997 resultados para Copper compounds


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Sugarcane spirit is a drink considered as a national symbol of Brazil. It is produced by large producers and by about 30 thousand small and medium home-distilling producers dispersed throughout the country. The copper originating from the home-distillers can become a serious problem since at high concentrations in beverages it may cause serious human health problems. Therefore, the objective of this study was to investigate the influence of the activated carbon used in commercial filters on the physicochemical and sensory characteristics of aged sugarcane spirit. Analyses of copper, dry extract, alcoholic degree, higher alcohols, volatile acids, aldehydes, esters, furfural, and methanol were performed. The sensory evaluation was performed by seven selected trained judges, who analyzed the yellow color, woody aroma and flavor, and intensity of alcoholic aroma and flavor of the cane spirit before and after the filtration process. The sensory tests were carried out using a 9 cm non-structured intensity scale. A reduction was observed in all compounds analyzed physicochemically, except for the esters, which increased after filtration. This increase is probably due to the esterification of the alcohols and acids present. According to the sensory results obtained, a reduction was observed in the intensity of the yellow color, aroma, and wood flavor characteristics, the major characteristics of the aging process.

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This study investigated the content of total phenolic compounds and antioxidant activity in fermented rice bran in order to evaluate the effect of solid state fermentation on these properties. The process was performed with the fungus Rhizopus oryzae CTT 1217 in tray reactors at 30 °C for 120 hours. Samples of fermented rice bran were collected every 24 hours. Antioxidant property was evaluated by the diphenyl-1-picrylhydrazyl radical scavenging method and through the inhibition of enzymatic oxidation and lipid peroxidation of olive oil. The methanol extract of the biomass obtained at 96 hours of fermentation inactivated 50% of free radical in 15 minutes. The same extract reduced the peroxide value in the olive oil by 57% after 30 days of storage. The aqueous extract of the biomass obtained at 120 hours was the most efficient inhibitor of the darkening reaction catalyzed by peroxidase.

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Seventy-one samples of sugarcane spirits from small and average size stills produced in the northern and southern Minas Gerais (Brazil) were analyzed for acrolein using HPLC (High Performance Liquid Chromatography). Ethanol and copper concentrations and volatile acidity were also determined according to methods established by the Ministry of Agriculture, Livestock and Supply (MAPA). A total of 9.85% of the samples tested showed levels of acrolein above the legal limits, while the copper concentrations of 21.00% of the samples and the volatile acidity of 8.85% of the samples were higher than the limits established by the Brazilian legislation. The concentration of acrolein varied from 0 to 21.97 mg.100 mL-1 of ethanol. However, no significant difference at 5% of significance was observed between the samples produced in the northern and southern Minas Gerais. The method used for determination of acrolein in sugarcane spirits involved the formation of a derivative with 2,4-dinitrophenylhydrazine (2,4-DNPH) and subsequent analysis by HPLC.

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Yellow mombin is a fruit tree that grows spontaneously in the Semi-Arid Northeastern Brazil. Its fruits are still extractively exploited. The pulp of yellow mombin fruit stands out regarding the commercial aspect due to the characteristic flavor and aroma felt when consumed in diverse ways. This study aimed to evaluate the presence of bioactive compounds, total extractable polyphenols, and antioxidant activity of yellow mombin fruits (Spondias mombin, L.), from clone and ungrafted genotypes. The fruits were harvested at commercial maturity from twelve yellow mombin tree genotypes from an experimental orchard located at the municipality of Joao Pessoa, Paraíba, Brazil, and evaluated for chlorophyll, carotenoids, yellow flavonoids, total extractable polyphenols, and antioxidant activity, which was measured by the β-carotene/linoleic acid method. The antioxidant activity showed a percentage of inhibition of oxidation higher than 75% for all genotypes evaluated at the time of 120 minutes. The fruits from clone genotypes showed a higher percentage of antioxidant activity.

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This study evaluated the fatty acid quantification, proximate and amino acid compositions, antioxidant activity, total phenolic compounds, vitamin E, and mineral contents of new amaranth (BRS Alegria) and quinoa (BRS Piabiru) cultivars which were produced in order to adapt these pseudocereals to the climatic conditions of central-western Brazil. They showed superior levels of protein and total lipids in comparison to their native counterparts. The lipid profile of the amaranth BRS Alegria was revealed to be better than those of other native cultivars. Quinoa BRS Piabiru presented a higher antioxidant capacity and phenolic content than the studied amaranth cultivar, but lower contents of tocopherols. All of the obtained results confirm that these new grains possess an overall amount of nutritional compounds that is better than those reported for many native counterparts of the studied samples. The employed analytical methods in this work contributed to a better understanding of the quinoa BRS Piabiru and amaranth BRS Alegria chemical compositions. Therefore, the diversity and quantity of all of the studied compounds in the samples denote the considerable importance of these grains for food science research area.

