967 resultados para Processing methods


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Background To our knowledge, there is little study on the interaction between nutrient availability and molecular structure changes induced by different processing methods in dairy cattle. The objective of this study was to investigate the effect of heat processing methods on interaction between nutrient availability and molecular structure in terms of functional groups that are related to protein and starch inherent structure of oat grains with two continued years and three replication of each year. Method The oat grains were kept as raw (control) or heated in an air-draft oven (dry roasting: DO) at 120 °C for 60 min and under microwave irradiation (MIO) for 6 min. The molecular structure features were revealed by vibrational infrared molecular spectroscopy. Results The results showed that rumen degradability of dry matter, protein and starch was significantly lower (P <0.05) for MIO compared to control and DO treatments. A higher protein α-helix to β-sheet and a lower amide I to starch area ratio were observed for MIO compared to DO and/or raw treatment. A negative correlation (−0.99, P < 0.01) was observed between α-helix or amide I to starch area ratio and dry matter. A positive correlation (0.99, P < 0.01) was found between protein β-sheet and crude protein. Conclusion The results reveal that oat grains are more sensitive to microwave irradiation than dry heating in terms of protein and starch molecular profile and nutrient availability in ruminants.

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Much of the bridge stock on major transport links in North America and Europe was constructed in the 1950s and 1960s and has since deteriorated or is carrying loads far in excess of the original design loads. Structural Health Monitoring Systems (SHM) can provide valuable information on the bridge capacity but the application of such systems is currently limited by access and bridge type. This paper investigates the use of computer vision systems for SHM. A series of field tests have been carried out to test the accuracy of displacement measurements using contactless methods. A video image of each test was processed using a modified version of the optical flow tracking method to track displacement. These results have been validated with an established measurement method using linear variable differential transformers (LVDTs). The results obtained from the algorithm provided an accurate comparison with the validation measurements. The calculated displacements agree within 2% of the verified LVDT measurements, a number of post processing methods were then applied to attempt to reduce this error.

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Groundnut cake (GNC) meal is an important source of dietary protein for domestic animals with a cost advantage over the conventional animal protein sources used in aquaculture feed production. It would be useful to evaluate the effects of GNC processing methods on the density and nutritional values of processed GNC meals. The use of processed GNC meals in the diets of Clarias gariepinus fingerlings was evaluated. Seven iso-proteic and iso-caloric diets were formulated, replacing fish meal with roasted and boiled GNC meals, each at three inclusion levels of 30%, 35%, and 40%. Diet I is 100% fishmeal, Diet II is 30% roasted GNC meal, Diet III is 35% roasted GNC meal, Diet IV is 40% roasted GNC meal, Diet V is 30% boiled GNC meal, Diet VI is 35% boiled GNC meal and Diet VII is 40% boiled GNC meal. Results showed that the crude protein content of GNC meals was 40.5% and 40.8% in boiled and roasted GNC meals respectively; the lower protein content for processed GNC meals might be due to heat denaturation of the seed protein, with boiled GNC meal being more adversely affected. The mean weight gain of fingerlings fed roasted GNC meals ranged between 5.29 – 5.64 while for boiled GNC meals, it was between 4.60 – 5.22. Generally, fish performed better when fed diets containing roasted GNC meals, than boiled GNC meals, and compared favorably with fish fed fish meal based diet. Body mass increase, total feed increase, protein efficiency ratio and specific growth rate by C. gariepinus fingerlings in all diets, showed no significant differences, suggesting that processed GNC meals could partially replace diets for C. gariepinus fingerlings without adverse consequences. This study showed that processed GNC meals could partially replace fish meal up to 30% without significantly influencing fingerling growth and health. It is recommended that the use of fish meal as the main basal ingredient for fingerlings could be discontinued, since GNC meal was a cheaper alternative, and could replace fish meal up to 35%, without any significant adverse effects on the fingerling performance. KEYWORDS: Clarias gariepinus, Fingerlings, Groundnut cake meal, Nutrient utilization, Performance.

