Acetic Acid Vinegar Research Articles

A new method to analysis synthetic acetic acid to vinegar: Hydrogen isotope ratio at the methyl site of acetic acid in vinegar by GC-IRMS

Acetic acid is the key organic substance used to verify the authenticity of vinegar. A new method for precisely determining acetic acid δDCH3 in vinegar via gas chromatography −pyrolytic-stable isotope ratio mass spectrometry (GC-P-IRMS) was established. The δDCH3 values were obtained via calibration with a series of standards. The optimised method demonstrated a repeatability standard deviation within 3 ‰. The standard deviation of accuracy of the new method compared with that of the SNIF-NMR method was within 2.6 ‰. The synthetic acetic acid δDCH3 values was −136.7 ‰ ± 29.6 ‰, and the δDCH3 value of acetic acid in vinegar was −414.9 ‰ ± 40.5 ‰, with significant isotopic distribution characteristics. This methodology serves as a supplementary method for measuring the δDCH3 value of acetic acid in vinegar. It has advantages over other methods in terms of time, sensitivity and operability. And provides a new idea for solving the problem of analyzing substances in the presence of exchangeable groups.

A rapid method for the determination of stable hydrogen isotope ratios of acetic acid in vinegar.

Vinegar is an everyday condiment made from fermented grains or fruits. It contains acetic acid which is the main organic material produced by fermentation. Vinegar suffers from the authenticity problem of exogenous adulteration due to the indistinguishability of low-cost chemical sources of synthetic acetic acid from acetic acid produced by fermentation. It is necessary to establish a simple and rapid measurement technique. Determination was according to the total acid content of vinegar diluted with acetone to a certain concentration. Online separation and determination of acetic acid δD in vinegar were carried out using gas chromatography-pyrolysis-isotope ratio mass spectrometry. An HP-Plot/U column was selected for online separation of acetic acid and water with molecular sieve characteristics. At the same time, combined with the instrument blowback function to remove water. Dilute solvent acetone was treated with a molecular sieve to remove trace water. The reproducibility of this method is less than 3‰. The long-term stability is within a reasonable error range. The accuracy correlation coefficient is greater than 0.99. The δD values of acetic acid in vinegar (-264.5 ± 20.3‰) and from chemical sources (-30.5 ± 90.8‰) were obtained. A rapid method was developed for identification of different sources of acetic acid. These different sources of acetic acid exhibited significant hydrogen isotope distribution characteristics. Additionally, it was observed that the carboxyl hydrogen of acetic acid exhibited facile exchange with water. In future investigations, we aim to mitigate this interference.

Comparative Study on Effectiveness of Wine Vinegar Over Commercially Available Vinegar Using Chemical Titration Technique for Chicken Quality Analysis

Aim: Vinegar producers are still on a mission to find acetic acid bacteria fermentation that produces extremely strong vinegar. Vinegar fermentation is caused directly by the acetic acid bacteria alcohol respiratory chain, which is found on the intracellular membrane. In the alcohol respiratory chain, enzyme activity is increased through Acetobacter pasteurianus’ semi-permanent vinegar biodegradation, so did the acetification rate. Acetic acid bacteria alcohol respiratory chain activity was increased in a series of experiments with the goal of achieving a high strength fermentation process. Materials and methods: Precursors of alcohol respiration-associated components (ferrous ions and hydroxybenzoic acid) were added, and the air flow rate was increased, to further improve acidification. Researchers examined the color and physical/chemical properties of the finished product, as well as the sensory quality of the vinegar-preserved whole chicken. Two groups are taken with 7 samples per group, G power 80%, coincidence interval will be 95%. Results And Discussion: The pH was found to be 2.37, with an acetic acid content of 8.2%. According to the present study the amount of acetic acid in vinegar was increased by 3.2% using this production method. and the statistical (p=0.001). Conclusion: Three parameters were discovered to increase alcohol oxidation into acetic acid in acetic acid bacteria cells: enzyme activity in the alcohol respiratory chain, precursor of ubiquinone production.

Hypoglycemic and Hypolipogenic Action of Acetic Acid and Monascus-Fermented Grain Vinegar: A Comparative Study.

