951 resultados para Color and sensory evaluation
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The influence of the addition of a potential probiotic culture of Lactobacillus paracasei and of the prebiotic fiber inulin on the texture profile and on the sensory evaluation of probiotic and synbiotic fresh cream-cheeses was monitored. Three cheese-making trials were prepared in quintuplicate, all supplemented with a Streptococcus thermophilus starter culture (T1, T2 and T3). L. paracasei subsp. paracasei was added to T1 and T2, and inulin, to T2. The instrumental texture profile was determined after 1, 7, 14 and 21 days of storage of the cheeses. Sensory evaluation was performed after 7 days of storage. The presence of Lactobacillus paracasei in cheeses T1 and T2 and of inulin in cheeses T2 did not alter the texture profile significantly. Cheeses T1 were the least preferred in the sensory evaluation and differed signifcantly from T2 and T3, due to acidic taste, according to panelists. On the other hand, T2 was the most preferred one, though not significantly different from T3. The addition of the prebiotic ingredient inulin to fresh cream cheese processed with a potentially probiotic Lactobacillus paracasei strain resulted in a product with appropriate features and with aggregated functional properties.
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The objective of this work was to evaluate the production of flour using by-products (cephalothorax) obtained from the shrimp (Litopenaeus vannamei) industry, and to perform a sensory analysis of shrimp flour-based products. Physicochemical and microbiological analyses on fresh cephalothorax and on manufactured flour were performed, as well as the determination of cholesterol content of this flour, and the sensorial evaluation of soup and pastry made with this flour. By the microbiological analyses, no pathogenic microorganism was detected in the samples. Physicochemical analyses of flour showed high levels of protein (50.05%) and minerals (20.97%). Shrimp cephalothorax flour showed high levels of cholesterol. The sensory evaluation indicated a good acceptance of the products, with satisfactory acceptability index (81% for soup, and 83% for pastry), which indicates that shrimp cephalothorax in the form of flour has a potential for developing new products.
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Response Surface Methodology (RSM) was applied to evaluate the chromatic features and sensory acceptance of emulsions that combine Soy Protein (SP) and red Guava Juice (GJ). The parameters analyzed were: instrumental color based on the coordinates a* (redness), b* (yellowness), L* (lightness), C* (chromaticity), h* (hue angle), visual color, acceptance, and appearance. The analyses of the results showed that GJ was responsible for the high measured values of red color, hue angle, chromaticity, acceptance, and visual color, whereas SP was the variable that increased the yellowness intensity of the assays. The redness (R²adj = 74.86%, p < 0.01) and hue angle (R²adj = 80.96%, p < 0.01) were related to the independent variables by linear models, while the sensory data (color and acceptance) could not be modeled due to a high variability. The models of yellowness, lightness, and chromaticity did not present lack of fit but presented adjusted determination coefficients bellow 70%. Notwithstanding, the linear correlations between sensory and instrumental data were not significant (p > 0.05) and low Pearson coefficients were obtained. The results showed that RSM is a useful tool to develop soy-based emulsions and model some chromatic features of guava-based emulsions through RSM.
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The potential of functional foods to decrease the risks of chronic non-communicable diseases has motivated the development of products with beneficial effects on fat and carbohydrate metabolism. The present study aimed at analyzing the physicochemical, microbiological, and sensory properties of a bioactive food blend developed to help the nutritional therapy provided to hypolipidemic and hyperglycemic patients with HIV/AIDS treated with antiretroviral therapy. The food blend was evaluated for moisture, protein, carbohydrate, fats, fixed mineral residue, total fiber content, and fatty acid composition, according to the standards established by the Instituto Adolfo Lutz. Food safety was assessed by microbiological analyses for Bacillus cereus, Salmonella spp, and coliforms. Sensory acceptance and intention to purchase were also evaluated. The food blend showed good nutritional potential, with low atherogenicity and thrombogenicity indexes, good macronutrient balance, and high energy value. The adoption of Good Manufacturing Practices (GMP) resulted in a product suitable for consumption. With respect to sensory aspects, the food blend showed satisfactory indexes of acceptability and promising marketing potential.
