79 resultados para Degradation of azo dye


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Marinated fish are fish products preserved by the combined action of salt and organic acids. The objective of this work was to analyze the variations in the chemical compounds of anchovy fillets that give them sensorial characteristics during the marinating process of Engraulis anchoita. The protein content decreased slightly and the TVB-N level decreased significantly in both the brining and marinating stages. In the marinating stage an increase in the total free aminoacids was observed. The NBV level in the brining and marinating solutions increased during these stages due to the solubilization of the non-protein nitrogenous compounds and the degradation of some protein compounds.The decrease of the contents of protein and TVB-N, and the increase of the acidity and the free aminoacids content during the marinating process give the marinated fillets the characteristic texture and aroma.

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Pleurotus ostreatus, worldwide known as oyster mushroom, was cultivated in banana straw using inocula produced by two different processes - liquid inoculum and the traditionally used solid inoculum. Different ratios (5, 10, 15, and 20%) were tested. Biological efficiency, yield, productivity, organic matter loss, and moisture of fruiting bodies as well as physical-chemical characteristics of banana straw were studied. Significant differences were observed for cellulose, lignin, and hemicellulose content between one and two harvests for both solid and liquid inocula. It was observed that P. ostreatus growth promoted higher degradation of lignin (80.36%), followed by hemicellulose (78.64%) and cellulose (60.37%). Significant differences between one and two harvests were also observed for the production parameters (biological efficiency and yield) for both kinds of inocula, liquid and solid. However, significant differences in productivity between harvests were observed only for solid inoculum.

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This study investigated the degradation kinetics of the sensory attributes of commercial whole mango (cv. Ubá) juice and evaluated its sensory acceptability during storage. Samples of the product were stored in a BOD incubator at 25, 35, and 45 ºC under 24 hours light (650 lux) for 120 days. Sensory analyses (Quantitative Descriptive Analysis - QDA) were conducted with trained panel and consumers. The correlations between sensory and physicochemical characteristics (instrumental color and vitamin C content) were also assessed. Flavor, aroma, and color vary with temperature and time of storage. Aroma and flavor were most affected by temperature with values of Q10 and Ea equal to 4.16 and 25.31 kcal.mol-1; and 3.61 and 22.80 kcal.mol-1, respectively. The sensory changes observed by the trained panel are related to the degradation of vitamin C and changes in the color coordinates (L* and ΔE*) of mango juice. However, consumers were unable to detect changes in the overall quality of the juices. It was observed that the QDA can be a useful tool to assess shelf-life.

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Curcumin is a powerful bioactive agent and natural antioxidant, but it is practically water-insoluble and has low bioavailability; a possible solution to this obstacle would be formulations of curcumin nanoparticles. Surfactants such as tween 80 can be used to stabilize low-solubility molecules preventing particle aggregation. The objectives of this study were the preparation of a suspension with curcumin nanoparticles in tween 80, the testing of pure curcumin solubility and of a simple mixture of curcumin with tween 80 and nanosuspension in water and ethanol as solvents, and finally the assessment of the antioxidant activity. We prepared the nanosuspension by injecting a curcumin solution in dichloromethane at low flow in water with tween 80 under heating and ultrasound. The analysis of particles size was conducted through dynamic light scattering; the non-degradation of curcumin was verified through thin-layer chromatography. The analyses of antioxidant activity were carried out according to the DPPH method. The method applied to reduce the particles size was efficient. Both the curcumin suspension and nanosuspension in tween 80 increased its solubility. Curcumin and the formulations presented antioxidant activity.