Peroxidase activity and total phenol content in citrus cuttings treated with different copper sources

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise da ionosfera usando dados de receptores GPS durante um período de alta atividade solar e comparação com dados de Digissondas

Cada vez mais é crescente o uso do GPS (Global Positioning System ) em estudos da atmosfera terrestre. Neste artigo, a atmosfera superior da Terra, denominada ionosfera, foi estudada durante um período de alta atividade solar (ano de 2001) usando dados de receptores GPS de dupla freqüência localizados na região brasileira, pertencentes à RBMC (Rede Brasileira de Monitoramento Contínuo). A partir dos dados GPS foram calculados os valores de TEC (Total Electron Content - Conteúdo Total de Elétrons) da ionosfera. Adicionalmente foram incluídos no estudo dados de freqüência crítica da camada F2 advinda de Digissondas localizadas em São Luís/MA (3ºS; 44ºW) e Cachoeira Paulista/SP (22ºS; 45ºW), para fins de comparação. de uma forma geral, os resultados mostraram maiores valores de TEC durante os meses próximos aos equinócios e menores durante os meses de inverno. Quanto à variação diária do TEC, os menores valores foram verificados por volta das 4-6 HL (Hora Local) e os maiores durante o período da tarde, com valores um pouco maiores para São Luís. O segundo pico da anomalia equatorial foi verificado em Cachoeira Paulista nos meses próximos aos equinócios e verão. Na maioria dos meses, uma alta correlação linear foi verificada quando realizada a comparação entre os valores de freqüência crítica da camada F2 e os de TEC, principalmente para São Luís.

Influence of carrageenan and total solids content on the rheological properties of lactic beverage made with yogurt and whey

The purpose of this work was to study the influence of carrageenan level (X 1) and total solids content of yogurt/whey mixture (X 2) on starter culture fermentation time, physicochetnical properties (pH, fat and total solids contents) and rheological characteristics of lactic beverages using response surface methodology. The physicochemical characteristics of the lactic beverages were similar to those of commercial products. All beverages showed non-Newtonian fluid behavior with thixotropy and yield stress. The total solids content of the lactic beverages had a greater influence on the rheological behavior of these products than the carrageenan level. Wide ranges of consistency measurements were observed by varying the stabilizer level and total solids content.

Simultaneous effects of total solids content, milk base, heat treatment temperature and sample temperature on the rheological properties of plain stirred yogurt

Response surface methodology was used to establish a relationship between total solids content, milk base, heat treatment temperature, and sample temperature, and consistency index, flow behaviour index, and apparent viscosity of plain stirred yogurts. Statistical treatments resulted in developments of mathematical models. All samples presented shear thinning fluid behaviour. The increase of the content of total solids (9.3-22.7 %) and milk base heat treatment temperature (81.6-98.4°C) resulted in a significant increase in consistency index and a decrease in flow behaviour index. Increase in the sample temperature (1.6-18.4°C) caused a decrease in consistency index and increase in flow behaviour index. Apparent viscosity was directly related to the content of total solids. Rheological properties of yogurt were highly dependent on the content of total solids in milk.

Antioxidant capacity and total phenolic content of hydrothermally-treated 'Fuerte' avocado

Avocados possess high nutritional value with proven effectiveness in preventing cardiovascular diseases, attributed primarily to their unsaturated fatty acids content. This fruit is also rich in carotenoids and vitamins, particularly vitamin E. This work evaluates the antioxidant capacity and total phenolic content of hydrothermally-treated Fuerte avocado. Fruits were selected and hydrothermally treated at 45°C for 5, 10, 15 and 20 min. They were then stored in a refrigerator (10 ± 10°C and 90±5% relative humidity) and evaluated over a 15-day period. The total phenolic content increased up to the sixth day of storage, and decreased thereafter, without differences between the treatments. The percentage of antioxidant capacity of the control and the hydrothermally-treated samples for 5 and 10 min increased during storage. Untreated fruits showed the highest percentage of antioxidant capacity. However, the antioxidant capacity of avocado fruits subjected to these treatments declined starting on the twelfth day of storage, possibly due to the fruits' senescence. Hydrothermal treatments for 15 and 20 min delayed fruit senescence while the antioxidant capacity continued to increase up to the fifteenth day of storage. No significant correlation was found between antioxidant capacity and total phenolic content. The antioxidant capacity of ripe Fuerte avocado was higher than that of unripe or overripe avocado.

Grade ionosférica para aplicações em posicionamento e navegação com GNSS

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

NIRS and iSPA-PLS for predicting total anthocyanin content in jaboticaba fruit

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Changes in polyamine, total protein and total carbohydrate content and peroxidase activity during the lifetime of chrysanthemum faroe

The aim of the present work was to evaluate the changes in polyamine (PA) content, peroxidase (POX) activity and levels of total protein and total soluble carbohydrates throughout the lifetime of leaves and inflorescences of chrysantemum 'Faroe' treated with gibberellic acidd (GA3) (used in production practices) and kept at room temperature and cold storage. The treatments were composed of four doses of GA3 (0, 15, 30 and 45 mg L-1) applied at the beggining of flower bud formation (28 days after transplanting of seedlings). After harvesting, the stems (95% of the expanded ligule) were stored at 10ºC and 95% relative humidity for 48 hrs, or kept at room temperature. For biochemical analysis samples of leaves and inflorescences were collected at the 4th, 8th, 12th and 16th day after harvest. The application of GA3 in the field and cold storage increased the content of PAs. There was an increase in POX activity in leaves and inflorescences during postharvest and this increase was related to oxidation of the PAs studied. The amount of proteins and carbohydrates in chrysantemum 'Faroe' decreased during the storage at 25ºC and under cold conditions.

Modified CUPRAC spectrophotometric quantification of total polyphenol content in beer samples using Cu(II)/neocuproine complexes

Cu(II)/neocuproine (2,9-dimethyl-1,10-phenanthroline) complexes were utilized for spectrophotometric determination of total polyphenol content in beers. This procedure is based on the reduction of Cu(II) by polyphenols in hydroethanolic medium (pH 7.0) in the presence of neocuproine, yielding Cu(I)/complexes with maximum absorption at 454 nm. The sensitivity of the proposed method was compared with the AOAC method using tannic and gallic acid as standards. The average apparent molar absorptivity, in L cm(-1) mol(-1), of tannic acid (3.50 +/- 0.20) x 10(5) and gallic acid (5.12 +/- 0.21) x 10(4), was twice as high for the proposed method. A lower limit of detection (LOD) (2.9 x 10(-1) mg L-1) was found when tannic acid was used in the proposed method. Additionally, less interference from the most common additives in beers was noticed. Total content of polyphenols was analyzed in 17 Brazilian samples. Results ranged from 35.5 to 556 mg L-1 of tannic acid, with higher values for recovery rates (45.4-118%, mean 85.0%) than for gallic acid. Although tannic acid is a mixture of polygalloyl glucoses, the total polyphenol content found in the samples suggests that tannic acid should be used as a standard. This is the first attempt to use this particular copper complex to quantify total polyphenol content in beer samples. (C) 2012 Elsevier Inc. All rights reserved.