Work

Lactoferrin content determined in bovine milk by HPLC and mid-infrared spectrometry - Relation to udder health and potential for detection of milk adulteration

Year: 2025

Type: article

Abstract: Lactoferrin (LF) isamultifunctional glycoprotein linked toudder health indairy cows. This study aimed todevelop acalibration model for LF quantification using mid-infrared spectrometry (MIR-FT), with ion-pair reversed-phase high-performance liquid chromatography (HPLC) asthe reference method. Two sets ofindividual milk samples (A: n= 120; B: n= 91) were collected from five dairy farms inthe Czech Republic. Set Aincluded ahigher proportion ofsamples with somatic cell count (SCC) above 300 000 cells/ml toensure broad LF variability. After merging both sets and removing six outliers, afinal calibration set C (n= 205) was created. The developed model achieved across-validated coefficient ofdetermination of0.5887 and astandard error ofcross-validation of67.33 mg/l. Correlation analysis showed that several milk parameters correlated with LF determined byMIR-FT inpatterns typical ofmastitis (SCC: r=0.450; lactose: r= –0.364; free fatty acids: r= 0.621; electrical conductivity: r= 0.442), indicating potential for MIR-FT inevaluating mammary gland health. The feasibility ofusing LF asanindicator ofmilk adulteration byartificial SCC reduction through centrifugation was also assessed. Two sample sets (n= 20 and n= 68) were analysed, each containing normal bulk tank milk and bulk tank milk supplemented with abnormal milk. Centrifugation caused minimal changes inLFdetermined byboth HPLC and MIR-FT (maximum 3.27%) while SCC decreased bynearly 50%, suggesting thatLF may serve asamarker for detecting artificial SCC reduction. However, practical application ofMIR-FT for accurate LF determination islimited bythe achieved validation parameters and the high expanded uncertainty (114.7mg/l). The method istherefore more suitable for monitoring relative LF changes inmilk than for determining exact LF content.

Source: Czech Journal of Animal Science

DOI: 10.17221/114/2025-cjas