109 resultados para cymbopogon citratus extract


Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the present work, a hydroethanolic extract was prepared from the entire seeds of pomegranate [Punica granatum L. (Punicaceae)] with Cachaça, a distilled Brazilian alcoholic beverage, protected from light for an 80-hour period. The desorption curve of the seeds, presented an optimal time extraction of approximately 24 hours. The extract was divided into two samples: protected from light, (Extract 1), or not, (Extract 2). The extracts were characterized by UV-Visible absorption spectroscopy, quantification of total phenolics by the Folin-Ciocalteu method, and the antioxidant activity was determined by the DPPH quenching method. Extract 2 presented 9.8% less total polyphenols than Extract 1. The pomegranate seeds extract lost 79% of its antioxidant activity during light exposure. Extract 1 up to 3% (w/v) showed neither cyto nor phototoxicity in the Hela cells. In conclusion, Punica granatum L. seeds contain a significant total polyphenol and TEAC amount and they can be used in simple extractive process, by direct contact with Cachaça in up to 80 hours in the darkness, which gives it good coloration, taste, and smell. This extract showed neither cytotoxicity nor post-irradiation phototoxicity with solar simulator even though the extract proved photoinstable.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this work, bromelain was recovered from ground pineapple stem and rind by means of precipitation with alcohol at low temperature. Bromelain is the name of a group of powerful protein-digesting, or proteolytic, enzymes that are particularly useful for reducing muscle and tissue inflammation and as a digestive aid. Temperature control is crucial to avoid irreversible protein denaturation and consequently to improve the quality of the enzyme recovered. The process was carried out alternatively in two fed-batch pilot tanks: a glass tank and a stainless steel tank. Aliquots containing 100 mL of pineapple aqueous extract were fed into the tank. Inside the jacketed tank, the protein was exposed to unsteady operating conditions during the addition of the precipitating agent (ethanol 99.5%) because the dilution ratio "aqueous extract to ethanol" and heat transfer area changed. The coolant flow rate was manipulated through a variable speed pump. Fine tuned conventional and adaptive PID controllers were on-line implemented using a fieldbus digital control system. The processing performance efficiency was enhanced and so was the quality (enzyme activity) of the product.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The effect of two levels (0.5 and 1%) of hydroalcoholic extract of Achyrocline satureioides on the safety (TBARS values) and quality (pH, water activity, colour, weight loss, and sensorial attributes) of salami was evaluated. The addition of Achyrocline satureioides extract decreased TBARS values significantly during the storage of salami when compared to the control, which was elaborated without Achyrocline satureioides extract. The treatment with 1% of "Marcela" extract showed larger lipid stability than that of the lot with 0.5%, However, it presented a decrease (p < 0.05) in the sensorial acceptance. The two levels of "Marcela" extract did not influence pH, water activity, colour, and weight loss significantly. This study indicates that the hydroalcoholic extract of "Marcela" was effective in decreasing the lipid oxidation and at 0.5% it did not alter the sensorial features; therefore, it may be used in salami to provide safer products for the consumers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The effects of mango seed extract (MSE) and butylated hydroxytoluene (BHT) on pH, lipid oxidation, and color of Bologna-type mortadella during refrigerated storage for 21 days were studied. Bologna-type mortadella samples were formulated to contain 0.1% MSE, 0.2% MSE, or 0.01% BHT. After 14 days of storage, the products containing MSE 0.1 or 0.2% had higher pH values than those containing BHT 0.01%. Lipid oxidation values increased with storage time but were not affected by the type of antioxidant. The highest values for color parameter L* were observed for mortadella containing BHT 0.01% after 7, 14, and 21 days of storage. Values for the color parameters a* and b* tended to decrease during mortadella storage. Products containing 0.1 or 0.2% MSE showed higher values for color parameter a* and lower values for color parameter b* compared to those containing 0.01% BHT. It can be concluded that MSE can be used in 0.1 or 0.2% levels in Bologna-type mortadella with similar or better antioxidant effects than those of BHT 0.01%.