Determination of bovine lactoferrin in lactoferrin-supplemented dairy products and raw milk by an automated latex assay.
Latex immune agglutination method with a multipurpose auto-analyser (the automated latex assay) was validated for determination of bovine lactoferrin (BLF) in various dairy products. Reproducibility-within-laboratory (intermediate precision) due to day for infant formula, UHT milk and yogurt supplemented with BLF at 50 mg/100 g for infant formula and UHT milk, and at 100 mg/100 g for yogurt were 1.62 to 3.10 mg/100 g. Reproducibility-within-laboratory due to analysis (morning, noon, and evening) for raw milk was 1.59 mg/100 g. Trueness, accuracy in determining known amounts added for BLF-supplemented dairy products was -4.7 to -2.0 mg/100 g. BLF concentration in raw milks was 20.3 to 21.8 mg/100 g. Although interference by the matrixes took place in infant formula and raw milk, BLF assays were accurately carried out by 2000-fold dilution or standard-addition method. Automated latex assay for BLF is simple, rapid, precise and accurate enough for a routine method in various dairy products containing BLF.
Soejima
Takashi
T
Analytical Research Center, Morinaga Milk Industry Co., Ltd., 5-1-83, Higashihara, Zama, Kanagawa 228-8583. t_soezim@morinagamilk.co.jp
Yamauchi
Koji
K
Yamamoto
Tomoko
T
Ohara
Yasuko
Y
Nagao
Eiji
E
Kanbara
Keiichi
K
Fujisawa
Munetoshi
M
Okuda
Yuko
Y
Namba
Shyunji
S
D000818:Animals; D001331:Automation / Q000379:methods; D002417:Cattle; D041943:Infant Formula / Q000737:chemistry; D007781:Lactoferrin / Q000032:analysis*; D007841:Latex Fixation Tests / Q000379:methods / Q000662:veterinary*; D008892:Milk / Q000737:chemistry*; D015014:Yogurt / Q000032:analysis
D007781:Lactoferrin