RESUMO

Radiocystis fernandoi R28 strain is a cyanobacterium which produces mostly the RR and YR microcystin variants (MC-RR and MC-YR, respectively). The effects of crude extract of the R. fernandoi strain R28 were evaluated on the protein phosphatases and on the structure and ultrastructure of the liver of the Neotropical fish, Hoplias malabaricus, after acute and subchronic exposure. Concomitantly, the accumulation of the majority of MCs was determined in the liver and muscle. The fish were exposed to 120.60 MC-RR+MC-LR kg-fish-1 (=100µg MC-LReq kg-fish-1) for 12 and 96h (one single dose, acute exposure) and 30days (one similar dose every 72h, subchronic exposure). MCs did not accumulate in the muscle but, in the liver, MC-YR accumulated after acute exposure and MC-RR and MC-YR accumulation occurred after subchronic exposure. Protein phosphatase 2A (PP2A) activity was inhibited only after subchronic exposure. Acute exposure induced liver hyperemia, hemorrhage, changes in hepatocytes and cord-like disorganization. At the ultrastructural level, the decreasing of glycogen and lipid levels, the swelling of mitochondria and whirling of endoplasmic reticulum suggested hepatocyte necrosis. Subchronic exposure resulted in a complete disarrangement of cord-like hepatocytes, some recovery of mitochondria and whirling endoplasmic reticulum and extensive connective tissues containing fibrous materials in the liver parenchyma. Despite microcystin toxicity and liver alterations, no tumor was induced by MCs. In conclusion, the increased algal mass of R. fernandoi in tropical freshwater, producing mainly MC-RR and MC-YR variants, results in fish liver impairments.

Assuntos

RESUMO

The impact of acute (48 h) and subchronic (14 days) exposures to environmentally realistic atrazine concentrations (2, 10 and 25 µg L(-1)) were evaluated on the gills of Prochilodus lineatus by assessing the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), the levels of reduced glutathione (GSH) and lipid peroxide (LPO) as well as the histopathological damage. Acute and subchronic exposure to atrazine at 2 or 25 µg L(-1) did not change the activities of GST, SOD, CAT or GPx or the concentrations of GSH and LPO; however, subchronic exposure to 10 µg L(-1) increased the activity of GST, SOD and CAT and the LPO level. Histopathological indexes indicated normal gill function with scattered epithelial changes after acute and chronic exposure to 2 or 10 µg L(-1) of atrazine; however, fish chronically exposed to 25 µg L(-1) of atrazine, although had scattered lesions, the severity of lesions resulted in slightly to moderately gill damage. Acute exposure to atrazine decreased the type 3 MCs (containing acid mucosubstances with sulfate esters) in fish exposed to 2 or 10 µg L(-1) and increased the type 4 MCs (containing all types of mucosubstances) in fish exposed to 25 µg L(-1). Chronic exposure to atrazine reduced the type 3 MCs in fish exposed to 10 or 25 µg L(-1). The gills showed a low sensitivity to atrazine after acute exposure. However, the persistence of atrazine in water (subchronic exposure) promoted an increase of LPO levels in the gills and increased the frequency and severity of histopathological changes. The decreased density of type 3 MCs in fish exposed to atrazine suggests a mechanism to wash toxic substances away from the gill surface.

Assuntos

RESUMO

Avaliou-se o efeito da substituição da pastagem pela silagem de rama de mandioca (SRM) sobre a produção e constituintes do leite e sobre a qualidade da gordura do leite de vacas da raça Holandesa. O delineamento experimental utilizado foi um duplo quadrado latino 4x4, e para o fator níveis de suplementação, foi usado regressão. A dieta-controle foi 50 por cento concentrado e 50 por cento volumoso, e as proporções de substituição do volumoso foram 0, 20, 40 e 60 por cento com base na matéria seca. Todas as dietas eram isoprotéicas. Foram analisados: produção de leite (PL), PL corrigida a 4 por cento (PLC), acidez, gordura ( por cento), densidade, proteína, lactose, sólidos totais, contagem de células somáticas (CCS), ureia e perfil dos ácidos graxos da gordura do leite. Houve efeito linear decrescente da substituição do volumoso pela SRM sobre a PL, PLC e ureia no leite, e efeito (P<0,05) linear crescente sobre a concentração de ácido gama linolênico e ácido palmítico. A acidez, densidade, proteína, gordura, lactose, sólidos totais, CCS e demais ácidos graxos da gordura do leite permaneceram inalterados com a incorporação da SRM na dieta.(AU)