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Lactic beverages containing probiotics were prepared with whole UHT milk, whey of Mozzarella cheese, soybean hydrosoluble extract and sugar. Three formulations were studied, each one containing a different combination of probiotic/starter bacteria, fermented at two different temperatures (37 and 45 °C). The aim of this work was to verify the influence of these variables on the viability of probiotic microorganisms and on the physicochemical stability of lactic beverages during storage under refrigeration (21 days at 7 °C). The results indicated that the fermentation temperature had a significant effect on the viability of probiotic bacteria. Counts for Lactobacillus acidophilus were affected by storage time, resulting appropriate after 21 days only for the beverage fermented at 37 °C. Physicochemical parameters did not exhibit drastic variations - proving the stability of formulations during storage. Cells of Bifidobacterium spp. showed high survival ability, probably due to the presence of growth promoters from soybean and cheese whey. The fermentation temperature of 37 °C allowed counts above the minimum limit for all the studied microorganisms, being preferred to the temperature of 45 °C. The inclusion of soybean hydrosoluble extract, a prebiotics source, resulted in a symbiotic product with more benefits to the health of consumers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study aimed to quantify the levels of catechins and caffeine in various forms of presentation of green tea: infusion tea bags, extract, and ready-to-drink beverage and, based on their content, identify the most suitable for consumption. High Performance Liquid Chromatography (HPLC) analytical method was used for the quantification of catechins and caffeine. The tea bags had the highest concentration of total catechins with 5 to 9.5% followed by the extract with 3.64 to 4.88%, and ready-to-drink green tea beverage showed low levels of catechins, from 0.14 to 0.26%. As for caffeine content, green tea extract had higher concentration (1.96 to 3.54%) compared to the tea bags (1.39 to 1.57%). Tea bags were found the most suitable for consumption because it contains higher amounts of catechins and smaller amounts of caffeine.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Xylose-to-xylitol bioconversion using 2.5 or 10% (v/v) rice bran extract was performed to verify the influence of this source of nutrients on Candida guilliermondii metabolism. Semisynthetic medium (SM) and sugarcane bagasse hemicellulosic hydrolysate detoxified with ion-exchange resins (HIE) or with alteration in pH combined with adsorption onto activated charcoal (HAC) were fermented in 125 mL Erlenmeyer flasks at 30 ºC and 200 rpm for 72 hours. Activated charcoal supplemented with 2.5% (v/v) rice bran extract was fermented by C. guilliermondii in a MULTIGEN stirred tank reactor using pH 5.0 and 22.9/hour oxygen transfer volumetric coefficient. Higher values of xylitol productivity (0.70, 0.71, and 0.62 g.Lh-1) and xylose-to-xylitol conversion yield (0.71, 0.69, and 0.63 g.g-1) were obtained with 2.5% (v/v) rice bran in semisynthetic medium, ion-exchange resins, and activated charcoal, respectively. Moreover, during batch fermentation, the xylitol volumetric productivity and fermentation efficiency values obtained were 0.53 g.Lh-1 and 61.1%, respectively.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

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.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study aimed to evaluate the use of rosemary (Rosmarinus officinalis) extract (RE), celery (Apium graveolis), and low levels of NO3 and NO2 as natural agents to enhance the quality of colonial salami. Salami was produced according to three treatments: (A) Control: 0.1% curing salt; (B) Rosemary: 0.05% curing salt + 0.5% RE (rosemary extract); and (C) Rosemary+celery: 0.14% Veg 503 + 0.27% Veg 504 (sea salt plus celery) + 0.5% of RE (rosemary extract). There was no effect (P > 0.05) of the treatments on water activity, Na content, and residual NO3 and NO2. Fatty acids C18:2 and C20:4 were reduced (P < 0.05) during the ripening period in the Control treatment indicating possible oxidation. The use of celery resulted in lower pH values (P < 0.05) in the salami. Reduced addition of NO3 and NO2 resulted in salami lighter in color (higher L* values, P < 0.05) at the 12th day of ripening. In conclusion, celery-based products proved to be an effective source of NO2 and NO3 for color development, but the low pH of the product indicates the need for better evaluation of its use in fermented salami. The RE (rosemary extract) reduced fat oxidation in salami, but this needs further evaluation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Antioxidants have the ability to neutralize free radicals produced in the body during lipid oxidation. The objective in this article was to study the effect of the barley extract on lipid oxidation in rats subjected to a high-fat diet. The experiment lasted 67 days. The animals were separated into three experimental groups: standard (P), high-fat diet group (L), and group with high-fat diet supplemented with barley extract (C). The feed intake of L and C groups was the lowest (p < 0.05). The treatments did not influence weight gain, organ weight, and the blood parameters measured. However, the levels of malondialdehyde present in the liver tissue were higher in the L group and lower in the P and C groups. Therefore, the results indicated an increased level of lipid peroxidation in the liver of rats subjected to high-fat diet, which was reduced by the consumption of barley.