73 resultados para Oxidative atmosphere


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The antioxidant effects of Caryocar brasiliense Camb, commonly known as the pequi fruit, have not been evaluated to determine their protective effects against oxidative damage in lung carcinogenesis. In the present study, we evaluated the role of pequi fruit against urethane-induced DNA damage and oxidative stress in forty 8-12 week old male BALB/C mice. An in vivo comet assay was performed to assess DNA damage in lung tissues and changes in lipid peroxidation and redox cycle antioxidants were monitored for oxidative stress. Prior supplementation with pequi oil or its extract (15 µL, 60 days) significantly reduced urethane-induced oxidative stress. A protective effect against DNA damage was associated with the modulation of lipid peroxidation and low protein and gene expression of nitric oxide synthase. These findings suggest that the intake of pequi fruit might protect against in vivo genotoxicity and oxidative stress.

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The purpose of this research was to determine the best gas mixture in controlled atmosphere conditions to store fresh-cut ‘Pérola’ pineapple, particularly in relation to the maintenance of visual quality and reduction of microbial growth. After sanitation, fruit was manually peeled, sliced and dipped in 20 mg.L-1 NaOCl solution for 30 seconds. Then, the excess liquid was drained and the slices were placed in sealed glass jars connected to a flowboard installed in a cold room (5 ± 1 °C). Desired gas mixtures were supplied continuously for 12 days from cylinders connected to the flowboard. Controlled atmospheres of 2:5, 2:10, 2:15, 5:5, 5:10, 5:15, 8:5, 8:10 and 8:15 (O2:CO2, %) and air were used. The product was evaluated for pulp color, total and fecal coliforms, mesophilic and psychrotrophic aerobic, mold and yeast counts. Total and fecal coliforms were not detected. The fresh-cut ‘Pérola’ pineapple was not very sensitive to storage in controlled atmosphere, considering that the slices had little browning and were free of contamination, that would affect the food safety at the end of the storage period

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The effect of gamma irradiation (0, 2, 4, and 6 kGy doses) applied to frozen and packed headed shrimp on the fatty acid profile, cholesterol content, and lipid and color stability was evaluated. Myristic acid was higher in shrimp irradiated with 4 and 6 kGy and palmitic acid was higher in samples irradiated with 2 and 6 kGy compared to non-irradiated samples. Stearic and behenic acids were lower in shrimp irradiated with 6 kGy compared to non-irradiated shrimp. With regard to non-irradiated shrimp, palmitoleic, oleic, and linoleic acids and total monounsaturated fatty acids were higher in shrimp irradiated with 6 kGy. Saturated fatty acid and cholesterol contents in irradiated samples were not different from those in non-irradiated shrimp. Lipid oxidation was higher in samples irradiated with 2, 4, and 6 kGy. Redness and yellowness of cooked shrimp were higher in samples irradiated with 6 kGy than in those in non-irradiated samples. The application of irradiation in doses up to 6 kGy on frozen and packed headed shrimp does not affect negatively the fatty acid profile, cholesterol content, and lipid and color stability.

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The aim of this experiment was to evaluate how susceptible spores become to mechanical damage during food extrusion after being submitted to CO2. B. stearothermophilus spores sowed to corn and soy mix were submitted to 99% CO2 for 10 days and extruded in a single-screw extruder. The treatments were: T1 - spore-containing samples, extruded at screw rotational speed of 65 rpm and barrel wall temperature of 80 °C; T2 - as T1, except for screw rotational speed of 150 rpm; and T3 - as T2, except that samples were submitted to the modified atmosphere. The results for cell viability, minimum and maximum residence times, and static pressure were T1 - 19.90 ± 3.24%, 123.3 ± 14.50 seconds; 203.3 ± 14.05 seconds; 2.217 ± 62 kPa; T2 - 21.42 ± 8.24%, 70.00 ± 5.77 seconds; 170.00 ± 4.67 seconds; 2.310 ± 107 kPa; and T3 - 11.06 ± 2.46%, 86.00 ± 7.23 seconds; 186.00 ± 7.50 seconds; 2.403 ± 93 kPa, respectively. It was concluded that the extrusion process did reduce the cell count. However, screw rotational speed variation or CO2 pre-treatment did not affect cell viability.

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This study was carried out with one of the most important cultivar grown in the State of Sao Paulo, Brazil, which has gained the preference of consumers, due to its sweet taste, intense skin color and large size; however, these fruits are susceptible to chilling injury when cold stored for long periods. The use of controlled atmosphere (CA) with elevated CO2 and reduced O2 concentrations prevent the onset of the chilling symptom. Thus, the effect of three different conditions of controlled atmosphere (CA1, CA2, CA3 and Control) was evaluated in order to extend the storage life of 'Douradão' peaches. After 14, 21 and 28 days, samples were withdrawn from CA and kept in fresh air at 25 ± 1 °C and 90 ± 5% RH to complete ripening. On the day of removal and after 4 days, were the peaches quality characteristics were evaluated. The results showed that the use of CA during cold storage reduced weight loss and prevented postharvest decay. CA2 and CA3 treatments were effective in keeping good quality of 'Douradão' peaches during 28 days of cold storage, the ripe fruits showed reduced incidence of woolliness, adequate juiciness and flesh firmness. CA1 and Control treatments did not present marketable conditions after 14 days of cold storage.

