Airborne ultrasonic application on hot air-drying of pork liver. Intensification of moisture transport and impact on protein solubility.

Nowadays, there is increasing interest in developing strategies for the efficient and sustainable use of animal by-products, such as pork liver. In order to stabilize the product, a prior dehydration stage may be required due to its high perishability. The water removal process of pork liver is energy costly and time consuming, which justifies its intensification using novel technologies. In this sense, the aim of this study was to assess the effect of the airborne application of power ultrasound on the hot air-drying of pork liver. For that purpose, drying experiments were carried out at 30, 40, 50, 60 and 70 °C on pork liver cylinders at 2 m·s-1 with (US) and without ultrasonic application (AIR). The drying process was modeled from the diffusion theory and, in the dried pork liver, the protein solubility was analyzed in order to determine the effect of drying on the protein quality. The ultrasound application increased the drying rate, shortening the drying time by up to 40% at 30 °C. The effect of power ultrasound at high temperatures (60 and 70 °C) was of lesser magnitude. Drying at 70 °C involved a noticeable reduction in the protein solubility for dried liver, while the impact of ultrasound application on the solubility was not significant (p > 0.05).

Intensification of heat transfer during mild thermal treatment of dry-cured ham by using airborne ultrasound.

The application of power ultrasound (PuS) could be used as a novel technology with which to intensify thermal treatments using hot air. Mild thermal treatments have been applied to improve the soft texture of dry-cured ham caused by defective processing. In this regard, the aim of this study was to assess the kinetic intensification linked to the application of airborne PuS in the mild thermal treatment using hot air of dry-cured ham. For this purpose, vacuum packed cylindrical samples (2.52±0.11cm in diameter and 1.90±0.14cm in height) of dry-cured ham were heated using hot air at different temperatures (40, 45, 50°C) and air velocities (1, 2, 3, 4, 6m/s) with (22.3kHz, 50W) and without PuS application. Heat transfer was analyzed by considering that it was entirely controlled by conduction and the apparent thermal diffusivity was identified by fitting the model to the heating kinetics. The obtained results revealed that PuS application sped up the heat transfer, showing an increase in the apparent thermal diffusivity (up to 37%). The improvement in the apparent thermal diffusivity produced by PuS application was greater at high temperatures (50°C) but negligible at high air velocities (6m/s). Heating caused an increase in the hardness and elasticity of dry-cured ham, which would correct ham pastiness defects, while the influence of PuS on such textural parameters was negligible.

Obesity and extent of emphysema depicted at CT.

AIM: To investigate the underlying relationship between obesity and the extent of emphysema depicted at CT. METHODS AND MATERIALS: A dataset of 477 CT examinations was retrospectively collected from a study of chronic obstructive pulmonary disease (COPD). The low attenuation areas (LAAs; ≤950 HU) of the lungs were identified. The extent of emphysema (denoted as %LAA) was defined as the percentage of LAA divided by the lung volume. The association between log-transformed %LAA and body mass index (BMI) adjusted for age, sex, the forced expiratory volume in one second as percent predicted value (FEV1% predicted), and smoking history (pack years) was assessed using multiple linear regression analysis. RESULTS: After adjusting for age, gender, smoking history, and FEV1% predicted, BMI was negatively associated with severe emphysema in patients with COPD. Specifically, one unit increase in BMI is associated with a 0.93-fold change (95% CI: 0.91-0.96, p<0.001) in %LAA; the estimated %LAA for males was 1.75 (95% CI: 1.36-2.26, p<0.001) times that of females; per 10% increase in FEV1% predicated is associated with a 0.72-fold change (95% CI: 0.69-0.76, p<0.001) in %LAA. CONCLUSION: Increasing obesity is negatively associated with severity of emphysema independent of gender, age, and smoking history.

Modelling drying kinetics of thyme (Thymus vulgaris L.): theoretical and empirical models, and neural networks.

The drying kinetics of thyme was analyzed by considering different conditions: air temperature of between 40°C and 70°C , and air velocity of 1 m/s. A theoretical diffusion model and eight different empirical models were fitted to the experimental data. From the theoretical model application, the effective diffusivity per unit area of the thyme was estimated (between 3.68 × 10(-5) and 2.12 × 10 (-4) s(-1)). The temperature dependence of the effective diffusivity was described by the Arrhenius relationship with activation energy of 49.42 kJ/mol. Eight different empirical models were fitted to the experimental data. Additionally, the dependence of the parameters of each model on the drying temperature was determined, obtaining equations that allow estimating the evolution of the moisture content at any temperature in the established range. Furthermore, artificial neural networks were developed and compared with the theoretical and empirical models using the percentage of the relative errors and the explained variance. The artificial neural networks were found to be more accurate predictors of moisture evolution with VAR ≥ 99.3% and ER ≤ 8.7%.

