Qualidade do café natural e despolpado após secagem em terreiro e com altas temperaturas

Objetivou-se no presente trabalho verificar a qualidade do café natural e despolpado durante a secagem em terreiro e secagem com ar aquecido a 40º e 60ºC. O trabalho foi realizado no Departamento de Engenharia e no Pólo de Tecnologia em Pós-Colheita do Café da Universidade Federal de Lavras (UFLA). A colheita do café, cultivar Topázio, foi seletiva. Parte do café foi despolpado e outra parte processado de forma natural. Uma parcela de cada tipo de café foi conduzida para a secagem em terreiro e outra parcela para secagem com temperaturas de 40ºC e 60ºC. Para avaliação da qualidade, foram feitos teste de condutividade elétrica e lixiviação de potássio; determinação de acidez titulável total; teste de acidez graxa; açúcares totais e redutores. Os resultados obtidos permitem concluir que: o tempo para secagem é afetado pelos diferentes tipos de secagem e processamentos; a condutividade elétrica, a lixiviação de potássio, a acidez titulável total e a acidez graxa aumentam com a elevação da temperatura de secagem, independente do tipo de processamento; os açúcares redutores e os açúcares totais diminuem com o aumento da tem peratura de secagem independente do tipo de processamento; a secagem com temperatura de 60ºC afetou negativamente a qualidade do café.

Effects of corn meal and sulphuric acid on the production of cachaça

Avaliou-se o efeito da adição do fubá de milho no mosto de xarope de cana e o tratamento ácido do pé-de-cuba sobre a microbiota do processo fermentativo, acidez do vinho, grau alcoólico, rendimento e composição da cachaça. O delineamento experimental utilizado foi o de blocos casualizados, no esquema fatorial 2x3 e cinco repetições. A metodologia empregada e as análises foram as recomendadas pelo setor aguardenteiro. Os resultados permitiram concluir que a adição do ácido sulfúrico no pé-de-cuba transferiu a acidez para o vinho, não influenciando na viabilidade das leveduras, rendimento e composição da cachaça. Por outro lado, a acidificação do meio controlou as bactérias láticas no pé-de-cuba. A adição do fubá aumentou a concentração de bactérias lácticas ao final do processo fermentativo e dos álcoois homólogos superiores na cachaça, particularmente, os álcoois propílico e isobutílico.

Armazenamento refrigerado de pomelos variedades flame e henderson revestidos com cera

Objetivou-se, neste trabalho, estudar a conservação de pomelos (Citrus paradisi Macfad.) varieties 'Flame' e 'Henderson' revestidos com cera Sparcitrus e mantidos sob refrigeração (8º C ± 1º C e 95% ± 5% UR). Para cada variedade estudada, utilizou-se delineamento inteiramente casualizado, disposto em esquema fatorial 2 x 5, com 3 repetições, onde o primeiro fator correspondeu aos tratamentos com e sem a aplicação de cera (controle) e o segundo, ao tempo armazenamento (0, 10, 20, 30 e 40 dias). Cada parcela experimental foi composta por cinco frutos. Foram estudadas as seguintes variáveis: perda de massa, rendimento do suco, pH, sólidos solúveis (SS), acidez titulável (AT), SS/AT, açúcares redutores, açúcares não redutores, açúcares solúveis totais, vitamina C e aparência externa. A aplicação de cera é efetiva na preservação da aparência de pomelos 'Flame' e 'Henderson', não afetando sua qualidade interna.

Acidez total titulável, pH e tempo de redução do azul de metileno no fluido ruminal de caprinos mantidos em pastagens artificiais, exclusiva de gramíneas, ou em caatinga

O objetivo deste trabalho foi o de determinar a concentração hidrogeniônica (pH), acidez total titulável e tempo de redução do azul de metileno no fluido ruminal de caprinos com ou sem raça definida, mantidos em pastagens artificiais, exclusivas de gramíneas, ou em caatinga, durante as épocas chuvosa e seca do ano. O delineamento experimental foi inteiramente casualizado, sendo analisado em esquema fatorial 2³ (animais com e sem raça definida, pastagens artificiais e em caatinga, épocas chuvosa e seca do ano). O tipo de pastagem influenciou significativamente (p < 0,05) os valores encontrados para acidez total titulável. em relação ao pH, o tipo de pastagem e época do ano foram significativamente (p < 0,05) os fatores mais incisivos. A atividade microbiana, avaliada através dos parâmetros estudados, foi mais intensa na época das águas e na caatinga em relação à da seca e pastagens artificiais, respectivamente. Na avaliação dos resultados desses testes, deve-se sempre levar em consideração principalmente a época do ano e o tipo de pastagem, sem, no entanto, desprezar o fator raça.

