Identification of markers of thermal processing ("roasting") in aqueous extracts of Coffea arabica L. seeds through NMR fingerprinting and chemometrics.

Roasting of Coffea arabica L. seeds gives rise to chemical reactions that produce more than 800 compounds, some being responsible for the desired organoleptic properties for which the beverage called "coffee" is known. In the industry, the "roasting profile," that is, the times and temperatures applied, is key to influence the composition of roasted coffee beans and the flavour of the beverage made from them.

Analysis of sitosteryl oleate esters in phytosterols esters enriched foods by HPLC-ESI-MS(2.).

Phytosteryl esters (PE)-enriched spreads are marketed for eating and cooking purposes. Temperature and also light exposure are the major factors leading to the formation of PE oxides in food matrix. In this study a high-speed HPLC-MS(2) method was developed to analyze the major PE present in PE-enriched spreads: sitosteryl oleate (SO) and its oxidation products, by using synthesized compounds as standards.

Dietary walnut oil modulates liver steatosis in the obese Zucker rat.

Purpose: Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. We aimed to clarify the impact of dietary walnut oil versus animal fat on hepatic steatosis, representing the initial step of multistage pathogenesis of NAFLD, in Zucker obese rats.

Methods: Zucker lean ad libitum (a.

Effects of industrial processing on folate content in green vegetables.

Folates are described to be sensitive to different physical parameters such as heat, light, pH and leaching. Most studies on folates degradation during processing or cooking treatments were carried out on model solutions or vegetables only with thermal treatments. Our aim was to identify which steps were involved in folates loss in industrial processing chains, and which mechanisms were underlying these losses.

Freeze-drying of enzymes in case of water-binding and non-water-binding substrates.

Enzymes typically have a critical instability, which dominates both formulation and process development. In this paper, the ability to preserve the enzyme activity during freeze-drying was investigated for both water-binding and non-water-binding substrates. For this purpose, acid phosphatase was used as model protein.

Investigation of biomarkers of bile tolerance in Lactobacillus casei using comparative proteomics.

The identification of cell determinants involved in probiotic features is a challenge in current probiotic research. In this work, markers of bile tolerance in Lactobacillus casei were investigated using comparative proteomics. Six L.

Comparative proteomic analysis of Lactobacillus plantarum for the identification of key proteins in bile tolerance.

Background: Lactic acid bacteria are commonly marketed as probiotics based on their putative or proven health-promoting effects. These effects are known to be strain specific but the underlying molecular mechanisms remain poorly understood. Therefore, unravelling the determinants behind probiotic features is of particular interest since it would help select strains that stand the best chance of success in clinical trials.

Effects of oxidation on the hydrolysis by cholesterol esterase of sitosteryl esters as compared to a cholesteryl ester.

Phytosteryl esters (PE) are used as ingredients in functional food to decrease plasma concentration of low density lipoprotein-cholesterol (LDL-C). Effective impairment of cholesterol absorption by PE suggests that these esters are hydrolyzed by the pancreatic cholesterol esterase (CEase, EC 3.1.

Enterocin 96, a novel class II bacteriocin produced by Enterococcus faecalis WHE 96, isolated from Munster cheese.

Enterococcus faecalis WHE 96, a strain isolated from soft cheese based on its anti-Listeria activity, produced a 5,494-Da bacteriocin that was purified to homogeneity by ultrafiltration and cation-exchange and reversed-phase chromatographies. The amino acid sequence of this bacteriocin, named enterocin 96, was determined by Edman degradation, and its structural gene was sequenced, revealing a double-glycine leader peptide. After a comparison with other bacteriocins, it was shown that enterocin 96 was a new class II bacteriocin that showed very little similarity with known structures.

2-DE and MS analysis of key proteins in the adhesion of Lactobacillus plantarum, a first step toward early selection of probiotics based on bacterial biomarkers.

The identification of cell components involved in probiotic activities is a challenge in current probiotic research. In this work, a new approach based on proteomics as an analytical tool for the identification of characteristic protein profiles related to adhesion to mucin as a model probiotic property was used. Three Lactobacillus plantarum strains with different adhesion rates were used for proteomic analysis: L.

Smearing of soft cheese with Enterococcus faecium WHE 81, a multi-bacteriocin producer, against Listeria monocytogenes.

Enterococcus faecium WHE 81, a multi-bacteriocin producer, was tested for its antimicrobial activity on Listeria monocytogenes in Munster cheese, a red smear soft cheese. The naturally delayed and superficial contamination of this type of cheese allowed the use of E. faecium WHE 81 at the beginning of the ripening as a surface culture.

Synthesis of highly pure oxyphytosterols and (oxy)phytosterol esters. Part II. (Oxy)-sitosterol esters derived from oleic acid and from 9,10-dihydroxystearic acid [1].

