Untitled

Tsereteli, G. I.; Belopolskaya, T. V.; Grunina, N. A.; Vaveliouk, O. L.

doi:10.1023/a:1010110727782

Cited by 31 publications

(27 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…28,29 After denaturation, globular proteins lost their tertiary structure, and the change in heat capacity becomes more evident. 30 The ΔCp of denatured whey proteins (WPI and BLG) during glass transition in the present study was very small (0.1 to 0.2 Jg −1°C−1 ), and much lower than that observed for other solid proteins, which are usually in the range between 0.3 and 0.5 Jg −1°C −1 . 30,31 Thus, the T g could not be detected for the WPI and BLG systems with water contents above 16% (Table 3).…”

Section: Discussioncontrasting

confidence: 59%

Effect of Water Content on Glass Transition and Protein Aggregation of Whey Protein Powders During Short-Term Storage

Zhou

Labuza

2007

Food Biophysics

View full text Add to dashboard Cite

The objectives of this study were to investigate the moisture-induced protein aggregation of whey protein powders and to elucidate the relationship of protein stability with respect to water content and glass transition. Three whey protein powder types were studied: whey protein isolate (WPI), whey protein hydrolysates (WPH), and betalactoglobulin (BLG). The water sorption isotherms were determined at 23 and 45°C, and they fit the GuggenheimAndersson-DeBoer (GAB) model well. Glass transition was determined by differential scanning calorimeter (DSC). The heat capacity changes of WPI and BLG during glass transition were small (0.1 to 0.2 Jg −1°C−1 ), and the glass transition temperature (T g ) could not be detected for all samples. An increase in water content in the range of 7 to 16% caused a decrease in T g from 119 down to 75°C for WPI, and a decrease from 93 to 47°C for WPH. Protein aggregation after 2 weeks' storage was measured by the increase in insoluble aggregates and change in soluble protein fractions. For WPI and BLG, no protein aggregation was observed over the range of 0 to 85% RH, whereas for WPH, ∼50% of proteins became insoluble after storage at 23°C and 85% RH or at 45°C and ≥73% RH, caused mainly by the formation of intermolecular disulfide bonds. This suggests that, at increased water content, a decrease in the T g of whey protein powders results in a dramatic increase in the mobility of protein molecules, leading to protein aggregation in short-term storage.

show abstract

Section: Discussioncontrasting

confidence: 59%

Effect of Water Content on Glass Transition and Protein Aggregation of Whey Protein Powders During Short-Term Storage

Zhou

Labuza

2007

Food Biophysics

View full text Add to dashboard Cite

show abstract

“…Only after the globular proteins are hydrated may an exceptionally broad or stretched out transition be observed by DSC and rheological techniques. 7,16,[19][20][21] As glass transition peaks can occur as the denaturation of the protein begins, it can be difficult to differentiate between the reversible and nonreversible event. Hence, glass transitions are easier to identify when the protein has lost some of its tertiary order.…”

Section: Introductionmentioning

confidence: 99%

Enthalpy relaxation of bovine serum albumin and implications for its storage in the glassy state

et al. 2005

View full text Add to dashboard Cite

Two endothermic peaks could be observed for five commercial samples of bovine serum albumin (BSA). The smaller peak observed by differential scanning calorimetry (DSC) corresponded to enthalpy relaxation. This peak was followed on storage of BSA, in its glassy state, after it had been heated above its denaturation temperature. Enthalpy and peak temperature increased with duration of storage. On storage for one week at 60 degrees C, a sample at 8.3% moisture showed a peak at 100 degrees C with an energy value of approximately 2 J per g protein. BSA samples were heated within the DSC sufficiently to eliminate the lower enthalpy peak but without altering the denaturation enthotherm. The amount of physical aging shown by these BSA samples was similar to that of the heat-denatured samples. It was concluded that the heating endotherms of dry BSA reflect both the storage and thermal history of the sample. Possible implications of the enthalpy relaxation of BSA on the behavior of this important protein are considered.

show abstract

“…7, if one supposes that all water was removed from the sample during the first heating run. The bound water may act as a natural plasticizer [34] in many biopolymers. The observed reproducibility of DNA-CTMA glass transition means that either some of the bound water remains confined despite heating up to 190°C (what would be surprising) or CTMA plasticizes DNA (what is a more realistic explanation).…”

Section: Resultsmentioning

confidence: 99%

“…In the available bibliography can be found ''first run'' DSC thermograms of solid DNA, that consist of visible singularities between 40 and 80°C [27,34]. These singularities were attributed to denaturation of DNA.…”

Section: Resultsmentioning

confidence: 99%

DNA-hexadecyltrimethyl ammonium chloride complex with enhanced thermostability as promising electronic and optoelectronic material

Nizioł

Fiedor

Pagacz

et al. 2016

J Mater Sci: Mater Electron

View full text Add to dashboard Cite

Recently DNA with hexadecyltrimethyl ammonium chloride (CTMA) complex has been included in some organic electronic devices. Thermal stability is one of key parameters required for successful applications in different electronic and optoelectronic devices. This work shows a possibility of enhancing thermal stability in this complexes and analyzes origin of this enhancement. Different techniques were applied to explore this issue of solid DNA-CTMA. Results of TGA analysis, DSC calorimetry, FTIR spectroscopy, and analysis of evolved gaseous products convince that chemical composition of DNA-CTMA complex remains fixed at temperatures \200-220°C. In contrast, broadband dielectric spectroscopy applied to freshly prepared thin films of DNA-CTMA revealed at 150-160°C a permanent and irreversible change of dielectric properties. This phenomenon may be attributed to a transformation affecting the microstructure. Some experiments were conducted also for the native DNA as a reference. We demonstrate that DNA-CTMA complex chemical composition is more stable at temperatures about 200°C with respect to DNA which is very important for laser operated optoelectronic applications.

show abstract

Untitled

Cited by 31 publications

References 8 publications

Effect of Water Content on Glass Transition and Protein Aggregation of Whey Protein Powders During Short-Term Storage

Effect of Water Content on Glass Transition and Protein Aggregation of Whey Protein Powders During Short-Term Storage

Enthalpy relaxation of bovine serum albumin and implications for its storage in the glassy state

DNA-hexadecyltrimethyl ammonium chloride complex with enhanced thermostability as promising electronic and optoelectronic material

Contact Info

Product

Resources

About