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A contaminação aleatória de alimentos por micotoxinas afeta as condições de sanidade das dietas de humanos e animais. Dentre as toxinas fúngicas, deoxinivalenol (DON) se destaca pela freqüente contaminação de produtos agrícolas e alimentos e pela sua resistência a degradação pelo emprego de métodos tradicionais de processamento, o que motiva políticas de controle e a busca por técnicas de descontaminação. A descontaminação biológica empregando processsos fermentativos tem sido apontada como uma alternativa promissora, pois permite degradar micotoxinas através do sistema enzimático microbiano e melhorar características funcionais e sensoriais de matérias-primas e insumos alimentícios. Este trabalho teve por objetivo estudar condições e mecanismos de biodegradação de deoxinivalenol empregando Aspergillus oryzae e Rhizopus sp. em sistemas fermentativos submersos. Para tanto, foi necessário adequar metodologia para reação de derivação na determinação cromatográfica de DON; estudar o potencial e condições de degradação via fermentação submersa por Aspergillus oryzae e Rhizopus sp.; e avaliar a atividade de oxidoredutases e a citotoxicidade dos extratos fementados. A otimização da metodologia estabeleceu a melhor condição para a reação de derivação com 200 µL de anidrido trifluoroacético e 18 mg de bicarbonato de sódio, durante 6 minutos a 74 °C na faixa entre 7 e 21 µg de DON. A quantificação de DON residual no meio fermentado mostrou que as espécies fúngicas Rhizopus sp. e Aspergillus oryzae possuem a capacidade de degradar DON demonstrando índices médios de 87,4 e 62,4% respectivamente, principalmente quando o meio submerso foi água estéril e fermentação realizada durante 48 horas. A velocidade máxima de degradação neste intervalo foi de 10,8 e 12,4 ppb/h, observando também um aumento na atividade específica da enzima peroxidase. Os extratos dos fermentados com A. oryzae e Rhizopus sp. apresentaram efeito de inibição de proliferação celular (IC50) quando concentrados 10 vezes em 48 e 72 horas respectivamente. Os meios fermentados com Rhizopus sp. apresentaram menor efeito (1,5 vezes) quando comparado com Aspergillus oryzae.

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Sardine oil is provided by the Dorosoma nasus Bloch, from the Clupeidae family, subfamily of Dorosomatinae. This note deals with a study on the sardine oil processing methods, physic-chemical composition and industrial uses.

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In this work, a platform to the conditioning, digitizing, visualization and recording of the EMG signals was developed. After the acquisition, the analysis can be done by signal processing techniques. The platform consists of two modules witch acquire electromyography (EMG) signals by surface electrodes, limit the interest frequency band, filter the power grid interference and digitalize the signals by the analogue-to- digital converter of the modules microcontroller. Thereby, the data are sent to the computer by the USB interface by the HID specification, displayed in real-time in graphical form and stored in files. As processing resources was implemented the operations of signal absolute value, the determination of effective value (RMS), Fourier analysis, digital filter (IIR) and the adaptive filter. Platform initial tests were performed with signal of lower and upper limbs with the aim to compare the EMG signal laterality. The open platform is intended to educational activities and academic research, allowing the addition of other processing methods that the researcher want to evaluate or other required analysis.

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The World Health Organization (WHO, 2005) recommends consumption of fruits and vegetables as part of a healthy diet with daily recommendation of 5 servings or at least 400 g per day. Fruits and vegetables are good sources of vitamins, minerals, antioxidants, and fiber. Papaya fruit is known for his high nutrient and fiber content, and with few exceptions, it is generally consumed ripe due to its characteristic flavor and aroma. Digestion improvement has been attributed to consumption of papaya; this we speculate is attributed to the fiber content and proteolytic enzymes associated with this highly nutritious fruit. However, research is lacking that evaluates the impact of papaya fruit on human digestion. Papain is a proteolytic enzyme generally extracted from the latex of unripe papaya. Previous research has focused on evaluating papain activity from the latex of different parts of the plant; however there are no reports about papain activity in papaya pulp through fruit maturation. The activity of papain through different stages of ripeness of papaya and its capacity of dislodging meat bolus in an in vitro model was addressed. The objective of this study was to investigate whether papain activity and fiber content are responsible for the digestive properties attributed to papaya and to find a processing method that preserves papaya health properties with minimal impact on flavor. Our results indicated that papain was active at all maturation stages of the fruit. Ripe papaya pulp displayed the highest enzyme activity and also presented the largest meat bolus displacement. The in vitro digestion study indicated that ripe papaya displayed the highest protein digestibility; this is associated with proteolytic enzymes still active at the acidity of the stomach. Results from the in vitro fermentation study indicated that ripe papaya produced the highest amount of Short Chain Fatty Acids SCFA of the three papaya substrates (unripe, ripe, and processed). SCFA are the most important product of fermentation and are used as indicators of the amount of substrate fermented by microorganisms in the colon. The combination of proteolytic enzymes and fiber content found in papaya make of this fruit not only a potential digestive aid, but also a good source of SCFA and their associated potential health benefits. Irradiation processing had minimal impact on flavor compounds of papaya nectar. However, processed papaya experienced the lowest protein digestibility and SCFA production among the papaya substrates. Future research needs to explore new processing methods for papaya that minimize the detrimental impact on enzyme activity and SCFA production.

