Abstract
Water is a principal component of all dairy products and significantly affects their properties. Milk powders, although almost devoid of water, may be exposed to high relative humidity if stored at inappropriate conditions. This work examines water in hydrated milk powders – specifically fat-filled milk powder – by employing nuclear magnetic resonance (NMR) spectroscopy. Free Induction Decay (FID), CPMG, and Inversion Recovery (IR) measurements were undertaken at several relative humidity levels at both of resorption and desorption conditions. FID measurements at magic angle spinning conditions made it possible to assign and fit the water peak in the chemical shift dimension and quantitatively measure the relative water contents. Water content measurements were accurate enough to observe minor hysteresis effects. Relaxation ordered spectroscopy by CPMG and inversion recovery methods measured 1H chemical shift and relaxation time distributions at several relative humidity levels. T1 and T2 of water increased with higher relative humidity – indicating the occupation of increasing larger spaces by water. Qualitative relaxation dispersion experiments indicated the possibility of exchange at the 100% relative humidity condition.
Original language | English |
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Publication date | 14 Apr 2024 |
Number of pages | 1 |
Publication status | Published - 14 Apr 2024 |
Event | 19th Food Colloids Conference - Thessaloniki, Greece Duration: 14 Apr 2024 → 18 Apr 2024 Conference number: 19 https://foodcolloids2024.org/wp-content/uploads/2024/03/FoodColloids2024_SciProgFULL_v5.pdf |
Conference
Conference | 19th Food Colloids Conference |
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Number | 19 |
Country/Territory | Greece |
City | Thessaloniki |
Period | 14/04/2024 → 18/04/2024 |
Internet address |
Keywords
- NMR
- Milk powder
- water
- fat
- relaxation