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The labneh or labaneh is a popular fermented milk in the Middle East. Another fermented product that deserves special mention is kefir since it has probiotic activity and unique sensory, nutritional, and therapeutic properties. The aim of the present study was to develop a functional probiotic labneh using kefir as a fermenting agent and to perform a sensory analysis of the obtained product. Kefir was obtained by growing grains in pasteurized milk. Samples of skimmed and whole labneh were prepared from the inoculation of 5% kefir milk (skimmed/whole) at 28 ºC for 24h, followed by cooling (12-18h) and whey drainage (12-24h), both at 4 ºC. Sensory analysis was performed with 70 untrained panelists using a 9-point scale hedonic in the acceptance tests. The paired t-test was used to compare the differences between the means of the scores obtained, with the significance level of 5%. The labneh prepared showed good acceptance by the judges, and the whole labneh samples had the highest scores in the acceptance test. Further studies on the analysis of microbiological viability, nutritional composition, and determination of shelf life, also to improve acceptability of the low-fat version of the product, are needed.
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Abstract The aim of this study was to evaluate the microbiological and sensory quality of the Jambu (Acmella oleracea L.) in natura and dried by cold air, and the determination of its drying curve. The microbiological analysis were performed to Salmonella spp, the coagulase-positive Staphylococcus, and coliforms in the both Jambu samples, at 45 °C. Tacacá, the typical food dish of Pará state, Brazil, has showed good consumer global acceptance in the sensory evaluation of Jambu in natura (score of 8.00 ± 1.46) and dried (score of 8.67 ± 0.66). Both samples, Jambu in natura and dried by cold air, were by the current legislation regarding the microbiological aspects, this is the absence of Salmonella spp, coagulase-positive Staphylococcus <1×101 CFU/g, and coliforms <3 MPN/g, at 45 °C. Thus, considering sensory and health aspects, the commercialization of dried Jambu becomes viable, facilitating its transportation and handling, as well as for reducing its vegetable mass.
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The processing of meats at the factory level can trigger the onset of lipid oxidation, which can lead to meat quality deterioration. Warmed over flavor is an off-flavor, which is associated with oxidative deterioration in meat. To avoid or delay the auto-oxidation process in meat products, synthetic and natural antioxidants have been successfully used. Grape (Vitis Vinifera) is of special interest due to its high content of phenolic compounds. Grape seed extract sold commercially as a dietary supplement, has the potential to reduce lipid oxidation and WOF in cooked ground beef when added at 1%. The objective of study 1 was to compare the antioxidant activity of natural antioxidants including grape seed extract and some herbs belonging to the Lamiaciae family: rosemary (Rosmarinus Officinalis), sage (Salvia Officinalis) and oregano (Origanum Vulgare) with commercial synthetic antioxidants like BHT, BHA, propyl gallate and ascorbic acid using the ORAC assay. All sample solutions were prepared to contain 1.8 gm sample/10 ml solvent. The highest antioxidant activity was observed for the grape seed extract sample (359.75 µM TE), while the lowest was observed for BHA, propyl gallate and rosemary also showed higher antioxidant potential with ORAC values above 300 μmol TE/g. ORAC values obtained for ascorbic acid and Sage were between 250-300μ mol TE/g while lowest values were obtained for Butylated Hydroxytoluene (28.50 µM TE). Based on the high ORAC values obtained for grape seed extract, we can conclude that byproducts of the wine/grape industry have antioxidant potential comparable to or better than those present in synthetic counterparts. The objective of study 2 was to compare three levels of grape seed extract (GSE) to commonly used antioxidants in a pre-cooked, frozen, stored beef and pork sausage model system. Antioxidants added for comparison with control included grape seed extract (100, 300, 500 ppm), ascorbic acid (AA, 100 ppm of fat) and propyl gallate (PG, 100 ppm of fat). Product was formed into rolls, frozen, sliced into patties, cooked on a flat griddle to 70C, overwrapped in PVC, and then frozen at –18C for 4 months. GSE- and PG-containing samples retained their fresh cooked beef odor and flavor longer (p<0.05) than controls during storage. Rancid odor and flavor scores of GSE-containing samples were lower (p<0.05) than those of controls after 4 months of storage. The L* value of all samples increased (p<0.05) during storage. Thiobarbituric acid reactive substances (TBARS) of the control and AA-containing samples increased (p<0.05); those of GSE-containing samples did not change significantly (p>0.05) over the storage period.
