The Antibacterial Principle of Buffered Vinegar (Powder)

1. Low pH environment inhibits microbial growth

The pH of ordinary vinegar is usually between 2.4 and 3.4, while buffered vinegar can adjust and stabilize the pH in a certain acidic range (depending on the application scenario).
The suitable growth pH of most microorganisms (such as bacteria, molds, and yeasts) is in the neutral to weakly acidic range (pH 4.5~7.0). Low pH will destroy the enzyme activity in microbial cells, interfere with cell membrane function, and inhibit their metabolism and reproduction ability.
For example:
Bacteria: Most pathogenic bacteria (such as Escherichia coli and Salmonella) are inhibited when pH <4.5;
Molds and yeasts: Although they have strong tolerance to acidic environments, their reproduction rate decreases significantly when pH <3.5.

2. Antibacterial effect of undissociated acetic acid

Buffered vinegar contains a large number of undissociated acetic acid molecules, which are highly lipid-soluble and can penetrate the microbial cell membrane and enter the cell. After entering the cell, the acetic acid molecule dissociates into acetate ions (CH₃COO⁻) and hydrogen ions (H⁺), causing the intracellular acidity to increase, destroying the acid-base balance, and consuming ATP energy (used to excrete H⁺), ultimately inhibiting the activity of microorganisms and even causing death.

3. Stability of the buffer system

The pH of ordinary vinegar is easily affected by external factors (such as dilution and contact with alkaline substances), while buffered vinegar can resist pH fluctuations through the dynamic balance of the buffer pair (acetic acid + acetate), ensuring that the system always maintains an acidic range for effective antibacterial effect.
For example, when a small amount of acidic or alkaline substances are added to the buffer vinegar, the buffer pair will maintain pH stability through the following reactions:
When the acidic substance increases: CH₃COO⁻ + H⁺ → CH₃COOH (consumes H⁺, inhibits pH decrease);
When the alkaline substance increases: CH₃COOH + OH⁻ → CH₃COO⁻ + H₂O (consumes OH⁻, inhibits pH increase).