Liming in the transition to no-till under a wheat-soybean rotation

Soil and subsoil aluminium toxicity has been one of the main limiting factors for soybean and wheat yields in tropical soils. Usually liming is the most effective way to deal with soil acidity and Al toxicity, but in no-till systems the soil is not disturbed making it impossible to incorporate lime in the arable layer, and lime has been usually applied on the soil surface. In this paper soybean and wheat responses to lime applied on the soil surface and/or incorporated in the soil arable layer were evaluated during the transition from conventional tillage to a no-till system. The experiment was conducted for 3 years in Parana, Brazil, using a wheat-soybean rotation. Lime rates ranging from 0.0 to 9.0 t ha(-1) were incorporated down to 20 cm and 4.5 t ha(-1) were spread or not on the soil surface. Soil samples were taken down to 60 cm, 39 months after the first lime application. Soil chemical characteristics were affected by lime application down to 60 cm deep in the profile. Soybean responded to lime irrespective of application method, but the highest accumulated yield was obtained when lime was incorporated into the arable layer. For wheat, the more sensitive the cultivar, the greater was the response to lime. During the introduction of a no-till system, lime must be incorporated into the arable layer when the wheat cultivar is Al-sensitive. (C) 2007 Elsevier B.V. All rights reserved.

Effects of nutritional factors on growth of Lactobacillus fermentum mixed with Saccharomyces cerevisiae in alcoholic fermentation

The growth of Lactobacillus fermentum was studied in mixed culture with Saccharomyces cerevisiae during alcoholic fermentation of high test molasses (HTM). Yeast extract or a group of 17 amino acids caused a strong and fast decrease in yeast viability due to the strong increase of acidity produced by bacteria. Pure culture of Lactobacillus fermentum in dry sugar cane broth confirmed amino acids as the main nutrients needed to stimulate the growth of bacterial contaminant during alcoholic fermentation. The absence of L. fermentum growth was obtained when leucine: isoleucine or valine were not added to the medium. Phenylalanine, alanine, glutamic acid, cystine, proline, histidine, arginine, threonine, tryptophane, serine and methionine inhibited the bacterial growth at least in one of the cultures of L. fermentum tested.

Study of some Brazilian Myrtaceae in Jaboticabal sp

The family Myrtaceae is one of the most important related to fruit species. In Brazil it encloses more than 100 species of native fruit from North to South of the country (Giacometti, 1992; Donadio, 1992; Mattos, 1992). The genus Eugenia, Campomanesia, Psidium and Myrciaria are the most important, grouping most of the species of some importance. The germplasm bank of the Universidade Estadual Paulista includes some of the major species. Some characteristics are typical for most of the Myrtaceae fruit species. The most relevant are the long juvenile period presented by the trees, taking long time to produce, when propagated by seed; the slow growing tree behavior; difficult to propagated by vegetative means; large variability in trees obtained by seed propagation. The cited characteristics are commented for some species as well as the fruit quality, from data obtained in trees at the same ecological conditions.The species evaluated are: 1) Eugenia stipitata Mc Vaugh; 2) Eugenia tomentosa Cambes; 3) Eugenia brasiliensis Lam.; 4) Eugenia uniflora L.; 5) Eugenia luchsnathiana Berg.; 6) Eugenia uvalha Cambess; 7) Camponesia spp; 8) Plinia edulis (Veil. Sobral); 9) Eugenia involucrata D.C.; 10) Psidium acutangulum Mart.; 11) Myrciaria dubia Mc Vaugh; 12) Engenia guabiju Berg. The main conclusions based on the data analysed are: the fruits of some species present good general characteristics, mainly for fresh consumption, as high Vitamin C, sugars, pulp and other characteristics; 'Araca-boi' presents some good fruit characteristics, but is more adapted for processing, by its high acidity; Some species present low % of edible portion and need to be improved to gain commercial acceptance. mainly the 'cabeludinha' and 'cambuca'.

Correlation between solvation of peptide-resins and solvent properties

The solvation properties of model resin and peptide-resins measured in ca. 30 solvent systems correlated better with the sum of solvent electron acceptor (AN) and electron donor (DN) numbers, in 1:1 proportion, than with other solvent polarity parameters. The high sensitivity of the (AN+DN) term to detect differentiated solvation behaviors of peptide-resins, taken as model of heterogeneous and complex solutes, seems to be in agreement with the previously proposed two-parameter model, where the sum of the Lewis acidity and Lewis basicity characters of solvent are proposed for scaling solvent effect. Besides these physicochemical aspects regarding solute-solvent interactions, important implications of this study for the solid phase peptide synthesis were also observed. Each class of peptide-resin displayed a specific salvation profile that was dependent on the amount and the nature of the resin-bound peptide sequence. Plots of resin swelling versus solvent (AN+DN) values allowed the visualization of a maximum salvation region characteristic for each class of resin. This strategy facilitates the selection of solvent systems for optimal solvation conditions of peptide chains in every step of the entire synthesis cycle. Moreover, only the AN and DN concepts allow the understanding of rules for solvation/shrinking of peptide-resins when in homogeneous or in heterogeneous mixed solvents.

