Direct analysis of aldehydes and carboxylic acids in the gas phase by negative ionization selected ion flow tube mass spectrometry: Quantification and modelling of ion-molecule reactions.

RATIONALE: The concentrations of aldehydes and volatile fatty acids have to be controlled because of their potential harmfulness in indoor air or relationship with the organoleptic properties of agri-food products. Although several specific analytical methods are currently used, the simultaneous analysis of these compounds in a complex matrix remains a challenge. The combination of positive and negative ionization selected ion flow tube mass spectrometry (SIFT-MS) allows the accurate, sensitive and high-frequency analysis of complex gas mixtures of these compounds. METHODS: The ion-molecule reactions of negative precursor ions (OH- , O•- , O2 •- , NO2 - and NO3 - ) with five aldehydes and four carboxylic acids were investigated in order to provide product ions and rate constants for the quantification of these compounds by negative ion SIFT-MS. The results were compared with those obtained by conventional analysis methods and/or with already implemented SIFT-MS positive ionization methods. The modelling of hydroxide ion (OH- )/molecule reaction paths by ab-initio calculation allowed a better understanding of these gas-phase reactions. RESULTS: Deprotonation systematically occurs by reaction between negative ions and aldehydes or acids, leading to the formation of [M - H]- primary ions. Ab-initio calculations demonstrated the α-CH deprotonation of aldehydes and the acidic proton abstraction for fatty acids. For aldehydes, the presence of water in the flow tube leads to the formation of hydrated ions, [M - H]- .H2 O. With the NO2 - precursor ion, a second reaction channel results in ion-molecule association with the formation of M.NO2 - ions. CONCLUSIONS: Except for formaldehyde, all the studied compounds can be quantified by negative ion SIFT-MS with significant rate constants. In addition to positive ion SIFT-MS with H3 O+ , O2 + and NO+ precursor ions, negative ionization with O•- , O2 •- , OH- , NO2 - and NO3 - extends the range of analysis of aldehydes and carboxylic acids in air without a preparation or separation step. This methodology was illustrated by the simultaneous quantification in single-scan experiments of seven aldehydes and six carboxylic acids released by building materials.

Sodium pyrophosphate enhances iron bioavailability from bouillon cubes fortified with ferric pyrophosphate.

Fe fortification of centrally manufactured and frequently consumed condiments such as bouillon cubes could help prevent Fe deficiency in developing countries. However, Fe compounds that do not cause sensory changes in the fortified product, such as ferric pyrophosphate (FePP), exhibit low absorption in humans. Tetra sodium pyrophosphate (NaPP) can form soluble complexes with Fe, which could increase Fe bioavailability. Therefore, the aim of this study was to investigate Fe bioavailability from bouillon cubes fortified with either FePP only, FePP+NaPP, ferrous sulphate (FeSO4) only, or FeSO4+NaPP. We first conducted in vitro studies using a protocol of simulated digestion to assess the dialysable and ionic Fe, and the cellular ferritin response in a Caco-2 cell model. Second, Fe absorption from bouillon prepared from intrinsically labelled cubes (2·5 mg stable Fe isotopes/cube) was assessed in twenty-four Fe-deficient women, by measuring Fe incorporation into erythrocytes 2 weeks after consumption. Fe bioavailability in humans increased by 46 % (P<0·005) when comparing bouillons fortified with FePP only (4·4 %) and bouillons fortified with FePP+NaPP (6·4 %). Fe absorption from bouillons fortified with FeSO4 only and with FeSO4+NaPP was 33·8 and 27·8 %, respectively (NS). The outcome from the human study is in agreement with the dialysable Fe from the in vitro experiments. Our findings suggest that the addition of NaPP could be a promising strategy to increase Fe absorption from FePP-fortified bouillon cubes, and if confirmed by further research, for other fortified foods with complex food matrices as well.

Effect of red wine consumption on biomarkers of oxidative stress.

AIMS: To evaluate the effect of acute and chronic consumption of red wine or de-alcoholized red wine with a similar antioxidant capacity on plasma total antioxidant capacity (TEAC), nuclear factor-κB (NF-κB) activity and F2-isoprostanes (8-iso-PGF(2α)) in healthy men. METHODS: Nineteen healthy men with an increased waist circumference (≥94 cm) and a body mass index above 25 kg/m(2) participated in a randomized, controlled crossover design trial. They daily consumed 450 ml of red wine (four drinks; 41.4 g alcohol) or 450 ml of de-alcoholized red wine during dinner for 4 weeks each. On the last day of each treatment period, blood was collected before and 1 h after a standardized dinner with red wine or de-alcoholized red wine and also 24-h urine was collected. RESULTS: Absolute TEAC levels were higher 1 h after dinner with red wine compared with dinner with de-alcoholized red wine (1.3 versus 1.1 mmol Trolox equivalents/l; P = 0.03). Consumption of dinner together with de-alcoholized red wine acutely stimulated NF-κB activity in peripheral blood mononuclear cells (0.4-0.7 HeLa equivalents/2.5 µg protein; P = 0.006), whereas this increase was completely suppressed when the dinner was combined with red wine. A chronic increase in urinary 8-iso-PGF(2α) after 4 weeks of red wine consumption compared with de-alcoholized red wine consumption (157 pg/mg creatinine and 141 pg/mg creatinine, respectively, P = 0.006) was also observed. CONCLUSIONS: Consumption of a moderate dose of red wine can acutely increase plasma TEAC and suppress NF-κB activation induced by a meal. Controversially, 4 weeks of red wine consumption compared with de-alcoholized red wine consumption increases the oxidative lipid damage marker 8-iso-PGF(2α).