Modeling of the process of moisture loss during the storage of dried apricots.

Moisture content is a reference parameter for dried food because the growth of most microorganisms is inhibited below certain water activity levels. In addition, it has a determining influence on the evolution of important parameters, such as color and flavor, and on other properties and deterioration reactions, such as texture, oxidation processes and nutritional value. During the storage of some dried fruits, moisture is produced due to Maillard reactions and exchanged with the surrounding environment through the packaging. The evolution of dried foods during their shelf life depends on the storage conditions. The aim of this study is to analyze the evolution of the moisture content in dried apricots packaged in different types of containers, namely glass and thermosealed polypropylene trays. The samples were stored at constant temperatures: 5, 15, 25 and 35 °C and were analyzed periodically over a period of 12 months. The sorption isotherms of apricots used in this study were also determined. In order to model how the moisture evolved, an empirical kinetic model was tested. This model considers both water transfer from the fruit and also water production as a result of the Maillard processes. The explained variance was higher than 95% in the samples stored in trays, which were thermosealed with film.

Drying modelling of defrosted pork meat under forced convection conditions.

Drying is the lengthiest and the most energy consuming step during the production of dry-cured ham, affecting also the curing process and consequently product quality. In order to manage the drying process, it is quite interesting to establish the complexity of model needed. For that purpose, pork meat cylinders (Biceps femoris and Semimembranosus muscles) were dehydrated under forced convection conditions (25°C and air velocity 0.6±0.1, 2.0±0.1 and 2.8±0.1 m/s). Experimental drying kinetics were modelled by means of 4 diffusion models: model 1 (not considering shrinkage and no external resistance), model 2 (considering shrinkage and no external resistance), model 3 (not considering shrinkage and considering external resistance) and model 4 (considering both shrinkage and external resistance). From the effective diffusivity values identified, it was concluded that when external resistance was negligible (air velocity 2.0±0.1 and 2.8±0.1 m/s), the results obtained for D(e) with the four models were the same. Nevertheless, when external resistance was not negligible (0.6±0.1 m/s) the D(e) identified was influenced by the model due to the fact that models 1 and 2 neglect that resistance and for that reason they do not describe experimental conditions properly. The effect of shrinkage did not influence the identified D(e) values for the drying conditions considered. In order to model water losses in meat curing chambers, external resistance must be considered.

Desorption isotherms and isosteric heat of desorption of previously frozen raw pork meat.

Some meat products involve drying previously frozen pork meat, which makes the knowledge of sorption characteristics very important for the design and management of meat dehydration processes. The sorption isotherms of raw pork meat from the Biceps femoris and Semimembranosus muscles were determined at four temperatures: 25, 30, 35 and 40°C. The experimental results were modelled using the GAB (Guggenheim, Anderson and De Boer) model. The effect of temperature was also taken into account to model the experimental sorption isotherms using four models (GAB, Oswin, Halsey and Henderson). The best results were provided by the GAB model. From the experimental sorption isotherms the isosteric heats of sorption were determined. For a moisture content higher than 0.15kgwater/kgdm, the isosteric heat of meat was similar to the latent heat of vaporization for pure water. For a lower moisture content, an increase in the isosteric heat was observed when the moisture content decreased.

High intensity ultrasound effects on meat brining.

Pork loin (longissimus dorsi) samples of two different geometries, cylinders and slabs, were immersed in saturated NaCl brine for 45min under different conditions: without brine agitation (STAT), with brine agitation (AG) and with ultrasound application (US) at eight levels of ultrasonic intensity. Moisture content change and NaCl gain were considered in order to evaluate the difference in the brining treatments. No significant differences were found in moisture and NaCl content of samples treated under STAT conditions and AG conditions, while the influence of ultrasound on the mass transfer process during meat brining depended on the intensity applied. There was an ultrasonic intensity threshold above which the influence of ultrasound appeared. At the highest level of intensity studied, the water content of samples was significantly higher than the initial water content of meat. As regards NaCl transfer, once above the intensity threshold, the increase in the NaCl content was proportional to the applied ultrasonic intensity. Not statistically significant differences were found for sample geometry.

Ordering properties of convolutions of exponential random variables.

Convolutions of independent random variables are usually compared. In this paper, after a synthetic comparison with respect to hazard rate ordering between sums of independent exponential random variables, we focus on the special case where one sum is identically distributed. So, for a given sum of n independent exponential random variables, we deduce the "best" Erlang-n bounds, with respect to each of the usual orderings: mean ordering, stochastic ordering, hazard rate ordering and likelihood ratio ordering.

Molecular analysis of lytic genes of bacteriophage 80 alpha of Staphylococcus aureus.