Acetic acid has been proposed to improve lifestyle-related diseases, including hyperlipidemia and hyperglycemia. This study compared the hypoglycemic and hypolipogenic effects of acetic acid vinegar (AV, contains only 4% acetic acid) and Monascus-fermented grain vinegar (MV) containing various bioactive compounds in 3T3L1 cells and C57BL/KsJ-db/db mice (DB). The DB were divided randomly into three treatment groups containing nine mice each; DB-, AV-, and MV-groups were orally administered 1 mL/kg/day of distilled water, acetic acid vinegar, and Monascus vinegar, respectively, for 8 weeks. Exposure to AV and MV inhibited the adipogenic differentiation of 3T3L1 preadipocytes and lipid accumulation during differentiation. Oral administration of AV or MV to the mice resulted in a marked reduction in the body weight, liver weight, and hepatic triglyceride content compared to the control DB-group. Moreover, treatment with AV and MV clearly increased the expression of cyclic adenosine monophosphate (cAMP) and AMP-activated protein kinase (AMPK) and suppressed the expression of fatty acid synthetase in liver tissues of DB. Significantly, lower levels of fasting blood glucose, insulin, leptin, and the glycosylated hemoglobin (HbA1c) as well as higher levels of the skeletal muscle GLUT4 expression were obtained in the AV- or MV-groups than levels determined in the control DB-group (P < .05). Although MV has the potential to be a natural alternative treatment for obesity-associated type 2 diabetes, this study suggests that acetic acid is the central ingredient in MV responsible for the hypoglycemic and hypolipogenic effects in the DB mice.

Contemporary pursuits of vinegar from scullery to dermatology

&lt;p class="keywords"&gt;Vinegar is widely available as a food ingredient for flavouring and as a preservative. It is one of the oldest skin remedy known to mankind. However, its status in treatment regimens has declined over the decades. This article is an attempt to highlight its therapeutic armamentarium in dermatology, venereology and leprosy. Acetic acid in vinegar has antibacterial, antifungal and antiviral properties. This review talks about various studies of acetic acid for various indications, such as screening for cervical cancer, healing of chronic wounds, atopic dermatitis, onychomycosis, marine dermatoses, acne vulgaris, warts, in sclerotherapy and many others dermatoses. Combination therapies and newer indications are also described in this article. Recently, its antiviral action in vitro has been demonstrated against the ongoing coronavirus disease of 2019 (COVID-19) pandemic.&lt;/p&gt;

Validation of Rapid Enzymatic Quantification of Acetic Acid in Vinegar on Automated Spectrophotometric System.

Vinegar is produced from the fermentation of agricultural materials and diluted acetic acid (diluted with water to 4–30% by volume) via sequential ethanol and acetic acid fermentation. The concentration of acetic acid must be measured during vinegar production. A Community method for analyzing acetic acid in vinegar is a non-specific method based on the assumption that the total acid concentration of the vinegar is attributable to the acetic acid. It consists of titration with a strong base in the presence of an indicator. This test is laborious and has a time-consuming character. In this work, a highly specific automated enzymatic method was validated, for the first time, to quantify the acetic acid in the wine vinegar, in terms of linearity, precision, repeatability, and uncertainty measurement. The results were compared to the Community method of analysis. Regression coefficient ≅ 1 and the normal distribution of residuals in the ANOVA test confirmed the method’s linearity. LLOD (0.946 ppm) and LLOQ (2.00 ppm) defined the method’s sensitivity. The results of the tested and the Community methods, linearly distributed in the Shapiro–Wilk test, confirmed the method’s repeatability. The few anomalous data in the Huber test were due to random errors. The high selectivity of the enzymatic method, which exclusively measures acetic acid concentration, determined the significant differences between the two tests, examined in the accuracy determination. The enzymatic method can be considered applicable since its precision and uncertainty were lower than the Community method values (relative percentage deviations = 10%). The enzymatic method compared to the Community method reduces the analysis time and the risk of errors due to operators (avoid pipetting errors and wrong calculations), minimizes solvent and the sample consumption and guarantees assay quality through method standardization.

