579 resultados para Food Science and
Resumo:
The soybean is a protein source of high biological value. However, the presence of anti-nutritional factors affects its protein quality and limits the bioavailability of other nutrients. The effect of heat-treatment, 150 ºC for 30 minutes, on hulled and hull-less soybean flour from the cultivar UFVTN 105AP on urease, trypsin inhibitor activity, protein solubility, amino acid profile, and in vivo protein quality was investigated. The treatment reduced the trypsin inhibitor activity and urease, but it did not affect protein solubility. Protein Efficiency Coefficient (PER) values of the flours were similar, and the PER of the hull-less soybean flour did not differ from casein. The Net Protein Ratio (NPR) did not differ between the experimental groups. The True Digestibility (TD) of the flours did not differ, but both were lower in casein and the Protein Digestibility Corrected Amino Acid Score (PDCCAS) was lower than the TD, due to limited valine determined by the chemical score. Therefore, the flours showed reduced anti-nutritional phytochemicals and similar protein quality, and therefore the whole flours can be used as a source of high quality protein.
Resumo:
This study was conducted to evaluate the physicochemical and microbiological characteristics of raspberries exposed to different radiation doses. The fruits were harvested in the city of Campestre, MG, packed in polyethylene bags, and transported to the Federal University of Lavras (UFLA), where they were separated into 4 lots. Irradiation was performed at the Center for Development of Nuclear Technology in Belo Horizonte, MG. The doses used were 0 (control), 0.5, 1.0, and 2.0 kGy. After irradiation, the fruits were transported back to UFLA and stored at 1 ºC and 95% relative humidity (RH) for 12 days. The physicochemical analyses for mass loss, total soluble solids, titratable acidity, pH, total soluble sugars, total soluble pectin, firmness, vitamin C content, total antioxidant activity, and total phenolic, and the microbiological assays (coliform at 35 and 45 ºC, psychrotrophic and filamentous fungi and yeasts) were performed after 0, 3, 6, 9, and 12 days of storage. Lower loss of mass and filamentous fungi and yeast count were observed in the irradiated fruits, and 2 kGy was determined as the most effective dose for microbial control, but this irradiation dose also resulted in increased loss of fruit firmness.
Resumo:
The aim of this study was to analyze the proximate and mineral composition of 21 types of biscuits. All biscuits showed high fat contents, significantly different (P < 0.05) from those described on the labels, except for three brands. Insoluble fiber fractions were predominant in the analyzed samples. Among the 21 biscuits analyzed, 16 showed food label values 20% higher than those allowed by law, according to RDC 360, for fat, protein, total fiber, calcium, and sodium levels. This difference reached 273% for the sodium content. The calcium content was included only on the label of three samples analyzed, and the values described were significantly lower than those obtained analytically. Considering that biscuits are consumed by people of all age groups and of different socioeconomic levels, the results can contribute to the plans for health policies, such as surveillance of nutritional labeling, ensuring the reliability of the information provided by the food industry and enabling the identification of the relationship between dietary factors and the occurrence of non-transmissible chronic diseases.
Resumo:
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.
Resumo:
The objective of this study was to evaluate the effect of the addition of oatmeal and palm fat in the elaboration of biscuits with added L-leucine and calcium in order to develop a product for sarcopenia in the elderly. The biscuits, or cookies, were elaborated applying a central composite rotational design with surface response methodology, and the significant linear, quadratic and interaction terms were used in the second order mathematical model. Physical, physicochemical and sensory analyses were performed by a trained panel. Based on the best results obtained, three cookie formulations were selected for sensory evaluation by the target group and physicochemical determinations. The formulations with the highest sensory scores for appearance and texture and medium scores for color and expansion index were selected. The addition of calcium and leucine increased significantly the concentration of these components in the biscuits elaborated resulting in a cookie with more than 30% of DRI (Dietary Reference Intake) for calcium and leucine. The formulations selected showed high acceptance by the target group; therefore, they can be included in the diet of elderly with sarcopenia as a functional food.
Resumo:
This article aims to discuss the needs and problems of marolo value chain, as well as to evaluate the rehydration process of this fruit as a possibility of using it as a by-product during the interharvest growth periods. The study of the value chain included interviews with producers, handlers, and fruit and by-product sellers. In order to evaluate the rehydration process of this fruit, marolo was dehydrated using a conventional procedure and freeze-drying. The experiments were conducted in a completely randomized design and a triple factorial scheme (2 × 2 × 6). ANOVA was performed, followed by the Tukey's test (p < 0.05). Regression models were generated and adjusted for the time factor. The precariousness of the value chain of marolo was observed. The best procedure for marolo dehydration should be determined according to the intended use of the dehydrated product since the water-absorption capacity of the flour is higher and convective hot-air-drying is more effective in retaining soluble solids and reducing damage to the fruit. These results aim at contributing to the marolo value chain and to the preservation of native trees in the Brazilian savanna biome and can be used to analyze other underutilized crops.
