A Method for Physical Analysis of Recombination Intermediates in Saccharomyces cerevisiae.

Meiosis is a process through which diploid cells divide into haploid cells, thus promoting genetic diversity. This diversity arises from the formation of genetic crossovers (COs) that repair DNA double-strand breaks (DSBs), through homologous recombination (HR). Deficiencies in HR can lead to chromosomal abnormality resulting from chromosomal nondisjunction, and genetic disorders. Therefore, investigating the mechanisms underlying effective HR is crucial for reducing genome instability. Budding yeast serves as an ideal model for studying HR mechanisms due to its amenability to gene modifications and the ease of inducing synchronized meiosis to yield four spores. During meiosis, at the DNA level, programmed DSBs are repaired as COs or non-crossovers (NCOs) through structural alterations in the nascent D-loop, involving single-end invasions (SEIs) and double-Holliday junctions (dHJs). This repair occurs using homologous templates rather than sister templates. This protocol, using Southern blotting, allows for the analysis and monitoring of changes in DNA structures in the recombination process. One-dimensional (1D) gel electrophoresis is employed to detect DSBs, COs, and NCOs, while two-dimensional (2D) gel electrophoresis is utilized to identify joint molecules (JMs). Therefore, physical analysis is considered the most effective method for investigating the HR mechanism. Our protocol provides more comprehensive information than previous reports by introducing conditions for obtaining a greater number of cells from synchronized yeast and a method that can analyze not only meiotic/mitotic recombination but also mitotic replication.

Safety of spinal anesthesia and analysis of cerebrospinal fluid in SARS-CoV-2 pregnant women undergoing cesarean section: an observational prospective study.

BACKGROUND: Systemic infection has always been considered a relative contraindication to neuraxial anesthesia, despite the fact that infectious complications are relatively uncommon. Pregnancy-related physiological changes and coronavirus disease (COVID-19) neurotropic features may facilitate the virus' entry into the central nervous system. The principal aim of this study was to test the safety of spinal anesthesia in "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2)-positive pregnant women and to examine cerebrospinal fluid (CSF) characteristics. METHODS: We conducted a prospective observational single-center study in asymptomatic or paucisymptomatic consecutive pregnant SARS-CoV-2 patients who underwent spinal anesthesia for cesarean section. Women with severe infection were excluded because they underwent general anesthesia. At the time of spinal anesthesia, we collected CSF samples, and then we performed a chemical-physical analysis to look for signs of inflammation and for SARS-CoV-2 genome. RESULTS: We included 26 women. No spinal anesthesia complications were reported in the perioperative period and after 2 months. All CSF samples were crystal clear, and all physical-chemical values were within physiological ranges: the median concentration of CSF/plasma glucose ratio was 0.66, IQR 0.5500 (0.6000-0.7100), and the average CSF protein concentration value was 23.2 mg/dl (SD 4.87). In all samples, genomes of SARS-CoV-2 and other neurotropic viruses were not detected. CONCLUSIONS: Spinal anesthesia was safe in SARS-CoV-2 pregnant women with mild disease; no clinical maternal complications were detected, and no CSF changes indicative of inflammatory or infectious diseases that would compromise the safety of the procedure were found.

Sucrose Concentration and Fermentation Temperature Impact the Sensory Characteristics and Liking of Kombucha.

Kombucha is a fermented tea beverage consumed for its probiotics and functional properties. It has a unique sensory profile driven by the properties of tea polyphenols and fermentation products, including organic acids. Fermentation temperature and sucrose content affect the fermentation process and the production of organic acids; yet less is known about their impacts on the sensory profile and consumer acceptance. Thus, we aimed to examine the impact of sucrose concentration and fermentation temperature on sensory attributes and liking. For this study, kombucha tea was fermented at three different concentrations of sucrose and fermented at two temperatures for 11 days. Fermentation was monitored by pH, brix, and titratable acidity, and consumers (n = 111) evaluated the kombucha for sensory attributes and overall liking. The fermentation temperature resulted in significant differences in titratable acidity, with higher temperatures producing more organic acids, resulting in higher astringency, and suppressed sweetness. The lower fermentation was reported as significantly more liked, with no difference in liking between the 7.5% and 10% sucrose kombucha samples. Fermentation temperature had the greatest impact on the sensory profile rather than sucrose concentration, which had a greater effect on the fermentation rate and production organic acids.