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Processed meat products are of worldwide importance and, because of their intrinsic factors as well as the processing methods, they are highly prone to fungal and mycotoxin contamination. Ochratoxin A (OTA) is the most significant mycotoxin in processed meat products. Penicillium nordicum is considered to be responsible for OTA contamination of meat products, as it is highly adapted to salt and protein-rich matrices and is moderately psycrotrophic. However, another OTA-producing fungus, Aspergillus westerdijkiae, adapted to carbon-rich matrices such as cereals and coffee beans, has been recently associated with high levels of OTA in meat products. Several Lactic Acid Bacteria (LAB) and yeasts have been tested as biocontrol agents against P. nordicum growth and OTA production in meat products, with promising results, but none of the studies have considered A. westerdijkiae. The aim of this work was to evaluate in vitro the effect of a commercial starter culture used in sausage fermentation and four yeasts isolated from dry-cured sausage on these two OTA-producing fungi, both in terms of fungal growth and of OTA production, using different meat-based culture media as model systems. The mechanisms underlying the observed effect were also studied. For this purpose, C. krusei, C. zeylanoides, R. mucilaginosa, R. glutinis, a mix of these yeasts and the starter culture were co-inoculated with P. nordicum and A. westerdijkiae in industrial sausage, traditional sausage, and ham-based media, under conditions of water activity, salt concentration and temperature that mimic real conditions at beginning and end of sausage curing process. Fungal growth was determined by measuring colony diameter, and OTA production was quantified by HPLC-FLD after extraction with methanol. Yeasts where found to inhibit significantly the growth of both fungi. P. nordicum was unable to produce detectable OTA in both sausage-based media under any condition. In ham, yeasts reduced OTA production, while the starter culture significantly increased it. Unexpectedly, OTA production by A. westerdijkiae was significantly stimulated in all media tested by all microorganisms. Matrix has a significant effect on OTA production by P. nordicum, but not by A. westerdijkiae, for which only temperature showed to have effect. By testing the mechanisms of action by which starter culture and C. zeylanoides influenced fungal responses, we were able to determine that direct contact and simultaneous growth of test organisms were the mechanisms more significantly involved in the responses. In conclusion, ochratoxigenic fungi do not all respond to antagonistic microorganisms in the same way. The use of biocontrol agents with the intent of reducing fungal growth and mycotoxin production by one fungus can have unexpected effects on others, thus leading to unforeseen safety problems. Further experiments are recommended to properly understand the reasons behind the different effects of microorganisms, to ensure their safe as biocontrol agents.

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In this work, we further extend the recently developed adaptive data analysis method, the Sparse Time-Frequency Representation (STFR) method. This method is based on the assumption that many physical signals inherently contain AM-FM representations. We propose a sparse optimization method to extract the AM-FM representations of such signals. We prove the convergence of the method for periodic signals under certain assumptions and provide practical algorithms specifically for the non-periodic STFR, which extends the method to tackle problems that former STFR methods could not handle, including stability to noise and non-periodic data analysis. This is a significant improvement since many adaptive and non-adaptive signal processing methods are not fully capable of handling non-periodic signals. Moreover, we propose a new STFR algorithm to study intrawave signals with strong frequency modulation and analyze the convergence of this new algorithm for periodic signals. Such signals have previously remained a bottleneck for all signal processing methods. Furthermore, we propose a modified version of STFR that facilitates the extraction of intrawaves that have overlaping frequency content. We show that the STFR methods can be applied to the realm of dynamical systems and cardiovascular signals. In particular, we present a simplified and modified version of the STFR algorithm that is potentially useful for the diagnosis of some cardiovascular diseases. We further explain some preliminary work on the nature of Intrinsic Mode Functions (IMFs) and how they can have different representations in different phase coordinates. This analysis shows that the uncertainty principle is fundamental to all oscillating signals.