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This study aimed at evaluating compositional changes in the quality of 'Ortanique' tangor after coating with the carnauba-based waxes Aruá Tropical® or Star Light®. The storage conditions studied simulated those of local marketing (22 ± 2 °C, 60 ± 5% RH). Non-destructive analysis, mass loss, peel color, and sensory evaluation, were performed upon coating and every three days up to the fifteenth day of storage. Destructive analysis, peel moisture content, chlorophyll of the peel, pulp color, juice content, soluble solids (SS), titratable acidity (TA), pH, and soluble solids to titratable acidity ratio, were performed upon coating and every four days up to the sixteenth day of storage. The assay was conducted using an entirely randomized design, with three replications (destructive analyses) or ten replications (non-destructive analyses), in a split plot scheme. Wax-coating, especially Aruá Tropical®, maintained fruit freshness by reducing mass loss and peel dehydration and retaining green color. Peel moisture content, chlorophyll content, and juice content had lower rates in the wax coated fruits. Puncture force, soluble solids, titratable acidity, pH, and soluble solids to titratable acidity ratio varied vary little over the course of storage. Sensory evaluation showed that the application of Aruá Tropical keeps 'Ortanique' tangor fresher for 6 days longer for commercialization.
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Pós-graduação em Aquicultura - FCAV
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The purpose of this study was to evaluate the acceptability and the microbiological safety of uncured fresh chicken sausages with reduced fat content, considering the scientific evidence that correlated cancer and cardiovascular diseases to this diet. Two formulations of uncured fresh chicken sausage were processed using different concentrations of cochineal carmine pigment, rosemary extracts and synthetic antioxidants, which are used to give color, appearance and pleasant flavor to the products. Then, instrumental color (L*, a*, b*, C* and h*), microbial contamination and sensory tests (ranking and acceptance) were used to evaluate the quality of the uncured chicken sausages. The instrumental color (chroma and hue) and the sensory properties of the A and B uncured sausages were similar to the commercial cured sausage (C). However, the sensory color and appearance of samples A and B were statistically higher than those of the commercial uncured sausages D, which are prepared without the addition of nitrite or pigments. The results showed that it is possible to produce safe and high-quality uncured fresh chicken sausage with reduced fat content, using natural pigments and antioxidants.
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The goal of this study was to develop a symbiotic lacteous drink, evaluate its physicochemical and sensory characteristics, and verify the viability of Lactobacillus acidophilus in the drink. The milk serum-based drink consisted of 50% milk serum containing 10% saccharose, 25% powdered milk, 15% yacon pulp, and cultures of Lactobacillus acidophilus-La 5E and Bifidobacterium bifidum BB12. It was stored for up to 21 days under refrigeration. The milk serum-based drink was analyzed for protein, ether extract, total dietary fiber, total frutans, carbohydrate content, color, pH, acidity, and contamination by coliforms, and Salmonella sp. Coliforms and Salmonella sp were not detected, and L. acidophilus and B. bifidum provided satisfactory probiotic counts up to 21 days of storage under refrigeration. Lactobacillus acidophilus resistance to gastric acids and bile salts was detected only up to seven days of storage when evaluated in vitro. Sensory analysis and purchase viability were evaluated by consumers at 0, 7, 14, and 21 days of storage. Based on the analytical results and consumer evaluation, the drink was acceptable up to seven days of storage.
