103 resultados para Physical and chemical variables


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The influence of fungi associated with coffee fruits was verified regarding the chemical and physicochemical composition of Coffea arabica L. raw grains. The fruits were harvested at EPAMIG Experimental farm in Lavras, State of Minas Gerais - making up the different samples here analyzed. After processing and drying, the grains were incubated in wet chamber for fungal exteriorization through the blotter test method and submitted to the following analyses: polyphenoloxidase, total reducing and non-reducing sugars, clorogenic acid, titrable acidity, potassium leaching, electric conductivity and caffeine. The occurrence of the P. variable, P. rugulosum, P. funiculosum, F. equiseti, F. semitectum, A.alutaceus, A. niger and C. cladosporioides fungi in the different samples was detected. From the analysis of the results obtained, it was observed that the presence of the Aspergillus alutaceus fungus reduces the activity of the enzyme polyphenoloxidase and increases the values of potassium leaching, electric conductivity and chlorogenic acid. The incidence of the Cladosporium cladosporioides fungus influenced the average values of potassium leaching and electric conductivity.

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The objective of this work was to characterize fruits from the Brazilian savanna by means of physical and chemical analyses. The results obtained for araça peel, araça pulp and marolo pulp, respectively, were: moisture (77.03, 80.41 and 70.56 g.100 g-1), ash (0.65, 0.44 and 0.54 g.100 g-1), protein (1.39, 1.87 and 1.99 g.100 g-1), lipids (0.32, 0.33 and 2.36 g.100 g-1), total carbohydrates (90.88 , 78.25 and 24.55 g.100 g-1), total soluble sugars (8.45, 9.99 and 127.4 g.100 g-1), pH (3.76, 3.99 and 4.49), soluble solids (11° Brix, 8.8 °Brix and 21.4 °Brix) and antioxidant potential (16.33, 12.75 and 34.29 discoloration DPPH/100 mL). Calcium was the predominant mineral in araça (490 mg.kg-1 peel and 485 mg.kg-1 pulp) while magnesium was in marolo (350 mg.kg-1). Citric acid was the predominant organic acid in araça (3125 μg.g-1 peel and 881.25 μg.g-1 pulp) and Malic acid was predominant in marolo (76.68 μg.g-1). Therefore, given their nutrient contents, the consumption of these fruits from the savanna should be encouraged.

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The effect of replacing shortening and sugar on the physical and chemical properties of mangaba ice cream and its acceptability were evaluated. Ice cream formulations were tested with the following fat replacers: Selecta Light, Litesse, and Dairy Lo and the following sugar substitutes: Lactitol and Splenda. All formulations were subjected to physical, chemical, and microbiological analyses and evaluated by acceptability tests. In the sensory analysis, it was observed a larger acceptance of the formulations containing Selecta Light (SL) and the combination of Litesse, Lactiol, and Splenda (LLS). The largest reduction in total energetic value (50%) was observed in the formulation LLS. The use of fat and/or sugar substitutes caused a reduction in the air incorporation (overrun) and affected viscosity. The highest melting speed was observed in the formulation with Dairy-Lo, Lactitol, and Splenda. All formulations showed good levels of global acceptability and appearance. The substitution of shortening for fat replacers caused a reduction in air incorporation and changes in ice-cream viscosity. The low-fat mangaba ice-cream elaborated with Selecta Light was the best formulation in terms of viscosity and air incorporation when compared with the control. It also showed a good level of acceptability and low fat content.

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The aim of this study was to evaluate the physical and chemical parameters of Williams pear, stored at 25 ºC for 15 days, with and without edible coating. Edible coatings prepared with alginate 2% and carrageenan 0.5% were tested. The analyses carried out on the samples were: weight loss, pH, soluble solids, firmness, and color. The edible coatings were characterized in terms of mechanical properties, permeability, thickness, and opacity. The results show that the application of edible coatings with carrageenan and alginate in pears influenced physical and chemical characteristics such as weight loss, pH, total soluble solids, color, and firmness of the fruit. However, the alginate coating showed the best results on pear conservation since it had lower water vapor permeability and greater tensile strength, and therefore it can be used as a protective film on these fruits.

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The effect of inulin addition and starters (Kefir grains or commercial starter culture) on the microbial viability, texture, and chemical characteristics of Kefir beverages prepared with whole or skim milk was evaluated during refrigerated storage. The type of starter did not influence microbial viability during the storage of the beverages, but the chemical and textural changes (decreases in pH, lactose concentration, and inulin and increased acidity, firmness, and syneresis) were more pronounced in the formulations fermented with grains than those fermented with the starter culture. The addition of inulin did not influence acidity or viability of lactic acid bacteria, but in general, its effect on the survival of acetic acid bacteria, Lactococcus and yeasts, firmness, and syneresis depended on the type of milk and starter culture used. Generally, the yeast, acetic acid bacteria, and Leuconostoc counts increased or remained unchanged, while the total population of lactic acid bacteria and Lactococcus were either reduced by 1 to 2 logs or remained unchanged during storage.