The effect of a partial substitution of pasture for cassava foliage silage (CFS) on milk production and composition on fat quality of Holstein cow milk was studied using a replicated 4 X 4 Latin square design with four treatments. Regression was used for the comparison of nutrition levels. The control diet contained 50 percent pasture and 50 percent concentrate on a dry matter basis. The substitution levels of pasture for CFS were 0, 20, 40, or 60 percent of the forage dry matter. All diets were isonitrogenous. The analyzed parameters were: milk production (MP); 4 percent fat-corrected milk production (FCM); acidity; density; concentrations of fat, protein, lactose, urea, and total solids; somatic cell counts (SCC), and milk fatty acids profile. There was a linear decrease effect (P<0.05) in MP, FCM, and urea content with increasing levels of CFS in the diet. Concentrations of gamma linolenic and palmitic acids in milk fat linearly increased (P<0.05) with higher proportions of CFS in the diet. Other contents of milk fatty acids remained similar among treatments as well as acidity; density; concentrations of protein, fat, lactose, and total solids; and SCC.(AU)

Assuntos

RESUMO

Avaliou-se o efeito da substituição da pastagem pela silagem de rama de mandioca (SRM) sobre a produção e constituintes do leite e sobre a qualidade da gordura do leite de vacas da raça Holandesa. O delineamento experimental utilizado foi um duplo quadrado latino 4x4, e para o fator níveis de suplementação, foi usado regressão. A dieta-controle foi 50 por cento concentrado e 50 por cento volumoso, e as proporções de substituição do volumoso foram 0, 20, 40 e 60 por cento com base na matéria seca. Todas as dietas eram isoprotéicas. Foram analisados: produção de leite (PL), PL corrigida a 4 por cento (PLC), acidez, gordura ( por cento), densidade, proteína, lactose, sólidos totais, contagem de células somáticas (CCS), ureia e perfil dos ácidos graxos da gordura do leite. Houve efeito linear decrescente da substituição do volumoso pela SRM sobre a PL, PLC e ureia no leite, e efeito (P<0,05) linear crescente sobre a concentração de ácido gama linolênico e ácido palmítico. A acidez, densidade, proteína, gordura, lactose, sólidos totais, CCS e demais ácidos graxos da gordura do leite permaneceram inalterados com a incorporação da SRM na dieta.

The effect of a partial substitution of pasture for cassava foliage silage (CFS) on milk production and composition on fat quality of Holstein cow milk was studied using a replicated 4 X 4 Latin square design with four treatments. Regression was used for the comparison of nutrition levels. The control diet contained 50 percent pasture and 50 percent concentrate on a dry matter basis. The substitution levels of pasture for CFS were 0, 20, 40, or 60 percent of the forage dry matter. All diets were isonitrogenous. The analyzed parameters were: milk production (MP); 4 percent fat-corrected milk production (FCM); acidity; density; concentrations of fat, protein, lactose, urea, and total solids; somatic cell counts (SCC), and milk fatty acids profile. There was a linear decrease effect (P<0.05) in MP, FCM, and urea content with increasing levels of CFS in the diet. Concentrations of gamma linolenic and palmitic acids in milk fat linearly increased (P<0.05) with higher proportions of CFS in the diet. Other contents of milk fatty acids remained similar among treatments as well as acidity; density; concentrations of protein, fat, lactose, and total solids; and SCC.

Assuntos

RESUMO

This work investigated the treatability of real textile effluents using several systems involving advanced oxidation processes (AOPs) such as UV/H2O2, UV/TiO2, UV/TiO2/H2O2, and UV/Fe2+/H2O2. The efficiency of each technique was evaluated according to the reduction levels observed in the UV absorbance of the effluents, COD, and organic nitrogen reduction, as well as mineralization as indicated by the formation of ammonium, nitrate, and sulfate ions. The results indicate the association of TiO2 and H2O2 as the most efficient treatment for removing organic pollutants from textile effluents. In spite of their efficiency, Fenton reactions based treatment proved to be slower and exhibited more complicated kinetics than the ones using TiO2, which are pseudo-first-order reactions. Decolorization was fast and effective in all the experiments despite the fact that only H2O2 was used.