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The objective of this study was to evaluate the processing methods (F-1 = to remove skin with pliers and then to cut in fillets; F-2 = cut in fillet and then to remove skin with knife and pliers help) and weight categories (W-1=250-300 g; W-2=301-350 g; W-3 = 351-400 g and W-4 = 401-450 g), on the carcass (CY), fillet (FY) and skin yield of Nile tilapia. Forty-eight fishes were used in a completely randomized design. There was effect for the processing method, being the F-1 mean (56.43 and 36.67 %) higher to the F-2 (53.46 and 32.89%) for CY and FY respectively. For the weight categories, W-1 (56.49 and 37.34%) and W-2 (56.34 and 36.40%) were superior as compared to W-3 (53.27 and 31.98%) and W-4 (53.71 and 33.42%), respectively for CY and FY. Crude skin percentage, clean and of fleshed were higher for F-2, but there was no effect for weight categories. The F-1 processing method promoted the best yield and skin results, and for the weight categories W-1 and W-2 higher yields.

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Background: Alterations in intestinal microbiota have been correlated with a growing number of diseases. Investigating the faecal microbiota is widely used as a non-invasive and ethically simple proxy for intestinal biopsies. There is an urgent need for collection and transport media that would allow faecal sampling at distance from the processing laboratory, obviating the need for same-day DNA extraction recommended by previous studies of freezing and processing methods for stool. We compared the faecal bacterial DNA quality and apparent phylogenetic composition derived using a commercial kit for stool storage and transport (DNA Genotek OMNIgene GUT) with that of freshly extracted samples, 22 from infants and 20 from older adults. Results: Use of the storage vials increased the quality of extracted bacterial DNA by reduction of DNA shearing. When infant and elderly datasets were examined separately, no differences in microbiota composition were observed due to storage. When the two datasets were combined, there was a difference according to a Wilcoxon test in the relative proportions of Faecalibacterium, Sporobacter, Clostridium XVIII, and Clostridium XlVa after 1 week's storage compared to immediately extracted samples. After 2 weeks' storage, Bacteroides abundance was also significantly different, showing an apparent increase from week 1 to week 2. The microbiota composition of infant samples was more affected than that of elderly samples by storage, with significantly higher Spearman distances between paired freshly extracted and stored samples (p

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O Relatório de estágio tem por desígnio, compreender e analisar, o statu quo das dimensões da satisfação (Contemplando o seu bem-estar pessoal e social) dos utentes das valências da Santa Casa da Misericórdia de Évora, por conseguinte, analisando e compreendendo a qualidade de vida desses mesmos utentes, debruçando-se, pois, sobre as potenciais e/ou evidentes necessidades institucionais por suprimir, e problemas sociais por erradicar. O levantamento da actual informação obteve-se através de dois instrumentos metodológicos de recolha de dados: inquérito por questionário de aplicação directa auto-administrada (utentes), e por intermédio de entrevistas semi-estruturadas (diretores técnicos das valências). Relativamente, aos métodos de tratamento de dados, no primeiro instrumento utilizou-se IBM SPSS 22, já no segundo análise de conteúdo. Após a detecção das necessidades existentes, procedeu-se a elaboração de uma proposta de intervenção sócio-organizacional, por forma a solucionar essas mesmas necessidades existentes. O presente documento estrutura-se em 4 eixos: o Eixo 1 – Componente teórica - ; o Eixo 2 – Componente metodológica - ; Eixo 3 – Componente dos resultados - ; Eixo 4 – Componente de intervenção sócio- organizacional; Abstract: Intervention of the Holy House of Mercy of Evora - The quality of the Social Responses and satisfaction perceived Internal SCME of users -. This work is to design, understand and analyze the status quo of the dimensions of satisfaction (Contemplating their personal and social welfare) of users of the valences of the Holy House of Mercy of Evora, therefore, analyzing and understanding the quality life of these same users, addressing therefore, on potential and / or obvious institutional needs to suppress and eradicate social problems. The survey of current information was obtained through two methodological tools for data collection: survey by self-administered direct application questionnaire (users), and through semi-structured interviews (technical directors of valences). With regard to the data processing methods, the first instrument was used SPSS 22, in the second content analysis. After detection of the needs, it proceeded to draw up a proposal for social and organizational intervention in order to solve these same existing needs. This document is divided into four axes: Axis 1 - Theoretical component -; Axis 2 - methodological component -; Axis 3 - Component of results -; Axis 4 - socio-organizational intervention component.