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To evaluate the potential for fermentation of raspberry pulp, sixteen yeast strains (S. cerevisiae and S. bayanus) were studied. Volatile compounds were determined by GC-MS, GC-FID, and GC-PFPD. Ethanol. glycerol and organic acids were determined by HPLC. HPLC-DAD was used to analyse phenolic acids. Sensory analysis was performed by trained panellists. After a screening step, CAT-1, UFLA FW 15 and S. bayanus CBS 1505 were previously selected based on their fermentative characteristics and profile of the metabolites identified. The beverage produced with CAT-1 showed the highest volatile fatty acid concentration (1542.6 mu g/L), whereas the beverage produced with UFLA FIN 15 showed the highest concentration of acetates (2211.1 mu g/L) and total volatile compounds (5835 mu g/L). For volatile sulphur compounds. 566.5 mu g/L were found in the beverage produced with S. bayanus CBS 1505. The lowest concentration of volatile sulphur compounds (151.9 mu g/L) was found for the beverage produced with UFLA FW 15. In the sensory analysis, the beverage produced with UFLA FW 15 was characterised by the descriptors raspberry, cherry, sweet, strawberry, floral and violet. In conclusion, strain UFLA FW 15 was the yeast that produced a raspberry wine with a good chemical and sensory quality. (C) 2010 Elsevier Ltd. All rights reserved.
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Frozen samples of mechanically deboned chicken meat (MDCM) with skin were irradiated with gamma radiation doses of 0.0 kGy (control) and 3 kGy at 2 different radiation dose rates: 0.32 kGy/h (3 kGy) and 4.04 kGy/h (3 kGy). Batches of irradiated and control samples were evaluated during 11 d of refrigerated (2 +/- 1 degrees C) storage for the following parameters: total psychrotrophic bacteria count, thiobarbituric acid reactive substances (TBARS), evaluation of objective color (L*, a*, and b*) and a sensory evaluation (irradiated odor, oxidized odor, pink and brown colors). No statistical difference (P > 0.05) was found amongst the TBARS values obtained for the MDCM samples irradiated with dose rates of 0.32 and 4.04 kGy/h. There was a significant increase (P < 0.05) in the psychrotrophic bacterial count as from the 7th day of refrigerated storage, for the MDCM samples irradiated at the dose rate of 4.04 kGy/h. With respect to the attribute of oxidized odor, the samples irradiated with a dose rate of 0.32 kGy/h showed a stronger intensity and were significantly different (P < 0.05) from the sample irradiated with a dose rate of 4.04 kGy/h on days 0 and 2 of refrigerated storage. Irradiation with a dose rate of 4.04 kGy/h (3 kGy) was shown to be the best condition for the processing of MDCM according to the evaluation of all the variables, under the conditions of this study. Practical Application The results obtained for the application of different dose rates of ionizing radiation to mechanically deboned chicken meat will provide the food industry with information concerning the definition of the best processing conditions to maximize the sensory and food quality.
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In this study, 73 South American red wines (Vitis vinifera) from 5 varietals were classified based on sensory quality, retail price and antioxidant activity and characterised in relation to their phenolic composition. ORAC and DPPH assays were assessed to determine the antioxidant activity, and sensory analysis was conducted by seven professional tasters using the Wine Spirits Education Trust`s structured scales. The use of multivariate statistical techniques allowed the identification of wines with the best combination of sensory characteristics, price and antioxidant activity. The most favourable varieties were Malbec, Cabernet Sauvignon, and Syrah produced in Chile and Argentina. Conversely, Pinot Noir wines displayed the lowest sensory characteristics and antioxidant activity. These results suggest that the volatile compounds may be the main substances responsible for differentiating red wines on the basis of sensory evaluation. (C) 2011 Elsevier Ltd. All rights reserved.