975 resultados para Ethanol Fermentation
Resumo:
Ginger (Zingiber officinale Roscoe) belongs to the Zingiberacea family. It is a spice of great commercial importance. In this work ginger oleoresin was obtained with ethanol, isopropanol and liquid carbon dioxide. The chemical compositions of the extract were compared with each other. All oleoresin samples had monoterpenes and sesquiterpenes. Carboxylic acids were found in organic solvent extracts for an extraction time of 2 hours. The component responsible the for pungent characteristic of the oleoresin, gingerois, were detected in samples obtained with organic solvent for extraction times of 6 hours and in samples obtained with CO2 liquid for extraction times of 2 hours.
Antioxidant activity of rosemary and oregano ethanol extracts in soybean oil under thermal oxidation
Resumo:
Four experiments were conducted to measure the antioxidant activity of ethanol extracts of rosemary and oregano compared with synthetic antioxidants such as TBHQ and BHA/BHT. The antioxidant activity was determined and results differed from those of the Oven test at 63º C. Peroxide values and absorptivities at 232 nm of soybean oil under Oven test were lower in treatments with 25, 50, 75, 100 and 200 mg.Kg-1 TBHQ than in treatments with 1000 mg.Kg-1 oregano extract (O), 500 mg.Kg-1 rosemary extract (R) and their mixture R+O. All the treatments were effective in controlling the thermal oxidation of oils; the natural extracts were as effective as BHA+BHT and less effective than TBHQ. The natural extracts were mixed with 25, 50, 75 and 100 mg.Kg-1 TBHQ and then added to the oil. No improvement in antioxidative properties was observed. The best antioxidant concentration could be determined from polynomial regression and quadratic equation from the experimental data.
Resumo:
The growing interest in lipase production is related to the potential biotechnological applications that these enzymes present. Current studies on lipase production by submerged fermentation involve the use of agro-industrial residues aiming at increasing economic attractiveness. Based on these aspects, the objective of this work was to investigate lipase production by Penicillium verrucosum in submerged fermentation using a conventional medium based on peptone, yeast extract, NaCl and olive oil, and an industrial medium based on corn steep liquor, Prodex Lac (yeast hydrolysate), NaCl and olive oil, as well as to characterize the crude enzymatic extracts obtained. Kinetics of lipase production was evaluated and the highest enzymatic activities, of 3.15 and 2.22 U.mL-1, were observed when conventional and industrial media were used, respectively. The enzymatic extract showed optimal activity in the range from 30 to 40 °C and at pH 7.0. Although the industrial medium presents economical advantages over the conventional medium, the presence of agro-industrial residues rich in nitrogen and other important nutrients seemed to contribute to a reduction in lipase activity.
Resumo:
Probiotics are supplementary foods developed by microbial strains that improve animal health beyond basic nutrition. Probiotics are consumed orally, regardless of being considered as normal inhabitants of the intestines, able to survive in enzimatic and biliary secretions. Kefir is a probiotic originated from the old continent, fermented by several bacteria and yeasts, encapsulated in a polyssacharide matrix, and resembles jelly grains. Kefir is also presented as its sourish product both in sugary or milky suspensions containing vitamins, aminoacids, peptides, carbohydrates, ethanol, and volatile compounds. Kefir is known to have a diverse microbial content depending on the country and fermentative substrates, which cause distinct probiotic effects. In this sense, the purpose of this work was to isolate, identify, and quantify the microbial content of a native sugary kefir sample (fermented suspension and lyophilized natural grains). Serial dilutions were plated on Rogosa agar (AR) and De Man, Rogosa and Sharpe (MRS), for Lactobacillus; Brain Heart Infusion (BHI), for total bacteria; Sabouraud-Dextrose-Agar (SDA), for yeasts and filamentous fungi; Thioglycolate Agar (TA), for Streptococcus, Acetobacteria and Leuconostoc; and Coconut Water Agar (CWA), and CWA supplemented with yeast extract (CWAY), for various genera. Genera and species for all strains were identified through biochemical reactions and specific API systems. The microbial profile of kefir was different from other sources of grains despite the presence of similar microorganisms and others which have not been reported yet. The data obtained with the CWA and CWAE media suggest that both substrates are alternative and salutary media for culture of kefir strains.
