acetic acid

Overview

Acetic acid is a simple carboxylic acid and one of the most widely encountered low-molecular-weight organic acids in chemistry, biology, food science, and environmental research. In biological systems, it is commonly present as acetate, its conjugate base, and participates in acid–base equilibria that influence pH, osmotic balance, and metabolic flux. Because of its acidity and reactivity, acetic acid is relevant both as a metabolic product and as an experimental reagent used to model inflammatory and physiological responses.

In biomedical and applied research, acetic acid is studied in several distinct contexts. It can arise from microbial metabolism, contribute to sour flavor and acidification in fermented foods, and affect aerosol thermodynamics in the atmosphere through dissociation and hygroscopic effects. Experimentally, acetic acid is also used to induce colonic inflammation in animal models, making it a useful tool for evaluating anti-inflammatory interventions and oxidative stress-related pathways involving mediators such as superoxide dismutase, catalase, malondialdehyde, and NO radicals.

Focus of Latest Publications

Recent publications have examined acetic acid in microbial metabolism, fermentation chemistry, environmental aerosol behavior, sensory science, and inflammation models.

In a bioenergy synthesis study using proteoliposomes as microreactors, alcohol dehydrogenase and aldehyde dehydrogenase were loaded into a system designed to mimic microbial metabolism. Within this cascade, ethanol was converted to acetic acid, showing that acetic acid can serve as a defined metabolic end product in engineered biochemical compartments. The work also involved the proton-transporting ATP synthase complex, highlighting the broader metabolic context in which acetic acid formation may be coupled to energy transduction.

In environmental research, acetic acid was evaluated together with formic acid in aerosol thermodynamic systems in a typical Chinese inland city. The study reported that water-soluble acetic acid acidifies aerosols through H⁺ release from carboxyl dissociation, while its conjugate base increases aerosol liquid water content by enhancing hygroscopicity and forming organic salts. This places acetic acid within the chemistry of atmospheric particles, where it influences acidity and water uptake.

Several food and fermentation studies linked acetic acid to kombucha quality and aroma. One investigation of pandan kombucha fermented with SCOBYs from different regions used gas chromatography-mass spectrometry, electronic sensing, and sensory analysis to characterize key aroma compounds. The authors reported that one sample showed intense sour notes from acetic acid and butanoic acid, alongside other sensory attributes. Another study on second fermentation with plant by-products found that acetic acid concentration increased while pH progressively declined, consistent with the metabolic activity of acetic acid bacteria. A separate synthetic microbial community study showed that acetic acid, together with ethanol, ethyl acetate, 3-methyl-1-butanol, ethyl caprylate, isoamyl acetate, and phenethyl alcohol, contributed significantly to the characteristic flavor profile of kombucha. These studies collectively position acetic acid as a major determinant of acidity and sensory character in fermented beverages.

In biomedical inflammation research, acetic acid was used to induce colonic inflammation in rats. One study evaluated pH-sensitive cross-linked chitosan-tripolyphosphate/Eudragit S100 nanoparticles loaded with silymarin and quercetin, and reported improvement in acetic acid-induced colonic inflammation. The reported effects were associated with modulation of Th1 cells, inflammatory cytokines, and oxidative stress. This work is notable because it connects acetic acid-induced tissue injury with antioxidant and anti-inflammatory responses, including pathways involving superoxide dismutase, catalase, malondialdehyde, and NO radicals. Mesalazine was also listed among the therapeutic context relevant to this line of research, reflecting the broader anti-colitis treatment framework.

Overall, these studies show acetic acid as both a biologically produced metabolite and an experimental agent with relevance to metabolism, fermentation, environmental chemistry, and inflammatory disease models.

Key Publications

• Jun Proteoliposomes containing ATPase as microreactors to mimic microbial metabolism for bioenergy synthesis. (Journal of colloid and interface science, 2026, PMID 41730821): "The alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) loaded in the microreactor can catalyze the cascade reaction of ethanol to acetic acid."
• Jun Revealing the impact of water-soluble formic and acetic acids on aerosol thermodynamic systems in a typical Chinese inland city. (Journal of environmental sciences (China), 2026, PMID 42070831): "Water-soluble formic acid and acetic acid (FA and AA) acidify aerosols through H⁺ release from carboxyl dissociation, while their conjugate bases (R-COO⁻) increase aerosol liquid water content (ALWC) by enhancing hygroscopicity and forming organic salts."
• Jun Characterization of Key Aroma Compounds in Pandan Kombucha Fermented With SCOBYs From Different Regions via GC-MS, E-Nose, E-Tongue, and Sensory Analysis Approach. (Journal of food science, 2026, PMID 42219551): "The ZH sample (27.24 µg/g) showed intense sour notes from acetic acid and butanoic acid, along with astringent notes from 4-ethylphenol and malty notes from 3-methyl-1-butanol."
• May The silymarin and quercetin-loaded pH-sensitive chitosan-tripolyphosphate/Eudragit® S100 nanoparticles improve acetic acid-induced colonic inflammation in rats by modulating Th1 cells, inflammatory cytokines, and oxidative stress. (European journal of pharmacology, 2026, PMID 42025668): "Colonic inflammation was induced with 4% acetic acid and followed by oral treatment with SM, Que, or EU S100/CS-TPP NPs."
• May Kombucha meets circular economy: A microbiome and metabolite perspective on second fermentation with plant by-products. (Food research international (Ottawa, Ont.), 2026, PMID 41794478): "Chemical analyses demonstrated an increase in acetic acid concentration and a progressive decline in pH throughout fermentation, consistent with the metabolic activity of acetic acid bacteria."
• May Construction of synthetic microbial community to modulate the sensory quality in kombucha fermentation. (Food research international (Ottawa, Ont.), 2026, PMID 41794507): "OPLS-DA analysis revealed that ethanol, ethyl acetate, acetic acid, 3-methyl-1-butanol, ethyl caprylate, isoamyl acetate, and phenethyl alcohol made significant contributions to the characteristic flavor profile of kombucha."