Analysis of milk and dairy products

Home Analysis Analysis of milk and dairy products

Milk samples and Dairy products

In addition to controlling the milk used to prepare dairy products, the standard also requires that finished products should also be periodically monitored. The objectives is to know the physicochemical and microbiological quality of these products.

Physicochemical tests conducted with official or reference methods

  • Fat
  • Proteins
  • Totales solids
  • pH
  • Ashes
  • Urea
  • Freezing point
  • Lactose (by calculation)
  • Stability (alcohol test)


Cheese producers could send samples to the laboratory to know the physicochemical quality and microbiological of their products.

Physicochemical tests carried out by reference or official methods

  • Fat by gravimetry
  • Total solids by gravimetry
  • Protein by volume (Kjeldahl)
  • Caseína by volume (Kjeldahl)
  • Fat, protein, lactose, total solids, ash by gravimetry and volumetry
  • pH by potentiometry
  • Cryoscopic point in milk by cryoscopic method
  • Stability in milk by alcohol test
  • Density at 20ºC in milk by densitometry
  • Oleic acidity in cream and butter by titration
  • Thorner acidity in milk by titration
  • Moisture in butter by gravimetry
  • Non-fat solids and fat in butter by gravimetry/Calculation
  • Fat and total solids in raw or pasteurized cream by infrared spectroscopy (NIR)
  • Fat, total solids, protein and ash in milk evaporated by infrared spectroscopy (NIR)
  • Fat, moisture, protein and ash in milk powder by infrared spectroscopy (NIR)

Other tests in milk and dairy products

  • M1 Aflatoxin in raw milk (Charm method)
  • M1 Aflatoxin in milk by liquid chromatography (HPLC-MS/MS)
  • chloramphenicol in raw milk (Charm method)
  • chloramphenicol in raw milk by liquid chromatography (HPLC-MS/MS)
  • Caseinoimacropeptids/Caseinoimacropeptid A in milk by liquid chromatography (HPLC-MS/MS)
  • ßlactámic and tetracycline residues in raw milk by Charm method
  • βlactámic (penicillin G, amoxicillin, ampicillina, cloxacillin, dicloxacillin, cephalexin, cefapirine, cefalonium, cefoperazone, cefquinome) residues in milk by liquid chromatography (HPLC-MS/MS)
  • Sulfamide and Trimetoprim residues (sulfadiazine, sulfatiazole, sulfamethazine, sulfachloropyridazine, sulfadoxine, sulfadimethoxine) in milk by liquid chromatography (HPLC-MS/MS)
  • Quinolone residues in raw milk (Charm method)
  • Quinolone residues (enrofloxacin, marbofloxacin, danofloxacin) in milk by liquid chromatography (HPLC-MS/MS)

Microbiological tests

  • Espores of Bacillus cereus
  • Listeria monocytogenes by inmunofluorescence method (VIDAS)
  • Salmonella spp. by inmunofluorescence method (VIDAS)
  • Plate count of Escherichia coli ß-glucoronidase positive
  • Plate count of Coliform at 30º C
  • Plate count of microorganism a 30º C
  • Plate count of Estafilococcus coagulase positive
  • Plate count of enterobacteria at 37º C
  • Plate count of psychotrophic Microorganisms
  • Plate count of Pseudomonas spp
  • Plate count of espores of mesophilic anaerobes
  • Plate count of mesophilic aerobes espores
  • Plate count of thermophilic aerobics
  • Plate count of Bacillus cereus
  • Plate count of Thermophilic microorganisms
  • Identification of microorganisms by mass espectrometry (VITEK MS)
  • Butyric espores in milk, impedance method (RABIT)
  • Molds and/or yeasts