A whole-grain-rich diet reduces urinary excretion of markers of protein catabolism and gut microbiota metabolism in healthy men after one week.

Epidemiological studies consistently find that diets rich in whole-grain (WG) cereals lead to decreased risk of disease compared with refined grain (RG)-based diets. Aside from a greater amount of fiber and micronutrients, possible mechanisms for why WGs may be beneficial for health remain speculative. In an exploratory, randomized, researcher-blinded, crossover trial, we measured metabolic profile differences between healthy participants eating a diet based on WGs compared with a diet based on RGs. Seventeen healthy adult participants (11 female, 6 male) consumed a controlled diet based on either WG-rich or RG-rich foods for 2 wk, followed by the other diet after a 5-wk washout period. Both diets were the same except for the use of WG (150 g/d) or RG foods. The metabolic profiles of plasma, urine, and fecal water were measured using (1)H-nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry (plasma only). After 1 wk of intervention, the WG diet led to decreases in urinary excretion of metabolites related to protein catabolism (urea, methylguanadine), lipid (carnitine and acylcarnitines) and gut microbial (4-hydroxyphenylacetate, trimethylacetate, dimethylacetate) metabolism in men compared with the same time point during the RG intervention. There were no differences between the interventions after 2 wk. Urinary urea, carnitine, and acylcarnitine were lower at wk 1 of the WG intervention relative to the RG intervention in all participants. Fecal water short-chain fatty acids acetate and butyrate were relatively greater after the WG diet compared to the RG diet. Although based on a small population and for a short time period, these observations suggest that a WG diet may affect protein metabolism.

Development of Distillation Sensors for Spirit Beverages Production Monitoring Based on Impedance Spectroscopy Measurement and Partial Least-Squares Regression.

During spirit beverages production, the distillate is divided into three parts: the head, the heart, and the tail. Acetaldehyde and ethanol are two key markers which allow the correct separation of distillate. Being toxic, the elimination of the head part, which contains a high concentration of acetaldehyde, is crucial to guarantee the consumer's health and security. Plus, the tail should be separated from the heart based on ethanol concentration. Nowadays, online or in-line sensors for acetaldehyde monitoring during distillation do not exist, and the online sensors for alcohol monitoring, based on density measurement, remain expensive for producers. In this work, we demonstrate the development of distillation monitoring sensors based on electrical impedance spectroscopy (EIS) measurements, combined with PLS-R (partial least-squares regression) modeling. Four types of sensors are proposed and tested with wine-based distillates. Using PLS-R, the best correlations were found for one electrode, named "SpotsSym". With an R 2 up to 89.9% for acetaldehyde concentration prediction and an R 2 up to 86.8% for ethanol, the obtained results indicate the promising potential of the proposed approach. To our knowledge, this is the first report of sensors capable of simultaneously measuring ethanol and acetaldehyde concentrations. Furthermore, these sensors offer the advantages of being low cost and nondestructive. Based on these results, the development of an in-line distillation monitoring system is possible in the near future, providing a promising tool for spirit beverages producers.

Attraction of Frankliniella occidentalis Females towards the Aggregation Pheromone Neryl (S)-2-Methylbutanoate and Kairomones in a Y-Olfactometer.

An understanding of insect olfaction allows for more specific alternative methods of pest control. We evaluated the responses of the western flower thrips (WFT, Frankliniella occidentalis) in a Y-olfactometer to estimate gas-phase concentrations of the aggregation pheromone neryl (S)-2-methylbutanoate and known kairomones such as methyl isonicotinate, (S)-(-)-verbenone, and p-anisaldehyde. The gas-phase concentrations of these compounds were obtained from the release rates measured in dynamic headspace cells. The compounds were collected from the headspace using dried solid-phase extraction (SPE) cartridges and analyzed with a triple quadrupole GC-MS/MS. We observed that the aggregation pheromone significantly attracted WFT females at doses of 10 and 100 µg, whereas methyl isonicotinate and p-anisaldehyde significantly attracted WFT females at the highest dose. Verbenone did not produce any significant results. A completely different picture was obtained when the gas-phase concentrations were considered. The minimal gas-phase concentrations of the pheromone required to attract WFT females was 0.027 ng/mL, at least 100 times lower than that of the other two compounds. The relevance and implications of our results are discussed in light of the insect's biology and pest management methods.

