Measurement of glass transition temperature by mechanical (DMTA), thermal (DSC and MDSC), water diffusion and density methods: A comparison study

Rahman, Mohammad Shafiur; Al-Marhubi, I.; Al-Mahrouqi, Abdullah Issa

doi:10.1016/j.cplett.2007.04.067

Cited by 93 publications

(63 citation statements)

References 21 publications

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“…In the case of MDSC, samples were scanned from 10 to 170°C at a constant heating rate of 2°C per min with an amplitude of ±1°C and 60 s period of modulation. Curves were analysed with respect to the total, reversible and non-reversible heat flow [5,27]. Glass transition was reported with parameters indicating its onset, midpoint and endpoint of a vertical shift in the reversing transition curve.…”

Section: Mdsc Studiesmentioning

confidence: 99%

The influence of trehalose–maltodextrin and lactose–maltodextrin matrices on thermal and sorption properties of spray-dried β-lactoglobulin–vitamin D3 complexes

Górska

Szulc

Ostrowska–Ligęza

et al. 2013

J Therm Anal Calorim

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In the study, the effect of lactose-maltodextrin and trehalose-maltodextrin matrices on the glass transition temperatures and moisture sorption characteristics of spray-dried b-lactoglobulin-vitamin D 3 complexes was investigated. Incorporation of sugars into complexes can influence the thermal properties and moisture sorption characteristics of powders. The glass transition temperature as an important physiochemical parameter that determines the processing conditions, product quality and stability of the final product was studied with the use of modulated differential scanning calorimetry method. Moisture sorption isotherms, water activity and moisture content as parameters related to sorption properties, were also investigated. Additionally, particle size, wettability and insolubility index were studied to characterise newly synthesized products. For the samples tested, two well-separated glass transitions were found. The dominant effect of maltodextrin on the glass transition temperatures was observed. An increase in the percentage of maltodextrin added resulted in increasing T g value of studied complexes. At low water activity all powdered complexes showed typical sorption behaviour of food systems. Trehalose as a carbohydrate component of powdered complexes, in comparison to lactose, delayed the occurrence of crystallization.

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Section: Mdsc Studiesmentioning

confidence: 99%

The influence of trehalose–maltodextrin and lactose–maltodextrin matrices on thermal and sorption properties of spray-dried β-lactoglobulin–vitamin D3 complexes

Górska

Szulc

Ostrowska–Ligęza

et al. 2013

J Therm Anal Calorim

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“…Rahman, Al‐Marhubi, and Al‐Mahrouqi (2007) measured glass transition of spaghetti by DMA from the change in slope in E′ , which was 10.5°C lower than the value measured by tan ( δ ) peak. They found it difficult to find a maximum in the loss modulus E″ curve.…”

Section: Resultsmentioning

confidence: 95%

Comparison of mathematical models to predict glass transition temperature of rice (cultivar IRGA 424) measured by dynamic mechanical analysis

Bertotto

Gastón

Batiller

et al. 2018

Food Science & Nutrition

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Dynamic mechanical analysis (DMA) was applied to measure the Tg of rice IRGA 424 at different moisture content values (9.3%–22.3% wet basis). To conduct temperature sweeps, the samples were heated at a rate of 2°C/min from 20 to 120°C keeping frequency to 1 Hz. Tg was measured both from the E″ peak temperature (Tgmidpoint) and from the tan (δ) peak temperature (Tgendset). Tgmidpoint and Tgendset increased from 31.8 to 86.6°C and 42.1 to 104.7°C, respectively, as moisture content decreased from 22.3 to 9.3%. Six models were tested for their ability to predict Tg as a function of the moisture content. As all residuals were normally distributed and homoskedastic, standard metrics were used to assess the fitted models. Goodness of fit by these models was established by comparing the coefficient of determination (R 2), standard error of the estimate (SEE), and mean relative deviation (MRD). The Gordon–Taylor linearized equation was the most accurate in predicting Tg. To predict Tg from the moisture content of the rice samples, a new expression was proposed. For the conditions considered in this work, the developed equation satisfactorily predicts the Tg of rice IRGA 424 without needing prior linearization.

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“…In the case of MDSC, samples were scanned from 10 to 170°C at a constant cooling rate of 2°C per min with an amplitude of ±1°C and 60 s period of modulation. Curves were analyzed with respect to the total, reversible and non-reversible heat flow [31,32]. Glass transition was reported with parameters indicating its onset, midpoint and endpoint of a vertical shift in the reversing transition curve.…”

Section: Mdsc Studiesmentioning

confidence: 99%

Effect of composition and drying method on glass transition temperature, water sorption characteristics and surface morphology of newly designed β-lactoglobulin/retinyl palmitate/disaccharides systems

Górska

Szulc

Ostrowska–Ligęza

et al. 2017

J Therm Anal Calorim

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Effect of composition and drying method on glass transition temperature, water sorption characteristics and surface morphology of newly designed b-lactoglobulin/retinyl palmitate/ disaccharides systems Abstract In the study, MDSC method was used to evaluate thermal properties of b-lactoglobulin-retinyl palmitate products enriched in disaccharides. Additionally, sorption behavior of powders was determined to define their stability. The obtained powders were also examined and visualized with scanning electron microscopy to find the relationship between food processing conditions and morphological changes in products. For the samples tested, a single glass transition was observed. The results have shown the impact of the composition of studied samples on the glass transition temperatures. The carbohydrate-blactoglobulin systems were characterized by higher T g values than disaccharides alone. At low water activity, all powdered complexes showed typical sorption behavior of food systems with the sigmoidal shape of the curve. The present study has shown that spray-dried and freeze-dried powdered products with lactose or trehalose have different time-dependent crystallization behavior. Trehalose as a carbohydrate component of samples, in comparison with lactose, delayed the occurrence of crystallization. The obtained images presented the dependence of the shape of the particles on the drying method used. Spray-dried powders were characterized by a spherical or close to spherical structure with the surface of larger particles often deformed. In the case of freeze-dried particles, irregular structures were observed.

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Measurement of glass transition temperature by mechanical (DMTA), thermal (DSC and MDSC), water diffusion and density methods: A comparison study

Cited by 93 publications

References 21 publications

The influence of trehalose–maltodextrin and lactose–maltodextrin matrices on thermal and sorption properties of spray-dried β-lactoglobulin–vitamin D3 complexes

The influence of trehalose–maltodextrin and lactose–maltodextrin matrices on thermal and sorption properties of spray-dried β-lactoglobulin–vitamin D3 complexes

Comparison of mathematical models to predict glass transition temperature of rice (cultivar IRGA 424) measured by dynamic mechanical analysis

Effect of composition and drying method on glass transition temperature, water sorption characteristics and surface morphology of newly designed β-lactoglobulin/retinyl palmitate/disaccharides systems

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