Mudanças nas pectinases, fibras dietéticas e índices físico-químicos relacionados ao sabor de frutos de cubiu durante a maturação

The objective of this study was to evaluate the changes in the activity of pectinases (pectinesterase and polygalacturonase), dietary fiber content (alcohol-insoluble solids, pectin, and total fiber), and physicochemical indices related to the flavor (pH, titratable acidity, soluble solids, Brix/acid ratio, and reducing and nonreducing sugars) of cubiu fruits (Solanum sessiliflorum Dunal) at different stages of ripening (green, turning, ripe, and fully ripe). Alcohol-insoluble solids and pectin were very similar, with the highest levels detected at the green and turning stages, and the lowest levels occurring at the fully ripe stage. The amount of total fiber was consistent at the green, turning, and ripe stages, but declined at the fully ripe stage. These changes correlated with the pectinase activities, the profiles of which resembled those of other species of the Solanaceae family during fruit ripening. However, cubiu fruits were significant sources of dietary fiber at all stages. The reducing sugar content reached the highest level at the turning stage, with glucose as the major sugar. The content of nonreducing sugars, such as sucrose, remained low at all stages. The other physicochemical indices displayed increases during ripening, characterizing cubiu as a very acidic fruit with a small degree of sweetness. © 2015, Eduem - Editora da Universidade Estadual de Maringa. All rights reserved

Effect of the Harvest Date on the Chemical Composition of Patauá (Oenocarpus bataua Mart.) Fruits from a Forest Reserve in the Brazilian Amazon

This study aims to evaluate the effect of harvest date on the chemical composition of patauá (Oenocarpus bataua Mart.). Fruits were harvested monthly during the harvest season (June-December, 2009) from native plants in the Adolpho Ducke Forest Reserve located in Manaus, Amazonas, Brazil. The patauá was assessed for pulp yield and chemical composition. Variations in the bunch size, quantity of fruits, chemical constituents and calories occur throughout the season. The pulp yield showed two plateaus, the first from June to September and the second from October to December. The pulp yield was highest in the last three months, the amount of added water equilibrates the total solids and the lipids stood out as the major chemical constituent. At the end of harvest, the patauá became dry and oily and less fibrous. Despite the significant differences, considering that the pulp yield and solids content can be standardized by added water, the entire period of the season may be indicated for the patauá can be periodically collected and considered as a high-energy food for the people of Amazon

Seleção de Basidiomycetes da Amazônia para produção de enzimas de interesse biotecnológico

Mushrooms, edible basidiomycetes, have been extensively used as producers of different substances of economical interest, such as enzymes, antibiotics, vitamins, amino acids, and steroids. The objective of this study is to detect the production of enzymes such as amylases, proteases, cellulases, phenoloxidases and pectinases for lineages of basidiomycetes originating from the Amazonian forest. For the production of enzymes, mushrooms were cultivated in a liquid medium with substratum (0,5%), pH adjusted for each enzyme, and incubated at 28 °C, under agitation and 140 rpm for 96 or 120 hours. After this period, the samples were filtered for the separation of the mycelial mass. The filtrates were inoculated in solid medium surface perforated cup-plates of 6 mm diameter, appropriate for the detection of enzymes in Petri dishes. The plates were incubated at 28 °C for 24 hours, for observation to reveal enzymatic halos. It was verified the activity of the amylase and protease produced by the mushrooms grown in the liquid medium, with different nutritive sources. It was possible to detect the cellulase and protease production for all the ones that were isolated, 40% produced amylases, 50% produced phenoloxidases, and 10% produced pectinases. Regarding the activity of the amylase, the wheat bran substrate presented the largest degradation halos revealing Daedalea sp.4E6 and Daedalea sp. 1A, Stereaceae 22B and Pycnoporus sanguineus 12B mushrooms. Considering the substrata tested for protease production, it was observed that the fish protein concentrate was the best. The P. sanguineus 12B, Stereaceae 22B and Cantharellus guyanensis 4Bl mushrooms were the best protease producers