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In Brazil, the grape and wine production takes place mainly in the state of Rio Grande do Sul, and the region "Serra" is known as the traditional wine region. In the last years, new areas have emerged, with emphasis for the Campanha region; the red wines from this region have low acidity, little color intensity, and are wines to drink while young, even when produced from grape varieties such as Merlot and Cabernet Sauvignon. The objective of this study was to evaluate the influence of different maceration types on the phenolic compounds of Merlot wines made with grapes produced in two regions of Rio Grande do Sul, Serra and Campanha, as well as to identify the key differences between the wines produced. The localization of the vineyards seems to have more influence on the wine characteristics than the maceration type. The color due copigmentation was an important aspect in the wines made with short maceration. The effect of extended maceration was different than the expected for the Campanha region wines; the extended maceration increased the extraction of tannins resulting in greater color intensity and a greater amount of anthocyanins. The pH control seems to be a key factor for the Campanha region wines.

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The aim of this study was to extract and identify volatile compounds from pineapple residues generated during concentrated juice processing. Distillates of pineapple residues were obtained using the following techniques: simple hydrodistillation and hydrodistillation by passing nitrogen gas. The volatile compounds present in the distillates were captured by the solid-phase microextraction technique. The volatile compounds were identified in a system of high resolution gas chromatography system coupled with mass spectrometry using a polyethylene glycol polar capillary column as stationary phase. The pineapple residues constituted mostly of esters (35%), followed by ketones (26%), alcohols (18%), aldehydes (9%), acids (3%) and other compounds (9%). Odor-active volatile compounds were mainly identified in the distillate obtained using hydrodistillation by passing nitrogen gas, namely decanal, ethyl octanoate, acetic acid, 1-hexanol, and ketones such as γ-hexalactone, γ-octalactone, δ-octalactone, γ-decalactone, and γ-dodecalactone. This suggests that the use of an inert gas and lower temperatures helped maintain higher amounts of flavor compounds. These data indicate that pineapple processing residue contained important volatile compounds which can be extracted and used as aroma enhancing products and have high potential for the production of value-added natural essences.

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The contents of total phenolic compounds (TPC), total flavonoids (TF), and ascorbic acid (AA) of 18 frozen fruit pulps and their scavenging capacities against peroxyl radical (ROO•), hydrogen peroxide (H2O2), and hydroxyl radical (•OH) were determined. Principal Component Analysis (PCA) showed that TPC (total phenolic compounds) and AA (ascorbic acid) presented positive correlation with the scavenging capacity against ROO•, and TF (total flavonoids) showed positive correlation with the scavenging capacity against •OH and ROO• However, the scavenging capacity against H2O2 presented low correlation with TF (total flavonoids), TPC (total phenolic compounds), and AA (ascorbic acid). The Hierarchical Cluster Analysis (HCA) allowed the classification of the fruit pulps into three groups: one group was formed by the açai pulp with high TF, total flavonoids, content (134.02 mg CE/100 g pulp) and the highest scavenging capacity against ROO•, •OH and H2O2; the second group was formed by the acerola pulp with high TPC, total phenolic compounds, (658.40 mg GAE/100 g pulp) and AA , ascorbic acid, (506.27 mg/100 g pulp) contents; and the third group was formed by pineapple, cacao, caja, cashew-apple, coconut, cupuaçu, guava, orange, lemon, mango, passion fruit, watermelon, pitanga, tamarind, tangerine, and umbu pulps, which could not be separated considering only the contents of bioactive compounds and the scavenging properties.

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The application of natural antifungal substances is motivated by the need for alternatives to existing methods that are not always applicable, efficient, or that do not pose risk to consumers or the environment. Furthermore, studies on the behaviour of toxigenic species in the presence of natural fungicides have enabled their safe application in the food chain In this study, Spirulina LEB-18 phenolic extract was assessed for its antifungal activity on 12 toxigenic strains of Fusarium graminearum isolated from barley and wheat. The susceptible metabolic pathways were assessed through the determination of structural compounds (glucosamine and ergosterol) and enzyme activity of the microorganisms' primary metabolism. The results indicate that phenolic extracts reduced the growth rate of the toxigenic species investigated. The IC50 was obtained by applying 3 to 8% (p/p) of phenolic compounds in relation to the culture medium. The use of this natural fungicide proved promising for the inhibition of fungal multiplication, especially in terms of the inactivation of enzymatic systems (amylase and protease) of Fusarium graminearum.

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Olive mill wastewater, hereafter noted as OMWW was tested for its composition in phenolic compounds according to geographical areas of olive tree, i.e. the plain and the mountainous areas of Tadla-Azilal region (central Morocco). Biophenols extraction with ethyl acetate was efficient and the phenolic extract from the mountainous areas had the highest concentration of total phenols' content. Fourier-Transform-Middle Infrared (FT-MIR) spectroscopy of the extracts revealed vibration bands corresponding to acid, alcohol and ketone functions. Additionally, HPLC-ESI-MS analyses showed that phenolic alcohols, phenolic acids, flavonoids, secoiridoids and derivatives and lignans represent the most abundant phenolic compounds. Nüzhenide, naringenin and long chain polymeric substances were also detected. Mountainous areas also presented the most effective DPPH scavenging potential compared to plain areas; IC50 values were 11.7 ± 5.6 µg/ml and 30.7 ± 4.4 µg/ml, respectively. OMWW was confirmed as a rich source of natural phenolic antioxidant agents.

