Table 3.

Different types of biochemical tests for the detection of foodborne pathogens.

Biochemical test	Chemical characteristics	Chemical reaction	Medium	Color	References
Oxidase test	Identify cytochrome oxidase enzyme	electron transport chain	Agar	Purple	[279]
Catalase test	Detoxifies hydrogen peroxide into water and oxygen	Bubbles of oxygen	Blood agar	_	[280]
Indole production test	Degradation of amino acid tryptophan and production of indole	Oxidizes tryptophan	tryptophan	Pink/Cherry red	[281]
Methyl red test	Fermentation of sugar	Oxidizes glucose	methyl red and Voges–Proskauer (MR-VP) broth	Red	[282]
Voges-Proskauer test	Production of nonacidic or neutral end product	Ferment sugars via the butanediol pathway	methyl red and Voges–Proskauer (MR-VP) broth	Red	[282]
Triple sugar iron agar test	Production of H2S	Cytochrome oxidase activity	Triple sugar iron agar	Yellow	[283]
Blood agar plate test	Production of hemolysins	Hemolysis activity	Blood agar	Colorless	[284]
Mannitol salt agar test	Production of acidic byproducts	Fermenting mannitol	Mannitol salt agar	Yellow	[285]
Starch hydrolysis test	Production of amylose and amylopectin	Starch hydrolysis into sugar	Starch agar	Yellow	[286]
Galactose hydrolysis test	Production of glucose	Galactose hydrolysis	Eosin methylene blue medium	Green	[286]
Carbohydrate fermentation test	Extraction of fatty acids	Fermenting mannitol	Proteose peptone medium	Yellow	[287]
Citrate utilization test	Utilizes citrate–carbon source	Fermenting citrate	Simmon’s citrate agar	Blue	[288]
Urease test	Detects the alkaline and forms ammonia	Hydrolyzing urea	Christensen’s urea agar	Pink	[289]
Hydrogen sulfide production test	Production of hydrogen sulfide	Reducing sulfur compound	Tryptone soya agar	Black	[283]
Nitrate reduction test	Formation of nitrate and ammonium	Reduction of nitrate	Nitrate broth	Red	[290]