Bioprospecting of a Metschnikowia pulcherrima Indigenous Strain for Chasselas Winemaking in 2022 Vintage.

Interest in Metschnikowia (M.) pulcherrima is growing in the world of winemaking. M. pulcherrima is used both to protect musts from microbial spoilage and to modulate the aromatic profile of wines. Here, we describe the isolation, characterization, and use of an autochthonous strain of M. pulcherrima in the vinification of Chasselas musts from the 2022 vintage. M. pulcherrima was used in co-fermentation with Saccharomyces cerevisiae at both laboratory and experimental cellar scales. Our results showed that M. pulcherrima does not ferment sugars but has high metabolic activity, as detected by flow cytometry. Furthermore, sensory analysis showed that M. pulcherrima contributed slightly to the aromatic profile when compared to the control vinifications. The overall results suggest that our bioprospecting strategy can guide the selection of microorganisms that can be effectively used in the winemaking process.

Isotopomics: a top-down systems biology approach for understanding dynamic metabolism in rats using [1,2-(13)C(2)] acetate.

Isotope labeled tracers are commonly used to quantify the turnover rates of various metabolic intermediates and yield information regarding physiological regulation. Studies often only consider either one nutritional state (fasted or fed) and/or one question (e.g., measure of lipid or protein turnover). In this article, we consider a novel application combining the global approach of metabonomics with widespread stable isotope labeling as a way of being able to map metabolism in open mammalian systems, an approach we call "isotopomics". A total of 45 15-week-old male Zucker rats were administrated different amounts (from 0.5 to 8 mmol/kg) of sodium [1,2-(13)C(2)] acetate. Plasma samples taken at 1, 4, and 24 h were analyzed with (13)C nuclear magnetic resonance (NMR) and gas chromatography/mass spectrometry (GC/MS) to measure (13)C isotopic enrichment of 39 plasma metabolites across a wide range of compound classes (amino acids, short-chain fatty acids, lactate, glucose, and free fatty acids). Isotopic enrichment from 0.1-7.1 mole percent excess (MPE) for the highest dose could be reliably measured in 16 metabolites, and the kinetics of their (13)C isotopic enrichment are reported. Clustering metabolites based on (13)C kinetic curves enabled highlighting of time dependent patterns of (13)C distribution through the key metabolic pathways. These kinetic and quantitative data were reported into a biochemical map. This type of isotopomic approach for mapping dynamic metabolism in an open system has great potential for advancing our mechanistic knowledge of how different interventions and diseases can impact the metabolic response of animals and humans.

Insights on the Structural and Metabolic Resistance of Potato (Solanum tuberosum) Cultivars to Tuber Black Dot (Colletotrichum coccodes).

Black dot is a blemish disease of potato tubers caused by the phytopathogenic fungus Colletotrichum coccodes. Qualitative resistance (monogenic) that leads to the hypersensitive response has not been reported against black dot, but commercial potato cultivars show different susceptibility levels to the disease, indicating that quantitative resistance (polygenic) mechanisms against this pathogen exist. Cytological studies are essential to decipher pathogen colonization of the plant tissue, and untargeted metabolomics has been shown effective in highlighting resistance-related metabolites in quantitative resistance. In this study, we used five commercial potato cultivars with different susceptibility levels to black dot, and studied the structural and biochemical aspects that correlate with resistance to black dot using cytological and untargeted metabolomics methods. The cytological approach using semithin sections of potato tuber periderm revealed that C. coccodes colonizes the tuber periderm, but does not penetrate in cortical cells. Furthermore, skin thickness did not correlate with disease susceptibility, indicating that other factors influence quantitative resistance to black dot. Furthermore, suberin amounts did not correlate with black dot severity, and suberin composition was similar between the five potato cultivars studied. On the other hand, the untargeted metabolomics approach allowed highlighting biomarkers of infection, as well as constitutive and induced resistance-related metabolites. Hydroxycinnamic acids, hydroxycinnamic acid amides and steroidal saponins were found to be biomarkers of resistance under control conditions, while hydroxycoumarins were found to be specifically induced in the resistant cultivars. Notably, some of these biomarkers showed antifungal activity in vitro against C. coccodes. Altogether, our results show that quantitative resistance of potatoes to black dot involves structural and biochemical mechanisms, including the production of specialized metabolites with antifungal properties.

A new chemical tool for absinthe producers, quantification of α/ß-thujone and the bitter components in Artemisia absinthium.