Anti-obesity and anti-inflammatory effects of synthetic acetic acid vinegar and Nipa vinegar on high-fat-diet-induced obese mice

Recently, food-based bioactive ingredients, such as vinegar, have been proposed as a potential solution to overcome the global obesity epidemic. Although acetic acid has been identified as the main component in vinegar that contributes to its anti-obesity effect, reports have shown that vinegar produced from different starting materials possess different degrees of bioactivity. This study was performed to compare the anti-obesity and anti-inflammatory effects of synthetic acetic acid vinegar and Nipa vinegar in mice fed a high-fat diet. In this work, mice were fed a high-fat diet for 33 weeks. At the start of week 24, obese mice were orally fed synthetic acetic acid vinegar or Nipa vinegar (0.08 and 2 ml/kg BW) until the end of week 33. Mice fed a standard pellet diet served as a control. Although both synthetic acetic acid vinegar and Nipa vinegar effectively reduced food intake and body weight, a high dose of Nipa vinegar more effectively reduced lipid deposition, improved the serum lipid profile, increased adipokine expression and suppressed inflammation in the obese mice. Thus, a high dose of Nipa vinegar may potentially alleviate obesity by altering the lipid metabolism, inflammation and gut microbe composition in high-fat-diet-induced obese mice.

2단계 발효에 의한 고산도 사과식초의 품질특성

본 연구에서는 사과 농축액을 이용하여 일체의 영양원을 첨가하지 않고 알코올 및 초산 발효과정으로 고산도 식초의 제조 조건을 조사하였다. 초기 알코올 함량(6, 7, 8 및 9%)을 달리하여 고산도 초산 발효액의 품질특성을 비교 분석하였다. 그 결과 알코올 함량 6% 및 7%에서 적정산도 12%의 고산도 식초 제조가 가능하였으며, 초기 알코올 함량이 낮을수록 유도기가 단축되어 수율이 높은 경향이었다. 상기 고산도 사과식초의 품질특성은 pH 2.91~3.20이고 적정산도 12.0%이며 유기산은 acetic, malic, citric 및 oxalic acid가 검출되었다. 이상의 결과 사과 농축액을 이용하여 알코올 발효 후 2단계 발효과정으로 고산도 사과식초 제조가 가능하였으나 산업적으로 활용하기 위해서는 유가식 첨가에 의한 발효기간 단축에 관한 연구가 요구되었다.

Using Mole Ratios of Electrolytic Products of Water for Analysis of Household Vinegar: An Experiment for the Undergraduate Physical Chemistry Laboratory

A simple 3-h physical chemistry undergraduate experiment for the quantitative analysis of acetic acid in household vinegar is presented. The laboratory experiment combines titration concept with electrolysis and an application of the gas laws. A vinegar sample was placed in the cathode compartment of the electrolysis cell. Electrolysis of water generated OH–(aq) in the cathode compartment. Acetic acid in the vinegar sample was neutralized by electrolytically generated OH–(aq). Phenolphthalein was used as a visual indicator to detect the end point of the titration. The volume of O2(g) produced at the anode was monitored. The amount of OH–(aq) produced at the cathode was determined from the volume of O2(g) produced at the anode. The amount of acetic acid present in the sample was determined from the mole relationships between H+(aq), OH–(aq), and O2(g). The concentration of acetic acid in household vinegar was determined to be 4.8%. The experimentally determined percentage of acetic acid was in agreement with the manufacturer’s label and the volumetric titration results. The electrolysis cell was directly powered by a 9 V battery. Preparation of an electrolysis cell, experimental procedure, and results of the electrolytic titration are presented.