Co-pyrolysis of neem wood bark and low-density polyethylene: influence of plastic on pyrolysis product distribution and bio-oil characterization.

In this study, the investigation on the effect of plastic during co-pyrolysis with biomass was carried out in a fixed reactor. Pyrolysis of neem wood bark (NB), low density polyethylene (LDPE) and their blends at different ratios was performed in order to evaluate the product distribution. The effects of reaction temperature and NB-to-LDPE blend ratio on product distribution and the chemical compositions of pyrolysis oil were examined. The co-pyrolysis of NB and LDPE increased the yield and quality of the bio-oil. The experiments were conducted under different LDPE addition percentages such as 20%, 40%, 50%, 60% and 80%. Under the optimum experimental condition of 60% addition of LDPE and a temperature of 450 °C, the maximum yield of bio-oil (64.8 wt%) and hydrocarbon (75.2%) was achieved with the lowest yield of oxygenated compounds. The calorific value of the co-pyrolysis oil was found to be higher than that of the NB pyrolysis oil. The relationship between NB and LDPE during co-pyrolysis was validated with the help of gas chromatography-mass spectrometry (GC-MS) analysis, which showed decreased oxygenated compounds.

Tear fluid collection methods: Review of current techniques.

Tear fluid, composed of lipid, aqueous, and mucin layers, contains electrolytes, water, proteins, peptides, and glycoproteins. Its components may serve as diagnostic indicators of local and systemic diseases. The aim of the study was to conduct literature review in order to identify the current methods of tear collection. The most commonly used method which was relatively easy to perform and allowed to obtain sufficient tear volume for further chemical and physical analysis was selected through PubMed database search for the following keywords: tear sampling, human tears, chemical analysis of tears, physical tear analysis, animal tear sampling. Final criteria of articles selection were: human tears, tear sample collection, chemical and physical analysis of tears. Time of publication of the articles not older than 1995. The analysis of 70 articles revealed that the most common tear fluid collection methods are Schirmer tear strips and capillary tubes. Thus, we recommend the use of Schirmer strips and microcapillary tubes as the cheapest and easiest methods for sampling of tear fluid for further chemical analysis.

Especiação de bactérias encontradas no gelo através do método MALDI-TOF-MS / Specification of bacteria found in the through the MALDI-TOF-MS method

Objetivo ­ Determinar a especiação de bactérias gram-negativas em quatro diferentes marcas de gelo através do método MALDI-TOFMS e avaliar sua potabilidade. Metodos ­ Com o equipamento multiparâmetros, da marca Hanna®, foram avaliados: pH, condutividade elétrica, oxigênio dissolvido e temperatura. Preparou-se meio Agar Mac Conkey para observação do crescimento bacteriano de Gramnegativas, sua morfologia através da coloração de Gram e a sua especiação pelo método MALD-TOF-MS. Resultados ­ Houve crescimento na amostra 4 e como método MALDI-TOF-MS foi identificada a espécie Pseudomonas monteilli. Conclusão ­ Os parâmetros físico-químicos estão de acordo com a Resolução 357/05 do CONAMA e a portaria 2.914/11 do MS. A espécie P. monteilli foi detectada em 15 minutos, podendo substituir o método tradicional que levaria dias para identificação, tornando um método revolucionário e de importância à saúde pública.