Bioprocessing of wheat bran in whole wheat bread increases the bioavailability of phenolic acids in men and exerts antiinflammatory effects ex vivo.

Whole grain consumption has been linked to a lower risk of metabolic syndrome, which is normally associated with a low-grade chronic inflammation. The benefits of whole grain are in part related to the inclusion of the bran, rich in phenolic acids and fiber. However, the phenols are poorly bioaccessible from the cereal matrix. The aim of the present study was to investigate the effect of bioprocessing of the bran in whole wheat bread on the bioavailability of phenolic acids, the postprandial plasma antioxidant capacity, and ex vivo antiinflammatory properties. After consumption of a low phenolic acid diet for 3 d and overnight fasting, 8 healthy men consumed 300 g of whole wheat bread containing native bran (control bread) or bioprocessed bran (bioprocessed bread) in a cross-over design. Urine and blood samples were collected for 24 h to analyze the phenolic acids and metabolites. Trolox equivalent antioxidant capacity was measured in plasma. Cytokines were measured in blood after ex vivo stimulation with LPS. The bioavailabilities of ferulic acid, vanillic acid, sinapic acid, and 3,4-dimethoxybenzoic acid from the bioprocessed bread were 2- to 3-fold those from the control bread. Phenylpropionic acid and 3-hydroxyphenylpropionic acid were the main colonic metabolites of the nonbioaccessible phenols. The ratios of pro-:antiinflammatory cytokines were significantly lower in LPS-stimulated blood after the consumption of the bioprocessed bread. In conclusion, bioprocessing can remarkably increase the bioavailability of phenolic acids and their circulating metabolites, compounds which have immunomodulatory effects ex vivo.

Bioavailability and kinetics of sulforaphane in humans after consumption of cooked versus raw broccoli.

The aim of this study was to determine the bioavailability and kinetics of the supposed anticarcinogen sulforaphane, the hydrolysis product of glucoraphanin, from raw and cooked broccoli. Eight men consumed 200 g of crushed broccoli, raw or cooked, with a warm meal in a randomized, free-living, open cross-over trial. Higher amounts of sulforaphane were found in the blood and urine when broccoli was eaten raw (bioavailability of 37%) versus cooked (3.4%, p ) 0.002). Absorption of sulforaphane was delayed when cooked broccoli was consumed (peak plasma time ) 6 h) versus raw broccoli (1.6 h, p ) 0.001). Excretion half-lives were comparable, 2.6 and 2.4 h on average, for raw and cooked broccoli, respectively (p ) 0.5). This study gives complete kinetic data and shows that consumption of raw broccoli results in faster absorption, higher bioavailability, and higher peak plasma amounts of sulforaphane, compared to cooked broccoli.

Ferulic acid from aleurone determines the antioxidant potency of wheat grain (Triticum aestivum L.).

Grain is an important source of phytochemicals, which have potent antioxidant capacity. They have been implicated in the beneficial health effect of whole grains in reducing cardiovascular disease and type 2 diabetes. The aim of the present study was to identify the most important antioxidant fractions of wheat grain. It was found that the aleurone content of these fractions was highly correlated with the antioxidant capacity of the fractions (r = 0.96, p < 0.0001). Ferulic acid appeared to be the major contributor to the antioxidant capacity in fractions with higher antioxidant capacity. The contribution of protein was rather limited. It was concluded that the antioxidant potency of wheat grain fractions is predominantly determined by aleurone content, which can be attributed to the presence of relatively large amounts of phenolic compounds, primarily ferulic acid.

The effect of Korean pine nut oil on in vitro CCK release, on appetite sensations and on gut hormones in post-menopausal overweight women.

