Preliminary Research Concerning the Determination of Beer Wort Flavor Compounds During Primary Fermentation

Generally beer contain numerous aromatic compounds, some naturally present in the raw materials and some formed during processing. In this work were analysed beer wort flavor compounds, during primary fermentation, taking into study two beer wort types: one obtained from Pilsner malt (100%), other from a mixture of Pilsner malt (80%) and Caramel Malt (20%). An Shimadzu GC/MS-QP2010 equipment was used for samples analysis. The major compounds founded in beer wort samples, was derived from a vast array of compounds that arise from a number of sources. In this way, during fermentation and conditioning we founded different categories of secondary products: higher alcohols, esters, vicinal diketones (VDK), organic acids and aldehydes. The concentration of this aroma compounds depends on malt type and the moment of wort examination. Was noticed that some compounds disappeared and others appeared, from the day to day of primary fermentation.

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Growth Response of Salmonella Typhimurium in the Presence of Natural and Synthetic Antimicrobials: Estimation of MICs from Three Different Models

Journal of Food Protection ◽

10.4315/0362-028x-70.10.2243 ◽

2007 ◽

Vol 70 (10) ◽

pp. 2243-2250 ◽

Cited By ~ 17

Author(s):

L. GUILLIER ◽

A. I. NAZER ◽

F. DUBOIS-BRISSONNET

Keyword(s):

Organic Acids ◽

Salmonella Typhimurium ◽

Aromatic Compounds ◽

Quantitative Method ◽

Quantitative Methods ◽

Growth Response ◽

Brain Heart Infusion ◽

Brain Heart Infusion Medium ◽

Experiment Duration

The aim of this study was to determine the MICs of 14 antimicrobials for Salmonella Typhimurium with three methods and to check the influence of experiment duration on the estimation of MICs. The growth of Salmonella Typhimurium in a brain heart infusion medium containing various concentrations of natural aromatic compounds, organic acids, or salts was monitored by absorbance measurements for 24 or 72 h. Three different ways of analyzing optical density (OD) curves were tested for the determination of MICs. Both quantitative methods gave similar MICs for most of the compounds. The semi-quantitative method does not allow estimating the MIC for all compounds. Noticeable differences were found between MICs obtained for 24- or 72-h experiments, whatever the method used. The proposed methods and models can be used for the estimation of MICs from OD data. MICs could be used for a quantitative approach to Salmonella Typhimurium growth.

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THE EFFECT OF THE INTENSITY OF AERATING THE MEDIUM ON THE METABOLIC ACTIVITY OF ALCOHOL YEAST

Food Science and Technology ◽

10.15673/fst.v12i4.1177 ◽

2019 ◽

Vol 12 (4) ◽

Author(s):

L. Levandovsky ◽

М. Kravchenko

Keyword(s):

Saccharomyces Cerevisiae ◽

Metabolic Activity ◽

Anaerobic Fermentation ◽

Raw Materials ◽

Modern Technology ◽

Higher Alcohols ◽

Great Decrease ◽

Technological Parameters ◽

Secondary Products ◽

Yeast Saccharomyces Cerevisiae

The article presents the results of investigating how the intensity of aerating the medium effects on the cultivation process and the metabolic activity of alcoholic yeast Saccharomyces cerevisiae, strain U-563, in the modern technology of alcohol and baking yeast from molasses. The chemical and technological parameters of media at the aerobic and anaerobic stages of the process, the level of accumulation of the major and secondary products of yeast metabolism, and their enzymatic activity have been determined by methods commonly employed in science and in the practice of alcohol biotechnology. The objects of research were the yeast Saccharomyces cerevisiae, molasses wort, the medium in the process of yeast cultivation, and fermented wash. It has been established that two factors are the most important in the accumulation of alcoholic yeast biomass: the intensity of aerating the medium, and the staged introduction of the substrate during biomass cultivation. The more aerated the medium, the more intensively secondary metabolites of yeast Saccharomyces cerevisiae are formed (glycerol, aldehydes, higher alcohols, volatile acids, and esters) – both at the yeast generation stage and during anaerobic fermentation. When yeast Saccharomyces cerevisiae is grown in a gradient-continuous manner in a battery of series-connected apparatuses, with undiluted substrate (molasses) added by degrees, yeast biosynthesis is significantly enhanced compared to the traditional homogeneous-continuous method. The results obtained indicate the active metabolism of carbohydrates in the Krebs cycle, when the medium is intensively aerated. Besides, the results reveal the high reactivity of aldehydes and esters that results in their transformation into other compounds, and in a great decrease in their amount at the anaerobic stage of the process. However, a progressive increase is observed in glycerol, higher alcohols, and volatile acids, starting from the first yeast generator and up to the last fermentation apparatus, irrespective of the level of aerating the medium during yeast cultivation. These findings can be effectively used to manufacture food, technical, and fuel ethanol industrially from sugar-based raw materials in the course of co-production of alcohol and baking yeast.