Objective ­ To determine the speciation of gram-negative bacteria in four different ice brands using the MALDI-TOF-MS method and to evaluate their potability. Methods - With the Hanna® multiparameter equipment, the following parameters were evaluated: pH, electrical conductivity, dissolved oxygen and temperature. Mac Conkey Agar medium was prepared for observation of Gram-negative bacterial growth, its morphology by Gram staining and its speciation by the MALD-TOF-MS method. Results ­ There was growth in sample 4 and as the MALDI-TOF-MS method was identified the species Pseudomonas monteilli. Conclusion ­ The physicochemical parameters are in accordance with CONAMA Resolution 357/05 and MS Ordinance 2.914 / 11. P. monteilli was detected within 15 minutes and could replace the traditional method that would take days to identify, making it a revolutionary method of public health importance.

Physical Processes in Polymeric Filters Used for Dialysis.

The key physical processes in polymeric filters used for the blood purification include transport across the capillary wall and the interaction of blood cells with the polymer membrane surface. Theoretical modeling of membrane transport is an important tool which provides researchers with a quantification of the complex phenomena involved in dialysis. In the paper, we present a dense review of the most successful theoretical approaches to the description of transport across the polymeric membrane wall as well as the cell⁻polymer surface interaction, and refer to the corresponding experimental methods while studying these phenomena in dialyzing filters.

Aurora A depletion reveals centrosome-independent polarization mechanism in Caenorhabditis elegans.

How living systems break symmetry in an organized manner is a fundamental question in biology. In wild-type Caenorhabditis elegans zygotes, symmetry breaking during anterior-posterior axis specification is guided by centrosomes, resulting in anterior-directed cortical flows and a single posterior PAR-2 domain. We uncover that C. elegans zygotes depleted of the Aurora A kinase AIR-1 or lacking centrosomes entirely usually establish two posterior PAR-2 domains, one at each pole. We demonstrate that AIR-1 prevents symmetry breaking early in the cell cycle, whereas centrosomal AIR-1 instructs polarity initiation thereafter. Using triangular microfabricated chambers, we establish that bipolarity of air-1(RNAi) embryos occurs effectively in a cell-shape and curvature-dependent manner. Furthermore, we develop an integrated physical description of symmetry breaking, wherein local PAR-2-dependent weakening of the actin cortex, together with mutual inhibition of anterior and posterior PAR proteins, provides a mechanism for spontaneous symmetry breaking without centrosomes.

Avaliação estrutural do braquete Roth Max ­ análise química, física e metalográfica / Structural assessment of roth max bracket ­ chemical, physical, and metallographic analysis

Introdução: As características ideais dos braquetes ortodônticos são alto potencial anticorrosivo, baixa concentração de níquel, boa dureza, curvatura da base adequada, paredes das canaletas lisas e ainda se constituirem em monobloco. O objetivo deste trabalho foi analisar as características químicas, físicas e metalográficas do braquete Roth Max, a fim de verificar os seus benefícios na clínica ortodôntica. Métodos: Foram utilizados dois conjuntos de braquetes ortodônticos. A análise química foi realizada através de três métodos: espectrometria, combustão e leitura por meio de infravermelho e nitrogênio total. A análise metalográfica foi realizada por meio de microscopia óptica, força atômica e magnética e ferritoscopia. A análise física foi realizada por meio de microdureza vickers. Resultados: A análise química mostrou a seguinte composição: Cr- 17%; Mn- 10.8%; Mo- 3.2%; C- 0.65%; N- 0.18%; Cu- 0.1%; Ni- 0.1%; Al- 0.1%; Co- 0.016%; Zn- 0.003%; Pb- 0.004%; Ti- 0.004%; Sn- 0.005% e V- 0.007%. Na análise metalográfica foi observada ausência de solda, presença de poros, estrutura duplex (ferrita e austenita). Na análise física, as médias das microdurezas na secção longitudinal foram de 242 HV1 (base), 213 e 212 HV1 (aletas). Na secção frontal foi de 217 HV1 (base). Conclusões: O teor de carbono excedeu o limite máximo indicado para os aços duplex. Os teores de nitrogênio e molibdênio elevaram o potencial anticorrosivo. A microdureza foi considerada eficiente para a clínica ortodôntica. A análise metalográfica não encontrou presença de solda, mas evidenciou uma grande quantidade de poros e heterogeneidade na microestrutura entre as frações volumétricas de ferrita e austenita.(AU)

