Measurement of the relative sweetness of stevia extract, aspartame and cyclamate/saccharin blend as compared to sucrose at different concentrations

Special diets are used to mitigate many human diseases. When these diets require changes in carbohydrate content, then sweetness becomes an important characteristic. The range of low-calorie sweeteners available to the food industry is expanding. It is essential to have an exact knowledge of the relative sweetness of various sweeteners in relation to different sucrose concentrations. The objective of this study was to determine the variation on the relative sweetness of aspartame (APM), stevia [Stevia rebaudiana (Bert.) Bertoni] leaf extract (SrB) and the mixture cyclamate/saccharin - two parts of cyclamate and one part of saccharin - (C/S) with the increase in their concentrations, and in neutral and acid pH in equi-sweet concentration to 10% sucrose, using magnitude estimation. Sweetness equivalence of SrB in relation to sucrose concentrations of 20% or higher and of APM and C/S to sucrose concentrations of 40% or higher could not be determined, because a bitter taste predominated. The potency of all sweeteners decreased as the level of sweetner increased. In equi-sweet concentration of sucrose at 10%, with pH 7.0 and pH 3.0, the potency was practically the same for all sweeteners evaluated.

GREEN MACHINING ORIENTED TO DIMINISH DENSITY GRADIENT FOR MINIMIZATION of DISTORTION IN ADVANCED CERAMICS

After sintering advanced ceramics, there are invariably distortions, caused in large part by the heterogeneous distribution of density gradients along the compacted piece. To correct distortions, machining is generally used to manufacture pieces within dimensional and geometric tolerances. Hence, narrow material removal limit conditions are applied, which minimize the generation of damage. Another alternative is machining the compacted piece before sintering, called the green ceramic stage, which allows machining without damage to mechanical strength. Since the greatest concentration of density gradients is located in the outer-most layers of the compacted piece, this study investigated the removal of different allowance values by means of green machining. The output variables are distortion after sintering, tool wear, cutting force, and the surface roughness of the green ceramics and the sintered ones. The following results have been noted: less distortion is verified in the sintered piece after 1mm allowance removal; and the higher the tool wear the worse the surface roughness of both green and sintered pieces.

Attitude stability of artificial satellites subject to gravity gradient torque

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dinâmica sazional de fungos micorrízicos arbusculares (Glomeromycota) em cerradão e brejo de altitude na Chapada do Araripe, CE

Arbuscular mycorrhizal fungi (AMF) are obligatory symbiotic organisms that associate with roots of a large number of plant taxa, and are found in all terrestrial ecosystems. These fungi promote greater tolerance to environmental stresses to associated plant, favoring the establishment of plant communities, especially where soil fertility is a limiting factor, as in the Caatinga, an exclusively Brazilian domain that has been focus of research due to its great biodiversity that can help clarify the history of vegetation in South America. Because of the ecological importance of AMF, the limited number of jobs and the potential diversity of the Caatinga, this work aims to inventory the diversity and determine AMF communities in areas with different faces occurrent in FLONA Araripe, Ceará (CE). The sample collection occurred in four periods at the beginning and end of the dry season (August and December 2011, respectively) and rainy (February and June 2012, respectively) in an area of marsh and woodland altitude of the Araripe, Crato, CE. The glomerosporos were extracted by wet sieving and centrifugation in water and sucrose (50%) mounted between slide and coverslip using PVLG and PVLG + Reagent Melzer. In total, we found 46 species of AMF distributed in eight families and 16 genera: Acaulospora (6), Ambispora (1), Cetraspora (2), Dentiscutata (5), Fuscutata (2), Gigaspora (6), Glomus (13) Intraornatospora (1), Kuklospora (1), Orbispora (1), Paradentiscutata (1), Quatunica (1), Racocetra (1), Scutellospora (2), Septoglomus (2) and a new genus. analysis showed that ecological each area of study has its own seasonal dynamics, with an area of woodland with a greater diversity of species throughout the year, while the marsh elevation showed greater variation in species found among the collection periods, showing that vegetation and rainfall has strong influence on the seasonal dynamics of AMF, as well as the availability of nutrients and soil pH so

Selection of X chromosome of buffaloes sperm with Percoll gradients

The aim of the present study was to evaluate the selection of X chromosome of buffaloes sperm with Percoll gradients. The stock solution of Percoll was prepared in the proportion of 1:11 (1 part of Percoll:11 parts of a solution containing KCl 1M, NaH(2)PO(4) 0.1M, NaCl 1.5M and sodium HEPES 23.8 g/ml). In order to prepare 9 different gradients were added to the stocked Percoll the A solution (glicine-yolk extender) in the following proportions: 90, 80, 72, 65, 57, 49, 34 and 25%. A sample of 0.7 ml of the fresh semen was deposited at 2 ml of Percoll 80% for the sperm wash. The precipitate was put in tube with 0.7 ml of each gradient. Then, the precipitated was washed in TES solution by centrifugation (500xg for 10 minutes), and collected again and diluted in TES solution to be freeze. The presence of the F body in the spermatozoa was observed in 58.7 +/- 5.4% of the control group and in 41.2 +/- 5.4% of the treated group (p<0.01). This result showed an increment of 17.55 of male sperm in the Percoll's group. The reduction of the centrifugation force did not improve the percentage of X sperm.