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Twists and Turns in the Salicylate Catabolism of Aspergillus terreus, Revealing New Roles of the 3-Hydroxyanthranilate Pathway

mSystems ◽

10.1128/msystems.00230-20 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Tiago M. Martins ◽

Celso Martins ◽

Paula Guedes ◽

Cristina Silva Pereira

Keyword(s):

Organic Acids ◽

Secondary Metabolism ◽

Aromatic Hydrocarbons ◽

Aromatic Compounds ◽

Aspergillus Terreus ◽

Raw Materials ◽

Pharmaceutical Drugs ◽

Content Type ◽

Cell Factories ◽

New Genes

ABSTRACT In fungi, salicylate catabolism was believed to proceed only through the catechol branch of the 3-oxoadipate pathway, as shown, e.g., in Aspergillus nidulans. However, the observation of a transient accumulation of gentisate upon the cultivation of Aspergillus terreus in salicylate medium questions this concept. To address this, we have run a comparative analysis of the transcriptome of these two species after growth in salicylate using acetate as a control condition. The results revealed the high complexity of the salicylate metabolism in A. terreus with the concomitant positive regulation of several pathways for the catabolism of aromatic compounds. This included the unexpected joint action of two pathways—3-hydroxyanthranilate and nicotinate—possibly crucial for the catabolism of aromatics in this fungus. Importantly, the 3-hydroxyanthranilate catabolic pathway in fungi is described here for the first time, whereas new genes participating in the nicotinate metabolism are also proposed. The transcriptome analysis showed also for the two species an intimate relationship between salicylate catabolism and secondary metabolism. This study emphasizes that the central pathways for the catabolism of aromatic hydrocarbons in fungi hold many mysteries yet to be discovered. IMPORTANCE Aspergilli are versatile cell factories used in industry for the production of organic acids, enzymes, and pharmaceutical drugs. To date, bio-based production of organic acids relies on food substrates. These processes are currently being challenged to switch to renewable nonfood raw materials—a reality that should inspire the use of lignin-derived aromatic monomers. In this context, aspergilli emerge at the forefront of future bio-based approaches due to their industrial relevance and recognized prolific catabolism of aromatic compounds. Notwithstanding considerable advances in the field, there are still important knowledge gaps in the central catabolism of aromatic hydrocarbons in fungi. Here, we disclose a novel central pathway, 3-hydroxyanthranilate, defying previously established ideas on the central metabolism of the aromatic amino acid tryptophan in Ascomycota. We also observe that the catabolism of the aromatic salicylate greatly activated the secondary metabolism, furthering the significance of using lignin-derived aromatic hydrocarbons as a distinctive biomass source.

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Twists and turns of the salicylate catabolism in Aspergillus terreus

10.1101/2020.07.23.217166 ◽

2020 ◽

Author(s):

Tiago M. Martins ◽

Celso Martins ◽

Cristina Silva Pereira

Keyword(s):

