Specific Volume Analysis Research Articles

Effect of cellulase on dough structure and quality characteristics of tough biscuits enriched with potato whole flour.

Potato whole flour is a promising way to improve the nutrition of tough biscuits, while its gluten-free characteristic was difficult to form acceptable texture properties. In this study, cellulase was used to degrade the cellulose in dough enriched with potato whole flour, so as to mitigate the interference of cellulose with the gluten network, resulting in forming the potato whole flour biscuit with great characteristics. Results indicated that cellulase within 0.2% led to the gradually reduced G' and G'' values of dough from 5.50×104 to 4.00×104 and 2.66×104 to 1.35×104, respectively. Cellulase at 0.2% resulted in the significantly increased tensile properties of the dough compared to the control. The incorporation of cellulase within 0.2% also led to the tightly ordered and intact network structure base on the results of SEM, disulfide bonds determination and FTIR. Those results indicated that cellulase was beneficial to improve the baking quality of dough, which was conductive to form tough biscuit with great characteristics. The hardness, crunchiness, crispness and specific volume analysis results confirmed that 0.2% cellulase resulted in the significantly decreased hardness by 45.25% and the significantly increased specific volume, crunchiness and crispness by 24.74%, 121.20% and 156.47%, respectively. Overall, cellulase ultimately improved the quality of the biscuits by improving the properties and structure of the dough. It was of great significance for the utilization of potato whole flour resources and the industrial production of its tough biscuits. PRACTICAL APPLICATION: The results showed that inclusion of cellulase led to the reduced hardness and increased crunchiness, crispness, and specific volume of potato whole flour tough biscuits. Cellulase could be used as a potential improver of tough biscuits. This study will provide guidance for practical uses of cellulase in improving potato whole flour dough and tough biscuit quality.

Caracterização físico-química, teste de aceitação e análise descritiva de perfil livre de pão sem glúten desenvolvido com amido e farinha de trigo sarraceno brasileiro

ABSTRACT: Buckwheat is a pseudocereal with a high starch content and compounds of nutritional interest, making it suitable for use in gluten-free baking. A simplex-centroid design was employed to investigate the effects of the mixture components of buckwheat flour, buckwheat starch, and rice flour in nine different proportions. The minimum and maximum limits for the components were 10% and 30% for buckwheat flour, 20% and 40% for buckwheat starch, and 50% and 70% for rice flour, aiming to create diverse gluten-free breads for evaluation. The utilized flours underwent characterization, and their micro- and macronutrient amounts, along with their amino acid compositions, were determined. Specific volume analysis, water loss determination, texture assessment, and sensory evaluations were conducted on the breads. It was observed that the proportion of starch and buckwheat flour directly influenced the specific volume and water loss during product storage. Through sensory analysis, the formulation with the highest acceptance and purchase intention among tasters was identified. Free-choice profiling analysis established the sensory profiles of the developed gluten-free bread formulations. According to tasters, the formulations exhibited characteristics of whole meal bread, noticeable softness, and a homogeneous alveolar distribution. The gluten-free bread was well-received by 124 tasters, with a purchase intention rate of 93.55%.

Studies on ion dynamics of polymerized ionic liquids through the free volume theory

Over the last decade, the volume has been envisioned as a critical variable controlling the dynamics of glass-forming systems in general, and charge transport of ionic conductors in particular. Herein, we use theoretical and experimental approaches to investigate the volume effects in a specific 1,2,3-triazolium-based poly(ionic liquid) (PIL) at both the macro and nano scales. The size of the local free volume cavity in the studied system was determined by positron annihilation lifetime spectroscopy (PALS). On the other hand, the theoretical approach enabled us to estimate the hard-core volume (Vhc) and thus free volume (Vf) in the studied PIL. Since the experimental value determined for Vf is relatively large it can be considered as the main factor controlling the superionic properties of this material. Furthermore, the analysis of specific volume and relaxation dynamics in T-P plane in terms of the locally correlated lattice (LCL) and cooperative free volume (CFV) models shows that none of them works for the studied system.