Introduction: Ideal characteristics of orthodontic brackets include high anti-corrosive potential, high nickel concentration, good hardness, adequate base curvature, smooth channel walls, and their monoblock form. The present study aimed to analyze the chemical, physical and metallographic characteristics of the Roth Max bracket to verify its benefits in orthodontic clinic. Methods: Two orthodontic bracket sets were used. Chemical analysis was performed using three methods: spectrometry, combustion, and scanning through infrared and total nitrogen. Metallographic analysis was performed by optical microscopy, atomic and magnetic force and ferrite measurement. Physical analysis was conducted using vickers microhardness. Results: Chemical analysis showed the following composition: Cr- 17%, Mn- 10.8%, Mo-3.2%, C- 0.65%, N- 0.18%, Cu- 0.1%, Ni- 0.1%, Al- 0.1%, Co- 0.016%, Zn- 0.003%, Pb- 0.004%, Ti- 0.004%, Sn- 0.005%, and V- 0.007%. Metallographic analysis presented absence of welding, the presence of pores, and a duplex structure (ferrite and austenite). In the physical analysis, microhardness averages in the longitudinal section were 242 HV1 (base), and 213 and 212 HV1 (flaps). In the front section, it was 217 HV1 (base). Conclusions: The carbon content exceeded the maximum limit indicated for duplex steels. Nitrogen and Molybdenum raised the anti-corrosive potential. Microhardness was considered efficient for orthodontics clinics. Metallographic analysis found no evidence of welding, but it did find a large quantity of pores and heterogeneity in the microstructure between the ferrite and austenite volumetric fractions.(AU)

Mixture Design Applied to the Development of Chickpea-Based Gluten-Free Bread with Attractive Technological, Sensory, and Nutritional Quality.

The aim of the study was utilized chickpea to create appealing, nutritious, and palatable gluten-free bread (GFB). The performance of chickpea flour (CF) in single and composite GFB formulations was studied with a mixture design and response surface methodology. Six simplex-centroid designs for 3 ingredients were used to identify the ideal proportions of CF in various blends with cassava starch (CS), maize starch (MS), potato starch (PS), and rice flour (RF) achieving the best physical properties. For each design, 3 single, 3 binary, and 3 ternary formulations were prepared. The results showed that CF alone is suitable for bread production, resulting in GFB with higher volume and crumb firmness and lower crumb moisture than single formulations of other raw materials. However, the interactions between CF and PS or CS enhanced the loaf volume and decreased the crumb firmness values. The GFB prepared with only CF was accepted (overall acceptability score of 7.1- on a 10-cm scale). Nevertheless, the composite formulations prepared with CF75:PS25 or CF75:CS25 (flour basis) received overall acceptability scores of 8.2, like those of their white GFB, prepared with RF50:PS50 blend (flour basis), and wheat bread counterparts, used as positive controls. Compared to white GFB, both composite formulations presented nearly a twofold increase in ash and protein contents and a threefold increase in total fiber content. These results show that blends of CF75:PS25 or CF75:CS25 can be used to develop GFB with a good physical and sensory properties, as well as an enhanced nutritional composition. PRACTICAL APPLICATION: Gluten-free bread (GFB) made with 75% chickpea flour (CF) blend with 25% potato or cassava starch showed improved total minerals, protein and dietary fiber content and bread quality characteristics. Therefore, CF is a valuable ingredient for food technologists in manufacturing better-tasting and healthy GFB, which is important for consumers with gluten-related disorders since GFB often lack nutrition content, appearance, texture, and mouthfeel.

Avaliação da qualidade de pepinos em conserva / Evaluation of the quality of canned cucumbers

O trabalho teve como objetivo avaliar as características físicas, as físico-químicas e a rotulagem de 11 marcas de pepinos em conserva comercializados no município de Itaqui, RS. Foram realizadas a contagem do número de pepinos nos recipientes, a determinação do diâmetro e do comprimento dos pepinos, peso bruto, peso líquido, peso drenado, espaço livre, vácuo, pH, acidez total titulável e cloretos. Os rótulos das amostras de pepinos em conserva avaliados obedeceram às normas de rotulagem geral de acordo com a legislação. Os valores de peso líquido e drenado foram superiores aos especificados pelos fabricantes. O espaço livre no frasco continente variou de 0,83 a 2,23 cm e o vácuo apresentou valores entre 2,67 e 8,33 pol. Hg. A acidez total titulável apresentou valores entre 0,48 e 0,92 g de ácido acético/100 g. O pH em todas as amostras foi menor do que 4,5. Os teores de cloretos variaram de 1,70 a 3,47 g de cloreto de sódio/100 g. Pode-se afirmar que os pepinos em conserva avaliados são seguros, pois apresentaram pH menor que 4,5. No entanto, as marcas comercializadas não apresentaram padrão para as demais variáveis, pois foram encontradas diferenças nesses parâmetros avaliados.

The objective of this study was to evaluate the physical, the physical-chemical characteristics and the labeling of 11 brands of canned cucumbers commercialized in the municipality of Itaqui, RS. The cucumbers quantity, diameter, length, gross weight, net weight, drained weight, free space, vacuum, pH, total titratable acidity and chlorides were determined. All of the evaluated canned cucumber labels complied with the general labeling standards in accordance with the legislation. The values of liquid weight and drained weight were higher than those stated by the manufacturers. The free space in the container ranged from 0.83 to 2.23 cm, and the vacuum values were from 2.67 to 8.33 in pol. Hg. The titratable total acidity presented values from 0.48 to 0.92 g of acetic acid/100 g. The pH for all of the samples was less than 4.5. The chloride contents (g sodium chloride/100 g) ranged from 1.70 to 3.47. It can be stated that the evaluated canned cucumbers are safe, since they presented pH lower than 4.5. However,the commercial brands did not show the standard for the other variables, as differences were found in these evaluated parameters.

Avaliação da qualidade de pepinos em conserva / Evaluation of the quality of canned cucumbers

O trabalho teve como objetivo avaliar as características físicas, as físico-químicas e a rotulagemde 11 marcas de pepinos em conserva comercializados no município de Itaqui, RS. Foramrealizadas a contagem do número de pepinos nos recipientes, a determinação do diâmetro edo comprimento dos pepinos, peso bruto, peso líquido, peso drenado, espaço livre, vácuo, pH,acidez total titulável e cloretos. Os rótulos das amostras de pepinos em conserva avaliadosobedeceram às normas de rotulagem geral de acordo com a legislação. Os valores de peso líquido edrenado foram superiores aos especificados pelos fabricantes. O espaço livre no frasco continentevariou de 0,83 a 2,23 cm e o vácuo apresentou valores entre 2,67 e 8,33 pol. Hg. A acidez totaltitulável apresentou valores entre 0,48 e 0,92 g de ácido acético/100 g. O pH em todas as amostrasfoi menor do que 4,5. Os teores de cloretos variaram de 1,70 a 3,47 g de cloreto de sódio/100 g.Pode-se afirmar que os pepinos em conserva avaliados são seguros, pois apresentaram pH menorque 4,5. No entanto, as marcas comercializadas não apresentaram padrão para as demais variáveis,pois foram encontradas diferenças nesses parâmetros avaliados.

The objective of this study was to evaluate the physical, the physical-chemical characteristicsand the labeling of 11 brands of canned cucumbers commercialized in the municipality ofItaqui, RS. The cucumbers quantity, diameter, length, gross weight, net weight, drainedweight, free space, vacuum, pH, total titratable acidity and chlorides were determined. All of theevaluated canned cucumber labels complied with the general labeling standards in accordancewith the legislation. The values of liquid weight and drained weight were higher than thosestated by the manufacturers. The free space in the container ranged from 0.83 to 2.23 cm, andthe vacuum values were from 2.67 to 8.33 in pol. Hg. The titratable total acidity presented valuesfrom 0.48 to 0.92 g of acetic acid/100 g. The pH for all of the samples was less than 4.5. Thechloride contents (g sodium chloride/100 g) ranged from 1.70 to 3.47. It can be stated thatthe evaluated canned cucumbers are safe, since they presented pH lower than 4.5. However,the commercial brands did not show the standard for the other variables, as differences werefound in these evaluated parameters.

Variability of traits and bioactive compounds in the fruit and pulp of six mamey apple (Mammea americana L.) accessions.

Our objective was to compare fruit morphology, physico-chemistry and bioactive compounds content of the edible pulp of six Mammea americana accessions. The results showed that this fruit was rather big, weighing on average 600 to 1100g depending on the accession, and spherical to oblate-shaped. The pulp represented between 50 and 70% of the weight of the whole fruit. The pulp adhered only partially to the seeds in 5 of the 6 accessions studied, while the last one exhibited full adherence. The fresh pulp was acidic, sweet, succulent and crunchy. The fruits studied had a variety of qualities, providing various opportunities for post-harvest uses: fruit salads, nectar preparation, jams and jellies, or export. We have established for the first time the total phenolic compounds and total flavonoids contents in the pulp of mamey apple fruits. The pulp colour was highly correlated with total phenolic compounds and total carotenoids contents.

Physical Function, Quality of Life, and Energy Expenditure During Activities of Daily Living in Obese, Post-Bariatric Surgery, and Healthy Subjects.

OBJECTIVES: This study aimed to evaluate physical function (PF), quality of life (QOL), and energy expenditure (EE) during activities of daily living (ADL) in late outcome post-bariatric surgery (BS) patients and to compare them to severe obese individuals and matched controls. METHODS: Sixty-three subjects were included: 21 patients in post-operative (PO) of BS (3-4 years post-Roux-en-Y gastric bypass) with a stable weight for at least 6 months (16 women, 41 ± 11 years old, BMI = 28 ± 4 kg m-2) (group PO); 21 obese individuals with BS indication (16 women, 44 ± 9 years old, BMI = 44 ± 6 kg m-2) (group OB); and 21 controls matched to PO by gender, age, and BMI (16 women, 42 ± 12 years old, BMI = 27 ± 6 kg m-2) (group MC). PF was objectively assessed by the Glittre and modified Glittre ADL-tests. QOL (SF-36), EE (activity monitoring during ADL), and body composition (bioelectrical impedance) were also assessed. RESULTS: OB had worse PF (Glittre ADL-test) compared to PO and MC (OB = 224 ± 76 s; PO = 143 ± 39 s; and MC = 118 ± 17 s; p < 0.0001). The same was observed for QOL (p < 0.05 for all SF-36 domains). OB also had higher total EE in the Glittre ADL-test. However, 63% of the activity time was in low-intensity EE. In the Glittre modified protocol, OB had poorer performance than PO and MC when walking up/downstairs, rising/sitting in a chair, and moving objects on a shelf. CONCLUSIONS: Post-BS patients have better PF and QOL and perform activities under lower total EE than obese subjects, very similar to matched controls.

Sourdough fermentation and chestnut flour in gluten-free bread: A shelf-life evaluation.

The effect of sourdough fermentation combined with chestnut flour was investigated for improving technological and nutritional quality of gluten-free bread during 5day shelf life by means of chemico-physical and nutritional properties. Sourdough fermentation by itself and with chestnut flour reduced volume of loaves and heterogeneity in crumb grain. Sourdough technology allowed increasing crumb moisture content with no significant variations during shelf-life. Chestnut flour darkened crumb and crust while no effects on colour were observed for sourdough. Sourdough and/or chestnut flour addition caused a significant increase in crumb hardness at time 0 while a significant reduction of staling was observed only at 5days, even if a decrease in amylopectin fusion enthalpy was observed. The percentage of hydrolysed starch during in vitro digestion was significantly reduced by sourdough fermentation with a presumable lower glycaemic index.