Penetration of zona-free hamster, bovine and equine oocytes by stallion and bull spermatozoa pretreated with equine follicular fluid, dilauroylphosphatidylcholine or calcium ionophore A23187

Experiments evaluated the ability of follicular fluid (FF), dilauroylphosphatidylcholine (PC12) and the calcium ionophore A23187 (A23187) to induce capacitation in stallion and bull spermatozoa, determined by the ability of the spermatozoa to penetrate zona-free hamster, bovine and equine oocytes. Spermatozoa suspensions were incubated at 37 degreesC in one of the following treatments: 1) a modified Tyrode's medium (BGM3) alone, 2) BGM3 + FF; 3) BGM3 + PC12; 4) BGM3 + FF + PC12; 5) BGM3 + A23187; and 6) BGM3 + FF + A23187. Treated spermatozoa were incubated with zona-free hamster, bovine and equine oocytes for 3 h, after which oocytes were stained to assess spermatozoa penetration. The number of hamster oocytes penetrated by spermatozoa incubated in BGM3 alone (1/30) or in presence of FF (2/31) was significantly lower (P < 0.05) than by spermatozoa treated with PC12 or A23187 (16/30 and 17/30, respectively). Processing stallion spermatozoa either by a swim-up procedure or by centrifugation through a Percoll gradient increased the percentages of motile spermatozoa in the final sample, and spermatozoa collected by both processes penetrated similar numbers of zona-free hamster oocytes (P > 0.05). Although treating spermatozoa with PC12 or A23187 enabled both stallion and bull spermatozoa to penetrate oocytes, higher numbers of bovine oocytes were penetrated by bull spermatozoa (25/30) than by stallion spermatozoa (4/30) regardless of spermatozoal treatment. However, the number of zona-free hamster and equine oocytes penetrated by bull spermatozoa (25/30 and 12/18 respectively) and stallion spermatozoa (17/30 and 15/21 respectively) were similar (P > 0.05). We conclude that both PC12 and A23187 capacitate stallion and bull spermatozoa sufficiently to permit the acrosome reaction to occur, enabling spermatozoa to penetrate homologous and heterologous zona-free oocytes. (C) 2001 by Elsevier B.V.

Baclofen into the lateral parabrachial nucleus induces hypertonic sodium chloride and sucrose intake in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of N-acetylcysteine on sucrose-rich diet-induced hyperglycaemia, dyslipidemia and oxidative stress in rats

This study examined whether sucrose-rich diet (SRD)-induced hyperglycaemia, dyslipidemia and oxidative stress may be inhibited by N-acetylcysteine (C5H9-NO3S), an organosulfur from Allium plants. Male Wistar 40 rats were divided into four groups (n = 10): (C) given standard chow and water; (N) receiving standard chow and 2 mg/l N-acetylcysteine in its drinking water; (SRD) given standard chow and 30% sucrose in its drinking water; and (SRD-N) receiving standard chow, 30% sucrose and N-acetylcysteine in its drinking water. After 30 days of treatment, SRD rats had obesity with increased abdominal circumference, hyperglycaemia, by dyslipidemia and hepatic triacylglycerol accumulation. These adverse effects were associated with oxidative stress and depressed lipid degradation in hepatic tissue. The SRD adverse effects were not observed in SDR-N rats. N-Acetylcysteine reduced the oxidative stress, enhancing glutathione-peroxidase activity, and normalizing lipid hydroperoxyde, reduced glutathione and superoxide dismutase in hepatic tissue of SRD-N rats. The beta-hydroxyacyl coenzyme-A dehydrogenase and citrate-synthase activities were increased in SRD-N rats, indicating enhanced lipid degradation in hepatic tissue as compared to SRD. SRD-N rats had reduced serum oxidative stress and diminished glucose, triacylglycerol, very-low-density lipoprotein (VLDL), oxidized low-density lipoprotein (alpha-LDL) and cholesterol/highdensity lipoprotein (HDL) ratio in relation to SRD. In conclusion, NAC offers promising therapeutic values in prevention of dyslipidemic profile and alleviation of hyperglycaemia in high-sucrose intake condition by improving antioxidant defences. N-Acetylcysteine had also effects preventing metabolic shifting in hepatic tissue, thus enhancing fat degradation and reducing body weight gain in conditions of excess sucrose intake. The application of this agent in food system via exogenous addition may be feasible and beneficial for antioxidant protection. (c) 2006 Elsevier B.V All rights reserved.