Appetite suppressants may be one strategy in the fight against obesity. This study evaluated whether Korean pine nut free fatty acids (FFA) and triglycerides (TG) work as an appetite suppressant. Korean pine nut FFA were evaluated in STC-1 cell culture for their ability to increase cholecystokinin (CCK-8) secretion vs. several other dietary fatty acids from Italian stone pine nut fatty acids, oleic acid, linoleic acid, alpha-linolenic acid, and capric acid used as a control. At 50 muM concentration, Korean pine nut FFA produced the greatest amount of CCK-8 release (493 pg/ml) relative to the other fatty acids and control (46 pg/ml). A randomized, placebo-controlled, double-blind cross-over trial including 18 overweight post-menopausal women was performed. Subjects received capsules with 3 g Korean pine (Pinus koraiensis) nut FFA, 3 g pine nut TG or 3 g placebo (olive oil) in combination with a light breakfast. At 0, 30, 60, 90, 120, 180 and 240 minutes the gut hormones cholecystokinin (CCK-8), glucagon like peptide-1 (GLP-1), peptide YY (PYY) and ghrelin, and appetite sensations were measured. A wash-out period of one week separated each intervention day.CCK-8 was higher 30 min after pine nut FFA and 60 min after pine nut TG when compared to placebo (p < 0.01). GLP-1 was higher 60 min after pine nut FFA compared to placebo (p < 0.01). Over a period of 4 hours the total amount of plasma CCK-8 was 60% higher after pine nut FFA and 22% higher after pine nut TG than after placebo (p < 0.01). For GLP-1 this difference was 25% after pine nut FFA (P < 0.05). Ghrelin and PYY levels were not different between groups. The appetite sensation "prospective food intake" was 36% lower after pine nut FFA relative to placebo (P < 0.05). This study suggests that Korean pine nut may work as an appetite suppressant through an increasing effect on satiety hormones and a reduced prospective food intake.

Moderate alcohol consumption and lipoprotein-associated phospholipase A2 activity.

BACKGROUND AND AIMS: To investigate the effect of moderate alcohol consumption on lipoprotein-associated phospholipase A2 activity, markers of inflammation and oxidative stress and whether these effects are modified by BMI. METHODS AND RESULTS: Eleven lean (BMI: 18.5-25 kg/m(2)) and 9 overweight (BMI>27 kg/m(2)) men participated in a randomized controlled crossover trial. After consuming 3 cans of beer (40 g ethanol) or alcohol-free beer daily during 3 weeks, fasting blood samples were taken. HDL cholesterol increased by 18.2% (p<0.001) after beer compared to alcohol-free beer, while LDL cholesterol decreased by 7.8% (p=0.008). Lipoprotein-associated phospholipase A2 activity was not different (p=0.23) between beer (47.5+/-0.8) and alcohol-free beer (48.9+/-0.8). High-sensitive C-reactive protein was unaffected, but urinary isoprostanes tended to increase (p=0.09) after beer (114.0+/-6.9) compared to alcohol-free beer (96.9+/-6.5). An interaction between BMI and treatment (p<0.05) on liver enzymes was observed, indicating an increase of liver enzymes after moderate alcohol consumption in overweight men only. CONCLUSION: Despite profound effects on HDL and LDL cholesterol, moderate alcohol consumption did not affect lipoprotein-associated phospholipase A2 activity. Liver enzymes increased after alcohol consumption in overweight men only, suggesting a less favorable response to moderate alcohol consumption in overweight people.

Decreased coenzyme Q10 concentration in plasma of children with cystic fibrosis.

OBJECTIVES: Coenzyme Q10 (CoQ10) is an effective lipophilic antioxidant and protects against lipid peroxidation by scavenging radicals. Patients with cystic fibrosis generally have fat malabsorption; thus, we hypothesized that overall plasma CoQ10 concentration in pediatric patients with cystic fibrosis might be diminished. Because these patients have increased oxidative stress due to chronic pulmonary inflammation, we also assumed that the oxidized form of CoQ10 might be relatively increased. PATIENTS AND METHODS: The total plasma CoQ10 levels and the oxidized and reduced form were measured by high-performance liquid chromatography in 30 children with cystic fibrosis (mean FEV1 % predicted = 88.5% +/- 18.7%) and 30 age-matched controls. RESULTS: Total plasma CoQ10 levels were significantly lower in the cystic fibrosis group as compared with the control group (0.87 +/- 0.42 micromol/L and 1.35 +/- 0.39 micromol/L, respectively; P < 0.001). When correcting for the lower serum cholesterol level in patients with cystic fibrosis, this difference remained significant: the CoQ10/cholesterol ratio (micromol/mol) was 268.8 +/- 136.7 and 334.0 +/- 102.9 in patients and controls, respectively (P < 0.05). However, the CoQ10 redox status was identical in patients and controls (86.4% +/- 7.1% and 85.4% +/- 7.3%, respectively). CONCLUSIONS: We found that the overall plasma CoQ10 concentration is lower in patients with cystic fibrosis, probably because of fat malabsorption. The CoQ10 redox status was not disturbed, indicating that CoQ10 could still be adequately regenerated in this group of patients with cystic fibrosis with mild-to-moderate pulmonary disease.