Organic Acids ◽

Secondary Metabolism ◽

Aromatic Hydrocarbons ◽

Aromatic Compounds ◽

Aspergillus Terreus ◽

Raw Materials ◽

Pharmaceutical Drugs ◽

Cell Factories ◽

New Genes ◽

First Time

ABSTRACTIn fungi, salicylate catabolism was believed to proceed only through the catechol branch of the 3-oxoadipate pathway, as shown e.g. in Aspergillus nidulans. However, the observation of a transient accumulation of gentisate upon cultivation of Aspergillus terreus in salicylate media questions this concept. To address this we have run a comparative analysis of the transcriptome of these two species after growth in salicylate using acetate as a control condition. The results revealed the high complexity of the salicylate metabolism in A. terreus with the concomitant positive regulation of several pathways for the catabolism of aromatic compounds. This included the unexpected joint action of two pathways: the nicotinate and the 3-hydroxyanthranilate, possibly crucial for the catabolism of aromatics in this fungus. New genes participating in the nicotinate metabolism are here proposed, whereas the 3-hydroxyanthranilate catabolic pathway in fungi is described for the first time. The transcriptome analysis showed also for the two species an intimate relationship between salicylate catabolism and secondary metabolism. This study emphasizes that the central pathways for the catabolism of aromatic hydrocarbons in fungi hold many mysteries yet to be discovered.IMPORTANCEAspergilli are versatile cell factories used in industry for production of organic acids, enzymes and pharmaceutical drugs. To date, organic acids bio-based production relies on food substrates. These processes are currently being challenged to switch to renewable non-food raw materials; a reality that should inspire the use of lignin derived aromatic monomers. In this context, Aspergilli emerge at the forefront of future bio-based approaches due to their industrial relevance and recognized prolific catabolism of aromatic compounds. Notwithstanding considerable advances in the field, there are still important knowledge gaps in the central catabolism of aromatic hydrocarbons in fungi. Here, we disclosed a novel central pathway, defying previous established ideas on the central metabolism of the aromatic amino acid tryptophan in Ascomycota. We also observed that the catabolism of the aromatic salicylate greatly activated the secondary metabolism, furthering the significance of using lignin derived aromatic hydrocarbons as a distinctive biomass source.

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Scientific Aspects of Identification Criteria for Fruit Distillates

Food Processing Techniques and Technology ◽

10.21603/2074-9414-2021-3-480-491 ◽

2021 ◽

pp. 480-491

Author(s):

Elena Dubinina ◽

Ludmila Krikunova ◽

Violetta Peschanskaya ◽

Marina Trishkaneva

Keyword(s):

Amino Acids ◽

Organic Acids ◽

Biochemical Composition ◽

Raw Materials ◽

Raw Material ◽

Volatile Components ◽

Higher Alcohols ◽

Black Currant ◽

Alcoholic Drinks ◽

Acid Index

Introduction. Beverages based on fruit distillates belong to elite alcoholic drinks. As a result, there is a high risk of counterfeit. Controlled indicators do not allow identifying distillates by the type of raw material. The research objective was to develop scientifically based identification criteria for fruit distillates. Study objects and methods. The research featured ten fruits and their distillates. It involved three schemes of pre-distillation processing: pulp fermentation, juice fermentation, and pulp fermentation with subsequent maceration. The biochemical composition of raw materials was assessed by the HPLC analysis of mass concentration of sugars, titratable acids, pH, mono- and disaccharides, free organic acids and amino acids, as well as by the sugar-acid index. The concentration of higher alcohols in the distillates was determined using gas chromatography. Results and discussion. The research revealed significant differences in the biochemical composition of raw materials, which made it possible to divide it into groups depending on the methods of pre-distillation processing. The groups can be identified by the ratio of the concentrations of the main higher alcohols: 1-propanol to the sum of isobutanol and isoamylol. The revealed differences were caused by the peculiarities of the ratio of organic acids and amino acids. For the distillates of Cornelian cherry, black currant, cherry-plum, plum, cherry, and apricot, the ratio of 1-propanol to the sum of isobutanol and isoamylol was within the following ranges: 0.02–0.06, 0.08–0.10, 0.30–0.35, 0.47–0.51, 0.55–0.65, and 0.69–0.92, respectively. The method of preparing raw materials for distillation did not affect the values of the identification indicator. Conclusion. The ratio of 1-propanol to the sum of isobutanol and isoamylol could serve as an indicator for the identification of distillates of Cornelian cherries, black currant, cherry-plum, plum, cherry, and apricot. However, it proved useless for distillates of pears, raspberries, tangerines, and mulberries, since its values were within comparable limits. Therefore, the research requires a GC-MS analysis to determine the concentration and ratios of other specific volatile components in other raw materials.