The effects of microfluidization on rheological and textural properties of gluten-free corn breads

This study presents the potential of microfluidization as a value adding process to corn gluten meal (CGM), which is often used as animal feed and is underutilized in food industry. In this study, we aimed to improve water holding ability of corn gluten and to investigate possibility of using this zein-rich byproduct as the main ingredient in gluten-free bread formulations. For this reason, microfluidization as a milling process for CGM, and its effects on rheological and textural properties of gluten-free bread formulations were investigated. In addition, the effects of pH modification and hydrocolloids were analyzed. Microfluidization led to a higher surface area by disintegrating the large CGM molecules, and the structure became compatible to be used in gluten-free bread formulations by overcoming hydrophobic nature. However, structural deformations were detected with pH modifications. The linear viscoelastic region of dough was observed at strains lower than 0.5%. For all formulations, elastic moduli (G') were higher than viscous moduli (G") indicating solid-like behavior. The addition of HPMC and guar resulted in higher moduli values. Microfluidization and pH modifications provided brighter color by revealing lutein and zeaxanthin due to decreased particle size. Texture profile showed that microfluidization and hydrocolloids decreased hardness, increased springiness and cohesiveness, which are desired characteristics for bread. Lastly, the addition of hydrocolloids led to an increase in specific volume by providing gas retention within the structure. HPMC provided 1.23–1.62 times bigger samples than control samples while it was only 1.02–1.12 times bigger for samples with guar according to specific volume analysis.

APLICAÇÃO DE AGENTES QUÍMICOS DE CRESCIMENTO EM BOLO DE CHOCOLATE

The cake is a food commonly consumed by people of different ages. It consists of a mixture of fat and sugar, with over other ingredients. In some formulations the use of chemical growth is required. The aim of this study was to analyze chemical growth agents such as baking powder, bicarbonate of soda and mix of both in chocolate cakes. The analysis of specific volume and acceptability fifty untrained judges test were performed. All cakes were accepted in sensory analysis. The sample with baking powder showed the highest and the lowest note in the taste Question on color attribute. The use of sodium bicarbonate of soda caused darkening of the cake dough.

Atomistic molecular dynamics study of cross-linked phenolic resins

In this study, we analyzed cross-linked phenolic resins by using atomistic molecular dynamics simulations. Cross-linked structures consisting of a network of three functional phenols and two functional methylenes with degrees of cross-linking of 0.70, 0.82, and 0.92 were prepared by cross-linking reactions of linear novolac-type phenolic resins in a unit cell under three-dimensional periodic boundary conditions. Uniaxial elongations of the cross-linked structures to a strain of 0.03 were performed at 300 K. At this temperature, all structures were apparently in a glassy state, which was confirmed by the analysis of specific volume as a function of the temperature. The uniaxial elongation did not cause a significant change in the distribution of bonding potential energies (i.e., bond stretching, angle bending, and torsion angle potentials). On the other hand, the change in the potential energies owing to the uniaxial elongation indicated that cross-links suppressed local segmental motions in the cross-linked structure, probably at the region around the linear and terminal phenols, which resulted in an increase in the degree of cross-linking accompanied by a decrease in Poisson's ratio and an increase in Young's modulus.

Obtention and characterization of gluten-free baked products

This work had as objective the development of gluten-free breads and muffins using rice flour and maize and cassava starches. From seven samples resulting from a Simplex-Centroid design, the sensory and instrumental analyses of specific volume, elasticity, and firmness were performed. For the sensory analysis, the optimized formulation contained 50% of rice flour and 50% of cassava starch, and for the instrumental evaluation, the optimal simultaneous point for the three conducted analyses were 20% of rice flour, 30% of cassava starch, and 50% of maize starch. A comparative analysis of specific volume, elasticity, firmness, and triangular test was performed with pre-baked, baked, and frozen bread. Physicochemical, nutritional, and microbiological analyses were performed for both bread and muffin according to the Brazilian legislation.

