Fiber depth, column coating and extraction time are major contributors in the headspace solid-phase microextraction–gas chromatography analysis of Nordic wild mushrooms

The aims of this research were to systematically study how extraction, desorption and gas chromatography (GC) parameters affect the volatiles composition of mushrooms in headspace solid-phase microextraction (HS-SPME) analysis. The study was carried out both with reference compounds and with Cantharellus cibarius Fr. mushroom sample. The experiments were carried out with full-factorial multivariate designs. In the desorption studies, high fiber depth in the GC injector port instead of desorption time or temperature was the most important variable for maximizing peak areas. This could be a function related to the temperature gradient inside the injector as well as a faster transfer of volatiles to the column. Out of the tested fibers, divinylbenzene/carboxen/polydimethylsiloxane (DVB/Car/PDMS) was the most suitable coating for mushroom volatiles. Additionally, extraction time of 45 vs 30 min had a high effect, while doubling the sample volume had a minimal effect. 21 volatiles were identified in C. cibarius. Hexanal and 1-octen-3-ol were the most abundant volatile compounds. Overall, aldehydes and unsaturated C6–C10 alcohols and aldehydes were the most abundant compound groups. This study demonstrated that despite the wide adaptation and history of SPME, fiber injection depth, fiber coating and extraction time are important factors that should still be carefully tested as a part of method development for mushroom-type matrices. Finally, the results of this study show that it is important to look at the extracted gas chromatogram as a whole instead of focusing on a few peaks of interest.</p

Human breast milk NMR metabolomic profile across specific geographical locations and its association with the milk microbiota

The composition of human breast milk is highly variable, and it can be influenced by genetics, diet, lifestyle, and other environmental factors. This study aimed to investigate the impact of geographical location and mode of delivery on the nuclear magnetic resonance spectroscopy (NMR) metabolic profile of breast milk and its relationship with the milk microbiome. Human milk metabolic and microbiota profiles were determined using NMR and 16S rRNA gene sequencing, respectively, in 79 healthy women from Finland, Spain, South Africa, and China. Up to 68 metabolites, including amino acids, oligosaccharides, and fatty acid-associated metabolites, were identified in the milk NMR spectra. The metabolite profiles showed significant differences between geographical locations, with significant differences (p </p

Effect of homogenised and pasteurised versus native cows' milk on gastrointestinal symptoms, intestinal pressure and postprandial lipid metabolism

Some people experience gastrointestinal symptoms related to cow's milk consumption even if neither lactose intolerance nor cow's milk allergy can be diagnosed. To investigate whether milk homogenization could cause gastrointestinal problems, homogenized and pasteurized milk and native milk were served to eleven volunteers who reported such sensitivity in a random order together with an ingestible pressure measuring capsule. Postprandial lipemia did not differ between the two milk types, but significant differences were found in the postprandial plasma fatty acid composition. No significant difference was found in the amount of gastrointestinal symptoms or in the intestinal pressure after the consumption of native and processed milk. However, the obtained results on pressure in the large intestine (P = 0.068) as well as reported symptoms (P = 0.103) suggest that further studies in this area are needed with a bigger subject group and with longer exposure times to differently processed milk types. (C) 2017 Elsevier Ltd. All rights reserved

Short-term salivary acetaldehyde increase due to direct exposure to alcoholic beverages as an additional cancer risk factor beyond ethanol metabolism

<p>Abstract</p> <p>Background</p> <p>An increasing body of evidence now implicates acetaldehyde as a major underlying factor for the carcinogenicity of alcoholic beverages and especially for oesophageal and oral cancer. Acetaldehyde associated with alcohol consumption is regarded as 'carcinogenic to humans' (IARC Group 1), with sufficient evidence available for the oesophagus, head and neck as sites of carcinogenicity. At present, research into the mechanistic aspects of acetaldehyde-related oral cancer has been focused on salivary acetaldehyde that is formed either from ethanol metabolism in the epithelia or from microbial oxidation of ethanol by the oral microflora. This study was conducted to evaluate the role of the acetaldehyde that is found as a component of alcoholic beverages as an additional factor in the aetiology of oral cancer.</p> <p>Methods</p> <p>Salivary acetaldehyde levels were determined in the context of sensory analysis of different alcoholic beverages (beer, cider, wine, sherry, vodka, calvados, grape marc spirit, tequila, cherry spirit), without swallowing, to exclude systemic ethanol metabolism.</p> <p>Results</p> <p>The rinsing of the mouth for 30 seconds with an alcoholic beverage is able to increase salivary acetaldehyde above levels previously judged to be carcinogenic in vitro, with levels up to 1000 μM in cases of beverages with extreme acetaldehyde content. In general, the highest salivary acetaldehyde concentration was found in all cases in the saliva 30 sec after using the beverages (average 353 μM). The average concentration then decreased at the 2-min (156 μM), 5-min (76 μM) and 10-min (40 μM) sampling points. The salivary acetaldehyde concentration depends primarily on the direct ingestion of acetaldehyde contained in the beverages at the 30-sec sampling, while the influence of the metabolic formation from ethanol becomes the major factor at the 2-min sampling point.</p> <p>Conclusions</p> <p>This study offers a plausible mechanism to explain the increased risk for oral cancer associated with high acetaldehyde concentrations in certain beverages.</p

The effect of heat treatments and homogenisation of cows’ milk on gastrointestinal symptoms, inflammation markers and postprandial lipid metabolism

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Liver and pancreatic fat content and metabolism in healthy monozygotic twins with discordant physical activity

Background & Aims: Ectopic fat in muscle and liver is linked to obesity and type 2 diabetes. Recently, pancreatic lipid accumulation has also been associated with beta-cell dysfunction and reduced insulin production, leading to the development of type 2 diabetes. Physical exercise training has been shown to attenuate beta-cell dysfunction in patients, but little is known about its effects on pancreatic and hepatic fat accumulation. In this study, we validated in-vivo proton magnetic resonance spectroscopy ((1)H MRS) in pancreatic fat measurement with biochemical measurements in a pig model. Thereafter, the effects of increased physical activity on the amounts of pancreatic and liver fat were studied in eight monozygotic twin pairs who have discordant physical activity and fitness. Methods: Pancreatic fat content was studied in 15 pigs using (1)H MRS and/or biochemical analyses. In addition, liver and pancreatic fat were assessed using (1)H MRS in eight monozygotic male twin pairs with 18% mean difference in VO(2max) between the twin brothers. Results: Twins with higher physical fitness had 23% less liver fat (1.3 +/- 1.3% vs. 2.1 +/- 2.6%, p = 0.022) but no such difference was observed in the pancreatic fat (8.2 +/- 9.3% vs. 9.8 +/- 8.5%, respectively, p = 0.3). Hepatic fat content was inversely associated with VO(2max). A positive association was found between pancreatic and liver fat contents (beta = 5.18, p = 0.012). Pancreatic fat content was also associated with insulin sensitivity indexes and plasma adiponectin and glutamyltransferase concentrations. Conclusions: Pancreatic fat content is associated with insulin resistance and hepatic fat content. An active lifestyle seems to beneficially influence hepatic fat metabolism. (C) 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved