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81.
Juliana Regina Barreiro Juliano Leonel Gonçalves Patrícia Aparecida Campos Braga Aline Gerato Dibbern Marcos Nogueira Eberlin Marcos Veiga dos Santos 《Journal of dairy science》2017,100(4):2928-2934
The purpose of this study was to evaluate the detection limit of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for direct identification, without previous microbiological culture, of bovine mastitis-causing bacteria from milk samples. Milk samples (n = 15) were experimentally contaminated with Staphylococcus aureus, Streptococcus uberis, Streptococcus agalactiae, Streptococcus dysgalactiae, and Escherichia coli to have bacterial counts ranging from 103 to 109 cfu/mL. These contaminated milk samples were subjected to a preparation protocol for bacterial ribosomal protein extraction using the MALDI Sepsityper kit (Bruker Daltonik, Bremen, Germany), which allowed MALDI-TOF MS coupled with Biotyper software (Bruker Daltonik) to identify bacterial fingerprints based on intact ribosomal proteins. The ability of MALDI-TOF MS to correctly identify bacterial strains from experimentally contaminated milk (without previous microbiological culture) depended on the bacterial count of the samples and on the species of the bacteria evaluated. Adequate identification at the bacterial species level (score ≥2.0) directly from milk samples required bacterial counts in the following ranges: ≥106 cfu/mL of Staph. aureus, ≥107 cfu/mL of E. coli, and ≥108 cfu/mL of Strep. agalactiae, Strep. dysgalactiae, and Strep. uberis. We concluded that direct identification of mastitis-causing pathogens is possible for Staph. aureus, E. coli, Strep. agalactiae, Strep. dysgalactiae, and Strep. uberis, but correct identification depended on the bacterial count in the milk samples. 相似文献
82.
Helio Langoni Carolina Polo Camargo da Silva Marcella Zampoli Troncarelli Alessandra Tata Katia Roberta Anacleto Belaz Marcos Nogueira Eberlin Samea Fernandes Joaquim Felipe Freitas Guimarães Renata Bonini Pardo Eduardo Nardini Gomes 《Journal of dairy science》2017,100(6):4287-4289
Corynebacterium bovis is a mastitis-causing microorganism responsible for economic losses related to decrease in milk production. The aim of the study was identify Corynebacterium spp. strains recovered from milk samples of subclinical mastitis by using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Samples were collected during a 10-mo mastitis-monitoring program in a high-production dairy farm. In this study, 80 strains were analyzed; from these 54 (67.5%) were identified at species level as Corynebacterium bovis, 24 (31.2%) isolates were identified at the genus level as Corynebacterium spp., and only 1 (1.35%) isolated had unreliable identification. Results demonstrated that MALDI-MS could be an important technique for the identification of Corynebacterium spp. in milk. 相似文献
83.
Supplementation of amino acids in apple must for the standardization of volatile compounds in ciders 下载免费PDF全文
Caroline Mongruel Eleutério dos Santos Aline Alberti Giovana de Arruda Moura Pietrowski Acácio Antonio Ferreira Zielinski Gilvan Wosiacki Alessandro Nogueira Regina Maria Matos Jorge 《Journal of the Institute of Brewing》2016,122(2):334-341
The aim of this study was to identify the main amino acids responsible for the production of esters in ciders. The experiments were carried out in apple must and synthetic must. The amino acids were analysed by high‐performance liquid chromatography and the volatile compounds by gas chromatography. Aspartate, asparagine and glutamate positively influenced the production of esters in the cider models and were used in the experiments with mixtures. The response surface generated by the proposed model yielded two regions that maximized the production of esters. In addition, the combination of aspartate and glutamate predicted a higher production. The optimal suggested concentrations were 43.4% of aspartate and 56.6% of glutamate for 120 mg/L of total nitrogen. The apple must supplemented with these two amino acids resulted in four times more esters than in the same cider without supplementation, demonstrating the effectiveness of the proposed model. 相似文献
84.
