Multipoint near-infrared spectrometry for real-time monitoring of protein conformational stability in powdered infant formula

Abstract

Powdered infant formula (PIF) can be the sole source of nutrition for babies and infants. Monitoring conformational changes in protein during manufacture of PIF is critical in order to maintain its nutritional value. This study presents the development of a calibration model for monitoring conformational changes in PIF protein by applying a novel multipoint near-infrared (NIR) spectrometry. NIR spectra were collected for PIF and PIF proteins, casein and whey protein isolate, before and after heat treatment. Results show that principal component analysis showed discrimination between native protein at room temperature and protein conformational changes caused at elevated temperature. Partial least squares regression analysis showed good calibration models with correlation coefficients ranging between 87% and 99% for the prediction of protein quality. This novel multipoint NIR spectrometry could serve as a simple in-line tool to rapidly monitor protein quality during processing stages, contributing to product nutritional value.

• ATR-FTIR
• near-infrared spectrometry
• partial least squares regression
• powdered infant formula
• principal component analysis

Declaration of interest

The authors have no conflicts of interest to declare. The research leading to these results has received funding from the European Community Seventh Framework Program (FP7/2207-2013) under grant agreement number 605134.