Optimisation of conditions for the extraction of casearins from Casearia sylvestris using response surface methodology

Optimal conditions for the extraction of casearins from Casearia sylvestris were determined using response surface methodology. The maceration and sonication extraction techniques were performed using a 3 x 3 x 3 full factorial design including three acidity conditions, three solvents of different polarities and three extraction times. The yields and selectivities of the extraction of casearins were significantly influenced by acidity conditions. Taking into account all variables tested, the optimal conditions for maceration extraction were estimated to involve treatment with dichloromethane saturated with ammonium hydroxide for 26 h. Similar yields and selectivities for casearins were determined for sonication extraction using the same solvent but for the much shorter time of I h. The best results for stabilisation of the fresh plant material were obtained using leaves that had been oven dried at 40 degrees C for 48 h. Copyright (c) 2006 John Wiley & Sons, Ltd.

Effect of 3,4,4 '-trichlorocarbanilide on growth of lactic acid bacteria contaminants in alcoholic fermentation

3,4,4'-trichlorocarbanilide (TCC) was rested as a new method of bacterial growth control for S. cerevisiae alcoholic fermentations of diluted high test molasses (HTM). Minimal inhibitory concentration (MIC) was tested to determine the necessary concentration of TCC to control bacterial growth. The fed-batch alcoholic fermentation process was used with cell recycle similar to industrial conditions and Lactobacillus fermentum CCT 1407 was mixed in the first inoculum to grow with the yeast. Yeast extract was added into the must to stimulate bacterial growth. The best results of TCC's MIC to bacterial growth of Lactobacillus fermentum and Leuconostoc mesenteroides (< 0.125-1.0 mu g/ml) and Saccharomyces cerevisiae (16 mu g/ml) occurred when it was combined with sodium dodecylsulphate (SDS) in a 1: 4 TCC/SDS ratio (wt/wt) in distilled water solution. 1.8 g/l TCC entrapped in calcium alginate added to the must with yeast extract inhibited the growth of Lactobacillus fermentum CCT 1407 maintaining a controlled acidity, higher yeast viability and up to 20.8% of improvement in the average of alcoholic efficiency. Addition of 0.075 g/l TCC entrapped in calcium alginate and 1.67 mg/l SDS in the wort with yeast extract (0-5.0 g/l), inhibited and controlled the extensive bacterial contamination for 19 cycles of fermentation. (C) 1998 Published by Elsevier B.V. Ltd.

Solubilização de fosfatos de rocha por Aspergillus niger em diferentes tipos de vinhaça

Aspergillus niger was inoculated into flasks containing mixed of different origins and fluorapatite as a source of phosphorus, or alternatively rock phosphates of different compositions. There was no difference in fungal growth or fluorapatite solubilization when sterilized or unsterilized vinasse was used. Total and soluble solid content was at least two times higher in 65/35 vinasse than in 10/1 vinasse. The higher total sugar content causing higher titratable acidity levels, or the lower fungal growth, may possibly have favored the greater accumulation of soluble phosphate in 10/1 than in 65/10 vinasse. No appreciable differences in residual soluble phosphate levels were detected with increasing fluorapatite concentrations. Rock phosphates of different origins and with different phosphorus concentrations affected the solubilizing ability of the fungus. Whereas crude concentrated apatite phosphorus favored the greatest accumulation of soluble phosphate in the culture medium (1.08 mg/ml), the highest solubilization (72% total phosphate) was achieved with Patos de Minas material obtained from the first crushing.