Validity and Reproducibility of the Glittre ADL-Test in Obese and Post-Bariatric Surgery Patients.

BACKGROUND: Obese and post-bariatric surgery (BS) subjects often present limitations in physical functioning (PF). The Glittre ADL-test is a simple and useful way to evaluate this outcome. It includes functional activities such as rising from a chair, lifting, carrying weights, and bending over and was never studied in the obese population. This study aimed to determine the validity and reproducibility of the Glittre ADL-test to evaluate PF in obese, post-BS, and healthy control subjects. METHODS: Twenty-one post-BS patients (3-4 years post-surgery) (16 women, 41 ± 11 years, BMI = 28 ± 4 kg m-2) (group PO); 21 obese individuals (16 women, 44 ± 9 years, BMI = 44 ± 6 kg.m-2) (group OB) and 21 control individuals matched to PO (16 women, 42 ± 12 years old, BMI = 27 ± 6 kg m-2) (group MC) were included. For the reproducibility analysis, the Glittre ADL-test was performed twice, with a 30-min interval. As criterion methods for the validation, subjects performed two walking tests and answered a health status questionnaire (SF-36). RESULTS: High intraclass correlation (OB: r = 0.91 and PO: r = 0.89; MC: r = 0.86; P < 0.0001 for all) and good Bland-Altman agreement between the two tests were found in all groups. However, learning effect ranged between 8.8 and 11.8 % and significant test-retest differences occurred. The test was valid for all groups (moderate-to-high significant correlations with the criterion methods). CONCLUSIONS: Glittre ADL-test is valid and reproducible to evaluate PF of obese, post-BS, and healthy control subjects. However, due to the large learning effect, two tests are required for accurate assessment.

Durum and soft wheat flours in sourdough and straight-dough bread-making.

In the present work, the bread-making performance of durum wheat flour under straight-dough and sourdough procedures were compared to those offered by soft wheat flour by means of selected physical properties (colour, texture, water dynamics, crumb grain characteristic, bulk volume) immediately after baking and during a 5-day shelf-life. The use of sourdough process better preserved both crumb grain characteristic and moisture content of the breads during shelf-life, independently of the wheat flour used. The flour seemed to significantly affect the water dynamics in sourdough breads, being the dehydration process of crust and under-crust faster in durum wheat breads. On the other hand, increasing trend of crumb firmness during the shelf-life was slower in durum wheat breads than in those obtained with soft wheat flour. Initial colour parameters of crust and crumb appeared to less change during shelf-life if durum wheat flour was used. Thus, the final quality of breads after baking and along the shelf-life was significantly affected by both the type of flours and the bread-making process. The results reported herein showed that technological performances of durum wheat flour, especially when combined with sourdough processes, could be successfully exploited for the production of innovative products in the bread-making industry.

Physicochemical characterization of two deproteinized bovine xenografts

Calcium phosphate salts, or more specifically hydroxyapatite, are products of great interest in the fields of medical and dental science due to their biocompatibility and osteoconduction property. Deproteinized xenografts are primarily constituted of natural apatites, sintered or not. Variations in the industrial process may affect physicochemical properties and, therefore, the biological outcome. The purpose of this work was to characterize the physical and chemical properties of deproteinized xenogenic biomaterials, Bio-Oss (Geistlich Biomaterials, Wolhuser, Switzerland) and Gen-Ox (Baumer S.A., Brazil), widely used as bone grafts. Scanning electron microscopy, infrared region spectroscopy, X-ray diffraction, thermogravimetry and degradation analysis were conducted. The results show that both materials presented porous granules, composed of crystalline hydroxyapatite without apparent presence of other phases. Bio-Oss presented greater dissolution in Tris-HCl than Gen-Ox in the degradation test, possibly due to the low crystallinity and the presence of organic residues. In conclusion, both commercial materials are hydroxyapatite compounds, Bio-Oss being less crystalline than Gen-Ox and, therefore, more prone to degradation.

