Quantitative Analysis of Organic Acids

Organic acids are a class of compounds containing carboxyl groups (excluding amino acids), which are carboxylic acids in the intermediate metabolism of amino acids, fats and sugars. They are widely distributed in the biological world, and most of them are combined with potassium, sodium, calcium and other metal ions or alkaloids. It exists in the form of salt, and in combination as ester. According to the characteristics of their structure, organic acids can be divided into three categories: aromatic, aliphatic and terpenoid organic acids.

Application Fields

Medicine research

Disease marker filtering，Etiology and pathological mechanism exploration，Disease recurrence diagnosis，Disease diagnosis and classify，Clinical efficacy evaluation，Pharmacotoxicological evaluation

Life science research

Research on abiotic environment relationship, metabolic pathway and functional genome research, plant and microorganism research, application in medicinal plant research, application in phenotypic identification

Sample Requirements

Animal tissue ≥ 0.2g
Urine ≥ 0.25ml
Stool ≥ 0.3g
Serum, plasma ≥ 0.3ml
Plant tissue ≥ 2g
Cells ≥ 5×10⁶
Dry ice shipping

Store in liquid nitrogen or -80°C

Case Analysis

Functional Role of Yeasts, Lactic Acid Bacteria and Acetic Acid Bacteria in Cocoa Fermentation Processes

Journal: FEMS Microbiology Reviews Impact factor: 13.92 Published date: July, 2020 Published by: Free University of Brussels, Belgium

Research Background

Cocoa beans is made possible by a succession of yeast, lactic acid bacteria (LAB), and acetic acid bacteria (AAB) activities. Yeasts ferment the glucose of the cocoa pulp into ethanol, perform pectinolysis, and produce flavour compounds, such as (higher) alcohols, aldehydes, organic acids, and esters.

Research Design

LAB ferment the glucose, fructose, and citric acid of the cocoa pulp into lactic acid, acetic acid, mannitol, and pyruvate, generate a microbiologically stable fermentation environment, provide lactate as carbon source for the indispensable growth of AAB, and contribute to the cocoa and chocolate flavours by the production of sugar alcohols, organic acids, (higher) alcohols, and aldehydes.

From cocoa to chocolate

Fermentation process of cocoa beans, including anaerobic and aerobic stages, and biotransformation reactions

Conclusion

AAB oxidize the ethanol into acetic acid, which penetrates into the bean cotyledons to prevent seed germination. Destruction of the subcellular seed structure in turn initiates enzymatic and nonenzymatic conversions inside the cocoa beans, which provides the necessary colour and flavour precursor molecules (hydrophilic peptides, hydrophobic amino acids, and reducing sugars) for later roasting of the cured cocoa beans, the first step of the chocolate-making.

Reference

De Vuyst Luc,Leroy Frédéric,Functional role of yeasts, lactic acid bacteria and acetic acid bacteria in cocoa fermentation processes.[J] .FEMS Microbiol. Rev., 2020, 44: 432-453