Resumo:
This work aims to evaluate deoxynivalenol degradation by Aspergillus oryzae and Rhizopus oryzae in a submerged fermentation system and to correlate it to the activity of oxydo-reductase enzymes. The submerged medium consisted of sterile distilled water contaminated with 50 μg of DON and 4 × 10(6) spore.mL-1 inoculum of Aspergillus oryzae and Rhizopus oryzae species, respectively in each experiment. Sampling was performed every 24 hours for monitoring the peroxidase specific activity, and every 48 hours for determining mycotoxin levels. Results showed that the fungi species were able to decrease DON levels as the peroxidase activity increased. The 48 hours fermentation interval presented the highest peroxidase specific activity (ΔABS/minute.μg.protein-1), 800 and 198, while the highest DON degradation velocity was 10.8 and 12.4 ppb/hour, respectively in both cases for Rhizopus oryzae and Aspergillus oryzae.
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.
Resumo:
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.
Resumo:
The study of the ecology of fermented sausage is fundamental to understand the physical and chemical changes that happen during fermentation and maturation. The aim of the present study was to determine the microbiological characteristics of sausages produced by spontaneous fermentation. Fifty samples of sausages produced in the South of Brazil by different small manufacturers were analyzed for the following microbiota: aerobic mesophilic bacteria; Micrococcaceae; mold and yeast; lactic acid bacteria; total and fecal coliforms; coagulase-positive Staphylococcus, and Salmonella. In most samples (72%), the count of lactic bacteria was higher than 6 log10 cfu.g-1, and the samples with the highest counts were above 8 log10 cfu.g-1. The counts of Micrococcaceae in most samples were between 5 log10 and 7 log10 cfu.g-1. With respect to the presence of molds and yeasts, there was a significant variation among the samples with counts ranging from 2 log10 cfu.g-1 and 6 log10 cfu.g-1. From the data obtained, it was possible to conclude that 24% of the analyzed samples did not comply with the current law in Brazil since the levels of fecal coliforms or coagulase-positive Staphylococcus exceeded the maximum limit allowed.
Resumo:
The aim of this study was to reduce the fermentation time of pizza dough by evaluating the development of the dough during fermentation using a Chopin® rheofermentometer and verifying the influence of time and temperature using a 2² factorial design. The focus was to produce characteristic soft pizza dough with bubbles and crispy edges and soft in the center. These attributes were verified by the Quantitative Descriptive Analysis (QDA). The dough was prepared with the usual ingredients, fermented at a temperature range from 27 to 33 ºC for 30 to 42 minutes, enlarged, added with tomato sauce, baked, and frozen. The influence of the variables time and temperature on the release of carbon dioxide (H'm) was confirmed with positive and significant effect, using a rheofermentometer, which was not observed for the development or maximum height of the dough (Hm). The same fermentation conditions of the experimental design were used for the production of the pizza dough in the industrial process; it was submitted to Quantitative Descriptive Analysis (QDA), in which the samples were described by nine attributes. The results showed that some samples had the desired characteristics of pizza dough, demonstrated by the principal component analysis (PCA), indicating a 30 % fermentation time reduction when compared to the conventional process.
Resumo:
The purpose of this study was to introduce yam in the development of two new composite flours containing soy and cassava. Two composite flours were obtained after fermentation of yam, soybean, and cassava in respectively 60, 30, and 10% proportions. Two varieties of yam were used: Dioscorea alata (variety "Bete bete") and Dioscorea cayenensis (variety "Lokpa"). Proximate composition, mineral content, some anti-nutritional factors (oxalates, phenols), microbiological quality, and α-amylase digestibility were determined for the fermented and unfermented composite flours. The results indicated that for the composite flours made of D. alata and D. cayenensis, fermentation increased ash and titrable acidity. Carbohydrates, pH, and energy decreased. Crude fat content was not affected by the fermentation process. Anti-nutritional factors such as oxalates and phenols were found to decrease significantly after the fermentation of the composite flours. Fermentation increased the mineral content (Mg, K, Fe, and Ca) of the composite flours. A decrease in P and Na was observed after fermentation. The microbiological study showed that safety flours contain no potential pathogenic germs. The in vitro α-amylase digestibility of the composite flours was significantly improved after fermentation. The biochemical characteristics and good hygienic quality of the obtained flours suggest that these flours can be considered as a feeding alternative for children in poor areas where yam is produced.
