Simultaneous Determination of Malic acid, Lactic acid, Acetic acid, Citric acid, Fumaric acid and Propionic acid in Feed Acidifier

Simultaneous Determination of Malic acid, Lactic acid, Acetic acid, Citric acid, Fumaric acid and Propionic acid in Feed Acidifier

Deng Hong, Lei Yan

DadHank (Chengdu) Biotech Corp., Chengdu 611130

Abstract: A method was established for the simultaneous determination of malic acid, lactic acid, acetic acid, citric acid, fumaric acid and propionic acid in feed acidifier using high performance liquid chromatography (HPLC). Using Sepax GP-C18 column (150 mm × 4.6 mm, 5 μm) for analysis. The mobile phase was a potassium dihydrogen phosphate aqueous solution with a pH value of 3.5 and its flow rate was 1.0 mL/min; The detection wavelength was 214 nm; The column temperature was 30℃. Under this chromatographic condition, the 6 organic acids were well separated. The average recovery rate was greater than 95%, and the RSD was less than 4%. The detection results indicated that this method was simple, easy to operate, accurate, and reliable, and can quickly detect the organic acid content of feed acidifier.

Feed acidifier, also known as pH regulators, refer to a type of substance that can acidify feed. It can reduce the pH value of feed in the digestive tract and provide the most suitable digestive environment for animals, and has been widely used domestically and internationally. After discovering antibiotics, it is an important additive alongside probiotics, enzyme preparations, and microecologics. It is an environmentally friendly additive without residue, drug resistance（non-resistance） and non-toxic effects. It can ensure the reasonable growth of beneficial bacterial communities, effectively inhibit pathogenic microorganisms, and achieve the effect of improving animal growth performance, feed utilization efficiency, and enhancing the body's disease resistance ^[1-3]. At present, acidifiers are not only applied in piglet production, but also have positive effects on poultry and ruminants. Various types of acidifiers have also emerged in market. The detection methods of organic acids reported at home and abroad mainly include Potentiometric titration, Capillary electrophoresis, Gas chromatography, and Liquid chromatography, etc. ^[4-10]. However, there have been no reports on the simultaneous analysis of malic acid, lactic acid, acetic acid, citric acid, fumaric acid, and propionic acid. This test established a high performance liquid chromatography method for the simultaneous determination of six organic acids in acidifiers.

4.6.4 Application prospect of feed acidity regulator

Organic acids in acidifiers are widely used as feed acidulants. It can not only improve the palatability of feed and promote feed intake, but also have（has） antiseptic and health care effects, and can prevent feed from being contaminated by mold（molds）; It also has anti-microbial function, which can reduce the reproduction of harmful microorganisms in the gastrointestinal tract of animals, reduce the pH value of feed, activate digestive enzymes, help to digest and absorb certain nutrients, improve feed conversion rate, and provide energy for animals ^[11]. Because these acids are completely metabolized, safe and non-toxic, they are approved in many countries to be used as dietary components in animal feed, and people's interest in their use is increasing ^[12].