Nucleotide sequencing of a 3779-bp fragment of the Staphylococcus aureus bacteriophage 80 alpha revealed two open reading frames: ORF1, designated as lytA, which encodes a polypeptide of 481 amino acids with an apparent M(r) of 53.81 kDa; and ORF2, designated as holin, which encodes for a hydrophobic polypeptide of 145 amino acids with an apparent M(r) of 15.58 kDa and exhibits two putative transmembrane helices. Both genes showed 100% sequence homology to that of the peptidoglycan hydrolase and holin genes of the S. aureus phage phi 11 reported earlier. In addition, the downstream sequences of the lytA gene were homologous to the phage attachment site (attP) of the phage phi 11. Based on our data we propose that the lytic system of the phage 80 alpha evolved from that of phage phi 11.

[Neuromyelopathy in the population of Noir-marron of Saint-Laurent du Maroni in French Guiana]. / Neuromyélopathies dans la population de Noirs marrons de Saint-Laurent du Maroni en Guyane française.

The neurological observations have been reported at André Bouron Hospital of Saint-Laurent du Maroni and at General Hospital of Cayenne during a period of 5 years. All patients belonged to the "Noir Marron" ethnic group and lived in the area of Saint-Laurent. There were six women and four men, aged 15-35 years. Neurological symptoms were isolated or associated to other organ failure. Neurological manifestations included retrobulbar optic neuropathy, spastic paraparesis, sensitive ataxia and cerebellar ataxia, psychiatric symptoms were observed. Other organs affected were cardiovascular, digestive, cutaneous or endocrinologic (thyroid). Diet consist mainly in cassava. Thiamin deficiency has been observed several times. Improvement of neurological deficits following thiamin administration points towards Thiamin as an etiological factor. Ethnological specificity of Saint-Laurent area may explain that such neurological manifestation have not been observed in the rest of the department.

Place des urgences medicales pediatriques dans un service medical a Pointe Noire

Les auteurs etudient les urgences medicales pediatriques chez les enfants ages de 0 a 15 ans dans un centre medico-social a Pointe Noire sur une periode de 5 ans (1988-1992). Ils constatent que les urgences medicales pediatriques representent 18;54 pour cent des admissions. Les principaux groupes etiologiques de ces detresses vitales sont par ordre de frequence les suivants: les urgences neurologiques (331 cas soit 52 pour cent); les urgences respiratoires (137 cas soit 21;5 pour cent); les urgences hematologiques (81 cas soit 12;70 cas) et les urgences gastro-enterologiques (73 cas soit 11;50 pour cent). Les autres urgences medicales pediatriques (etats infectieux severes: rougeoles; septicemies; urgences cardiologiques et les intoxications medicamenteuses severes) representent 2;30 pour cent des cas. La prevention des principales causes de ces detresses vitales; avant que les strategies preconisees par les soins de sante primaires et l'initiative de Bamako soient la cle de voute du systeme sanitaire dans notre region; passe par une education constante pour la sante

Ingestions accidentelles de produits toxiques chez l'enfant : a propos de 308 cas observes au centre medico-social d'Elf Congo; Pointe-Noire

A partir de 308 cas d'intoxications colliges en 6 ans chez l'enfant de 0 a 5 ans; les auteurs ont evalue a 6;3 pour cent la frequence hospitaliere de cette pathologie. Les toxiques les plus souvent en cause etaient le petrole : 213 cas (69;2 pour cent) et les medicaments : 63 cas (20;4 pour cent). L'indigestion avait lieu au domicile familial dans 268 cas (87 pour cent) et le delai de prise en charge therapeutique etait compris entre 2 et 6 heures dans 55;8 pour cent. Les auteurs insistent sur la prevention des intoxications par l'education pour la sante

Contribution a l'etude des convulsions chez l'enfant : aspect [sic] epidemiologiques et cliniques : a propos de 275 observations (CMS Elf-Congo; Pointe-Noire

La crise convulsive; symptome tres frequent en pediatrie represente le type meme d'urgence parce qu'elle peut reveler une maladie necessitant un traitement immediat. Il est question ici d'une etude; realisee dans le CMS de Elf-Congo a Pointe-Noire; portant sur 275 cas de convulsions colliges dans le service du 1er novembre 1988 au 31 decembre 1990. Il ressort de cette etude que la frequence globale de ce symptome est de 3;2 pour cent des admissions pediatriques pendant cette periode; les nourrissons sont les plus touches (78;20 pour cent) et la manifestation clinique la plus frequente est la crise tonique. Ces resultats constituent donc un cri d'alarme pour une prevention du paludisme par une prophylaxie bien codifiee et correctement suivie; seule arme pour reduire les consequences de cette endemie tres meurtriere sous les tropiques