Developing an optical backscatter method for determining casein micelle particle size in heated milk. (November 2022)

• Record Type: Journal Article
• Authors: Taterka, Heather; Zamora, Anna; Castillo, Manuel
• Is Part Of: Food research international. Volume 161(2022)
• Publication Date: 2022-11
• Subjects: Casein micelle size -- Whey protein denaturation -- Milk -- In-line -- Process monitoring -- Optical sensor -- Near infrared spectroscopy; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2022.111745
• Languages: English
• ISSNs: 0963-9969

Abstract

Graphical abstract: Highlights: Modeled particle size as a function of milk pH, temperature and light backscatter. Identified spectral regions related to attachment of denatured whey proteins to micelles. Particle size growth follows an exponential curve from initial casein micelle size. Abstract: A plethora of different factors, such as heat treatment, pH, soluble calcium and phosphate concentrations, colloidal calcium phosphate, ionic strength, redox potential, etc., affect functionally of critical milk components such as casein micelles, fat globules and whey proteins. These physicochemical changes induce fat- or protein-protein interactions that would be associated to changes in particle size that might be revealed using light backscatter measurements. We hypothesized that inline, simple, low-cost light backscatter measurements might have the potential to provide functionally related information, representing an interesting opportunity for process control. Casein micelle particle size and near infrared light backscatter spectra were measured in milks heat treated at 80 and 90 °C and pH 6.3, 6.7 and 7.1 in order to obtain prediction models for estimating changes in casein micelle particle size during milk heat treatment. Light intensity was measured over a spectral range of 200–1100 nm using a simple optical backscatter sensor and was implemented into models for particle size predictions as a function of heat treatment temperature and pH. Models which included an exponential factor containing a ratio of two specific wavebands were found to improve R 2 when compared to single wavelength models. The best model exhibited an R 2 of 0.993 and SEP of 2.36 nm. The developed prediction models show promise for in-line monitoring of whey protein denaturation and casein micelle particle size.