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Acidity regulators, or pH control agents, are food additives used to change or maintain pH (acidity or basicity). [1] They can be organic or mineral acids, bases, neutralizing agents, or buffering agents. Typical agents include the following acids and their sodium salts: sorbic acid, acetic acid, benzoic acid, and propionic acid. [2]
A buffer solution is a solution where the pH does not change significantly on dilution or if an acid or base is added at constant temperature. [1] Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical ...
Portable, or field pH meters, are handheld pH meters that are used to take the pH of a sample in a field or production site. [19] In-line or in situ pH meters, also called pH analyzers, are used to measure pH continuously in a process, and can stand-alone, or be connected to a higher level information system for process control. [20]
At 25 °C (77 °F), solutions of which the pH is less than 7 are acidic, and solutions of which the pH is greater than 7 are basic. Solutions with a pH of 7 at 25 °C are neutral (i.e. have the same concentration of H + ions as OH − ions, i.e. the same as pure water). The neutral value of the pH depends on the temperature and is lower than 7 ...
Acetic acid is an example of a weak acid. The pH of the neutralized solution resulting from HA + OH − → H 2 O + A −. is not close to 7, as with a strong acid, but depends on the acid dissociation constant, K a, of the acid. The pH at the end-point or equivalence point in a titration may be calculated as follows.
Phosphate-buffered saline (PBS) is a buffer solution (pH ~ 7.4) commonly used in biological research. It is a water-based salt solution containing disodium hydrogen phosphate, sodium chloride and, in some formulations, potassium chloride and potassium dihydrogen phosphate. The buffer helps to maintain a constant pH.
In and of themselves, pH indicators are usually weak acids or weak bases. The general reaction scheme of acidic pH indicators in aqueous solutions can be formulated as: HInd (aq) + H 2 O (l) ⇌ H 3 O + (aq) + Ind − (aq) where, "HInd" is the acidic form and "Ind −" is the conjugate base of the indicator. Vice versa for basic pH indicators ...
The scientific approach to food and nutrition arose with attention to agricultural chemistry in the works of J. G. Wallerius, Humphry Davy, and others.For example, Davy published Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture (1813) in the United Kingdom which would serve as a foundation for the profession worldwide, going into a fifth edition.