Composition dependence of in high-vinyl polybutadiene/ cis-polyisoprene blends studied by means of positron annihilation lifetime spectroscopy

The positron annihilation lifetime spectroscopy (PALS) and differential scanning calorimetry (DSC) techniques were utilized to study high-vinyl polybutadiene (HVBD)/ cis-polyisoprene (CPI) blends. A single DSC glass transition temperature is observed, whose composition dependence strongly deviates from additivity, showing an apparent cusp when the weight fraction of HVBD . The orthopositronium (o-Ps) intensities, , and lifetimes, , obtained from PALS were used to determine the free-volume hole size, , and the scaled fractional free volume, . In the glass, and are smaller for CPI than for HVBD, but the thermal expansion coefficient for the hole volume, , is larger for CPI than for HVBD in the melt; thus, an iso-hole-volume temperature occurs in these blends at . Using free-volume quantities obtained from PALS, a quantitative interpretation of the cusp in the composition dependence of can be obtained, via a modified version of the analysis of Kovacs, from which we assume that the free volume of the high- component becomes constant. Specific volume analysis was also performed on the pure materials, from which the fractional free volume at room temperature, and hence the values of the scaling constants and , are obtained. This enables us to determine that the free volume of the high- component `freezes in' at a particular value intermediate between those of the pure components at their respective s

The inquiry into the reliability of the specific volume analysis by means of hardness testing

As the survey on the change of spesific volume makes it possible to analyse the change which takes place inside the material, this method was tried to examine the aging phenomenon of aluminium alloys, as a method in industrial operation. As the resultof this study, it was found that this method can be successfully used for this purpose.10 sorts of specimens such as 1S, 2S, 3S, 17S etc., on which the change in specific volume had already been known by previous study, were applied for this experiment, where in the tempered aging was made for them under the increasing temperature from 20°C to 400°C. The change in vickers hardness and knoop hardness under different temperature were measured and the relation between change in hardness and specific volume analysis was studied.As the result of the experiment, the specific volume analysis was quit reliable as a method for examining the aging in aluminium alloys. The result was also carefully studied from the viewpoint of the knoop ratio.

Some experiment on the aging of Al-Cu alloy by means of specific volume analysis

The authors repoted previously that the specific volume analysis could be applied to the industrial method for analysing the aging mechanism in aluminium alloys. In this paper, details of the experimental study are reported as a continuation of previous report, on the aging of three sorts of Al-Cu alloy, i. e. 3.116% Cu, 4.240% Cu and 6.200 Cu, the internal change of which was investigated well by H. K. Hardy and others, by means of specific volume analysis.The experiments are pursued just like those in the previous report, that is, after being kept at 500-520°C for 30 minutes, the specimens are quenched in water and recieve the temperd aging for a long time at the prescribed temperature, and then the change of specific volume is pursued. And further the specific volume analyses are applied on the aging at raised temperature of the quenched specimens and the aging (at 20°C) of the rehardened specimens which are quenched into water from 200°C.We appreciate that this research has been done at the expence of the Grant-in-aid of the Scholarship from the Institute of Light Metal Foundation.

An experimental study on the aging of aluminium alloy by means of specific volume analysis

This paper deals with the experimental study on the aging of eight sorts of Al-alloy, e. g. 2S, 3S, 52S, 75S, Al-Cu-Sn alloy and so on, by means of specific volume analysis. The specimen of the standard dimension 10×10×20mm, is finished with a 04 emery paper as in the case of preparing the specimen for microscopy, polished with chromium oxide, and then its specific volume (significant figures: five figures) is measured by means of a precision chemical balance. After being kept in 500°C for 30 minutes, the specimens are quenched in water and temper aged for a long time at the prescribed temperature (seven degrees of 20, 80, 120, 150, 180, 200 and 220°C tempering). Then the changes of specific volume are pursued. Furthermore, some interesting results in the change of specific volume were obtained when the quenched specimens were aged in rising temperature.We add that this research owes its expence to the Grant-in-aid of the Scholarship of the Institute of Light Metal Foundation.