Monitoring cheese ripening by single-sided nuclear magnetic resonance

Abstract

The noninvasive, longitudinal study of products and food processing is of interest for the dairy industry. Here, we demonstrated that single-sided nuclear magnetic resonance (NMR) can be used for noninvasive monitoring of the cheese ripening process. The maturation of soft-ripened Camembert-like molded cheese samples was monitored for 20 d measuring 1-dimensional and 2-dimensional NMR relaxation and diffusion data at various depths, ranging from the hard surface layer to the soft center. Gelation and gel shrinkage were observed throughout ripening, and a complete loss of free water signal was observed at the cheese rind. Transversal ( T 2 ) relaxation distributions include 3 components that evolve with ripening time and position, corresponding to water inside the casein gel network, water trapped in casein, and fat. Two-dimensional T 1 - T 2 relaxation experiments provided enhanced resolution of the 3 components, allowing quantification of the relative proportions of each phase. Furthermore, diffusion ( D )- T 2 relaxation correlation experiments revealed the bimodal size distribution of fat globules. The study demonstrated that single-sided NMR can provide spatially resolved signal intensity, relaxation, and diffusion parameters that reflect structural changes during the ripening process and can be exploited to understand and monitor the ripening of cheeses.

Two-Dimensional Laplace NMR Reconstruction through Deep Learning Enhancement

“…Additionally, analysis of the relative peak integrals in the T 1 −T 2 maps revealed that protein and fat peaks increased proportionally with the ripening time, which is widely used in the food industry. 38−40 These peak assignments are in accord with findings from previous studies, 38,41,42 However, due to the ill-posed nature of ILT, the percentages of these components can only roughly reflect their relative proportions, making them unsuitable for precise quantification.…”

“…Fourth, T 1 relaxation and T 2 relaxation (T 1 −T 2 ) correlation experimental data of cheese ripening: 38 three sets of 2D Laplace data were collected on the 10th, 15th, and 20th days of the cheese curing process, which was prepared from 400 mL of pasteurized milk with additives. Laplace NMR experiments were performed on a Magritek Profile NMR-Mouse PM 25 instrument with a 13.29 MHz 1 H resonance frequency and 7.28 T m −1 gradient, Kea 2 spectrometer, and Prospa software.…”

Ultrafast Nuclear Magnetic Resonance as a Tool to Detect Rapid Chemical Change in Solution

“…As these changes are best revealed by changes in T 1 , T 2 , and D , they can be tracked using ultrafast Laplace NMR in a way that traditional 2D NMR cannot. Examples include examining water movement in silica and cement, , the monitoring of cheese ripening, or monitoring the aggregation of ionic liquids. , Regardless of evident potential, these methods have not yet broadly been applied to studying chemical reactions, although there is one example using changes in T 2 and D to monitor binding of pyridine to an iridium catalyst and its metal-catalyzed deuteration (Figure d) …”

CAT on MOUSE: Control and automation of temperature for single‐sided NMR instruments such as NMR‐MOUSE

“…Such a feature has been widely utilized in the study of art artifacts, 15–19 medical materials, 20 car tires, 21 cartilage, 22,23 and skin 24 . In addition, the NMR‐MOUSE has also been widely utilized in studies where depth profiling is not measured, such as geopolymer curing, 25 archeology, 26,27 and food manufacturing and control 28–32 . Novel Ultra‐Fast Laplace NMR sequences are also feasible with NMR‐MOUSE, 33–36 which opens the possibility to study fast processes using single‐sided magnet.…”

“…24 In addition, the NMR-MOUSE has also been widely utilized in studies where depth profiling is not measured, such as geopolymer curing, 25 archeology, 26,27 and food manufacturing and control. [28][29][30][31][32] Novel Ultra-Fast Laplace NMR sequences are also feasible with NMR-MOUSE, [33][34][35][36] which opens the possibility to study fast processes using single-sided magnet.…”