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The sensory quality of 'Douradão' peaches cold stored in three different conditions of controlled atmosphere (CA1, CA2, CA3 and Control) was studied. After 14, 21 and 28 days of cold storage, samples were withdrawn from CA and kept for 4 days in ambient air for ripening. The sensory profile of the peaches and the descriptive terminology were developed by methodology based on the Quantitative Descriptive Analysis (QDA). The panelists consensually defined the sensory descriptors, their respective reference materials and the descriptive evaluation ballot. Fourteen panelists were selected based on their discrimination capacity and reproducibility. Seven descriptors were generated showing similarities and differences between samples. The data were analyzed by ANOVA, Tukey test and Principal Component Analysis (PCA). Results showed significant differences in the sensory profiles of the peaches. The PCA showed that CA2 and CA3 treatments were more characterized by the fresh peach flavor, fresh peach appearance, juiciness and flesh firmness, and were effective in keeping the good quality of the 'Douradão' peaches during the 28 days of cold storage. The Control and CA1 treatments were characterized by the mealiness and were ineffective for quality maintenance of the fruits during cold storage.

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In this study, it was evaluated the quality of yellow passion fruits stored under refrigeration and controlled atmospheres of different composition aiming to extend the postharvest life of the fruits. The characteristics of skin color, appearance, mass loss, as well as the chemical quality of the juice of yellow passion fruits stored at: 21% O2 plus 0.03% CO2; 1% O2 plus 0.03% CO2; 5% O2 plus 0.03% CO2; 12% O2 plus 5% CO2; and 5% O2 plus 15% CO2, with 1 control treatment (refrigeration at 13 ºC and 90% UR) were determined. The analyses were performed before and after 30 days of storage and after removing the controlled atmospheres and storage for 9 days under refrigeration at ambient atmosphere. The data were interpreted by simple statistical analysis using the test by confidence intervals with 95% of probability. It was concluded that the application of atmospheres with low oxygen concentration and high carbon dioxide level minimized quality losses. At atmosphere with 5% O2 and 15% CO2, it was observed the lowest color change indexes and mass loss, and also the smallest decrease in acidity, soluble solids content, vitamin C, reducing sugars, and total soluble sugars.

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White tea is an unfermented tea made from young shoots of Camellia sinensis protected from sunlight to avoid polyphenol degradation. Although its levels of catechins are higher than those of green tea (derived from the same plant), there are no studies addressing the relationship between this tea and obesity associated with oxidative stress.The objective of this study was to evaluate the effect of white tea on obesity and its complications using a diet induced obesity model. Forty male C57BL/6 mice were fed a high-fat diet to induce obesity (Obese group) or the same diet supplemented with 0.5% white tea extract (Obese + WTE) for 8 weeks. Adipose tissue, serum lipid profile, and oxidative stress were studied. White tea supplementation was not able to reduce food intake, body weight, or visceral adiposity. Similarly, there were no changes in cholesterol rich lipoprotein profile between the groups. A reduction in blood triacylglycerols associated with increased cecal lipids was observed in the group fed the diet supplemented with white tea. White tea supplementation also reduced oxidative stress in liver and adipose tissue. In conclusion, white tea extract supplementation (0.5%) does not influence body weight or adiposity in obese mice. Its benefits are restricted to the reduction in oxidative stress associated with obesity and improvement of hypertriacylglycerolemia.

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In Brazil, the largest producer of sugarcane in the world, the industrial process transforms this crop into ethanol and/or granulated sugar. Some cultivars exhibit enzymatic browning in the extracted sugarcane juice at levels harmful to the manufacturing process of white granulated sugar. The objective of this study was to assess the effect of sugarcane straw used as soil coverage, the use of different planting systems, and treatments with hydrogel polymer on enzymatic activity. The cultivar RB 86 7515 was sampled for 8 months; the first sample was obtained by cutting the upper portion of the stalk at the internode, which was taken to the laboratory for determination of the enzymatic activity of polyphenoloxidase (PPO) and peroxidase (POD). The soil coverage with different forms of straw as well as the planting systems did not change the enzymatic activity of polyphenoloxidase (PPO) and peroxidase (POD). The polyphenoloxidase (PPO) activity increased with the use of a polymer due to increased polyphenoloxidase (PPO) activity in the groove system. The enzymes studied showed changes in activity during the experimental period. The production of sugar at the end of the season (August to November) avoids the periods of highest enzymatic activity.

