207 resultados para food color
Resumo:
Anthocyanins are highly important due to their antioxidant capacity. They are the most important among the phenolic compounds and one of the main natural dyes used in the food industry. In this research, residue of processed grapes was used to investigate the presence of anthocyanins, the possibility of their extraction from the residue, and their stability. The extraction solution consisted of 70 mL of ethanol 70% and 30 mL of HCl 0.1% at pH 2.0. The results found for the processed grapes residue was 26.20 mg.100 g-1. In order to evaluate stability, caffeic acid was added at 0.5:1 w/v; 0.8:1 w/v; and 1:1 w/v concentrations. Anthocyanins extract reached the greatest stability at 0.5:1 w/v concentration, with 82.47% color retention and a half-life period of 15 days. Therefore, the use of this organic acid as a stabilizer for anthocyanins is feasible.
Resumo:
Functional and technological properties of wheat depend on its chemical composition, which together with structural and microscopic characteristics, define flour quality. The aim of the present study was to characterize four Brazilian wheat cultivars (BRS Louro, BRS Timbauva, BRS Guamirim and BRS Pardela) and their respective flours in order to indicate specific technological applications. Kernels were analyzed for test weight, thousand kernel weight, hardness, moisture, and water activity. Flours were analyzed for water activity, color, centesimal composition, total dietary fiber, amylose content and identification of high molecular weight glutenins. The rheological properties of the flours were estimated by farinography, extensography, falling number, rapid visco amylography, and glutomatic and glutork equipment. Baking tests and scanning electron microscopy were also performed. The data were subjected to analysis of variance and principal component analysis. BRS Timbauva and BRS Guamirim presented results that did not allow for specific technological application. On the other hand, BRS Louro presented suitable characteristics for the elaboration of products with low dough strength such as cakes, pies and biscuits, while BRS Pardela seemed suitable for bread and pasta products.
Resumo:
The physiological state of a fruit is closely related to ripening and climatic conditions during the growing period when the fruit undergo changes in color, texture, and flavor. The ripening of the fruit can involve a complex series of biochemical reactions with alteration in enzymes activities, phenols, tannins, and ascorbic acid. The activity of enzymes (carboximethylcellulase, polygalacturonase, and pectinlyase), the total concentration of phenolic compounds, condensed tannins, and vitamin C in five stages of maturation were studied. Significant changes were observed between the maturity stages. The phenolic compounds were higher at green stage (705.01 ± 7.41); tannins were higher at green/purple stage (699.45 ± 0.22). The results showed that the ascorbic acid levels of the pulp varied significantly from 50.81 ± 1.43 to 6.61 ± 1.04 mg.100 g-1 during maturation. The specific activity of pectin lyase was higher at green stage (1531.90 ± 5.83). The specific activity of polygalacturonase was higher at mature stage (1.83 ± 0.0018). The specific activity of carboximetilcelulose was higher at ripe mature stage (4.61 ± 0.0024). The low ascorbic acid content found in jambolan fruit indicates that this fruit is not a rich source of this nutrient; however, other characteristics can make jambolan products fit for human consumption.
Resumo:
Umbu pulp is an important product in the economy of the northeastern region of Brazil, and its preservation can be ensured by heat treatment. A complete factorial design with 2 factors (time and temperature) and 3 central points was used to verify the effect of the HTST process on the physicochemical, chemical, physical, microbiological, and sensory qualities of umbu pulps. The results showed that the heat treatments applied resulted in products without significant alterations on the physicochemical, chemical, and microbiological characteristics. With respect to color, the parameters L and a* were altered by increases in temperature indicating by darkening of color. The sensory evaluation indicated that a treatment of 88 °C for 10 seconds was the best processing condition due to the greater similarity of the resulting product to the reference sample (blanched pulp).
Resumo:
Based on the concept that the trellising system affects not only sunlight interception and carbon assimilation, but also the fruitzone microclimate, which has a great impact on fruit composition and consequently on wine quality, the effect of two trellising systems - Vertical Shoot Position (VSP) and modified Geneva Double Curtain (GDC) - on wine and berry composition of Syrah grapes grown in João Pinheiro, Northeast region of Minas Gerais State, Brazil was investigated. The parameters such as pH, berry size and weight, and seeds total phenolic contents were not affected by the training system. The GDC system produced fruits with the highest Brix and lowest titratable acidity. Berries from the VSP system presented lower anthocyanin concentration than those from the GDC system. Similar results were found for the total phenolic content of the skin of grape berries from the VSP system. GDC wines were characterized by high anthocyanin content and red color, resulting in wines with high color intensity. These data suggest that in the tropical region of Minas Gerais state, with high temperature and high sunlight intensity, the trellising system, which protects bunches against excessive radiation, should be chosen.