Association between consumption of cruciferous vegetables and condiments and excretion in urine of isothiocyanate mercapturic acids.

A high intake of cruciferous vegetables is associated with a reduced risk of cancer and cardiovascular diseases. This protective effect has been linked to isothiocyanates, enzymatic hydrolysis products of glucosinolates. In this study, the metabolic fate of glucosinolates and isothiocyanates after ingestion of 19 different cruciferous vegetables was studied in three male subjects. After the consumption of 13 cruciferous vegetables (glucosinolate content, 0.01-0.94 mmol/kg) and six condiments (isothiocyanate content, 0.06-49.3 mmol/kg), eight different isothiocyanate mercapturic acids were determined in urine samples. Excretion levels after the consumption of raw vegetables and condiments were higher (bioavailability, 8.2-113%) as compared to cooked vegetables (bioavailability, 1.8-43%), but the excretion rate was similar (t1/2=2.1-3.9 h). Isothiocyanates in urine remain longer at a nonzero level after the consumption of glucosinolates from cooked vegetables, as compared to raw vegetables and condiments, and maximal levels in urine were reached about 4 h later. Isothiocyanate mercapturic acids can be used as a biomarker to reflect the active dose of isothiocyanates absorbed.

Co-ingestion of a protein hydrolysate with or without additional leucine effectively reduces postprandial blood glucose excursions in Type 2 diabetic men.

This study examined postprandial plasma insulin and glucose responses after co-ingestion of an insulinotropic protein (Pro) hydrolysate with and without additional free leucine with a single bolus of carbohydrate (Cho). Male patients with long-standing Type 2 diabetes (n = 10) and healthy controls (n = 10) participated in 3 trials in which plasma glucose, insulin, and amino acid responses were determined after the ingestion of beverages of different composition (Cho: 0.7 g/kg carbohydrate, Cho+Pro: 0.7 g/kg carbohydrate with 0.3 g/kg protein hydrolysate, or Cho+Pro+Leu: 0.7 g/kg carbohydrate, 0.3 g/kg protein hydrolysate and 0.1 g/kg free leucine). Plasma insulin responses [expressed as area under the curve (AUC)] were 141 and 204% greater in patients with Type 2 diabetes and 66 and 221% greater in the controls in the Cho+Pro and Cho+Pro+Leu trials, respectively, compared with those in the Cho trial (P < 0.05). The concomitant plasma glucose responses were 15 and 12% lower in the patients with Type 2 diabetes and 92 and 97% lower in the control group in the Cho+Pro and Cho+Pro+Leu trials, respectively, compared with those in the Cho trial (P < 0.05). Plasma leucine concentrations correlated with the insulin response in all subjects (r = 0.43, P < 0.001). We conclude that co-ingestion of a protein hydrolysate with or without additional free leucine strongly augments the insulin response after ingestion of a single bolus of carbohydrate, thereby significantly reducing postprandial blood glucose excursions in patients with long-standing Type 2 diabetes.

Effects of gastric emptying on the postprandial ghrelin response.

Distension and chemosensitization of the stomach are insufficient to induce a ghrelin response, suggesting that postgastric feedback is required. This postgastric feedback may be regulated through insulin. We investigated the relation between gastric emptying rate and the postprandial ghrelin response as well as the role of insulin and other hormones possibly mediating this response. Fifteen healthy men [BMI 21.6 kg/m2 (SD 1.9), age 20.5 yr (SD 2.5)] were studied in a single-blind, crossover design. Subjects received two treatments separated by 1 wk: 1) a dairy breakfast in combination with a 3-h intravenous infusion of glucagon-like peptide-1 (GLP-1), which delays gastric emptying, and 2) a dairy breakfast in combination with a 3-h intravenous infusion of saline. Blood samples were drawn before breakfast and during the infusion. Postprandial ghrelin (total) responses were lower following the saline infusion compared with the GLP-1 infusion (P < 0.05). Acetaminophen concentrations, an indirect measurement of gastric emptying rate, were inversely correlated with total ghrelin concentrations (saline r = -0.76; 95% CI = -0.90, -0.49, GLP-1 r = -0.47; 95% CI = -0.76, -0.04). Ghrelin concentrations were only weakly correlated with insulin concentrations (saline r = -0.36; 95% CI = -0.69, 0.09; GLP- 1 r = -0.42; 95% CI = -0.73, 0.03), but strongly inversely correlated with GIP concentrations (saline r = -0.74; 95% CI= -0.89, -0.45; GLP-1 r = -0.63; 95% CI = -0.84, -0.27). In conclusion, our results support the hypothesis that ghrelin requires postgastric feedback, which may not be regulated through insulin. Conversely, our data suggest a role of glucose-dependent insulinotropic polypeptide in ghrelin secretion.