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Food industries have been concerned about managing the waste generated by their production processes in order to minimize environmental impacts and also about the development of formulations with different and innovative ingredients such as fruits from the Brazilian savanna. Seeking to meet the expectations of consumers who desire healthy and practical products, this study aimed to evaluate the oxidative stability and the variations in chemical composition and antioxidant potential of cereal bars made with fruit peels and baru nuts packaged in different types of packaging. The bars formulated were packed in four different types of packaging: laminated without vacuum (LWV), transparent without vacuum (TWV), transparent under vacuum (TV), and laminated under vacuum (LV); they were subsequently analyzed for proximate composition, fatty acid profiles, antioxidant activity, and oxidative capacity. The results showed that the cereal bars made with fruit peel and baru are sources of protein, dietary fiber, and fat, especially unsaturated fatty acids such as oleic and linoleic acids. The cereal bars exhibited oxidative stability up to 120 days of storage, and the type of packaging was not significant for the variables evaluated; therefore, they can be stored in low cost packaging such as transparent packaging without vacuum for a period of 120 days.

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Modified atmosphere is a method of food preservation that provides increased lifetime, decreases deterioration losses, and facilitates marketing. The objective of this study was to evaluate the efficiency of different plastic films in modifying the atmosphere around Eva apples to assure quality maintenance during postharvest storage. The fruits were cleaned and separated into three treatment groups: polypropylene, low density polyethylene, and high density polyethylene packing with a total of 5 fruits per package for each evaluation period. A group of control apples was not submitted to atmospheric modification. After the treatment, all fruits were stored at 0.5±0.5°C (cold storage) for up to 225 days. The analyses were performed at 45, 135, and 225 days after cold storage. Respiration, ethylene production, firmness, mass loss, total pectin, soluble pectin, soluble solids, total acidity, and epidermis background color of each treatment group were evaluated. The high density polyethylene film treatment did not show a decrease in ethylene production during storage and allowed the fruits to maintain a greater firmness and smaller percentage of mass loss during the study period. Moreover, the storage of the Eva apple cultivar under modified atmosphere allowed the preservation of quality for up to seven months.

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Stability of minimally processed radicchio (Cichorium intybus L.) was evaluated under modified atmosphere (2% O2, 5% CO2, and 93% N2) on 3, 5, 7 and 10 days of storage at 5°C. The samples were hygienized in sodium hypochlorite or hydrogen peroxide solutions to identify the most effective sanitizing solution to remove microorganisms. Microbiological analysis was conducted to identify the presence of coliforms at 35°C and 45°C, mesophilic microorganisms, and yeast and mold. Physicochemical analyses of mass loss, pH, soluble solids, and total acidity were conducted. The color measurements were performed using a Portable Colorimeter model CR-400. The antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic methods. The sensory evaluation was carried out using a hedonic scale to test overall acceptance of the samples during storage. The sodium hypochlorite (150 mg.L-1) solution provided greater safety to the final product. The values of pH ranged from 6.17 to 6.25, total acidity from 0.405 to 0.435%, soluble solids from 0.5 to 0.6 °Brix, mass loss from 1.7 to 7.2%, and chlorophyll from 1.068 to 0.854 mg/100g. The antioxidant activity of radicchio did not show significant changes during the first 3 days of storage. The overall acceptance of the sample stored in the sealed package without modified atmosphere was 70%, while the fresh sample was obtained 77% of approval. Although the samples packaged under modified atmosphere had a higher acceptance score, the samples in sealed packages had satisfactory results during the nine days of storage. The use of modified atmosphere, combined with cooling and good manufacturing practices, was sufficient to prolong the life of minimally processed radicchio, Folha Larga cultivar, for up to ten days of storage.

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INTRODUCTION: Enhanced inflammatory-oxidative status is well established in chronic kidney disease. OBJECTIVE: The objective of this study was to evaluate the oxidative- inflammatory status and iron indices in patients undergoing maintenance hemodialysis (HD) with serum ferritin lower than 500ng/mL, and to correlate them with nutritional status. METHOD: In a cross-sectional survey 35 HD patients (23 with normal nutritional status, 12 with Protein-Energy-Wasting syndrome, PEW), and healthy volunteers (n = 35) were studied. Serum concentration of iron, ferritin, transferrin saturation, malondialdehyde (MDA), protein carbonyl (PC), high-sensitive serum C -reactive protein (hs-CRP) and blood counts were determined. The nutritional status was determined by anthropometric and biochemical criteria. RESULTS: HD patients showed low values of hemoglobin and higher values of ferritin, MDA and PC when compared with healthy volunteers. HD subjects with PEW had higher values of PC and hs-PCR as compared to HD patients with normal nutritional status. A multiple logistic regression analysis showed that the independent variables PC (Wald Statistic 4.25, p = 0.039) and hs-CRP (Wald Statistic 4.83, p = 0.028) where related with the patients' nutritional condition. CONCLUSION: In HD patients with serum ferritin below 500 ng/mL was observed one association of the markers of oxidative stress and inflammation with poor nutritional status independently of serum ferritin, gender and age.