DIVERSITY OF PERCEPTIONS OF MEAT TENDERNESS AND JUICINESS BY CONSUMERS: A TIME-INTENSITY STUDY

Seven judges, untrained in sensory assessment, were trained in the use of Time Intensity (TI) and asked to monitor the tenderness and juiciness of a range of cooked beef and pork samples. The subjects were given no definitions concerning sensory cues to monitor in their assessments, nor did they confer with each other. The shapes of the TI curves they recorded for tenderness and juiciness differed between individuals, although there were similarities in the curve shapes for the 2 attributes for each individual. Correlations between the intensity parameters of the curves (maximum intensity and area under curve) and the chewing time were not significant for the subjects as a group for tenderness, although significant correlations were found for some of the subjects when examined individually. The results indicate that subjects differ in their concepts of sensory tenderness and juiciness, and that perceived tenderness does not correlate with chewing time for all subjects. In more general terms the study supports the use of TI assessments for interpreting individual differences in sensory perceptions.     

Texturization of Sweetened Mango Pulp: Optimization using Response Surface Methodology

Sugar added mango pulp was texturized with alginate. To optimize both the mechanical properties and thermostability of the products, an experimental design was used combined with response surface methodology. Alginate concentration was the major factor affecting mechanical properties of texturized pieces with higher strength as the gelling agent concentration increased. Furthermore, gel strength and thermostability generally increased as calcium and glucono-δ-lactone concentrations, and/or heat treatment duration increased. As large quantities of sweetened pulp were used, texturized pieces with high dry matter content and good flavor qualities were obtained.     

A Distributed and Cooperative Environment for Computer Algebra

In this paper, we describe theCentral Control, a software component that enables several symbolic systems to cooperate and exchange data. The Central Control has been designed to be the kernel of an environment for scientific computations which can offer a common and concurrent access to several tools needed by the scientist and the engineer: general purpose and specialized computer algebra systems, visualization tools, links with numerical libraries and tools to manipulate numerical programsetc. The user can interact with the Central Control through one or more (graphical) user interfaces. The Central Control achieves its goals by requiring as little as possible from the tools and by using a particular programming language to provide a unified view for the objects and the operations performed by the connected tools. The Central Control will be used as the basis of theComprehensive Solverthat will provide common access to all the programs developed within the project. We give a simple example of an actual use of the Central Control for computing primary decompositions of ideals.     

EXPERIMENTAL AND NUMERICAL STUDY OF THE PARTICLE FLUCTUATING MOTION INDUCED BY COLLISIONS BETWEEN PARTICLES IN A VERTICAL GAS-SOLID FLOW

ABSTRACT

The effect of interparticle collisions on the gravitational motion of large particles in a vertical convergent channel is experimentally and numerically investigated. A probabilistic collision model is implemented in a three-dimensional Monte Carlo type Lagrangian simulation code. The numerical predictions are compared to the experimental results. It is shown that an interparticle collision model is necessary to reproduce the experimentally observed particle fluctuating motion characteristics. The simulation results using the present probabilistic collision model are found to yield satisfactory agreement with experimental observations, even though the collision frequency seems to be slightly overestimated. In particular, reduction of initial anisotropy of the particle fluctuating motion with increasing particulate mass flow rate is well reproduced by the simulation. A rather good agreement is also observed between experimental results and quantitative predictions of statistical properties of the flow such as particle axial and transverse velocity distributions and standard deviations.     

Comparison of Spray-drying, Drum-drying and Freeze-drying for β-Carotene Encapsulation and Preservation

Pure β-carotene was encapsulated in 25 Dextrose Equivalent maltodextrin by three drying processes (spray, freeze and drum). Stability was studied at 11% and 32% RH and 25°C, 35°C and 45°C. No significant influence of %RH was observed on the retention of β-carotene. Oxidation followed first order kinetics with an initial fast first order reaction followed by a second much slower first order reaction period. Although drum-drying caused more initial loss in drying, the lower surface carotenoids and larger particle size resulted in greater stability as compared to the other methods. The chromametric measurements of “L” and “a” corresponded to the other kinetics and indicated that the first period rapid loss corresponded to the oxidation of surface carotenoids.     

纵向通风隧道内火灾烟气流动的控制

讨论了纵向通风隧道火灾和相关烟气形成现象。利用计算机流体动力模型模拟烟气流动，获得可以与试验数据进行比较的预测结果。在Richardson数字基础上，采用了不同参考稳定值，结果发现，直接利用火灾热释放速率所获得的温度值会产生最有用的结果。试验结果与数值预测结果的比较发现，两者吻合较好。笔者验证了利用容积测定火源模拟火灾的情况。结果的准确性很大程度上取决于对墙和屋顶的热传递。     

Water vapour permeability of edible bilayer films of wheat gluten and lipids

Various formulations and methods of fabricating edible bilayer films consisting of wheat gluten as a structural layer and a thin lipid layer as a moisture barrier were investigated and examined for water vapour permeability. Solid lipids such as beeswax or paraffin wax deposited in a molten state onto the base film were the most effective water vapour barriers. A film consisting of wheat gluten, glycerol and diacetyl tartaric ester of monoglyceride as one layer, and beeswax as the other yielded a water vapour permeability of 0.0048 g mm m⁻² mmHg⁻¹ 24h⁻¹, which was less than that obtained with low density polyethylene.     

Mass transfer phenomena during osmotic dehydration of apple II. Frozen plant tissue

In Part 1, mass transfer phenomena during osmotic dehydration of fresh apple tissue were qualitatively interpreted in terms of simultaneous osmotic and diffusive effects. This second part gives results obtained with frozen apple tissue, using the same experimental procedures with response-surface methodology and microscopic analysis. Results indicated that transfers were only diffusive and confirmed that high molecular weight solutes were the most effective in forming a dense solute barrier layer at the surface of the product, thus enhancing the dewatering effect during soaking treatment in the concentrated solution.     

Illumination conditions in microsphere-assisted microscopy

White-light microsphere-assisted microscopy is a full-field and label-free imaging promising technique making it possible to achieve a subdiffraction lateral resolution. However, performance of this technique depends not only on the geometrical parameters but also on the illumination conditions of the optical system. In the present work, experimental measurements and computer simulations have been performed in air in order to determine the influence of the two diaphragm apertures of the Köhler arrangement and the spectral width of the light source on both the depth-of-focus of the microsphere and the optimization of the imaging contrast. Furthermore, the super-resolution phenomenon is demonstrated and the cumulated optical aberrations are shown through the measurement of the optical transfer function for the different arrangements of the illumination part.