Resumo:
Yolk color and egg white (albumen) cleanliness and viscosity are important parameters by which consumers judge the quality of eggs. This study aimed to investigate changes in albumen viscosity during storage of eggs for up to 36 days from two different commercial laying hen strains (Carijo Barbada and Isa Brown) fed a diet containing annatto (1.5 and 2.0%) or a synthetic additive without synthetic colorants (control). Analyses of humidity, albumen height, pH, viscosity, foam formation, and stability were carried out on eggs. Carijo Barbada strain had smaller albumen, lower humidity and higher egg white viscosity than Isa Brown strain; however, with storage, viscosity lowered significantly on both strains. Initially, the addition of 2.0% of annatto or a synthetic additive increased viscosity in both strains, but with storage only the control maintained longer viscosity. Lower viscosity did not change foam density and stability.
Resumo:
The goal of this study was to evaluate the sensory profile of eleven peach cultivars grown in an experimental orchard located in the city of Lapa (PR, Brazil) in two seasons. The peach cultivars analyzed were Aurora I, Chimarrita, Chiripá, Coral, Eldorado, Granada, Leonense, Maciel, Marli, Premier, and Vanguarda. The sensory analysis was performed by previously trained panelists; 20 of them in the first season and 10 in the second season. The sensory evaluation was performed using Quantitative Descriptive Analysis, in which the following attributes were measured: appearance, aroma, flesh color, flesh firmness, flavor, and juiciness. The results showed preference for sweet, soft, and juicy fruits. Chimarrita, Chiripá, and Coral fruits showed better sensorial performance than the other peach cultivars. It was also verified that the analysis of the attributes aroma, flesh firmness, and flavor is enough for performing the sensory profile of peach fruits for in natura consumption.
Resumo:
The coating of papayas with Cassava Starch (CS) and carboxymethyl starch (CMS) is an alternative to extend the shelf life of these fruits. This study evaluated the effect of the three different levels of CS and CMS (1, 3, and 5%) on sensory characteristics of papayas during storage. Nine selected and trained assessors evaluated 13 sensory attributes using the Multiple Comparison Test. The appearance and flavor attributes of the papayas treated with CS and CMS were compared to the control or reference sample (R - fruit without coating) using a nine-point scale, which varied from 1: less intense than R; 5: equal to R; 9: more intense than R. The samples were coded with three digit numbers and evaluated with repetition by a panel of assessors. In general, appearance was more affected by the coatings than flavor. Fruits coated with 3 and 5% of both coatings kept the green color longer than the other coatings concentrations, and at 5% the color of the fruits was less uniform on the last evaluation day. The 3 and 5% CS coating gave greater brightness to the fruits. 5% CMS favored the presence of fungi and damaged the fruit surface at the 14th day of storage. The CS coating at 5% presented peeled surface during all experimental time. Changes in fruits flavor were perceived at the 12th and 14th days of storage. A less characteristic flavor and a bitter taste were noticed in the fruits coated with CS and CMS at 5% at the 12th day of storage.
Resumo:
The DNA extraction is a critical step in Genetically Modified Organisms analysis based on real-time PCR. In this study, the CTAB and DNeasy methods provided good quality and quantity of DNA from the texturized soy protein, infant formula, and soy milk samples. Concerning the Certified Reference Material consisting of 5% Roundup Ready® soybean, neither method yielded DNA of good quality. However, the dilution test applied in the CTAB extracts showed no interference of inhibitory substances. The PCR efficiencies of lectin target amplification were not statistically different, and the coefficients of correlation (R²) demonstrated high degree of correlation between the copy numbers and the threshold cycle (Ct) values. ANOVA showed suitable adjustment of the regression and absence of significant linear deviations. The efficiencies of the p35S amplification were not statistically different, and all R² values using DNeasy extracts were above 0.98 with no significant linear deviations. Two out of three R² values using CTAB extracts were lower than 0.98, corresponding to lower degree of correlation, and the lack-of-fit test showed significant linear deviation in one run. The comparative analysis of the Ct values for the p35S and lectin targets demonstrated no statistical significant differences between the analytical curves of each target.