Efeitos da aplicação de transglutaminase na fabricação do pão de forma / Effects of transglutaminase application on breadmaking

Este trabalho teve o objetivo de avaliar o efeito da adição da transglutaminase microbiana (MTGase) na fabricação de pão de forma, através do desenvolvimento de formulação ideal, com combinações de aditivos e enzima, e da avaliação do efeito da enzima nas proteínas, na massa crua, na massa após a fermentação e no produto final. Para comparar a qualidade dos pães produzidos com ou sem enzima, foram testadas três formulações: a básica, livre de aditivos (pão Zero); com a adição de emulsificante e ácido ascórbico (pão Controle); e a preparada com a formulação básica adicionada de enzima (pão MTGase). A avaliação da qualidade dos pães foi feita por meio de medidas físicas e instrumentais. A análise de textura foi realizada pelo método TPA (Texture Profíle Analysis), cujas respostas de firmeza, elasticidade, mastigabilidade e gomosidade podem ser correlacionadas com análises sensoriais. Paralelamente, de amostras de farinha, de massa e de pão foram obtidas as frações protéicas de gliadinas, gluteninas e os resíduos de extração. As gliadinas e as gluteninas foram analisadas por cromatografia líquida de alta eficiência em fase reversa e por eletroforese em gel de poliacrilamida contendo SDS. Os resultados de volume e de firmeza dos diferentes pães apresentaram diferenças significativas a nível de 5%, em que as respostas do pão MTGase foram melhores que as do pão Zero, porém ainda inferiores às do Controle. A melhor formulação foi obtida por meio de um planejamento composto central, com variações nas concentrações de emulsificante, ácido ascórbico e enzima, com os resultados avaliados pela metodologia de superfície de resposta. Exceto para a coesividade, todos os outros parâmetros de volume, dureza (TA), firmeza, elasticidade, mastigabilidade e gomosidade (TPA) apresentaram resultados positivos pela ação da transglutaminase a 0,6%, combinada com 0,2 % de emulsificante e 70 ppm de ácido ascórbico. Os resultados sugerem que a enzima foi capaz de modificar as propriedades químicas das proteínas, o comportamento reológico da massa e as propriedades funcionais do pão, melhorando a força da massa, a textura e o volume dos pães. As análises das frações gliadínicas apresentaram cerca de 3% de Nitrogênio total, em base seca, e as frações glutenínicas apresentaram entre 2 e 5% de Nitrogênio total. Os perfis cromatográficos e eletroforéticos dessas frações sugerem que as gliadinas não foram afetadas pela presença da enzima, que envolveram sobretudo as gluteninas. O conjunto de resultados indica que a aplicação de MTGase em associação com aditivos convencionais pode ser uma alternativa à panificação, embora os mecanismos de sua ação na massa não estejam completamente esclarecidos

The application of microbial transglutaminase on weak gluten flour used in breadmaking was studied over the process. To verify the enzyme effects, three formulations were tested: Base formulation, characterized by the absence of enzyme and emulsifying agents; Control formulation, comprised by the presence of emulsifying agents and ascorbic acid and MTGase formulation, with the enzyme. Samples of flour, dough and bread were analyzed. The effect of enzyme on bread quality was estimated by parameters of Texture Analysis, Texture Profile Analysis and specific volume. The protein contents from those samples were determined by the total nitrogen in glutenin and gliadin fractions, that were also analyzed by RP-HPLC (reversed phase high performance liquid chromatography) and by SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis). Although the MTGase bread did not reach the same quality parameters as those achieved by the Control samples, it showed as an alternative formulation to reduce the quantity of emulsifying agents and ascorbic acid as compared to the Control. The results indicate that the enzyme modified chemical and functional properties of glutenin fraction, improving dough strength and bread volume. Results of total nitrogen content, and electrophoretic and chromatographic profiles of the protein fractions suggest that while glutenin proteins were modified by enzyme, gliadin proteins were not affected