Analysis of Bovine Lactoferrin in Infant Formula and Adult Nutritional Products by Optical Biosensor Immunoassay: First Action 2021.07.

Abstract

Bovine lactoferrin is increasingly being used as an ingredient in infant formula manufacture to enhance nutritional efficacy through the provision of immunoprotective, growth, and antimicrobial factors to the neonate. To evaluate the analytical performance of an optical biosensor immunoassay for compliance with the method performance requirements described in SMPR 2020.005. Following dilution of the sample in buffer, an automated, label-free, real-time optical biosensor immunoassay was used in a direct assay format to quantitate bovine lactoferrin by its interaction with an immobilized anti-lactoferrin antibody. Quantitation was accomplished by the external standard technique with interpolation from a 4-parameter calibration regression. The analytical range (0-200 mg/hg), method detection limit (0.8mg/hg), recovery (96.1-109.2%), and repeatability (1.0-5.3%) complied with the requirements given in the lactoferrin SMPR. The method was shown to be specific for native, intact lactoferrin; thermally denatured lactoferrin generated no measurable binding response. The method described is suitable for the quantification of intact, undenatured lactoferrin in milk products, infant formulas (bovine milk protein-based, soy protein-based, and amino acid-based), and adult nutritionals and has been demonstrated to meet the performance requirements defined in SMPR 2020.005. A single-laboratory validation (SLV) of an automated biosensor immunoassay for the determination of intact, undenatured lactoferrin is described.