Efeito do processamento de defumação na qualidade de bijupirá (Rachycentron canadum): atributos bacteriológicos, químicos e sensoriais / Effect of smoking-method on the keeping quality of cobia (Rachycentron canadum): bacteriological, chemical and sensory attributes

O objetivo do presente trabalho foi desenvolver a carne de bijupirá defumada, assim como avaliar o rendimento, a qualidade bacteriológica, a composição centesimal e a aceitabilidade do produto. Análises microbiológicas de pesquisa de Salmonella sp. e contagens de Staphylococcus aureus, coliformes totais e Escherichia coli foram realizadas. Foi determinada a composição centesimal e realizado o teste de aceitação do produto. O rendimento médio da carne após a salga foi de 83,41%, com base no peso do charuto. A análise microbiológica da carne defumada apresentou-se positiva em apenas uma amostra para Staphylococcus aureus e negativa para as demais bactérias. O produto possui boa qualidade nutricional e alcançou 97% de aceitação para o aspecto global, atingindo média de 6,26 (± 0,99). A carne de bijupirá defumada obteve condições higiênico-sanitárias satisfatórias, boa qualidade nutricional, além de alto índice de aceitação sensorial, destacando-se os atributos textura e sabor. Evidenciou-se, assim, que esse tipo de processo pode ser realizado em escala artesanal ou industrial.(AU)

The objective of the study was to develop the smoked cobia meat and to evaluate the yield, the bacteriological quality, the centesimal composition, and the acceptability of the product. Microbiological analysis of Salmonella sp. and Staphylococcus aureus, total coliforms and Escherichia coli counts were performed. The centesimal composition was determined and the acceptance test was performed. The average yield of the product after salting was 83.41% based on the fish roll weight. The microbiological analysis of the smoked meat showed positive in only one sample for Staphylococcus aureus and negative for the other bacteria. The product has a good nutritional quality and was accepted obtaining 97% for the overall aspect, average of 6.26 (± 0.99). The smoked cobia meat obtained satisfactory hygienic-sanitary conditions, good nutritional quality, besides a high index of sensorial acceptance emphasizing the texture and flavor attributes. Smoked process can be easily carried out on an artisanal or industrial scale.(AU)

Contactless Investigation of Dielectric Samples with a High-Q Millimeter-Wave Sensor.

Experiments using an on-chip sensor in silicon technology for dielectric measurements at 120 GHz are presented. The passive sensor element, a coplanar strip line (CPS) bandpass filter, consists of a combination of short-ended T-stubs placed inside a CPS, yielding a resonant transmission behavior of the sensor. The high quality factor of this bandpass filter is achieved by both: using edge-coupled lines and removing the substrate beneath the transducer by silicon back-side etching. Measurements showed that the unloaded transducer exhibits a quality factor of 11. The sensor is applied to characterize the cultivation progress of yeast in a glucose medium. Sparameter measurements using RF probes show a recorded S21 center frequency that shifts from 124GHz to 125GHz within 22 hours of cultivation. The typical dynamic behavior and cultivation phases of yeast are confirmed by millimeter-wave monitoring the cell culture. Experiments prove that detection and characterization of dielectric samples in small volumes can be performed without contact to the sample and label-free.

Self-calibrating highly sensitive dynamic capacitance sensor: towards rapid sensing and counting of particles in laminar flow systems.

In this report we propose a sensor architecture and a corresponding read-out technique on silicon for the detection of dynamic capacitance change. This approach can be applied to rapid particle counting and single particle sensing in a fluidic system. The sensing principle is based on capacitance variation of an interdigitated electrode (IDE) structure embedded in an oscillator circuit. The capacitance scaling of the IDE results in frequency modulation of the oscillator. A demodulator architecture is employed to provide a read-out of the frequency modulation caused by the capacitance change. A self-calibrating technique is employed at the read-out amplifier stage. The capacitance variation of the IDE due to particle flow causing frequency modulation and the corresponding demodulator read-out has been analytically modelled. Experimental verification of the established model and the functionality of the sensor chip were shown using a modulating capacitor independent of fluidic integration. The initial results show that the sensor is capable of detecting frequency changes of the order of 100 parts per million (PPM), which translates to a shift of 1.43 MHz at 14.3 GHz operating frequency. It is also shown that a capacitance change every 3 µs can be accurately detected.

Label free sensing of creatinine using a 6 GHz CMOS near-field dielectric immunosensor.

In this work we present a CMOS high frequency direct immunosensor operating at 6 GHz (C-band) for label free determination of creatinine. The sensor is fabricated in standard 0.13 µm SiGe:C BiCMOS process. The report also demonstrates the ability to immobilize creatinine molecules on a Si3N4 passivation layer of the standard BiCMOS/CMOS process, therefore, evading any further need of cumbersome post processing of the fabricated sensor chip. The sensor is based on capacitive detection of the amount of non-creatinine bound antibodies binding to an immobilized creatinine layer on the passivated sensor. The chip bound antibody amount in turn corresponds indirectly to the creatinine concentration used in the incubation phase. The determination of creatinine in the concentration range of 0.88-880 µM is successfully demonstrated in this work. A sensitivity of 35 MHz/10 fold increase in creatinine concentration (during incubation) at the centre frequency of 6 GHz is gained by the immunosensor. The results are compared with a standard optical measurement technique and the dynamic range and sensitivity is of the order of the established optical indication technique. The C-band immunosensor chip comprising an area of 0.3 mm(2) reduces the sensing area considerably, therefore, requiring a sample volume as low as 2 µl. The small analyte sample volume and label free approach also reduce the experimental costs in addition to the low fabrication costs offered by the batch fabrication technique of CMOS/BiCMOS process.

Terahertz gas-phase spectroscopy: chemometrics for security and medical applications.

We describe a spectrometer consisting of a vector network analyzer, a gas absorption cell, and a quasi-optical bench that acquires terahertz spectra of gaseous substances and mixtures. We tested volatile organic compounds that are medical biomarkers or chemicals which can be found on the US Environment Protection Agency list of harmful substances. Absorption spectra at gas pressures between 10 Pa and 5000 Pa were recorded. A subsequent multivariate data analysis demonstrated excellent qualitative and quantitative identification of pure substances and complex mixtures. The applied multivariate algorithms are principal components analysis, partial least square regression and soft independent modelling of class analogy.

Problems encountered by parents and guardians of elementary school-age children in obtaining immunizations.

This study surveyed 265 parents of children in kindergarten through third grade in an urban New Jersey public school to determine problems encountered in obtaining regular immunizations. The most frequent reasons parents failed to obtain immunizations were cost, lesser use of WIC and AFDC, and lower perceived susceptibility of child to consequences of disease.

Nutritional beliefs and practices of adolescent athletes.

Recent research suggests that the adolescent athlete is neither aware of nor prepared for the dual demands of sound nutritional practices in general and those demanded by his or her chosen sport activities. The dietary practices of young athletes fail to meet the energy requirements for high performance and may also threaten their well-being. To ascertain the dietary practices and beliefs of an adolescent athlete population, a survey was conducted among high school students who were engaged in at least one sport. The results show that students were consuming excessive fats and sugars, and failed to recognize nutritional practices critical to the demands of athletics.