Phytochemistry Profile,Nutritional Properties and Pharmacological Activities of Mauritia flexuosa 下载免费PDF全文
Joilane Alves Pereira Freire Karla Bruna Nogueira Torres Barros Layana Karine Farias Lima Julyanna Maciel Martins Yan de Carvalho Araújo George Laylson da Silva Oliveira Jailane de Souza Aquino Paulo Michel Pinheiro Ferreira 《Journal of food science》2016,81(11):R2611-R2622
Mauritia flexuosa L. (Arecaceae) is a popular Brazilian fruit known as “buriti” and belonging to the category of functional foods. This work reviewed the phytochemistry profile, nutritional and pharmacological activities of M. flexuosa. The main bioactive compounds reported to buriti were carotenoids, tocopherols, ascorbic acid, phenolic compounds, fiber, phytosterols, and mono‐ and poly‐unsaturated fatty acids. These compounds were mainly related to antioxidant, hypolipemiant, photoprotector, antiaggregant, antithrombotic, anti‐inflammatory, hypoglycemiant, antimicrobial, and antitumor activities. Furthermore, some compounds present in buriti fruit and its properties were tested in vitro and in vivo and showed biotechnology applications, especially for extraction of fiber, polysaccharides, pigments, antioxidants, and oil. Howerer, the buriti fruit shows great relevance to the development of new products in food, pharmaceutical and chemical industry, this fruit is still underexploited and it has need to expand its production chain and processing to encourage their consumption and utilization. 相似文献
85.
Alexandre B. dos Santos Thiago Vieira Nogueira Coelho Maria José Pontes Daniel Discini Silveira 《Journal of Modern Optics》2013,60(19):1582-1588
This article analyzes the polarization mode dispersion (PMD) in optical fibers and presents a new approach for its measurement. This approach permits the combined analysis of the first-order PMD and the second-order polarization mode dispersion (SOPMD) in optical systems for different values of temperature. The relation between SOPMD and the differential group delay (DGD) in a single-mode fiber is discussed. The analysis is based on time/wavelength and temperature variations changing/impacting PMD and DGD measured values. We present long-term statistical characteristics of SOPMD acquired by a PMD emulator constructed with some pieces of high birefringence fiber, and the correlation between the SOPMD, depolarization (Depol) and polarization-dependent chromatic dispersion (PCD) was investigated. A new interpretation of SOPMD is presented to analyze the problem of the temperature spectral stability. The actual techniques for SOPMD determination, consequently Depol and PCD, use the variation with time and/or wavelength. In some studies, the results obtained for SOPMD are correlated to first-order PMD. We demonstrate experimentally that the temperature is an important factor for the correlation between SOPMD and PMD and cannot be neglected in the optimization of high-speed optical communications links. 相似文献
86.
Pedro A. Rodriguez-Aumente María del Carmen Rodriguez-Hidalgo José I. Nogueira Antonio Lecuona María del Carmen Venegas 《Applied Thermal Engineering》2013,50(2):1496-1503
Energy needs for heating and cooling in Spain are of paramount interest in the context of the European roadmap to a decarbonized environment; because of that, it is highly desirable that more examples of district heating and cooling networks are developed. The present work evaluates the implementation of one of them into the climatic environment of Madrid. It consists on a complex of business office buildings with a total useful surface of 50,000 m2, linked with heating and cooling rings of 1 km of loop length. Basic energy needs of buildings lead to the following design values: 1.7 MW of electricity, 1.3 MW of heating and 2 MW of cooling. They will be supplied by the trigeneration plant here proposed, which relies on an internal combustion engine.The high demand of cooling for air conditioning makes the dimensioning of the engine critical because of the large differences between the heat demand for summer and the one for winter. If the total amount of the cooling demand is covered with an absorption chiller, the heat demand during the summer reaches about 5 MW. In consequence, a critical decision has to be taken relative to the way the cooling demand is attended: with an absorption chiller (single or double effect) or with a conventional chiller powered by electricity. Applying the criteria developed in the present work, which are focused on maximum primary energy reduction, the fraction of the cooling demand to be met with each technology is determined as a function of the engine nominal power, on the grounds of the instantaneous demand.The high cooling demand during the summer season suggests the inclusion of a thermal solar collector field, to be used for complementing the waste heat rejection from the engine to drive the absorption chiller. During the winter, the heat provided by the solar field could be applied in attending a fraction of the heating demand. Thus a hybrid Trigeneration Plant is introduced. This way, over sizing of the engine can be avoided, as the electric demand is small.The analysis is based on the solution of energy and mass balance equations for a trigeneration plant. Monthly demands and environmental conditions (ambient temperature and solar irradiance) are introduced as input data into the model. Monthly and annual primary energy consumption and CO2 emission reductions are obtained as outputs. Economical data, such as fuel and operating costs, electricity prices, tariffs and subsidies are considered in order to optimize the size of the plant in terms of its payback period. 相似文献
87.