SUPLEMENTAÇÃO DE CREATINA EM IDOSOS

O envelhecimento populacional é um fato na sociedade moderna devido a urbanização e aos avanços tecnológicos que possibilitaram o aumento da expectativa de vida da população. Assim, os idosos passaram a ser um grupo etário expressivo na organização familiar, o que faz surgir o interesse de estudos deste contingente com o intuito de melhorar sua qualidade de vida. Nesse sentido, o presente estudo tem por objetivo estudar os benefícios da suplementação de creatina em idosos. Trata-se de uma revisão da literatura nacional e internacional da última década. O estudo foi realizado utilizando as bases científicas: Scientific Electronic Library Online, Public Medline, Google Acadêmico e da Revista Brasileira de Nutrição Esportiva, identificando artigos sobre o tema referenciados em seus trabalhos. Portanto, conclui-se que a suplementação de creatina em idosos, aliada a prática regular de atividade física, traz benefícios a sua qualidade de vida

Partial characterization of amylases of two indigenous central amazonian rhizobia strains

Amylase production and partial characterization of crude enzyme preparations from two rhizobia strains (R-926 and R-991) were evaluated. For both the strains, maximal amylase activities were achieved during the early-to-midexponential growth phase; both were active over a pH range from 4.5 to 8.5 and temperature from 30 to 50 °C. None of the ions studied (K+, Na+, Ca2+, Hg2+, Mg2+, Mn2+, Cu2+ and Zn2+) was required for the catalytic activity of strain R-926; amylase activity of strain R-991 was stimulated in the presence of K+, Hg2+ and Zn2+. The surfactants SDS, Triton X-100 and Tween-80 did not have a pronounced inhibitory effect on enzyme activities; SDS and Tween-80 caused the highest stimulatory effects. Amylase activities from the rhizobia strains were reduced by up to 30% in the presence of EDTA; amylase activity of R-926 was also inhibited by HgCl2, suggesting that Ca2+and cysteine residues could be important for activity of this strain

Conservation of pcjibaye heart-of-Palm in modified atmosphere

The market for pejibaye (Bactris gasipaes) heart-of-palm is expanding rapidly in Brazil and is starting to differentiate into various market niches, including a fresh product niche. Conservation of ready-to-use, minimally processed fresh heart is difficult and requires research on refrigeration and modified atmosphere to enhance shelf-life. The sensory characteristics of fresh heart-of-palm were evaluated during its storage in polyethylene bags under refrigeration with and without an oxygen absorber. Texture, crispness, fiber, humidity, astringency and acridity remained acceptable until the end of the trial at 25 days, although each was extremely variable from day to day, probably due to within-package genotype variation. Color, appearance, sweetness and sourness remained acceptable for 14 days and deteriorated from the 18th day on. Sourness increased significantly (p = 0.02) in the treatment with reduced oxygen, especially after the 18th day and was the most objectionable characteristic. The use of oxygen absorbent did not significantly improve the shelf-life of fresh heart-of-palm, although the use of polyethylene may have reduced the efficiency of the absorbent.O mercado do palmito de pupunha (Bactris gasipaes) está expandindo rapidamente no Brasil e diferenciando-se com a inclusão do palmito fresco ou minimamente processado. Devido sua alta perecibilidade, a conservação desse palmito fresco é difícil e requer estudos de conservação em refrigeração aliada à atmosfera modificada. As qualidades sensoriais do palmito fresco foram avaliadas ao longo de sua conservação sob refrigeração, em sacos de polietileno, com e sem absorvente de oxigênio. A textura, crispidez, fibrosidade, umidade, adstringência e irritação permaneceram aceitáveis até os 25 dias, embora altamente variáveis de um dia para o outro, provavelmente devido à variação entre os genótipos em cada embalagem. A cor, aparência, doçura e amargor permaneceram aceitáveis até 14 dias e deterioraram a partir do 18º dia. O amargor aumentou significativamente (p = 0,02) no tratamento com absorvente de oxigênio, especialmente a partir do 18º dia, sendo a principal característica responsável pela rejeição do palmito. O uso do absorvente de oxigênio não aumentou significativamente a vida de prateleira do palmito fresco, embora o polietileno usado possa ter reduzido a eficácia do absorvente

Quality Attributes of Cupuaçu Juice in Response to Treatment with Crude Enzyme Extract Produced by Aspergillus japonicus 586

Cupuaçu (Theobroma grandiflorum Schum) is an Amazonian Basin native fruit whose fruit pulp is consumed as a juice which presents high density, viscosity, and turbidity. Pectic enzymes, usually yielded by microorganisms, are used to reduce the juice viscosity and turbidity. The present study aims to evaluate the use of pectic enzymes when processing cupuaçu juice. The cupuaçu juice was obtained by using Aspergillus japonicus 586 crude enzyme extract and incubation at 50°C with agitation (140 rpm) for one hour. Enzyme activities were determined, and the juices were evaluated as to their yield, turbidity, viscosity, and chemical composition. The juice produced by using crude enzyme extract presented higher soluble solids, reducing sugars, and lower viscosity and turbidity