Several efficient synthetic routes giving readily access to (oxy)-sitosterol esters and (oxy)-cholesterol esters derived respectively from oleic acid and from 9,10-dihydroxystearic acid were developed for the first time. This approach allowed that sufficient amounts of the latter were available in order to carry out further biological studies.

Synthesis of highly pure oxyphytosterols and (oxy)phytosterol esters Part I. Regioselective hydrogenation of stigmasterol: an easy access to oxyphytosterols.

The synthesis of several oxyphytosterols is described starting from stigmasterol, the key step being the regioselective hydrogenation of the 22-23 double bond of the latter.

Mitochondrial perturbation, oxidative stress and lysosomal destabilization are involved in 7beta-hydroxysitosterol and 7beta-hydroxycholesterol triggered apoptosis in human colon cancer cells.

We reported previously that 7beta-hydroxysitosterol and 7beta-hydroxycholesterol induced apoptosis in Caco-2 cells. Apoptosis caused by 7beta-hydroxysitosterol but not by 7beta-hydroxycholesterol was related to a caspase-dependent process. In the present report, we compared the effects of both compounds on mitochondria integrity and on various modulators of apoptosis.

Perturbation of polyamine metabolism and its relation to cell death in human colon cancer cells treated by 7beta-hydroxycholesterol and 7beta-hydroxysitosterol.

7beta-OHsitosterol and 7beta-OHcholesterol are natural compounds of plant and animal cells with high structural similarity. Recently it was reported that both compounds induced apoptosis on human colon cancer cells by targeting different signalling pathways. Our study aimed at comparing their effects on polyamine metabolism and its relation to apoptosis.

Quantitative analysis of beta-sitosterol oxides induced in vegetable oils by natural sunlight, artificially generated light, and irradiation.

UV radiation is able to induce lipid peroxidation. Photooxidation-induced beta-sitosterol oxides were monitored in four vegetable oils exposed to sunlight for 10, 20, and 30 days during May 2005 (northeastern France), exposed to artificial light generated by a high-pressure Hg lamp for 21, 42, and 63 h at room temperature, and exposed to a 10 MeV electron beam at 0.93, 2.

Separation of Delta5- and Delta7-phytosterols by adsorption chromatography and semipreparative reversed phase high-performance liquid chromatography for quantitative analysis of phytosterols in foods.

A method for the separation, isolation, and identification of phytosterols was developed. A commercial phytosterols mixture, Generol 95S, was fractionated first by adsorption silica gel column chromatography and then separated by means of a semipreparative reverse phase high-performance liquid chromatography fitted with a Polaris C8-A column (250 mm x 10 mm i.d.

Gram-scale chromatographic purification of beta-sitosterol. Synthesis and characterization of beta-sitosterol oxides.

An effective purification method for beta-sitosterol was developed starting from a commercial source of a phytosterol mixture using preparative adsorption column chromatography. beta-Sitosterol (> or = 95% purity) was obtained on a gram-scale. Thus, the synthesis of six beta-sitosterol oxides, including 7alpha-hydroxy, 7beta-hydroxy, 5,6alpha-epoxy, 5,6beta-epoxy, 7-keto, and 5alpha,6beta-dihydroxysitosterol, were successfully carried out.

Identification and quantitative analysis of beta-sitosterol oxides in vegetable oils by capillary gas chromatography-mass spectrometry.

As vegetable oils and phytosterol-enriched spreads are marketed for frying food or cooking purposes, temperature is one of the most important factors leading to the formation of phytosterol oxides in food matrix. A methodology based on saponification, organic solvent extraction, solid-phase extraction (SPE), followed by mass spectrometric identification and quantitation of beta-sitosterol oxides using capillary gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode was developed and characterized. Relative response factors of six beta-sitosterol oxides, including 7alpha-hydroxy, 7beta-hydroxy, 5,6alpha-epoxy, 5,6beta-epoxy, 7-keto, and 5alpha,6beta-dihydroxysitosterol, were calculated against authentic standards of 19-hydroxycholesterol or cholestanol.

DNA comet assay for the detection of time-temperature abuse during the storage of poultry.

Effects of abusive storage conditions on the quality of fresh chicken were studied by detecting DNA damage to breast fillets and liver with the neutral comet assay. Chilled samples were kept at 4 degrees C for prolonged periods, whereas frozen samples were exposed to temperatures of 4 degrees C, representing inadvertent thawing, and 20 degrees C, representing extreme abuse in the distribution chain. Comets' mean tail moment distributions reflected the increasing patterns of DNA damage, but the differences of values between close levels of treatment were sometimes insignificant.