Transfer of Salmonella Enteritidis to four types of surfaces after cleaning procedures and cross-contamination to tomatoes 总被引:1,自引:0,他引:1
Soares VM Pereira JG Viana C Izidoro TB Bersot Ldos S Pinto JP 《Food microbiology》2012,30(2):453-456
The objectives of the present study were to evaluate the spread of Salmonella Enteritidis to different cutting boards (wood, triclosan-treated plastic, glass, and stainless steel) from contaminated poultry skin (5 log CFU/g) and then to tomatoes and to analyze the effect of different protocols used to clean these surfaces to control contamination. The following procedures were simulated: (1) no cleaning after handling contaminated poultry skin; (2) rinsing in running water; (3) cleaning with dish soap and mechanical scrubbing; and (4) cleaning with dish soap and mechanical scrubbing, followed by disinfection with hypochlorite. The pathogen was recovered from all surfaces following procedure 1, with counts ranging from 1.90 to 2.80 log, as well as from the tomatoes handled on it. Reduced numbers of S. Enteritidis were recovered using the other procedures, both from the surfaces and from the tomatoes. Counts were undetectable after procedure 4. From all surfaces evaluated, wood was the most difficult to clean, and stainless steel was the easiest. The use of hypochlorite as a disinfecting agent helped to reduce cross-contamination. 相似文献
88.
Bianca Cristina Nogueira Fernandes Bruna Barbon Paulo Maria Clara Guimarães Claire Isabel Grigoli de Luca Sarantopoulos Nathália Ramos de Melo Ana Silvia Prata 《Comprehensive Reviews in Food Science and Food Safety》2022,21(3):2309-2334
Food safety and extended shelf life linked to convenience were the major reasons for the development of the packaging field. However, advances in material science and the widespread encapsulation technologies are allowing the establishment of new concepts for packages, such as intelligent and active packages. Particulate systems have been developed in recent years for the most diverse area with several purposes that can be employed to improve packaging performance mainly focusing on the modification of barrier properties. This review analyzes the recent developments using encapsulation in food packaging and the main concepts about mass transfer evolved in the functionality of these packages, as well as discusses the research challenges faced by the food packaging sector. 相似文献
89.
Praveen Kumar Mehta Mércia de Sousa Galvão Alysson Caetano Soares Juliete Pedreira Nogueira Narendra Narain 《Food Analytical Methods》2018,11(3):733-749
The volatile compounds of jambolan (Syzygium cumini L.) fruit were determined at three different maturity stages (unripe, half-ripe, and ripe) by headspace solid-phase microextraction (HS-SPME)–gas chromatography-mass spectrometry (GC-MS) technique using five different fibers (Fused silica PDMS/DVB, DVB/CAR/PDMS, PEG, Stable flex PDMS/DVB, and PDMS). The optimal extraction conditions were evaluated using different variables such as adsorption temperature (minimum 25 °C, maximum 55 °C), salt quantity (minimum 0, maximum 30.0%), and extraction time (min 10, max 30 min). The major classes of compounds identified were ester, terpene, alcohol, aldehyde, and carboxylic acid. Ninety volatile compounds with characteristics aroma attributes were identified, and the primary compounds linked with development of characteristics aroma of ripe jambolan fruit pulp were trans-β-ocimene, β-ocimene, caryophyllene, humulene, D-α-pinene, L-β-pinene, β-pinene, D-limonene, α-terpineol, neo-allo-ocimene, 2-hexenal (E), δ-cadinene, 3-hexen-1-ol, (Z) β-linalool, terpinolene, eremophilene, valencene, 1-hexanol, longipinene, γ-terpinene, γ-muurolene, endo-borneol, o-cymene, nonanal, terpinen-4-ol, β-terpineol, α-muurolene, fenchol, α-fenchene, β-thujene, benzaldehyde, (E)-2-hexenal, β-cadinene, and decanal. 相似文献
90.
Aline Alberti Cíntia Maia Braga Henrique Jaster Alessandro Nogueira 《Journal of the Institute of Brewing》2014,120(1):65-70
Oxygen can influence the composition and quality of apple must and cider. In this study, the effect of unit operations on oxygen dissolution during apple must processing was investigated and the technological implications discussed. Oxygen dissolution after different apple must processing unit operations, and also the effect of enzymatic browning reaction on dissolved oxygen uptake were analysed. During pressing, the highest and first oxygen dissolution occurred in the must at 6.8 mg/L, on average. The enzymatic browning reaction after 10 min was responsible for an oxygen uptake above 80%. The addition of sulphur dioxide or maceration of crushed apple results in a must with more oxygen content, however the beverage colour is negatively affected. The incorporation of oxygen into the must by bubbling oxygen or the movement of liquid may not be effective owing to consumption by the reaction of residual polyphenol oxidase. Moreover, this can affect the alcoholic fermentation because of the oxidation of nutrients such as vitamins. If the apple must is depectinized, racked and filtered, there will be enough oxygen to obtain a quality cider. These results and observations can be useful for selecting unit operations in cider companies in order to improve the beverage quality. Copyright © 2014 The Institute of Brewing & Distilling 相似文献