Provided that they are scientifically substantiated, nutrition and health (NH) claims linked to food products can help consumers make well-informed food choices. The new European legislation on NH claims made on foods entered into force on 19 January 2007. The law sets out conditions for their use, establishes a system for their scientific evaluation, and will create European lists of authorised claims.

Comprehensive analysis of vitamin E constituents in human plasma by liquid chromatography-mass spectrometry.

The present paper describes the development and validation of a normal-phase liquid chromatography-mass spectrometry (NP-HPLC-MS) method for the screening and quantification of vitamin E constituents in human plasma and food matrixes. Liquid-liquid extraction combined with isotope dilution was applied to extract the lipophilic target analytes. Baseline separation of alpha-tocopherylacetate, alpha-tocopherol, alpha-tocotrienol, alpha-tocopherylquinone, beta-tocopherol, gamma-tocopherol, beta-tocotrienol, gamma-tocotrienol, delta-tocopherol, and delta-tocotrienol was achieved utilizing a normal-phase amine column operated with n-hexane and 1,4-dioxane as solvents.

History of safe use as applied to the safety assessment of novel foods and foods derived from genetically modified organisms.

Very few traditional foods that are consumed have been subjected to systematic toxicological and nutritional assessment, yet because of their long history and customary preparation and use and absence of evidence of harm, they are generally regarded as safe to eat. This 'history of safe use' of traditional foods forms the benchmark for the comparative safety assessment of novel foods, and of foods derived from genetically modified organisms. However, the concept is hard to define, since it relates to an existing body of information which describes the safety profile of a food, rather than a precise checklist of criteria.

Improvement of nutritional status and incidence of infection in hospitalised, enterally fed elderly by feeding of fermented milk containing probiotic Lactobacillus johnsonii La1 (NCC533).

Probiotics have potential to improve host immunity; however, there is less evidence showing their efficacy against infections and nutritional status in the elderly. We conducted a double-blinded feeding trial in the elderly to elucidate the effect of fermented milk containing Lactobacillus johnsonii La1 (LC1) on infections and nutritional status. Twenty-four completely enterally fed elderly in-patients aged over 70 years were randomly assigned into two groups.

Analytical procedures for water-soluble vitamins in foods and dietary supplements: a review.

Water-soluble vitamins include the B-group vitamins and vitamin C. In order to correctly monitor water-soluble vitamin content in fortified foods for compliance monitoring as well as to establish accurate data banks, an accurate and precise analytical method is a prerequisite. For many years microbiological assays have been used for analysis of B vitamins.

The taxonomy of Enterobacter sakazakii: proposal of a new genus Cronobacter gen. nov. and descriptions of Cronobacter sakazakii comb. nov. Cronobacter sakazakii subsp. sakazakii, comb. nov., Cronobacter sakazakii subsp. malonaticus subsp. nov., Cronobacter turicensis sp. nov., Cronobacter muytjensii sp. nov., Cronobacter dublinensis sp. nov. and Cronobacter genomospecies 1.

Background: Enterobacter sakazakii is an opportunistic pathogen that can cause infections such as necrotizing enterocolitis, bacteraemia, meningitis and brain abscess/lesions. When the species was defined in 1980, 15 biogroups were described and it was suggested that these could represent multiple species. In this study the taxonomic relationship of strains described as E.

How to comprehensively analyse proteins and how this influences nutritional research.

Proteomics, the comprehensive analysis of a protein complement in a cell, tissue or biological fluid at a given time, is a key platform within the "omic" technologies that also encompass genomics (gene analysis), transcriptomics (gene expression analysis) and metabolomics (metabolite profiling). This review summarises protein pre-separation, identification, quantification and modification/interaction analysis and puts them into perspective for nutritional R and D. Mass spectrometry has progressed with regard to mass accuracy, resolution and protein identification performance.

Bacterial imprinting of the neonatal immune system: lessons from maternal cells?

Objective: We examined the presence of a natural bacterial inoculum in breast milk and its intracellular transport from the maternal intestine to the breast through the circulation.

Methods: Breast milk and peripheral blood were collected aseptically from healthy donors at various times after delivery, and the presence of viable bacteria was determined through plating. Temporal temperature gradient gel electrophoresis was used to examine the bacterial ribosomal DNA content in milk cells, maternal peripheral blood mononuclear cells, and feces and in corresponding infant feces.

Gamma study of pH, nitrite, and salt inhibition of Aeromonas hydrophila.

The gamma hypothesis states that there are no interactions between antimicrobial environmental factors. The time to growth of Aeromonas hydrophila challenged with pH, NaNO(2), and salt combinations at 30 degrees C was investigated. Data were examined using a model based on the gamma hypothesis (the gamma model), which takes into account variance-stabilizing transformations and which gives biologically relevant parameters.

Comparison of available analytical methods to measure trans-octadecenoic acid isomeric profile and content by gas-liquid chromatography in milk fat.

Accurate quantification of trans-fatty acids (TFAs) could be achieved by infrared spectroscopy or by gas-liquid chromatography (GLC). Accurate quantification by GLC should be achieved using specific highly polar capillary columns such as 100 m CP-Sil 88 or equivalent. A pre-fractionation of cis and trans-fatty acids could be performed by silver-ion thin-layer chromatography (Ag-TLC), silver-ion solid-phase extraction (Ag-SPE), or by high-performance liquid-chromatography (HPLC).

A study of the Gamma hypothesis: predictive modelling of the growth and inhibition of Enterobacter sakazakii.

Although the temperature growth profile of the opportunistic pathogen Enterobacter sakazakii is known, few other environmental factors affecting growth have been analysed. Using a model based on the Gamma hypothesis--that antimicrobial factors in mixtures exert independent effects--a range of weak acids (lactic, acetic, propionic, citric, sorbic and benzoic), pH, salt and temperature and some of their combinations were examined. The weak acids examined inhibited principally with the acid-form of the weak acid, however, benzoic, sorbic and propionic acids also displayed an inhibitory contribution from their respective anionic forms.

An investigation of the Gamma hypothesis: a predictive modelling study of the effect of combined inhibitors (salt, pH and weak acids) on the growth of Aeromonas hydrophila.

The Gamma hypothesis, that multiple inhibitory factors combine independently, is the underlying hypothesis for the quantification of the Hurdle concept used in food manufacture. The literature, however, is confused as to whether interactive effects exist and under which circumstances they occur, if at all. Using the method of time to detection (TTD), the inhibitory effect of pH, salt and specific weak acids (acetic, propionic, sorbic and benzoic) and combinations of these with respect to the growth of Aeromonas hydrophila (ATCC 7966) were analysed.

Carbohydrate specification limits for the authenticity assessment of soluble (instant) coffee: statistical approach.

Carbohydrates are very good tracers for the authenticity assessment of soluble (instant) coffee. Total glucose and total xylose were determined in 1002 samples of commercial soluble coffees using high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) according to AOAC Method 995.13 and ISO standard 11292.