N-acetylcysteine in high-sucrose diet-induced obesity: Energy expenditure and metabolic shifting for cardiac health

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

N-Acetylcysteine an Allium Plant Compound Improves High-Sucrose Diet-Induced Obesity and Related Effects

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Temporal and spatial variability in the macrozoobenthic community along a salinity gradient in the Castillos Lagoon (Uruguay)

The macrozoobenthic community of the Castillos Lagoon system (East Coast of Uruguay) was sampled during autumn, winter, spring and summer of 1991, in order to describe the community structure and the spatial and temporal patterns of distribution. Eleven sampling stations were distributed along a salinity gradient in a north-south direction (8 replicates were collected at each station). The maximum density of organisms was found at the central part of the lagoon (stations 6 and 7) where the bivalve Erodona mactroides and gastropod Heleobia australis were dominants. No significant correlation between the overall abundance of organisms and salinity could be demonstrated (r = 0.43, p > 0.1). However, a reduction in organism abundance between the autumn and the summer coincided with a marked drop in salinity. Falling levels of dissolved oxygen could have influenced the decreasing density of organisms (r = 0.75, p < 0.05). Species richness and diversity were correlated (p < 0.1) with salinity but the degree of correlation was not uniformly significant between sampling periods.

Sucrose hydrolysis by gelatin-immobilized inulinase from Kluyveromyces marxianus var. bulgaricus

The crude cell-free medium from a culture of Kluyveromyces marxianus var. bulgaricus was immobilized in a gelatin-water support, with an immobilization yield of 82.60% for inulinase activity. The optimum pH for both free and immobilized inulinase was the same (3.5) and the optimum temperatures were 55 degrees C for the free and 60 degrees C for the immobilized enzyme. The Arrhenius plots were linear and activation energies were 56.20 (free enzyme) and 20.27 kj/mol K (immobilized enzyme). The kinetic parameters were calculated by Lineweaver-Burk plots and the V-max and K-m were 37.60 IU/mg protein and 61.83 mM for the free inulinase and 31.45 IU/mg protein and 149.28 mM for the immobilized enzyme, respectively. The operational stability of the immobilized inulinase was studied in a continuous fixed-bed column reactor for 33 days, at the end of which the sucrose conversion was 58.12%. (c) 2008 Elsevier Ltd. All rights reserved.

Influence of nitrogen source and sucrose concentration on inulinase production by Kluyveromyces marxianus in fed-batch fermentation

This work studied the influence of nitrogen source and sucrose concentration in the feeding medium for biomass and inulinase production by Kluyveromyces marxianus var. bulgaricus. The results show that the best nitrogen source was a combination of 5 g/L of yeast extract and 10 g/L of peptone. Both cellular growth and enzymatic activity increased with sucrose concentration in the feeding medium (from 200 to 500 g/L). When the sucrose concentration reached 600 g/L, both cellular growth and enzymatic activity decreased.

Reproductive phenology of Euterpe edulis (Arecaceae) along a gradient in the Atlantic rainforest of Brazil

The palm Euterpe edulis Mart. is one of the dominant tree species in the Atlantic rainforest and considered a key resource for many frugivorous birds. We compared the reproductive phenology of E. edulis in three types of Atlantic rainforest (two lowland forests, restinga and coastal-plain, and a premontane forest) on Cardoso Island (Cananeia, São Paulo, Brazil), aiming to answer the following questions: (i) whether the reproduction of E. edulis is annual and seasonal across the years in the three forest types studied; (ii) what are the environmental factors influencing the reproductive phenology of E. edulis; and (iii) how does the timing of fruiting and fruit production of E. edulis vary among the three forest types? We evaluated the presence of flowers and fruits (immature, unripe and ripe) from August 2001 to July 2004 in 150 individuals (50 per forest), and estimated the number of infructescences with ripe fruits and the production of fruits and seeds by collecting them on the forest floor in the three forest types. Flowering and fruiting of E. edulis were annual and significantly seasonal in the three forest types, with a high synchrony of flowering and medium to low synchrony of fruiting. Flowering peaked in November and December, and immature and unripe fruits peaked in January and March, all during the rainy season. Immature and unripe fruit phases were correlated with the daylength, precipitation and temperature, important factors for fruits development. Ripe fruits peaked in April and May, in the less rainy season, with significant differences in the mean dates among forests. The number of infructescences with ripe fruits and the biomass of fruits and seeds collected on the ground also differed significantly among the forest types, being greater in the restinga and coastal plain forests, respectively. Differences in productivity were related to palm density in each area and the soil fertility. The complementary fruiting pattern of E. edulis in the forests studied may affect the distribution and abundance of certain frugivorous bird species that feed on their fruits.

Variation in liana abundance and biomass along an elevational gradient in the tropical Atlantic Forest (Brazil)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)