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The use of fruit industrial waste in the processing new foods represents an important new step for the food industry. This study aimed to develop cookie recipes using different amounts of guava peel flour (GPF) levels (30%, 50%, and 70%) to evaluate the proximate composition, and the phenolic compound, lycopene, and β-carotene levels in the cookies and flour and to evaluate the cookie sensory acceptance. The results demonstrated low moisture, lipid and carbohydrate contents in the flour and cookies. GPF was considered rich in fiber, ash, polyphenols, and β-carotene. The sensory analysis showed satisfactory acceptance of the cookies containing 30% GPF regarding the aroma, flavor, and texture attributes. The cookies containing 50% and 70% GPF received satisfactory acceptance regarding to aroma only. In conclusion, GPF can be used to partially replace wheat flour in the preparation of cookies to improve the nutritional quality without affecting the product sensory quality.

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This study aimed to characterize the chemical composition, determine the fatty acid profile, and quantify the bioactive compounds present in guava seed powder (Psidium guajava L.). The powder resulted from seeds obtained from guava pulp processing. The agro-industrial seeds from red guava cv. paluma were used, and they were donated by a frozen pulp fruit manufacturer. They contain varying amounts of macronutrients and micronutrients, with a high content of total dietary fiber (63.94 g/100g), protein (11.19 g/100g), iron (13.8 mg/100g), zinc (3.31 mg/100g), and reduced calorie content (182 kcal/100g). Their lipid profile showed a predominance of unsaturated fatty acids (87.06%), especially linoleic acid (n6) and oleic acid (n9). The powder obtained contained significant amounts of bioactive compounds such as ascorbic acid (87.44 mg/100g), total carotenoids (1.25 mg/100 g) and insoluble dietary fiber (63.55 g/100g). With regard to their microbiological quality, the samples were found suitable for consumption. Based on these results, it can be concluded that the powder produced has favorable attributes for industrial use, and that use of these seeds would be a viable alternative to prevent various diseases and malnutrition in our country and to reduce the environmental impact of agricultural waste.

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Blackberry (Rubus fruticosus, cultivar Tupy), an expanding fruit crop in southern Brazil, is greatly appreciated for its flavor and bioactive potential with limited characterization of its metabolite content. The purpose of this study was to characterize the bioactive and volatile organic compound (VOC) content of mature blackberry fruit of cultivar Tupy. Gallic acid, (-)-epicatechin, ferulic acid, and quercetin were the main phenolic compounds found in mature fruit. Among the VOCs identified in 'Tupy' blackberry were important flavor components characteristic of fruit berries, including hydrocarbons, alcohols, aldehydes, ketones, esters, and terpenoids. Some of the VOCs had not been previously found in blackberry, while others have been associated with typical blackberry flavor.

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Over the last decade a considerable increase in the number of studies addressing the use of antioxidants from natural sources has led to the identification and understanding of the potential mechanisms of biologically active components. This results from the fact that they can be used to replace synthetic antioxidants commonly used in food. Murtilla (Ugni molinae Turcz) is a native berry grown in Chile, and in the present study, the phenolic composition and antioxidant activity of its fruits were studied. Hydroalcoholic extracts of dehydrated fruits from two genotypes of murtilla (Ugni molinae Turcz.) were produced. Extracts of wild murtilla and 14-4 genotype fruits had 19.35 and 40.28mg GAE/g for Total Phenolic Compounds, 76.48, and 134.35μmol TEAC/g for DPPH, and 157.04 and 293.99 μmol TEAC/g for ABTS, respectively. Components such as quercetin, epicatechin, and gallic, benzoic and hydrocaffeic acids were identified by CG/MS analysis. All of them showed antioxidant activity. Therefore, it is possible to say that the hydroalcoholic extracts of murtilla have antioxidant potential to be used in lipidic food.

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The aroma characteristics of wines from four Vitis vinifera grape varieties (‘Cabernet sauvignon’, ‘Merlot’, ‘Chardonnay’, and ‘Italian Riesling’) grown in three shoot positions were evaluated by HS-SPME-GC/MS. In this study, the numerous significant differences found in most of the aromatic compounds influence of different shoot positions on the quality of wine. The results showed that the middle shoot position increased significantly the aroma concentration in the majority of wines investigated. The volatile components showing the greatest differences in the wines of different cultivars were aldehydes and terpenes. 8 and 11 compounds were found and quantified (OAVs>1) in the two red wines and white wines at concentrations higher than their corresponding odor thresholds, respectively; and therefore they significantly contributed to the wine aromas. According to their OAVs, fruity, floral, cheese and fatty aroma strongly influenced the characteristics of the four monovarietal wines, while the two white wines showed the green and fresh aroma characteristics. These results are related to the different microclimate of the canopies of the different shoot positions and varieties. They suggest that proper elevating the fruiting zones could improve the accumulation of aroma compounds in wines from the different varieties. On the other hand, grapevines trained to systems with uniform fruiting zones could improve the quality of wine.