title: Spreeta-based biosensor immunoassays to detect fraudulent adulteration in milk and milk powder.
abstract: Biacore biosensors (Biacore AB, Uppsala, Sweden) have proven to be robust analytical tools for the automated immunochemical detection of different adulterants and contaminants in milk and milk powder. However, the significant cost of the instruments is a disincentive for their wide application in food control laboratories. Therefore, a low-cost alternative optical biosensor (Spreeta, Texas Instruments, Attleboro, MA) was built into an affordable liquid handling system. Using this prototype biosensor, an inhibition immunoassay for bovine K-casein was evaluated for the detection of cow's milk in ewe's and goat's milk and for the detection of bovine rennet whey powder in milk powder. Comparable sensitivities were obtained for both adulterants in the Spreeta-based prototype biosensor and a Biacore 3000 instrument. The limit of detection for cow's milk was 0.17% (v/v) and bovine rennet whey powder could be detected in milk powder above 1% (w/w). The Spreeta sensor was also useful in the control of fraudulent water additions to milk, simply by measuring differences in the bulk response.
authors.affiliation: RIKILT-Institute of Food Safety, PO Box 230, 6700 AE Wageningen, The Netherlands. willem.haasnoot@wur.nl
authors.forename: Willem
authors.initials: W
authors.lastname: Haasnoot
authors.forename: Gerardo R
authors.initials: GR
authors.lastname: Marchesini
authors.forename: Kees
authors.initials: K
authors.lastname: Koopal
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods*; D015374:Biosensing Techniques / Q000379:methods; D002364:Caseins / Q000032:analysis; D002417:Cattle; D003611:Dairy Products; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods*; D008892:Milk; D008894:Milk Proteins / Q000032:analysis; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D002364:Caseins; D008894:Milk Proteins