Cinética de secagem da polpa cupuaçu (Theobroma grandiflorum) pré desidratada por imersão-impregnação

The osmotic dehydration is an important unitary operation to transform the perishable fruits in new products with added value and longer shelf life. The application of reliable mathematical models allows prediction the behavior of various phenomena that occur during the drying process, which implies in reduction of operating cost. The cupuaçu pulp is commonly used to prepare juices and ice creams, but during the crop it is produced in large quantity, which is often discarded because of the cost of production is higher than the selling price. The aim of this study was to investigate the effect of binary and ternary solutions at the rate of convective drying and evaluate the adequacy of mathematical models to describe the drying curves of the cupuaçu. In the experiment, osmotic dehydration was carried out with binary (sucrose at 40°Brix) and ternary (80% sucrose/20% sodium chloride) solutions for three hours at room temperature, followed by conventional drying in an oven (air-circulating) at 65°C to constant weight. The experimental data were adjusted using the models of Page and Midilli, Kucuk and Yapar. The binary solution used during predrying, reduced the time of the subsequent conventional drying. Varying from 99.64 to 99.77% in the coefficient of determination (R2), the Page model showed a better adjustment to experimental data

Enzimas hidrolíticas extracelulares de isolados de rizóbia nativos da Amazônia Central, Amazonas, Brasil

Legumes enrich the soil by contributing nitrogen through symbiotic biological nitrogen fixation by rhizobia bacteria. However, very little is known about the extracellular enzymatic profile of these microorganisms. In this context, the production of extracellular hydrolytic enzymes by indigenous strains of rhizobia in Central Amazonia was evaluated. This screening constitutes the first step in selecting indigenous microorganisms that are potentially exploitable as enzyme producers. Indigenous strains of rhizobia were screened for extracellular amylolytic, carboxymethylcellulolytic, lactolytic, lipolytic, pectinolytic and proteolytic activities on modified YMA. Ureolytic activity was detected on a urea-agar slant. Rhizobia strains isolated from cowpea nodules produced more enzymes than those isolated from soybean nodules. Out of all the extracellular hydrolytic enzymes evaluated, only pectinase was not detected in this study. The most frequent rhizobia enzymes were amylase (32.8%), protease (28.4%), urease (20.9%) and carboxymethylcellulase (9.0%). In this study, only amylase and protease enzymes varied significantly among rhizobia strains. INPA strains R-926 and R-915 showed the highest enzymatic levels for amylase (EI = 3.1) and protease (EI = 6.6), respectively. This paper showed some indigenous strains of rhizobia from Central Amazonia as promising sources of industrially relevant enzymes for biotechnological purposes

Produção de amilase por rizóbios, usando farinha de pupunha como substrato

Amylases are among the most important industrial enzymes and are of great significance in present-day biotechnology. Although they can be derived from various sources, enzymes from microbial sources are generally the most required by industry. Species of the genus Bacillus are considered to be the main sources of amylases, although screening for new microbial sources is increasing all over the world. The objective of the present study was to evaluate the production of amylase by indigenous rhizobia, using peach palm flour as substrate. In this study, a completely randomized experimental design was adopted with three replicates. Pearson's correlation coefficients were calculated for medium pH, extracellular protein, cellular biomass, mean colony diameter (MCD), mean halo diameter (MHD), enzymatic index (EI) and amylolytic activity variables from the bacteria selected. Out of the 19 rhizobia strains with amylolytic activity on modified YMA, seven (36.8%) strains showed "EI" ≥ 2,1, and they were considered as good producers of amylase. The "IE" presented by bacteria INPA R-987, R-950 and R-915B were significantly lower (p < 0.01) than those shown by the INPA R-926, R-975 and R-957. The amylolytic activity varied significantly (p < 0.01) among the rhizobia strains. INPA R-975 and R-926 strains presented, respectively, the highest (1.00 U.min-1.mL-1) and the lowest (0.31 U.min-1.mL-1) activity average. In general terms, the extracellular protein was correlated positively with "EI" (r = 0.52*; p < 0.05) and "MHD" (r = 0.55*; p < 0.05). The cellular biomass showed positive correlations with amylolytic activity (r = 0.55*; p < 0.05) and "MHD" (r = 0.54*; p < 0.05), and a negative with final pH medium (r = 0.93**; p < 0.01)