Assuntos

RESUMO

The analyzed milk samples were collected from cross Saanen goats of different ages and different cross breeding types, throughout the lactation period, from September 1996 to December 1997. For the physical-chemical characteristics measured in this experiment, the following average values were obtained, followed by their respective standard deviations: pH (6.69 +/- 0.20); acidity (12.96 +/- 3.64 degrees D); density (1.030 +/- 0.009 mg.cm-3); fat (3.83 +/- 1.04%); crude protein (3.34 +/- 0.73%) and total solids (12.25 +/- 1.94 g.100 g-1). The lactation period influenced the values of acidity, fat, crude protein and total solids; these values decreased during the initial months and increased at the end of the lactation. The correlations were analyzed among the studied characteristics during the lactation, resulting in positive (p < 0.05) acidity/density correlation (r = 0.2115), stand out also the positive correlations (p < 0.01) among fat/total solids (r = 0.7715) and crude protein/total solids (r = 0.6228).

Assuntos

RESUMO

Total lipids from meat portions of breast, thigh, wing, side and back with and without skin from 10 roasted chickens were extracted with chloroform and methanol and gravimetrically determined, and their fatty acids were analysed as methyl esters by gaseous chromatography, using a flame ionization detector and capillary column. The main fatty acids found were: C16:0, C18:1 omega 9, and C18:2 omega 6. The average ratio observed between PUFA/SFA was of 0.98, mainly due to the great concentration of the C18:2 omega 6 fatty acid, with an average of 26.75%. Regarding to the lipids content, the skinless breast showed the lowest content, 0.78 g/100 g, while the back with skin was the one with the highest content, 12.13 g/100 g except for the pure skin, with 26.54 grams of lipids by 100 grams.

Assuntos

RESUMO

The effects of two fattening systems on muscle composition and fatty acid profile were determined in an experiment using samples of the longissimus dorsi (LD) muscle of 24 ram lambs (slaughter weight 29-31kg). The fattening systems were: (i) drylot (a mixture of maize, soybean, wheat and minerals) and (ii) grazing (Cynodon dactylon). The lambs fattened in the drylot system presented higher fat levels (p<0.01), but lower concentrations of moisture (p<0.01) and cholesterol (p<0.05). The lipid content presented a negative correlation with moisture and protein. In lambs fattened in the drylot system increasing levels of fatness of LD muscle were associated with a decrease (p<0.05) in myristic and palmitic acids, but myristic, palmitic and linoleic acids increased (p<0.05) as the cholesterol levels of the muscles increased.

RESUMO

Ripe fruits of Barbados cherry Malpighia glabra L. proceeding from the fruit-growing section of Iguatemi Experimental Farm of Universidade Estadual de Maringa (PR), were triturated in a liquefier and hulled in a stainless steel sieve with 25 mesh. The bagasse (seeds and hull) was discarded and the vitamin C content was immediately determined, which was 1.79 g by 100 g of pulp. After that, the integral pulp was packed in glass flasks and submitted to the exhaustion and pasteurization processes and then hermetically closed. After the heat treatment the vitamin C content was 1.54 g by 100 g of pulp. The sealed flasks of Barbados cherry pulp, with and without the aluminum foil protection, were stored for 40 days. The first portion was kept at room temperature, the second in a refrigerator (1 degree C), and the third in a freezer (-18 degrees C). The vitamin C content analysis were realized on the 5th, 10th, 15th, 20th, 30th and 40th day. For the flasks stored without the aluminum foil protection, there was a loss of 22.08%, 7.79% and 1.30% and with aluminum foil the loss was of 10.40%, 3.90% and 1.30% for the storage at room, refrigeration and freezing temperatures, respectively. The results show that freezing method is the best form of vitamin C preservation.

Assuntos

RESUMO

The acerola Malpighia glabra L., originally from the Antillas and North of South America, known by the people as cereja-das-antilhas or cereja-do-pará distinguish itself by its high content of vitamin C. The ripe and fresh acerola fruits utilized in experiments, were obtained from farmers of Maringá region, Paraná State, Brazil. The fruits were hulled in steel sieve with 25 mesh and the bagasse (seeds and hull) discarded. These physico-chemical analysis were realized in the pulp: vitamin C, moisture, protein, carbohydrate, fiber, lipids and fatty acids composition. We also determined the content of ash and cadmium, calcium, lead, copper, chrome, iron, magnesium, manganese, potassium, sodium and zinc minerals. The average content of vitamin C was 1.79 g/100 g of pulp, it was higher than the one for other fruits, like pineapple, araçá, cashew, guava, kiwi, orange, lemon, and strawberry and lower than the camu-camu sylvestral fruit of Amazônia. The contents of moisture, carbohydrate, fiber, lipids and minerals in the acerola were not significantly different when compared to other fruits.

Assuntos