Optimized Extraction Method of Acetic Acid in Vinegar and Its Effect on SNIF-NMR Analysis to Control the Authenticity of Vinegar

Site-specific natural isotope fractionation by nuclear magnetic resonance (SNIF-NMR) is an accurate method for examining food adulteration. SNIF-NMR can be used to determine the ratio of deuterium to hydrogen (D/H) of a specific molecule position. Because the quantity of D differs between synthetic and fermented acetic acids, the method can be used to accurately monitor food adulteration. However, the effect of pretreated food on the results of SNIF-NMR has rarely been discussed. We present an extractive distillation method to increase the purity of acetic acid for fractionation; we used an orthogonal array experimental design to determine the optimal extraction conditions. We discuss the influence of extract solvents and sample concentration on the (D/H)CH3 values calculated from the NMR results. The optimal conditions for extracting acetic acid were found to be a sample-to-solvent ratio of 1:1, seven extractions, and an extraction time of 15 min. The extraction rates for acetic acid were 93.65% and 80.57% when ethyl acetate and diethyl ether, respectively, were used. The acetic acid concentration of the ethyl acetate- and diethyl ether-extracted samples was further improved by distillation from 5 g/100 mL to 33.84 and 51.65 g/100 mL, respectively.

From biofuel to bioproduct: is bioethanol a suitable fermentation feedstock for synthesis of bulk chemicals?

AbstractThe first pilot‐scale factories for the production of bioethanol from lignocellulose have been installed, indicating that we are on the brink of overcoming most hurdles for an economically feasible process. When bioethanol is competitive as biofuel with fuels originating from petrochemical resources, it will also become interesting to use lignocellulose as a feedstock for the fermentative synthesis of bulk chemicals. Lignocellulose hydrolysates, however, are highly complex and viscous media, posing challenges to oxygen transfer, product formation at low sugar concentration, product recovery, etc. Bioethanol is an exceptional product in this respect because it can be produced anaerobically, at low sugar concentrations, and can be easily removed from the broth by distillation. For products that do not have these benefits, another approach may be interesting, in which lignocellulose is first converted to bioethanol, which in turn serves as a substrate for a second conversion into the desired product, similar to the traditional production of acetic acid in vinegar. In this perspective, we compare these one‐stage and two‐stage conversions with respect to overall yield and productivity of the fermentation process and the differences that occur in product removal. © 2011 Society of Chemical Industry and John Wiley &amp; Sons, Ltd

Measurement of the Isotope Ratio of Acetic Acid in Vinegar by HS-SPME-GC-TC/C-IRMS

Acetic acid is the main ingredient of vinegar, and the worth of vinegar often depends on the fermentation of raw materials. In this study, we have developed a simple and rapid method for discriminating the fermentation of the raw materials of vinegar by measuring the hydrogen and carbon isotope ratio of acetic acid using head space solid-phase microextraction (HS-SPME) combined with gas chromatography-high temperature conversion or combustion-isotope ratio mass spectrometry (GC-TC/C-IRMS). The measurement of acetic acid in vinegar by this method was possible with repeatabilities (1sigma) of +/-5.0 per thousand for hydrogen and +/-0.4 per thousand for carbon, which are sufficient to discriminate the origin of acetic acid. The fermentation of raw materials of several vinegars was evaluated by this method.

Effect of food acids on postprandial glucose levels

Studies examining effects of vinegar on blood glucose regulation report that vinegar given with a high-carbohydrate meal (HCM) reduces postprandial glycemia in both healthy and insulin resistant or Type 2 DM subjects. Researchers hypothesized that acetic acid in vinegar may cause the glucose lowering effect. The study's purpose was to examine how different test substances (treatments) of food acids affect blood glucose levels after consuming a HCM (95 g bagel, 20 g butter and 8 fl oz orange juice). On 6 separate occasions subjects were fed the HCM and given the treatments. Treatments were: vinegar, pickle juice, acetic acid pill, lemon juice, lime juice, and placebo. Healthy subjects (14 female & 4 males) aged 18–53 years old (mean age 23.6 ± 8.1) completed the study. Subjects fasted overnight, blood samples were collected at baseline, 30 and 60 minutes after consuming the meal and treatment. SPSS was used; repeated measures ANOVA showed vinegar significantly lowered (p<.001) blood glucose at 30 minutes compared to other treatments and placebo. Although other treatments did not improve postprandial glycemia, our data is consistent with other research suggesting that vinegar does have a favorable effect on reducing glycemia after a HCM in healthy subjects. Data also suggest acetic acid alone may not be responsible for reduction in postprandial glycemia but that other compound(s) in vinegar might contribute to the effect.