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Quantitative imaging in oncology aims at developing imaging biomarkers for diagnosis and prediction of cancer aggressiveness and therapy response before any morphological change become visible. This Thesis exploits Computed Tomography perfusion (CTp) and multiparametric Magnetic Resonance Imaging (mpMRI) for investigating diverse cancer features on different organs. I developed a voxel-based image analysis methodology in CTp and extended its use to mpMRI, for performing precise and accurate analyses at single-voxel level. This is expected to improve reproducibility of measurements and cancer mechanisms’ comprehension and clinical interpretability. CTp has not entered the clinical routine yet, although its usefulness in the monitoring of cancer angiogenesis, due to different perfusion computing methods yielding unreproducible results. Instead, machine learning applications in mpMRI, useful to detect imaging features representative of cancer heterogeneity, are mostly limited to clinical research, because of results’ variability and difficult interpretability, which make clinicians not confident in clinical applications. In hepatic CTp, I investigated whether, and under what conditions, two widely adopted perfusion methods, Maximum Slope (MS) and Deconvolution (DV), could yield reproducible parameters. To this end, I developed signal processing methods to model the first pass kinetics and remove any numerical cause hampering the reproducibility. In mpMRI, I proposed a new approach to extract local first-order features, aiming at preserving spatial reference and making their interpretation easier. In CTp, I found out the cause of MS and DV non-reproducibility: MS and DV represent two different states of the system. Transport delays invalidate MS assumptions and, by correcting MS formulation, I have obtained the voxel-based equivalence of the two methods. In mpMRI, the developed predictive models allowed (i) detecting rectal cancers responding to neoadjuvant chemoradiation showing, at pre-therapy, sparse coarse subregions with altered density, and (ii) predicting clinically significant prostate cancers stemming from the disproportion between high- and low- diffusivity gland components.

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Sound radiators based on forced vibrations of plates are becoming widely employed, mainly for active sound enhancement and noise cancelling systems, both in music and automotive environment. Active sound enhancement solutions based on electromagnetic shakers hence find increasing interest. Mostly diffused applications deal with active noise control (ANC) and active vibration control systems for improving the acoustic experience inside or outside the vehicle. This requires investigating vibrational and, consequently, vibro-acoustic characteristics of vehicles. Therefore, simulation and processing methods capable of reducing the calculation time and providing high-accuracy results, are strongly demanded. In this work, an ideal case study on rectangular plates in fully clamped conditions preceded a real case analysis on vehicle panels. The sound radiation generated by a vibrating flat or shallow surface can be calculated by means of Rayleigh’s integral. The analytical solution of the problem is here calculated implementing the equations in MATLAB. Then, the results are compared with a numerical model developed in COMSOL Multiphysics, employing Finite Element Method (FEM). A very good matching between analytical and numerical solutions is shown, thus the cross validation of the two methods is achieved. The shift to the real case study, on a McLaren super car, led to the development of a mixed analytical-numerical method. Optimum results were obtained with mini shakers excitement, showing good matching of the recorded SPL with the calculated one over all the selected frequency band. In addition, a set of directivity measurements of the hood were realized, to start studying the spatiality of sound, which is fundamental to active noise control systems.

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Nowadays, Recommender systems play a key role in managing information overload, particularly in areas such as e-commerce, music and cinema. However, despite their good-natured goal, in recent years there has been a growing awareness of their involvement in creating unwanted effects on society, such as creating biases of popularity or filter bubble. This thesis is an attempt to investigate the role of RS and its stakeholders in creating such effects. A simulation study will be performed using EcoAgent, an RL-based multi-stakeholder recommendation system, in a simulation environment that captures key user interactions, suppliers and the recommender system in order to identify possible unhealthy scenarios for stakeholders. In particular, we focus on analyzing the document catalog to see how the diversity of topics that users have access to varies during interactions. Finally, some post-processing methods will be defined on EcoAgent, one reactive and one proactive, which allows us to manipulate the agent’s behavior in order to study whether and how the topic distribution of documents is affected by content providers and by the fairness of the system.