Resumo:
Physalis species are used in folk medicine for phytotherapeutic properties. The extracts of medicinal plants are known to possess cytotoxic and chemopreventative compounds. In this study we investigated antibacterial, antioxidant, DNA damage preventative properties of Physalis peruviana (golden berry) on leaf and shoot ethanol extracts and their effects on cytotoxicity of HeLa cells and expression of apoptotic pathway genes. Among the tested bacteria for antibacterial activity, maximum inhibition zone was determined in Lactococcus lactis. The phenolic content was found higher in leaf extracts than shoot extracts. The antioxidant activity showed the highest TEAC values of the leaf (2 mg/mL) and the shoot (0.5 mg/mL) extracts as 0.291±0.04 and 0.192±0.015, respectively. In DNA damage prevention assay both leaf and shoot extracts, especially 30 and 20 µg/mL concentrations, exhibited significant protection against DNA damage-induced by hydroxyl radical generated by Fenton reaction. Our results suggest that leaf and shoot extracts possess cytotoxic effect on HeLa cells when applied as 100 µg/mL concentration. Also mRNA expression analysis showed the alteration of antiapoptotic genes, so the results suggest that P. peruviana ethanol extracts induce apoptotic cell death and should be investigated for identification of active compounds and their mechanisms of action.
Resumo:
One component that contribute to the flavor and aroma of chocolate are the polyphenols, which have received much attention due to their beneficial implications to human health. Besides bioactive action, polyphenols and methylxantines are responsible for astringency and bitterness in cocoa beans. Another important point is its drastic reduction during cocoa processing for chocolate production and the difference between cultivars. Thus, the present study aimed to evaluate the modifications in monomeric phenolic compounds and methylxanthines during fermentation of three cocoa cultivars grown in southern Bahia. Cocoa beans from three cultivars were fermented and sun dried and monomeric phenolic compounds and methylxantines were determinated. The results showed that each cultivar have different amounts of phenolic compounds and the behaviour of them is different during fermentation. The amount of methylxantines varied but there was not a pattern for methylxantines behavior during process. In addition a huge reduction in phenolic compounds could be observed after drying. Differently of phenolic compounds, methylxantines did not have great modification after sun drying. So, the differences observed in this study between cultivars, take to the conclusion that the compounds studied in those cocoa cultivars have different behavior during fermentation and drying, which consequently, give to these cultivars differences in sensory characteristics.
Resumo:
Abstract The use of agroindustrial residues is an economical solution to industrial biotechnology. Coffee husk and pulp are abounding residues from coffee industry which can be used as substrates in solid state fermentation process, thus allowing a liberation and increase in the phenolic compound content with high added value. By employing statistical design, initial moisture content, pH value in the medium, and the incubation temperature were evaluated, in order to increase the polyphenol content in a process of solid state fermentation by Penicillium purpurogenum. The main phenolic compounds identified through HPLC in fermented coffee residue were chlorogenic acid, caffeic acid, and rutin. Data obtained through HPLC with the radical absorbance capacity assay suggest the fermented coffee husk and pulp extracts potential as a source of phenolic acids and flavonoids. Results showed good perspectives when using P. purpurogenum strain to enhance the liberation of phenolic compounds in coffee residues.
Resumo:
The fermented herbal juices are capable of curing and preventing diseases and reducing the aging progress. The present study was performed to investigate the fermentation of Phyllanthus emblica fruit by Lactobacillus paracasei HII01 with respect to carbon sources, polyphenols, and antioxidant properties. The physical changes, for instance, color, odor, taste, turbidity and gas formation, throughout the fermentation process was manually monitored. The fermented product was rich in polyphenolic content. The acid content and pH of the product were under the norms of Thai community product standards. Antioxidant properties of the fermented product were proved using ABTS, and FRAP assays. Chelation based study suggested that fermented P. emblica fruit juices are healthy enough to stabilize the oxidized form of the metal ion. The optimum fermentation period was 15 days. All the results supported that studied carbon sources did not interfere with the quality of the product. This report is the prelude study on the use of probiotic starter culture for the production of P. emblica fruit based lactic acid bacteria fermented beverages (LAFB) enriched with bioactive compounds. Further research on the impact of different carbon sources and upstream processes on the quality of LAFB is currently in progress.