A thiourea-based chromoionophore for selective binding and sensing of acetate

Highly selective binding and sensing of acetate over various monovalent inorganic anions (MeCO2−≫H2PO4−>Cl−, Br−, I−, SCN−, NO3−, HSO4−, ClO4−) are achieved by N,N′-bis(p-nitrophenyl)thiourea as a hydrogen-bonding chromoionophore in 1% water–99% MeCN (v/v), and acetic acid in vinegar is successfully determined by the complexation-induced chromogenic response of this chromoionophore.

Two-parameter determination in vinegar by a flow injection-pervaporation system.

A flow injection method (FI) for the sequential determination of ethanol and acetic acid in vinegar is reported. The determination of ethanol is based on the oxidation of the pervaporated ethanol by K2Cr2O7. The acetic acid is determined by an acid-base reaction with Thymol Blue as the indicator. Both reactions are monitored photometrically at 600 nm using a single detector. Optimisation studies and assessment of the sequential Fl method are also reported. The linear determination range is 0-12% v/v for ethanol and 0-10% (grams of acetic acid in 100 ml) for acetic acid. The sample throughput of the sequential manifold is seven per hour. The new method was applied to vinegar samples and the results obtained were in excellent agreement with those from reference methods used in Spain.

Determination of Acetic Acid in Vinegar by Gas Phase Molecular Absorption Spectrometry After Methyl Acetate Generation

This paper describes a method for the quantitative determination of acetic acid by gas-phase molecular absorption spectrometry. The proposed method is based on the generation of methyl acetate with subsequent measureme nt of the volatile absorbance at 216 nm. The generation, transport and measurement conditions are optimized. Under the recommended conditions, the analytical characteristics are obtained, with a detection limit of 0.005 M. The method is tested with vinegar samples. The analytical results obtained by the proposed method agree with those of a reference method.

Determination of Acetic Acid in Vinegar by Gas Phase Molecular Absorption Spectrometry After Methyl Acetate Generation

Determination of Acetic Acid in Vinegar by Gas Phase Molecular Absorption Spectrometry After Methyl Acetate Generation

Flow Injection Potentiometric Determination of Coke Acidity and Acetic Acid Content in Vinegar Using an Antimony Electrode

Abstract A flow injection potentiometric procedure is proposed for the determination of acidity of several samples using an antimony/ antimony oxide electrode. The ΔE/pH curve in phosphate buffer solutions in the pH range from 1.58 to 12.00 showed a linear sub-Nernstian behavior with an operational slope S =-42.1mV/pHc and a conditional standard potential of 264.8mV. This flow potentiometric electrode responds linearly to low acidity variations of dilute acetic acid solutions from 3.16 to 100mM with a slope of 30.1mV/dec and analytical frequency of 23 results/h. Good reproducibility and an average standard deviation of ±0.5% was obtained. The application of this sensor for the determination of coke acidity and acetic acid in vinegar is reported.

Determination of trace amounts of acetic acid in ethanol by fluoride isoconcentration using the method of standard additions

The large and systematic change in cell potential resulting from the addition of 0–1%m/m of acetic acid to a solution of ethanol containing 1 × 10–3M tetraethylammonium fluoride (TEAF) as background electrolyte, using a fluoride ion-selective electrode and a calomel reference electrode filled with lithium chloride, provides a graphical method for the rapid determination of acetic acid in ethanol. Readings obtained by direct potentiometry show good reproducibility and stability. The method, characterised by its accuracy and simplicity of operation, compares favourably with gas chromatographic methods and can be used for the determination of acetic acid in vinegar.

Liquid Chromatographic Determination of Acetic Acid in Foods

Abstract A liquid chromatographic (LC) method has been developed for the determination of acetic acid in vinegar and other foods. The LC system includes an Aminex HPX-87H column and a UV detector set at 210 nm. The mobile phase is 0.009N H2S04 at a flow rate of 0.7 mL/min. The method is simple and specific for acetic acid. Recoveries of acetic acid from a variety of products ranged from 93.3 to 102% with coefficients of variation from 2.4 to 4.6%.