The concentrations of α/ß-thujone and the bitter components of Artemisia absinthium were quantified from alcoholic wormwood extracts during four phenological stages of their harvest period. A solid-phase micro-extraction method coupled to gas chromatography-mass spectrometry was used to determine the concentration of the two isomeric forms of thujone. In parallel, the combination of ultra-high pressure liquid chromatography and high resolution mass spectrometry allowed to quantify the compounds absinthin, artemisetin and dihydro-epi-deoxyarteannuin B. This present study aimed at helping absinthe producers to determine the best harvesting period.

Natural carbon isotope abundance of plasma metabolites and liver tissue differs between diabetic and non-diabetic Zucker diabetic fatty rats.

BACKGROUND: 'You are what you eat' is an accurate summary for humans and animals when it comes to carbon isotope abundance. In biological material, natural(13)C/(12)C ratio is subject to minute variations due to diet composition (mainly from ingestion of C3 and C4 metabolism plants) and to the discrimination between 'light' and 'heavy' isotopes during biochemical reactions (isotope effects and isotopic fractionation). METHODOLOGY/PRINCIPAL FINDINGS: Carbon isotopic abundance was measured in ZDF (fa/+) and ZDF (fa/fa), (lean and obese-diabetic rats respectively) fed the same diet. By analysing plasma metabolites (glucose and non-esterified fatty acids), breath and liver tissue by high-precision isotope ratio mass spectrometry, we demonstrate for the first time statistically distinguishable metabolic carbon isotope abundance between ZDF (fa/+) and ZDF (fa/fa) rats based on plasma glucose, palmitic, oleic, linoleic, arachidonic acids and bulk analysis of liver tissue (P<0.005) resulting into clear isotopic fingerprints using principal component analysis. We studied the variation of isotopic abundance between both groups for each metabolite and through the metabolic pathways using the precursor/product approach. We confirmed that lipids were depleted in (13)C compared to glucose in both genotypes. We found that isotopic abundance of linoleic acid (C18: 2n-6), even though both groups had the same feed, differed significantly between both groups. The likely reason for these changes between ZDF (fa/+) and ZDF (fa/fa) are metabolic dysregulation associated with various routing and fluxes of metabolites. CONCLUSION/SIGNIFICANCE: This work provides evidence that measurement of natural abundance isotope ratio of both bulk tissue and individual metabolites can provide meaningful information about metabolic changes either associated to phenotype or to genetic effects; irrespective of concentration. In the future measuring the natural abundance δ(13)C of key metabolites could be used as endpoints for studying in vivo metabolism, especially with regards to metabolic dysregulation, and development and progression of metabolic diseases.

Daytime pattern of post-exercise protein intake affects whole-body protein turnover in resistance-trained males.

BACKGROUND: The pattern of protein intake following exercise may impact whole-body protein turnover and net protein retention. We determined the effects of different protein feeding strategies on protein metabolism in resistance-trained young men. METHODS: Participants were randomly assigned to ingest either 80g of whey protein as 8x10g every 1.5h (PULSE; n=8), 4x20g every 3h (intermediate, INT; n=7), or 2x40g every 6h (BOLUS; n=8) after an acute bout of bilateral knee extension exercise (4x10 repetitions at 80% maximal strength). Whole-body protein turnover (Q), synthesis (S), breakdown (B), and net balance (NB) were measured throughout 12h of recovery by a bolus ingestion of [15N]glycine with urinary [15N]ammonia enrichment as the collected end-product. RESULTS: PULSE Q rates were greater than BOLUS (~19%, P<0.05) with a trend towards being greater than INT (~9%, P=0.08). Rates of S were 32% and 19% greater and rates of B were 51% and 57% greater for PULSE as compared to INT and BOLUS, respectively (P<0.05), with no difference between INT and BOLUS. There were no statistical differences in NB between groups (P=0.23); however, magnitude-based inferential statistics revealed likely small (mean effect±90%CI; 0.59±0.87) and moderate (0.80±0.91) increases in NB for PULSE and INT compared to BOLUS and possible small increase (0.42±1.00) for INT vs. PULSE. CONCLUSION: We conclude that the pattern of ingested protein, and not only the total daily amount, can impact whole-body protein metabolism. Individuals aiming to maximize NB would likely benefit from repeated ingestion of moderate amounts of protein (~20g) at regular intervals (~3h) throughout the day.