Comparative Study of Quality Changes Occurring on Dehydration and Rehydration of Cooked Chickpeas (Cicer Arietinum L.) Subjected to Combined Microwave–Convective and Convective Hot Air Dehydration

ABSTRACT:  Convective hot air dehydration (100 °C) of cooked chickpeas was compared with the combination of microwave–convective hot air dehydration, in terms of microstructure, density, color, texture, dehydration, and rehydration. In the combined drying experiments, 2 levels of microwave power (100 W and 200 W) were investigated, combined continuously with convective air drying at 100 °C. Compared with convective hot air drying, combination drying led to a considerable reduction in dehydration time. Combination drying also improved the porosity of the finished dehydrated product, leading to faster rehydration kinetics. Cryogenic scanning electron microscopy micrographs showed that chickpeas subjected to combined drying experienced less shrinkage than those dried by convective hot air. Combination drying at the higher (200 W) level produced a darker ( P < 0.05) rehydrated product with significantly lower relative rehydrated moisture content ( P < 0.05) when compared with the lower (100 W) level of combination drying.     

Rapid detection of aflatoxin-producing strains of the Aspergillus flavus group isolated from mixed feed and cereal grain in Spain

A total of 133 samples (mixed feeds and cereal grains) were examined in order to detect the incidence of strains of the Aspergillus flavus group. The ability to produce aflatoxin was tested in all strains isolated on cracked rice, aflatoxin-producing-ability (APA) medium and glucose-yeast extract agar (GYA) medium. Ten out of the 67 isolations were aflatoxin-producing strains in rice and GYA medium; only three of them were aflatoxin-positive on the APA test. Of those isolated 95% were identified as A. flavus. The GYA medium is the most efficient and easiest way to detect B₁, B₂, G₁ and G₂ aflatoxin-producing-strains.     

Emotional and cognitive adjustment in abused children

Research on the impact of maltreatment on children has increased in the last years, as there is a need to design appropriate treatment strategies. Social, cognitive, and emotional areas may be affected in these children. This research is aimed to study the psychological functioning of child victims, particularly in their emotional and cognitive adjustment. Nineteen children (10.3 years old) with case histories of at least 2 years of physical and emotional parental abuse and a group of 26 nonmaltreated children (9.4 years old) matched in socio-economic characteristics and coming from the same community area were compared in depressive symptomatology and attributional style by using the standardized measures from Kovacs' Children's Depression Inventory (CDI) and Kaslow's Children Attributional Style Questionnaire (CASQ). General and detailed statistical analyses on the emotional and cognitive areas assessed showed significant differences between groups. Child victims showed greater feelings of sadness, lower self-esteem and self-worth, and they perceived the aversive events in their lives as unpredictable which generated helplessness. This is a result of their lack of control of those aversive events. Results are contrasted with those obtained by other researchers who used similar methodology and are discussed in terms of the learned helplessness' model proposed and developed by Seligman, Kaslow, Alloy, Peterson, Tanenbaum, and Abramson (1984). Implications for the child abuse victims' emotional and cognitive rehabilitation are also analyzed and discussed.     

Natural fermentation of lentils Influence of time, concentration and temperature on protein content, trypsin inhibitor activity and phenolic compound content

Lentil (Lens culinaris var. vulgaris) flour was naturally fermented for 4 days at different temperatures (28°C, 35°C and 42°C) and concentrations (79 g/1, 150 g/1 and 221 g/1). Samples were analysed to establish the changes of total protein content and in vitro protein digestibility, trypsin inhibitor activity (TIA) and phenolic compound content during natural fermentation of lentils. The preparation of lentil flour suspensions to be fermented caused a slight increase in total protein and in vitro protein digestibility content, a decrease of TIA and a sharp decrease the tannin/catechin ratio. During the whole fermentation procedure, the minimum initial lentil concentration and temperature used (79 g/1, 28°C) achieved the maximum protein content and the lowest tannin/catechin ratio. The TIA was more affected by temperature than by concentration, and a 62.5% reduction was observed at 42°C and 79 g/1.     

Nanocomposites from plasticized high‐amylopectin,normal and high‐amylose maize starches

Three types of maize starch with different amounts of amylose and amylopectin were used to prepare plasticized starch/clay nanocomposite films by casting. Studies by X‐ray diffraction (XRD) and transmission electron microscopy (TEM) indicated that the intercalation/exfoliation of the plasticized starch molecules took place into the clay galleries for the three types of starch. However, the plasticized waxy starch molecules were the easiest of them all to be intercalated/exfoliated, which was reflected in the highest increment of the stress at peak of these nanocomposites. Moreover, the lowest water uptake was showed by the plasticized high‐amylose starch/clay nanocomposites. It was concluded that varying contents of amylose and amylopectin influenced the formation of intercalated/exfoliated clay structures and also affected the interactions of clay with water. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Relationship of personal exposure to volatile organic compounds to home, work and fixed site outdoor concentrations

Personal exposures of 100 adult non-smokers living in the UK, as well as home and workplace microenvironment concentrations of 15 volatile organic compounds were investigated. The strength of the association between personal exposure and indoor home and workplace concentrations as well as with central site ambient air concentrations in medium to low pollution areas was assessed. Home microenvironment concentrations were strongly associated with personal exposures indicating that the home is the driving factor determining personal exposures to VOCs, explaining between 11 and 75% of the total variability. Workplace and central site ambient concentrations were less correlated with the corresponding personal concentrations, explaining up to 11-22% of the variability only at the low exposure end of the concentration range (e.g. benzene concentrations < 2.5 μg m⁻³). One of the reasons for the discrepancies between personal exposures and central site data was that the latter does not account for exposure due to personal activities (e.g. commuting, painting). A moderate effect of season on the strength of the association between personal exposure and ambient concentrations was found. This needs to be taken into account when using fixed site measurements to infer exposures.     

Density of Electron States and Volume of Solution of Hydrogen in SiC Alloys

The new reactor concepts are characterized by higher efficiency, better utilization of nuclear fuel and nuclear waste minimization. This approach means that it is necessary to continue a continued research and test of new materials in order to apply them in new reactors. In this study, the authors fbcused on the analysis of SiC alloys because, due to their particular properties, this alloy can be used in high temperature conditions where the pure silicon, semiconductor material par excellence, is inadequate to support them.     

Modification of a Nafion membrane by n-dodecyltrimethylammonium cation inclusion for potential application in DMFC

Changes in a protonated Nafion-112 membrane as a result of the incorporation of the cation n-dodecyltrimethylammonium (DTA⁺) by proton exchange mechanism are studied. Membrane surface modifications were analysed by AFM, XPS and contact angle measurements in order to obtain information about changes in the membrane surface roughness, chemical nature and hydrophobic character, while electrochemical impedance spectroscopy (EIS) and methanol permeation measurements were carried out to establish changes in the bulk membrane. The reduction obtained for the surface roughness and the hydrophobic character of Nafion-112/DTA⁺ equilibrated membrane as well as for the fluorine atomic concentration percentage and the increase in nitrogen percentage indicates modification of Nafion-112 membrane surface, while the increase of electrical resistance and the decrease of methanol permeability give information on bulk membrane changes. The higher thermal stability and lower water loss of the Nafion-112/DTA⁺ membrane are points of interest for applications such as PEMFC or DMFCs, respectively.