Precipitation chemistry in semi-arid areas of Southern Africa: A case study of a rural and an industrial site

Experimental data on the precipitation chemistry in the semi-arid savanna of South Africa is presented in this paper. A total of 901 rainwater samples were collected with automatic wet-only samplers at a rural site, Louis Trichardt, and at an industrial site, Amersfoort, from July 1986 to June 1999. The chemical composition of precipitation was analysed for seven inorganic and two organic ions, using ion chromatography. The most abundant ion was SO(4)(2-) and a large proportion of the precipitation is acidic, with 98% of samples at Amersfoort and 94% at Louis Trichardt having a pH below 5.6 ( average pH of 4.4 and 4.9, respectively). This acidity results from a mixture of mineral and organic acids, with mineral acids being the primary contributors to the precipitation acidity in Amersfoort, while at Louis Trichardt, organic and mineral acids contribute equal amounts of acidity. It was found that the composition of rainwater is controlled by five sources: marine, terrigenous, nitrogenous, biomass burning and anthropogenic sources. The relative contributions of these sources at the two sites were calculated. Anthropogenic sources dominate at Amersfoort and biomass burning at Louis Trichardt. Most ions exhibit a seasonal pattern at Louis Trichardt, with the highest concentrations occurring during the austral spring as a result of agricultural activities and biomass combustion, while at Amersfoort it is less pronounced due to the dominance of relatively constant industrial emissions. The results are compared to observations from other African regions.

Precipitation chemistry and wet deposition in Kruger National Park, South Africa

The chemical composition, as well as the sources contributing to rainwater chemistry have been determined at Skukuza, in the Kruger National Park, South Africa. Major inorganic and organic ions were determined in 93 rainwater samples collected using an automated wet-only sampler from July 1999 to June 2002. The results indicate that the rain is acidic and the averaged precipitation pH was 4.72. This acidity results from a mixture of mineral acids (82%, of which 50% is H2SO4) and organic acids (18%). Most of the H2SO4 component can be attributed to the emissions of sulphur dioxide from the industrial region on the Highveld. The wet deposition of S and N is 5.9 kgS.ha(-1).yr(-1) and 2.8 kgN.ha(-1).yr(-1), respectively. The N deposition was mainly in the form of NH4+. Terrigenous, sea salt component, nitrogenous and anthropogenic pollutants have been identified as potential sources of chemical components in rainwater. The results are compared to observations from other African regions.

Synergism among lactic acid, sulfite, pH and ethanol in alcoholic fermentation of Saccharomyces cerevisiae (PE-2 and M-26)

The industrial production of ethanol is affected mainly by contamination by lactic acid bacteria besides others factors that act synergistically like increased sulfite content, extremely low pH, high acidity, high alcoholic content, high temperature and osmotic pressure. In this research two strains of Saccharomyces cerevisiae PE-2 and M-26 were tested regarding the alcoholic fermentation potential in highly stressed conditions. These strains were subjected to values up to 200 mg NaHSO3 l(-1), 6 g lactic acid l(-1), 9.5% (w/v) ethanol and pH 3.6 during fermentative processes. The low pH (3.6) was the major stressing factor on yeasts during the fermentation. The M-26 strain produced higher acidity than the other, with higher production of succinic acid, an important inhibitor of lactic bacteria. Both strains of yeasts showed similar performance during the fermentation, with no significant difference in cell viability.

Natural trans-crotonin: the antiulcerogenic effect of another diterpene isolated from the bark of Croton cajucara Benth.

The nor-clerodane diterpene trans-crotonin isolated from the bark of Croton cajucara BENTH. was investigated for its ability to prevent the formation of gastric-mucosa ulceration in different experimental models in mice. The results obtained from crotonin were compared with those obtained with another diterpene, DHC (trans-dehydrocrotonin) in the same models. When previously administered (p.o.) at the dose of 100 mg/kg, crotonin, as well as DHC, significantly reduced (p<0.05) gastric injury induced by stress (72, 67%), indomethacin/bethanechol (78, 29%) and pylorus ligature (35, 30%). In the HCl/ethanol-induced gastric ulcer model, at oral doses of 100 and 250 mg/kg, crotonin significantly prevented (p<0.05) the formation of gastric lesions by 51 and 56%, respectively, when compared to the control group. Gastric injury was also of significantly less magnitude in the DHC treatment group (p<0.05). In the pylorus-ligature model, crotonin (p.o.), like cimetidine, increased the volume of gastric juice when compared to the control group (p<0.05). No significant modifications where found in gastric parameters such as pH or total acid content after oral crotonin treatment. However, systemic alterations were observed when crotonin (100 mg/kg) was previously administered intraduodenally to mice. We observed significant changes (p<0.001) in gastric-juice parameters such as an increase in volume and a decrease in gastric acidity. Those pre-treated with crotonin as well as with DHC did not increase free mucus production (p>0.05). The results suggest that crotonin presents a significant anti-ulcer effect when assessed in these ulcer-induced models. As with DHC, the antiulcerogenic effects of crotonin are probably related to anti-secretory or/and gastroprotective properties of this substance. In light of results obtained with DHC and natural trans-crotonin in the present study, we concluded that the A-ring of both diterpenes is not directly involved in the antiulcerogenic activity.