Staling of sponge cakes with added emulsifiers

The effect of three types of emulsifiers (polyglycerol monostearate ester – E475, sucrose stearate ester – E473 and modified inulin palmitate ester – HP-25) on the starch retrogradation in sponge cake (SC) during storage was investigated. The method of differential scanning calorimetry (DSC) was applied to determine the changes in the starch retrogradation during the staling process. The retrogradation temperature and the enthalpy of the endothermic transition decreased when emulsifiers were added. The lowest values of the enthalpy for the whole storage period were found for SC with 1% HP-25. The methods of differential thermal analysis (DTA) and thermogravimetry analysis (TGA) showed significantly bigger (1.43 times) amount of strongly bound water in the crumb of the SC with E475 and HP-25 in comparison to the control sample on the sixth day of storage. Based on our results, emulsifiers possessed retarding effect on the starch retrogradation and extend the shelf-life of the SC.

Microencapsulation of Red Sorghum Phenolic Compounds with Esterified Sorghum Starch as Encapsulant Materials by Spray Drying

Phenolic compounds with antioxidant properties are highly sensitive molecules, which limits their application. In response, extruded esterified starch has been proposed as efficient encapsulating material. In this work, we aim to describe the encapsulation of red sorghum phenolic compounds by spray drying using extruded phosphorylated, acetylated and double esterified sorghum starch as wall material. Their respective encapsulation yields were 77.4, 67.4 and 56.8 %, and encapsulation efficiency 91.4, 89.7 and 84.6 %. Degree of substitution confirmed esterification of the sorghum starch and Fourier transform infrared spectroscopy showed the significant chemical and structural changes in the extruded esterified starch loaded with phenolic compounds. Microcapsules from phosphorylated sorghum starch showed the highest endothermic transition (173.89 °C) and provided a greater protection of the phenolic compounds during storage at 60 °C for 35 days than the other wall materials. Extruded esterified sorghum starch proved to be effective material for the protection of phenolic compounds due to its high encapsulation efficiency and stability during storage.

Thermal studies on Arabic gum - carrageenan polysaccharides film

<p>The main objective of this work is to develop film and study the thermal characteristics of polysaccharides films at various concentration of carrageenan in the mixture by calculating activation energy of polysaccharides films. There were four (4) film samples of two polysaccharides combination; arabic gum (AG) and carrageenan (C) with different formulations; sample A, sample B, sample C and sample D prepared. Sample A film is the control sample that contained only arabic gum and distilled water (DI) with 40% weight arabic gum per volume DI water (w/v%). Meanwhile for sample B and C were prepared with concentration 40 w/v% of Arabic gum and two differents of carrageenan concentrations; 1 w/v% and 10 w/v% respectively. Polyethylene glycol 400 (PEG 400) as a plasticiser was added into sample D film. The sample films were thermally characterized using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) under nitrogen atmosphere. The major thermal transitions as well as, activation energies of the major decomposition stages were determined. Sample A and B films exhibited the highest (112.43 kJ/mol) and the lowest (102.89 kJ/mol) activation energy of thermal decomposition, respectively. The activation energies were lower at larger amounts of sulfate groups from carrageenan on the degradation reactions. The DSC trend for all samples shows two (2) major intense peaks recorded in the DSC thermograms; an endothermic transition at temperature around 100^°C and followed by an exothermic transition at temperature around 300^°C. The endothermic transition is due to the heat absorption for dehydration of water, H2O and the decomposition of samples process. Meanwhile, the exothermic transition is caused by the formation of H₂O, CO and CH₄ in polysaccharide film from dehydration, depolymerisation and decomposition at the high-temperature stages.</p><p>Chemical Engineering Research Bulletin 19(2017) 80-86</p>

A metallic carbon allotrope with superhardness: a first-principles prediction

From first-principles calculations, a novel carbon material with superhardness and metallicity is proposed and a possible endothermic transition is evaluated.

Effect of PH-Shifting Treatment on the Biochemical and Thermal Properties of Myofibril Protein

The pH-shifting treatment (including acid treatment and alkali treatment) caused partly denaturation and degrading of myofibril. The pH-shifting treatment increased the surface hydrophobicity, surface -SH content and total -SH content, reduced the Ca-ATPase activity. Acid treated myofibril (ACM) did not show any endothermic transition peak in differential scanning calorimetry (DSC); while alkali treated myofibril (AKM) showed reduced T max value for myosin and actin. The SDS-PAGE indicated that acid treatment caused severe degrading of myosin heavy chain. High turbidity of ACM indicated more myofibril aggregated during acid treatment. The final G’ was in the decline order of M (550 Pa), AKM (135 Pa), and ACM (25 Pa). In conclusion, the alkali treatment was milder than the acid treatment.