Differential Scanning Calorimetry (DSC) for the Measurement of Food Thermal Characteristics and Its Relation to Composition and Structure

2021 ◽  
pp. 283-328
Author(s):  
Preetinder Kaur ◽  
Manpreet Singh ◽  
Preeti Birwal
Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1958
Author(s):  
Jolanta Tomaszewska-Gras ◽  
Mahbuba Islam ◽  
Liliana Grzeca ◽  
Anna Kaczmarek ◽  
Emilia Fornal

The aim of this study was to describe the thermal properties of selected cultivars of flaxseed oil by the use of the differential scanning calorimetry (DSC) technique. The crystallization and melting profiles were analyzed depending on different scanning rates (1, 2, 5 °C/min) as well as oxidative induction time (OIT) isothermally at 120 °C and 140 °C, and oxidation onset temperatures (Ton) at 2 and 5 °C/min were measured. The crystallization was manifested as a single peak, differing for a cooling rate of 1 and 2 °C/min. The melting curves were more complex with differences among the cultivars for a heating rate of 1 and 2 °C/min, while for 5 °C/min, the profiles did not differ, which could be utilized in analytics for profiling in order to assess the authenticity of the flaxseed oil. Moreover, it was observed that flaxseed oil was highly susceptible to thermal oxidation, and its stability decreased with increasing temperature and decreasing heating rate. Significant negative linear correlations were found between unsaturated fatty acid content (C18:2, C18:3 n-3) and DSC parameters (OIT, Ton). Principal component analysis (PCA) also established a strong correlation between total oxidation value (TOTOX), peroxide value (PV) and all DSC parameters of thermo-oxidative stability.


Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6344
Author(s):  
Philipp S. Borchers ◽  
Patrick Gerlach ◽  
Yihan Liu ◽  
Martin D. Hager ◽  
Andrea Balducci ◽  
...  

In this work, two new redox-active ionic liquids, one based on 2,2,6,6-tetramethylpiperidine-N-oxide and the other based on 4,4′-bipyridine, are synthesized and characterized. A ferrocene-based redox-active ionic liquid is used for referencing the results. All ionic liquids are formed via salt-metathesis from halogenate to bis(trifluoromethylsulfonyl)imide. Their fundamental thermal characteristics are assessed with differential scanning calorimetry. While the imidazolium ionic liquids show no melting point, the phase transition is well observable for the viologen-based ionic liquid. The properties of the neat redox-active ionic liquids and of binary mixtures containing these ionic liquids (0.1 m) and 1-butyl-1-methyl pyrrolidinium-bis(trifluoromethylsulfonyl)imide have been investigated. Finally, the use of these binary mixtures in combination with activated carbon-based electrodes has been considered in view of the use of these redox-active electrolytes in supercapacitors.


2019 ◽  
pp. 089270571987919
Author(s):  
Volodymyr Krasinskyi ◽  
Ivan Gajdos ◽  
Oleh Suberlyak ◽  
Viktoria Antoniuk ◽  
Tomasz Jachowicz

The structure and thermal characteristics of nanocomposites based on polyvinyl alcohol (PVA) and montmorillonite (MMT) intercalated with polyvinylpyrrolidone were investigated by X-ray diffraction analysis and differential scanning calorimetry. The modification of PVA with intercalated MMT reduces the degree of crystallinity of the resulting nanocomposites but significantly increases their thermal stability. Under ultrasound, the intercalated MMT was completely distributed in a PVA solution and formed a monocrystalline structure. Films based on PVA with modified MMT were cross-linked at 110°C in the presence of 5 wt% acrylic acid and 0.5 wt% Ferrous(II) sulfate as an initiator. The formed films have a homogeneous cross-linked structure.


2017 ◽  
Vol 31 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Artur Gryszkin ◽  
Tomasz Zięba ◽  
Małgorzata Kapelko-Żeberska

Abstract The objective of this study was to determine the effect of heating a water dispersion of corn starch to various temperatures, followed by its freezing and defrosting, on selected properties of re-formed starch pastes. A suspension of starch was heated to various temperatures ranging from 59 to 94°C, and afterwards frozen and defrosted. The differential scanning calorimetry (Mettler Toledo, 822E) thermal characteristics of starch pre-heated to temperatures not inducing complete pasting revealed transitions of: (I) retrograded amylopectin, (II) non-pasted starch, (III) amylose-lipid complexes, (IV) retrograded amylose, and (V) highly thermostable starch structures. The application of higher temperatures during heating caused disappearance of transitions II and V. The increase of pre-heating temperature induced firstly a decrease and then stabilization of the swelling power as well as a successive decrease in starch solubility. Pastes pre-heated to temperatures over 79°C contained large macroparticles that were increasing viscosity of the re-formed starch paste (their size was positively correlated with viscosity value).


2013 ◽  
Vol 721 ◽  
pp. 625-628
Author(s):  
Yuan Yan Yu

This work describes the aqueous-solution technique preparation and characterization of the complex between human-like collagen and copper (II). Pure human-like collagen and the copper complex were characterized by thermo gravimetric (TG) and differential scanning calorimetry (DSC) analysis. The TG curves and DSC data reveal the significant thermal differences between pure protein and the copper complex, demonstrating the formation of a new chemical compound, which is different from the free HLC and with more stable thermodynamic properties.


2018 ◽  
Vol 5 (1) ◽  
pp. 39
Author(s):  
Ridhawati Ridhawati ◽  
Abdul Wahid Wahab ◽  
Nursiah La Nafie ◽  
Indah Raya

Mesoporous silica SBA-15 is an interesting material having highly ordered nanopores and large surface area, which is synthesized by sol gel and hydrothermal methods. In this study, mesoporous silica SBA-15 was synthesised with two different methods and the characteris was using X-Ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC). SBA-15 was prepared TEOS as precursor and Pluronic 123 as surfactant. Thermoporous mesoporous DSC thermogram results of the SBA-15A mesoporous silica is (Tg 79oC and Tc 158oC). This is relatively lower than SBA-15B (Tg 86oC and Tc 158oC). The measurement of low angle X-Ray Diffraction SBA-15A has a crystal size 9.46 nm and SBA-15B has a crystal size 9.96 nm. The synthesis of SBA-15 using the hydrothermal method needs to be studied further to obtain thermal characteristics and a more stable crystal structure


2014 ◽  
Vol 695 ◽  
pp. 207-210 ◽  
Author(s):  
Muhamad Rasyidi Husin ◽  
Agus Arsad ◽  
Othman Y. Alothman

Polyaniline (PANI) was synthesized by using ultrasonic polymerizations at various frequencies of 5 to 20 kHz. PANI was synthesized in the present using hydrochloric acid (HCl) as a dopant and ammonium persulfate (APS) as an oxidant. The characteristics of PANI based on 1H proton, its molecular structure was characterized by using nuclear magnetic resonance (NMR) and at 7-8 ppm confirmed the PANI structure. Thermal characteristics have also been investigated by using differential scanning calorimetry (DSC). Glass transitions temperature (Tg) at about ~100 °C was it is correlated observed due to recrystallization or cross-linking reaction of PANI. The polymerization at frequency wave of 20 kHz shows the best overall properties of produced PANI nanofiber.


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