Abstract
Robust and easy-to-use NMR sensor technology is proposed for accurate, on-site determination of fat and protein contents in milk. The two parameters are determined using fast consecutive 1H and 35Cl low-field NMR experiments on milk samples upon the 1:1 addition of a low-cost contrast solution. Reliable and accurate measurements are obtained without tedious calibrations and the need for extensive database information and may readily be conducted by non-experts in production site environments. This enables on-site application at farms or dairies, or use in laboratories harvesting significant reductions in costs and time per analysis as compared to wet-chemistry analysis. The performance is demonstrated for calibration samples, various supermarket milk products, and raw milk samples, of which some were analyzed directly in the milking room. To illustrate the wide application range, the supermarket milk products included both conventionally/organically produced, lactose-free milk, cow’s, sheep’s and goat’s milk, homogenized and unhomogenized milk, and a broad nutrient range (0.1–9% fat, 1–6% protein). Excellent agreement between NMR measurements and reference values, without corrections or changes in calibration for various products and during extensive periods of experiment conduction (4 months) demonstrates the robustness of the procedure and instrumentation. For the raw milk samples, correlations between NMR and IR, NMR and wet-chemistry, as well as IR and wet-chemistry results, show that NMR, in terms of accuracy, compares favorably with the other methods.
Highlights
Introduction published maps and institutional affilMilk is a world-wide major food resource and as such is subject to extensive analysis requirements to ensure quality, nutritional yield, animal health, and production output
On-site quantification of fat and protein contents in milk, we propose here an easy protocol allowing direct quantification using low-field nuclear magnetic resonance (NMR) on milk samples upon the 1:1 addition of a simple contrast solution and temperature stabilization
The primary vertical axis shows the calibrated direct correlation with reference values, while the secondary axis relates 1:1 to the observed NMR parameter. The latter is the 1 H NMR intensity measured for concentration range of interest, we analyzed five dilutions of the calibration samples mixed 1:1 with demineralized water
Summary
Milk is a world-wide major food resource and as such is subject to extensive analysis requirements to ensure quality, nutritional yield, animal health, and production output. Routine analysis is performed on milk delivered to dairies, and regular analyses are performed on the milk from individual animals providing indications on the nutritional balance of the milk as well as the health of the animal. The milk analyses provide essential information to control and optimize feeding and breeding strategies. At dairies and for milk manufacturers, milk analysis is performed as an essential part of the process control. The main parameters in milk analysis are typically the contents of fat and protein. Often the fat and protein contents are used to calculate the milk’s value directly determining payment to farmers for delivered milk
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