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Tandem Mass Spectrometric Evaluation of Core Structures of Aromatic Compounds after Catalytic Deoxygenation

10.26434/chemrxiv.5410807.v1 ◽

2017 ◽

Author(s):

Xueming Dong

Keyword(s):

Aromatic Compounds ◽

Supported Catalyst ◽

Mass Spectrometric ◽

Spectrometric Method ◽

Mass Spectrometric Method ◽

Aromatic Rings ◽

Tandem Mass Spectrometric ◽

Catalytic Deoxygenation ◽

Oxygen Atoms

Catalytic deoxygenation of coal enhances the stability and combustion performance of coal-derived liquids. However, determination of the selectivity of removal of oxygen atoms incorporated in or residing outside of aromatic rings is challenging. This limits the ability to evaluate the success of catalytic deoxygenation processes. A mass spectrometric method, in-source collision-activated dissociation (ISCAD), combined with high resolution product ion detection, is demonstrated to allow the determination of whether the oxygen atoms in aromatic compounds reside outside of aromatic rings or are part of the aromatic system, because alkyl chains can be removed from aromatic cores via ISCAD. Application of this method for the analysis of a subbituminous coal treated using a supported catalyst revealed that the catalytic treatment reduced the number of oxygen-containing heteroaromatic rings but not the number of oxygen atoms residing outside the aromatic rings.<br>

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Tandem Mass Spectrometric Evaluation of Core Structures of Aromatic Compounds after Catalytic Deoxygenation

10.26434/chemrxiv.5410807 ◽

2017 ◽

Author(s):

Xueming Dong

Keyword(s):

Aromatic Compounds ◽

Supported Catalyst ◽

Mass Spectrometric ◽

Spectrometric Method ◽

Mass Spectrometric Method ◽

Aromatic Rings ◽

Tandem Mass Spectrometric ◽

Catalytic Deoxygenation ◽

Oxygen Atoms

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INFLUENCE OF DICARBOXYLIC ACIDS ON SOWING QUALITY OF SPRING BARLEY

Vestnik of the Russian agricultural science ◽

10.30850/vrsn/2018/5/22-25 ◽

1970 ◽

pp. 22-25

Author(s):

N. N. Loy ◽

S. N. Gulina

Keyword(s):

Organic Acids ◽

Spring Barley ◽

Dose Range ◽

Dicarboxylic Acids ◽

Rotary Machine ◽

Working Solution ◽

Negative Effect ◽

Sprouted Seeds

The effect of presowing seed treatment on various concentrations of dicarboxylic (organic) acids on the sowing characteristics of spring barley has been studied. Seeds were treated with organic acids obtained by exposing cuttings to the radiation with a dose of 100 kGy and consequent hydrolysis, in concentrations: 1•10-7 %; 1•10-9; 1•10-11; 1•10-13 and 1•10-15 % on a laboratory rotary machine RVO-64 for one day before laying for germination. Distilled water was used for the control case. The rate of application of the working solution calculated as 10 liters / ton of seeds. Seeds were germinated in filter paper rolls in accordance with GOST 12038-84 requirements. The temperature was maintained at +24 ° C in the thermostat where the glasses with rolls were placed. For determination of germinative power and laboratory germination the sprouted seeds were evaluated after three and seven days, respectively. In laboratory experiments it was established that the treatment of barley seeds of varieties Zazersky 85, Nur and Vladimir with organic acids (OK) in different concentrations had both a stimulating and a negative effect. On the Zazersky 85 variety, in variants with acid concentrations of 1•10-9 and 1•10-11, an increase in germination energy (EP) by 2-4% and a significant decrease (by 3-4%) of laboratory germination (LV) of barley seeds were noted. On the Nur variety, the increase in EP was observed at 4% (concentration 1•10-11), LV and seed growth force (CPC) by 2-7% at a concentration of 1•10-7 and in the dose range 1•10-11 - 1•10-14 compared to the control values. On the grade of Vladimir, an increase in EP, LV, and CPC was found to increase by 1-6% at concentrations OK 1•10-7 and 1•10-13. It was shown that the treatment of seeds with acids led to an increase in the length of the germ in all studied varieties (by 3-9%) and dry biomass of 7-day-old seedlings - by 3-6%. Consequently, the treatment of seeds with a mixture of dicarboxylic acids has a stimulating effect on the sowing quality of spring barley.

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