Identification of mammalian feces by coprostanol thin layer chromatography: method development

Area of Science:

• Food safety and analysis
• Analytical chemistry
• Microbiology

Background:

• Current methods for identifying mammalian fecal contamination in food are often inadequate.
• Visual identification of small fecal particles is challenging.
• Existing biochemical methods, like fecal alkaline phosphatase detection, have limitations with inactivated enzymes and herbivore feces.

Purpose of the Study:

• To develop a novel, reliable method for detecting mammalian fecal particles in food.
• To utilize coprostanol as a specific and stable fecal indicator.
• To improve the sensitivity and applicability of fecal identification methods in food matrices.

Main Methods:

• A new analytical method was developed using coprostanol as the target biomarker.
• Suspect particles undergo hexane extraction and are applied to silica gel thin-layer chromatography (TLC) plates.
• Plates are impregnated with phosphomolybdic acid, developed using a diethyl ether-heptane solvent system, heated, and visually analyzed for coprostanol presence.

Main Results:

• The method successfully identified small amounts of mammalian feces.
• As little as 0.15 mg of rat feces and 0.5 mg of cow feces were detected.
• Coprostanol proved to be a heat-stable and effective indicator for mammalian feces.

Conclusions:

• The developed coprostanol-based method offers a sensitive and reliable approach for identifying mammalian fecal contamination in food.
• This technique overcomes the limitations of existing visual and enzymatic methods.
• It provides a valuable tool for ensuring food safety and quality by detecting animal residues.