Resumo:
The impact of automatic and manual shelling methods during manual/visual sorting of different batches of Brazil nuts from the 2010 and 2011 harvests was evaluated in order to investigate aflatoxin prevention.The samples were tested as follows: in-shell, shell, shelled, and pieces in order to evaluate the moisture content (mc), water activity (Aw), and total aflatoxin (LOD = 0.3 µg/kg and LOQ 0.85 µg/kg) at the Brazil nut processing plant. The results of aflatoxins obtained for the manually shelled nut samples ranged from 3.0 to 60.3 µg/g and from 2.0 to 31.0 µg/g for the automatically shelled samples. All samples showed levels of mc below the limit of 15%; on the other hand, shelled samples from both harvests showed levels of Aw above the limit. There were no significant differences concerning the manual or automatic shelling results during the sorting stages. On the other hand, the visual sorting was effective in decreasing the aflatoxin contamination in both methods.
Resumo:
The main problem related to rice bran use is that it goes rancid right after its production. The objective of the present study was to apply a mathematical model to evaluate the kinetics of the lipase activity and hydrolytic rancidity of the raw rice bran (RRB), extruded rice bran (ERB), and parboiled rice bran (PRB) stored in low density polyethylene bags at room temperature for 180 days. Extrusion and parboiling were efficient in preventing free fatty acid formationin ERB and PRB.Extrusion reduced the velocity constant of lipase activity as compared to that of RRB while parboiling increased it, and both decreased the lipase activity after equilibrium from 150 days. The extrusion and parboiling treatments increased the velocity constants for the liberation of free fatty acids although the equilibrium was reached with reduced production of free fatty acids in relation to the production of raw rice bran after 150 days ofstorage. Extrusion proved the best treatment under the storage temperature conditions of rice bran from cultivar BRS Primavera.
Resumo:
The objective of this study was to evaluate the physicochemical and microbiological parameters of pork meat submitted to dry salting. Sodium chloride (NaCl) was added at levels of 0%, 2.5%, 5%, 7.5% or 10% by the meat weight. Dry salting technique was used, which consists of rubbing the sodium chloride manually, followed by a rest period. The data were submitted to analysis of variance using a completely randomized experimental design. The means were compared by Duncan test at 5%. The salting process reduced (P < 0.05) humidity and water activity, and it increased (P < 0.05) ash, chloride, palmitic acid, and water holding capacity levels compared to those of the control. Luminosity (L*) was lower (P < 0.05) in the control, and a* color was more intense in samples with 2.5% NaCl. Cooking loss was lower (P < 0.05) in the samples salted with 5% and 10% NaCl, and similarity was observed between the levels 0 and 7.5% salt. The treatments with levels 0% and 2.5% NaCl had higher mesophilic counts. The other microbiological parameters were within limits established by law. Therefore, salting with 5% NaCl can be used in pork meat in order to maintain the physicochemical and microbiological characteristics of the final product.
Soymilk plain beverages: correlation between acceptability and physical and chemical characteristics
Resumo:
The objective of the research was to relate the physical and chemical characteristics of soymilk plain beverages to its sensory acceptance. Five commercial products and a new product formulated based on the less accepted sample were used. The overall acceptance was evaluated by 102 assessors using a 10-point hybrid hedonic scale. The hedonic scores ranged from 3.8 (sample E) to 7.0 (A). Most assessors (55%) preferred sample A, which was viscous (26.6 cp), dark (L* = 77.7), and slightly acidic (pH = 6.6). Sample C, which had lower solid content and higher acidity, was preferred by 29% of the assessors. These two beverages showed the greatest commercial potential of the products analyzed. The least-accepted sample (E), preferred by 8% of the assessors, had a lighter color (L* = 96.8), lower viscosity (13.5 cp), higher lipid content (2.2 g/100 g), and less protein (1.68 g/100 g) than the other products evaluated. A reformulation of the least preferred product (E) with the addition of maltodextrin and also vanilla and milk flavors increased its acceptance, yielding an average score of 7.2. Overall, it was observed that a soymilk plain beverage with higher viscosity, darker color, and higher protein content best meets consumer expectations.
