Development of a low resolution 1H NMR spectroscopic technique for the study of matrix mobility in fresh and freeze-thawed hen egg yolk

Three experiments were conducted in developing a low resolution proton nuclear magnetic resonance (H-1 NMR) spectroscopic technique to study matrix mobility in fresh and freeze-thawed gelled yolk. The Carr-Purcell-Meiboom-Gill (CPMG) sequence was used to measure spin-spin relaxation times of proton pools representing major yolk constituents. A component identification test distinguished 3-4 pools. The least mobile pool was assigned to proteins, protein-lipid and protein-water interactions, and the most mobile to unbound water. The remaining pools were assigned to lipids, lipid-protein and lipid-water interactions. A stability test indicated that yolk had varied matrix mobility within the same sample across five days of refrigeration storage. A reproducibility test demonstrated high repeatability of fresh yolk measurements, but significant differences (p < 0.05) were found within gelled yolk samples. This research determined that H-1 NMR spectroscopy, a non-destructive technique, can identify yolk components and detect changes in the matrix. (C) 2016 Elsevier Ltd. All rights reserved.