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this study was to evaluate the effect of Moringa oleifera Lam. leaf extract on the sedimentation of impurities in the treatment of sugarcane juice and the effects on sugar quality and on the clarified juice. The experimental design used was a 4x2 factorial arrangement with four replications. The main treatments performed included the extracted original sugarcane juice, the synthetic polyelectrolyte (Flomex 9076), the leaf extract, and a control. The secondary treatments consisted of the sugarcane varieties RB92579 and RB867515. The clarification process used was simple defecation, in which the flocculating agents and the juice, limed and heated, were poured simultaneously into a decanter. The microbiological and chemico-technological characteristics of the extracted and clarified juices were evaluated. The clarified juice was concentrated up to 60° Brix (syrup) and subjected to boiling in a pilot pan using seeds to perform the graining: The sugar was recovered by centrifugation and analyzed for microbiological and chemico-technological characteristics. It was concluded that the use of the Moringa oleifera Lam. leaves extract resulted in a better quality of clarified juice and sugar.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pseudomonas oleovorans were grown on sugary cassava extracts supplemented with andiroba oil for the synthesis of a mediumchain- length polyhydroxyalkanoate (PHA MCL). The concentration of total sugars in the extract was approximately: 40 g/L in culture 1, 15 g/L in cultures 2 and 3, and 10 g/L in culture 4. Supplementation with 1% andiroba oil and 0.2 g/L of (NH4)2HPO4 was performed 6.5 hours after growth in culture 3, and supplementation with the same amount of andiroba oil and 2.4 g/L of (NH4)2HPO4 was performed at the beginning of growth in culture 4. The synthesis resulted mainly in 3-hydroxy-decanoate and 3-hydroxy-dodecanoate units; 3-hydroxy-butyrate, 3-hydroxy-hexanoate; and 3-hydroxy-octanoate monomers were also produced but in smaller proportions. P. oleovorans significantly accumulated PHA MCL in the deceleration phase of growth with an oxygen limitation but with sufficient nitrogen concentration to maintain cell growth. The sugary cassava extract supplemented with andiroba oil proved to be a potential substrate for PHA MCL production.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The antimicrobial activity of a methanolic extract of amurca (olive oil lees) was determined against both Gram-positive (L. monocytogenes and S. aureus) and Gram-negative (E. coli O157:H7 and S. enteritidis) foodborne pathogens at 10 °C or 37 °C using microdilution and disk diffusion methods, and its relative activity was compared to selected antibiotics. Minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations of amurca extract ranged from 60 to 80 µl/ml at 37 °C after 24 h against all tested strains. At 10 °C, amurca was more inhibitory with MIC and MBC values of 40 and 60 µl/ml, respectively, after 7 d against tested strains. Amurca at 40 µl/ml reduced numbers of tested pathogens by 2.5 to 3.2 log10 CFU/ml at 10 °C after 7 d, but was not inhibitory at 37 °C after 24 h. Protein prepared from amurca was not antimicrobial. The relative antimicrobial activity (inhibition zone ratio) of 80 µl/ml amurca methanolic extract compared to chloramphenicol, erythromycin, gentamycin and tetracycline ranged from 0.36 to 1.0 against Gram-negative and from 0.45 to 2.0 against Gram-positive bacteria. In addition, amurca extract inhibited E. coli O157:H7 02-0628 and S. aureus 26127 which were resistant to tetracycline and chloramphenicol, respectively.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The effect of an edible film obtained from a commercial Aloe vera extract, on the quality maintenance of minimally processed grapes belonging to three different cultivars (Sugar One, Victoria and Black Magic) was evaluated by enzymatic (PPO, PME, β-GAL), physicochemical (pH, acidity, °Brix), and sensorial methods. All the analyzed parameters were measured in extracts obtained from minimally processed grapes packaged in ordinary atmosphere and stored at 4 °C for 15 days. Samples dipped into Aloe vera showed significant differences (p≤0.05) compared to untreated ones. The determination of such parameters and the evaluation of consumer acceptability were helpful to determine the effectiveness of the post-harvest treatment with Aloe vera for a storage period of 15 days.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

AbstractPurple sweet potato (PSP) can provide products with attractive color besides nutritious benefits in food processing. So, the compositions and color stability of an aqueous anthocyanin-based PSP extract were investigated in order to promote its wide use in food industry. PSP anthocyanins were extracted with water, and nine individual anthocyanins (48.72 ug mL–1 in total, 24.36 mg/100 g fresh PSP in yield) were found by HPLC analysis. The PSP extract also contained 17.11 mg mL–1 of protein, 0.44 mg mL–1 of dietary fiber, 2.82 mg mL–1 of reducing sugars, 4.02 ug mL–1 of Se, 54.21 ug mL–1 of Ca and 60.83 ug mL–1 of Mg. Changes in color and stability of the PSP extract, as affected by pH, heat, light and extraction process, were further evaluated. Results indicated that PSP anthocyanins had good stability at pH 2.0-6.0, while the color of PSP extract kept stable during 30 days of storage at 20 °C in dark. Both UV and fluorescent exposure weakened the color stability of PSP extract and UV showed a more drastic effect in comparison. A steaming pretreatment of fresh PSP is beneficial to the color stability.