Resumo:
The Brazilian government has approved many transgenic maize lines for commercialization and has established a threshold of 1% for food labeling, which underscores need for monitoring programs. Thirty four samples including flours and different types of nacho chips were analyzed by conventional and real-time PCR in 2011 and 2012. The events MON810, Bt11, and TC1507 were detected in most of the samples, and NK603 was present only in the samples analyzed in 2012. The authorized lines GA21, T25, and the unauthorized Bt176 were not detected. All positive samples in the qualitative tests collected in 2011 showed a transgenic content higher than 1%, and none of them was correctly labeled. Regarding the samples collected in 2012, all positive samples were quantified higher than the threshold, and 47.0% were not correctly labeled. The overall results indicated that the major genetically modified organisms detected were MON810, TC1507, Bt11, and NK603 events. Some industries that had failed to label their products in 2011 started labeling them in 2012, demonstrating compliance with the current legislation observing the consumer rights. Although these results are encouraging, it has been clearly demonstrated the need for continuous monitoring programs to ensure consumers that food products are labeled properly.
Resumo:
The opportunity to supplement common cassava biscuits with a product of higher nutritional value meets consumer expectations. In this work it was studied the effects of process parameters and flaxseed addition on physical properties of expanded snacks. Extrusion process was carried out using a single screw extruder in a factorial central composite rotatable design with four factors: flaxseed flour percentage (0-20%), moisture (12-20%), extrusion temperature (90-130 °C) and screw speed (190-270). The effect of extrusion variables was investigated in terms of expansion index, specific volume, water absorption index, water solubility index, color parameters (L*, a* ,b*) and hardness. The data analysis showed that variable parameters of the extrusion process and flaxseed flour affected physical properties of puffed snacks. Among the experimental conditions used in the present study, expanded snack products with good physical properties can be obtained under the conditions of 10% flaxseed flour, 230 rpm screw speed, temperature of 90 °C and moisture of 12%.
Resumo:
Annona crassiflora offers an edible fruit native to the Savanna. This study aimed to develop a flour meal from Annona crassiflora pulp; analyze the chemical composition of the fresh pulp and its flour; develop and verify the acceptance of formulations with different concentrations of the flour of Annona crassiflora pulp. Fruit used were selected and processed. The pulp was dried in an oven at 60-65 ºC/48h. We analyzed the chemical composition, and two formulations of breads were prepared with 10 and 20% Annona crassiflora pulp. The results showed that the drying of Annona crassiflora pulp enriched its nutritional value. The Annona crassiflora pulp showed important chemical components, as insoluble fibers (pulp and flour), minerals (potassium, calcium, manganese and others) and antioxidant compounds. The formulations were well-accepted in a sensory point of view and proved to be a good alternative to the exploitation of the fruit.
Resumo:
Jaboticaba is a Brazilian fruit, native to the Atlantic forest, which belongs to the Myrtaceae family. In this work we describe the effect of the thinning of "flower", "fruit" and "flower & fruit" compared to non-thinned fruit (control) and of edible coatings with respect on nutritional composition, overall acceptability and shelf-life of jaboticaba ‘Sabara’, grown in an irrigated commercial orchard. "Flower and fruit" thinning allows fruit with higher quality as diameter, volume and mass. Non-thinned fruit shows higher yield, however fruit have lower quality. As a result of the improving quality at harvest, the shelf life was twice (~8 days) for thinned fruit. The lack of change in concentration of soluble sugar and absence of formation of volatile compounds during storage indicate that there was no natural fermentation of the jaboticaba pulp after harvest. Treatments with wax and calcium did not improve the jaboticaba shelf life.
Resumo:
Brazilian peach production is insufficient for domestic supply. Aiming to increase production in the state of Minas Gerais, 16 new peach tree varieties were introduced in the Serra da Mantiqueira region and their fruit were analyzed for sugar, total phenol and total carotenoid contents by colorimetric methods, and for organic acid content by high-performance liquid chromatography. In addition, we examined the effect of fruit bagging on the levels of such constituents. To do so, the fruit of half the trees of each variety were bagged. The levels of sugars, phenols, carotenoids and organic acids are genotypic characteristics and significantly differed among varieties. Despite being a good form of fruit protection, providing better aspect and reducing the need for pesticides, bagging leads to lower contents of components such as sugars, phenols and organic acids in most varieties. However, it cannot be stated that this practice interferes with sensory characteristics. Knowledge of the chemical constituents of these new varieties allows determining those ideal for fresh consumption (e.g., "Maciel", "Diamante", "T. Beauty", "Ouromel 2" and "C.1056", among others) and those more suitable for industrial processing (e.g., "A. Gold", "C.1122" and "C.1050"), as well as those which serve both purposes.