Resumo:
The aim of this study was to use a factorial design approach for developing a palatable and stable soy-based dessert with the addition of Soy Protein (SP), oligofructose, and Passion Fruit Juice (PFJ). Panelists (n = 50) used a seven-point hedonic scale to assess the overall liking, degree of liking of creaminess, taste, and color of the desserts. In addition, the samples were submitted to a preference ranking test in order to evaluate the products' preference. Water Holding Capacity (WHC) and backscattering (BS) measures were also determined to assess the physical stability of the trials. Sample F3 (35% PFJ and 2% SP) was the only one that presented a WHC index of 94.8%; moreover, none of the developed samples had synerisis after 72 hours of storage indicating adequate physical stability of the emulsion process. Samples F2 (25% PFJ, and 3.0% SP), F4 (35% PFJ, and 3.0% SP), and F5 (30% PFJ, and 2.5% SP) presented mean hedonic scores above 'slightly liked' for all sensory attributes. The acceptance index of samples varied from 62.50 to 88% showing the great sensory potential of such products.
Resumo:
Food processes must ensure safety and high-quality products for a growing demand consumer creating the need for better knowledge of its unit operations. The Computational Fluid Dynamics (CFD) has been widely used for better understanding the food thermal processes, and it is one of the safest and most frequently used methods for food preservation. However, there is no single study in the literature describing thermal process of liquid foods in a brick shaped package. The present study evaluated such process and the influence of its orientation on the process lethality. It demonstrated the potential of using CFD to evaluate thermal processes of liquid foods and the importance of rheological characterization and convection in thermal processing of liquid foods. It also showed that packaging orientation does not result in different sterilization values during thermal process of the evaluated fluids in the brick shaped package.
Resumo:
The efficiency of four Sanitizers - peracetic acid, chlorhexidine, quaternary ammonium, and organic acids - was tested in this work using different bacteria recognized as a problem to meat industry, Salmonella sp., S. aureus, E. coli and L. monocytogenes. The effects of sanitizer concentration (0.2, 0.5, 0.6, 1.0, 1.1 and 1.4%), at different temperatures (10 and 45 °C) and contact time (2, 10, 15, 18 and 25 minutes) were evaluated. Tests in an industrial plant were also carried out considering previously obtained results. In a general way, peracetic acid presented higher efficiencies using low concentration (0.2%) and contact time (2 minutes) at 10 °C. The tests performed in industrial scale showed that peracetic acid presented a good performance in concentration and contact time lower than that suggested by the suppliers. The use of chlorhexidine and quaternary ammonium led to reasonable results at the indicated conditions, and organic acids were ineffective under concentration and contact time higher than those indicated by the suppliers in relation to Staphylococcus aureus. The results, in general, show that the choice for the most adequate sanitizer depends on the microorganism contaminant, the time available for sanitizer application, and also on the process cost.
Resumo:
Cubiu (Solanum sessiliflorum Dunal) is an Amazonian Basin native fruit. Its importance comes from its high contents of pectin. Currently, processing technologies are necessary for the substitution of the traditional system (small crops and small-scale processing) for a larger scale system and thus increase the use of biodiversity and promote the implementation of Local Productive Arrangements of agribusiness in the Amazon. This research aims to evaluate the methods of peeling cubiu. Ripe fruits were divided into lots (150 each) and subjected to the following treatments: immersion in 2.5% NaOH boiling solution for 5 minutes, exposure to water vapor, and immersion in water at 96 ºC for 5, 10, 15 and 20 minutes. The peel released during heat treatment and immediately removed under running tap water. In the control treatment, the fruits were manually peeled (unheated) with a stainless steel knife. The treatments were evaluated for completeness and ease of peeling, tissue integrity, texture, and peroxidase activity. The immersion in 2.5% NaOH boiling solution (5 minutes) stood out as the best treatment since it inhibited the enzymatic browning and intensified the natural yellow color of the cubiu fruit and easily and fully peeled the whole fruit more rapidly without damaging its tissues. This treatment was chosen as the most advantageous because it can promote simultaneous peeling and bleaching. Therefore, it is recommended for cubiu industrial processing.
Resumo:
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.
Resumo:
The aim of this work was to perform the microbiological and physicochemical characterization of surimi made from waste of piramutaba filleting. The results of physicochemical characterization of the waste and surimi were: moisture (76.37 and 79.11%), total lipids (5.35 and 0.74%), proteins (14.92 and 10.79%), ash (3.03 and 2.35%), pH (6.9 and 7.4), caloric value (109.15 and 77.86 kcal.g-1), and water activity (both 0.98), respectively. The results of the levels of total volatile bases were 7.29 mgN/100-1 g (waste) and 7.01% carbohydrate (surimi). The values of total lipids and proteins were reduced during the preparation of surimi, probably due to successive washes during the processing. Waste and surimi were examined microbiologically and are in compliance with required parameters. The results show a loss of red (a* parameter) and yellow (b* parameter) color. On the other hand, the L* parameter (lightness) increased after the processing of surimi. It can be concluded that piramutaba waste can be used for surimi preparation and as a source of nutrients for human consumption, providing an alternative use of these wastes avoiding their disposal polluting the environment.