NMR relaxometry as a tool to understand the effect of microwave heating on starch-water interactions and gelatinization behavior

2017-09-15
Starch-water interactions during gelatinization by microwave heating was investigated by Low-field H-1 Nuclear Magnetic Resonance (LF NMR) relaxometry experiments. Effect of microwave heating time on longitudinal (T-1) and transverse relaxation times (T-2), gel matrix structures, changes in proton populations and firmness values were evaluated. One to one corn starch (CS) to water ratio samples had the lowest T-2 change during gelatinization indicating lower granule expansion which was attributed to the high amylose content of CS. Non-Negative-Least-Square (NNLS) analysis of the transverse relaxation curves provided detailed information on starch-water interactions during gelatinization. Rice starch (RS) samples had relatively lower changes in peak areas which was related to the better hydration of RS granules.,While microscope images revealed the changes in the granule structures after distinct gelatinization intervals, firmness measurements supported the structural changes. With increasing microwave heating time, both T-1 and T-2 showed a decreasing trend. Two distinct proton populations detected on relaxation spectrum indicated the exchanging protons during gelatinization. A noticeable reduction in firmness at the later moments of microwave heating was detected. The results showed that starch gelatinization by microwave heating had some distinct features in terms of mechanism of the gelatinization and could be investigated by NMR relaxometry.
LWT-FOOD SCIENCE AND TECHNOLOGY

Suggestions

Quantum chemical calculations of warfarin sodium, warfarin and its metabolites
Tekin, Emine Deniz (Calisir); ERKOÇ, Figen; YILDIZ, İLKAY; Erkoç, Şakir (2008-07-01)
The structural, vibrational and electronic properties of warfarin sodium, warfarin and its metabolites have been investigated theoretically by performing the molecular mechanics (MM+ force field), the semi-empirical self-consistent-field molecular-orbital (AM1), and density functional theory calculations. The geometry of the molecules have been optimized, the vibrational dynamics and the electronic properties of the molecules have been calculated in their ground state in gas phase.
Kinetic analysis of in situ combustion processes with thermogravimetric and differential thermogravimetric analysis and reaction tube experiments
Kök, Mustafa Verşan (1995-01-01)
This research comprises the determination of kinetic parameters of in situ combustion processes by reaction tube and thermal (thermogravimetric analysis (TGA)/differential thermogravimetric analysis (DTGA)) experiments. A previously developed laboratory model and a Du Pont 9900 thermalanalyzer unit were used to run the experiments. Three reaction regions for combustion of crude oil in porous media were observed in the reaction tube and TGA/DTGA experiments and are defined as low temperature oxidation, fuel ...
Optical properties of Cu3In5S9 single crystals by spectroscopic ellipsometry
Işık, Mehmet; Nasser, H.; Ahmedova, F.; Guseinov, A.; Hasanlı, Nızamı (2018-01-01)
Cu3In5S9 single crystals were investigated by structural methods of x-ray diffraction and energy dispersive spectroscopy and optical techniques of ellipsometry and reflection carried out at room temperature. The spectral dependencies of optical constants; dielectric function, refractive index and extinction coefficient, were plotted in the range of 1.2-6.2 eV from ellipsometric data. The spectra of optical constants obtained from ellipsometry analyses and reflectance spectra presented a sharp change around ...
Quantum-chemical treatment of the linoleic acid molecule and two of its conjugated isomers
Kurban, Sevil; ERKOÇ, Figen; Erkoç, Şakir (Wiley, 2009-10-01)
The structural, vibrational and electronic properties of die linoleic acid molecule and two of its conjugated isomers were investigated theoretically by performing the molecular mechanics (MM+ force field), the semi-empirical self-consistent-field molecular-orbital (PM3), and the density functional theory (B3LYP) calculations. The geometries of the considered molecules were optimized; the vibrational dynamics and the electronic properties were calculated in their ground states in the gas phase. It was found...
Critical behaviour of the thermodynamic quantities close to phase transitions in molecular crystals using raman data
Özdemir, Hilal; Yurtseven, Hasan Hamit; Department of Physics (2017)
In this thesis we investigate the pressure and temperature dependence of the Raman frequencies for diffirent modes of benzene at ambient conditions (P=0 GPa and T=300 K). By using the experimental data we calculated the volume and frequency as a function of pressure at constant temperature and as a function of temperature at constant pressure, thus isothermal and isobaric mode Grüneisen parameter has been inferred in the diffrent modes. Our calculations show that calculated Raman frequencies agree well with...
Citation Formats
B. Özel, M. KILERCIOGLU, S. G. Şümnü, and H. M. Öztop, “NMR relaxometry as a tool to understand the effect of microwave heating on starch-water interactions and gelatinization behavior,” LWT-FOOD SCIENCE AND TECHNOLOGY, pp. 10–17, 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/32085.