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Background: Osteopontin (OPN) is an important protein in human milk, and is of growing interest to infant formula (IF) manufacturers. OPN is present at low quantities in bovine milk and its derived ingredients, and there is a need for an accurate quantitative method in complex matrixes such as IF and growing-up milks (GUMs)., Objective: The objective of this work was to validate a method to quantify OPN in several dairy powders produced from bovine milk, including skimmed milk powder (SMP), whey protein concentrate (WPC), demineralized WPC and α-lactalbumin-enriched WPC (α-lac WPC). The method was further validated in intact-protein IF and GUM powders produced using combinations of these ingredients., Methods: Test samples were digested using trypsin, and the most appropriate peptide fragmentation transitions were identified by UHPLC-MS/MS. Quantification was made against a standard curve constructed from OPN reference material, and isotopically-labelled peptide standards were used as internal standards. Curve linearity was assessed, and samples were spiked at two OPN levels., Results: The validation parameters were met in almost all cases, with precision RSDr and RSDiR values ranging from 0.26-7.43% and 1.22-12.70%, respectively, and spike recoveries ranging from 88-102%. The method was used to accurately measure OPN in bovine milk-based IF and GUM powders with intact protein systems, based on comparisons with mass balance calculations., Conclusions: The results from this study show that the method is fit-for-purpose to support IF and GUM manufacturers in evaluating OPN contents of raw materials and products containing whole, intact protein systems from bovine milk., Highlights: An LC-MS/MS method was developed to measure OPN in dairy powders, IF and GUMs containing whole, intact protein systems from bovine milk., (© AOAC INTERNATIONAL 2020. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: There is a need for a standardized method for quantification of lactoferrin in infant formulas, and manufacturers have started fortifying lactoferrin to mimic the higher levels found in human milk. A variety of current methods exist, but specificity and accuracy are challenging with the infant formula matrix. The use of signature peptides and MS is becoming more prevalent in the realm of analytical chemistry for quantification of proteins. Objective: The objective of this work was to develop and validate a method through a single-laboratory validation for quantification of lactoferrin in milk-based infant formula and begin to lay the foundation for a standardized method. Methods: The method presented uses signature peptides to quantify lactoferrin in milk-based infant formulas by ultra-high performance LC-tandem mass spectrometry (MS/MS). These peptides are produced through tryptic digestion, and fragments produced from these peptides through MS/MS allow the specific quantification using correlating isotopically labeled peptides. Results: The validation parameters were all met with precision RSD r ranging from 2.1 to 7.1 and intermediate RSD R ranging from 7.0 to 10.4 across different fortified milk-based infant formulas. Accuracy with certified reference material resulted in mean recoveries of 91.7-96.4%. Conclusions: The results from this study demonstrate the method is fit for purpose to support manufacturing specifications and nutritional labeling requirements.

Self-esteem/self-concept and aesthetics were measured in three groups. One group prior to orthodontic treatment, one group following completion of active orthodontic treatment and an untreated group. Improvement in dental and/or facial aesthetics does not necessarily lead to an increase in self esteem.