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The aim of this study was to evaluate some physical and chemical parameters (total solids, pH, acidity, fat, acid degree value of fat, salt, protein and nitrogen fractions) and their effects on the beneficial (lactic acid bacteria: LAB) and undesirable microbial populations (coliforms, Escherichia coli, Staphylococcus aureus, moulds, and yeast) during ripening of Artisanal Corrientes Cheese, an Argentinian cow's milk variety, to determine whether a longer ripening period than usual improve its hygienic-sanitary quality. The protein content was much higher than that of other cow's milk cheeses with similar values of fat. The larger peptides showed values three times higher in the 30 day-old cheese than those obtained in the beginning of the process. Staphylococcus aureus and Escherichia coli were detected (3.04 ± 1.48 log10 cfu/g of cheese, 2.21 ± 0.84 log10 MPN/g of cheese) even at 15 and 30 days of ripening, respectively. The distribution of three hundred LAB strains classified to the genus level (lactococci:lactobacilli:leuconostocs) was maintained during the ripening period. The high number of LAB in rennet may have contributed to the fermentation as a natural whey starter, unknown source of LAB for this specific cheese so far. The physicochemical changes that occur during ripening were not big enough to inhibit the growth of undesirable microorganisms.

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The chemical composition and antioxidant capacity of five seeds, chia, golden flax, brown flax, white perilla, and brown perilla, were determined. The chemical properties analyzed included moisture, ash, crude protein, carbohydrates, total lipids, fatty acids, and antioxidant capacity (ABTS•+, DPPH•, and FRAP). The results showed the highest amounts of protein and total lipids in brown and white perilla. Perilla and chia showed higher amounts of alpha-linolenic fatty acid than those of flaxseed varieties, ranging between 531.44 mg g-1 of lipids in brown perilla, 539.07 mg g-1 of lipids in white perilla, and 544.85 mg g-1 of lipis in chia seed. The antioxidant capacity of the seeds, evaluated with ABTS•+, DPPH• , and FRAP methods, showed that brown perilla had greater antioxidant capacity when compared with white perilla, flax, and chia seeds.

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In many industrialized countries, including Brazil, sodium intake exceeds the nutritional recommendations. Excessive consumption is associated with hypertension and premature death by cardiovascular diseases. The industry's challenge is to produce products with reduced sodium that are similar to regular products in texture and flavor and consistent with consumers' dietary habits. The present study aimed at substituting 25 and 50% NaCl for KCl in marinated beef and chicken meat with the addition of aromatic herbs and spices. The following microbiological analyses were carried out: macronutrient, chemical composition, and sensorial analysis. The meats showed a reduction in NaCl contents without any changes in their physical and chemical characteristics, and the products´ quality and microbiological safety were maintained. Beef and chicken tenderness was maintained for both treatments. Furthermore, the use of 50% KCl did not cause any changes in the products' sensory quality, and the overall acceptance of both types of meat was maintained. Results showed that a reduction by 50% in the NaCl contents of marinated meat products with a combination of herbs and spices is possible. Future applications in other meat products and sausages are highly promising.

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Pumpkin (Cucurbita maxima), popularly known as squash, is a widely grown vegetable in Brazil. In this study, pumpkin seed flours (PSF) with different granulometries were used: PSF 1 (medium granulometry) and PSF 2 (coarse granulometry) in the preparation of cereal bars (CB) with different combinations with brown oats. Five formulations were prepared: CB-1 (control - 25% brown oats and 0% PSF); CB-2 (12.5% PSF 1 and 12.5% brown oats); CB-3 (25% PSF 1 and 0% brown oats); CB-4 (12.5% PSF 2 and 12.5% brown oats); and CB-5 (25% PSF 2 and 0% brown oats). The acceptance test results were analyzed in a conventional preference mapping which indicated that the bars CB-2 and CB-5 received mostly the maximum hedonistic score. With the objective of developing a cereal bar replacing oats with PSF, the bars CB-2 and CB-5 were compared to the conventional bar CB-1. The cereal bars CB-2 and CB-5 showed an increase in crude protein (87.5% and 62.5%) and in dietary fiber (77% and 44%), respectively. These results allowed the classification of CB-2 and CB-5 as fiber sources; they can, therefore, be classified as light products according to the Brazilian legislation.

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The objective of this paper was to determine the chemical composition of the avocado fruit of cultivars Fortuna, Collinson, and Barker and to carry out a detailed analysis of the fatty acid composition of the pulp, seed, and peel oils. The saturated fatty acid (SFA) of the pulp oils accounted for around 22.3, 29.4, and 41.3% of the total fatty acids in the Fortuna, Collinson and Barker cultivars, respectively, and these values indicate better quality of pulp oil of Fortuna and Collinson cultivars than that of the Barker cultivar. There was very little variation in the content monounsaturated fatty acids of the peel oils between the cultivars. However, the seed oil of the Collinson cultivar was the best since it contained the lowest (30.8% of total fatty acids) content of SFA, but it had very high concentrations of 9,12-octadecadienoic (23.9 to 29.4% of total fatty acids) and 9,12,15-octadecatrienoic (9.9 to 18.3% of total fatty acids) acids.

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Mixed flavor beverages represent a trend that is gaining the allegiance of potential fruit juice consumers. The present study proposed to prepare mixed flavor beverages and verify their consumer acceptance. Cajá beverage (sample A) was used as the standard. The other beverages were prepared by mixing the cajá-flavored product with other flavors: strawberry (B), pineapple (C), jabuticaba (D), mango (E) and cashew (F). The consumer profiles in the two regions studied were similar. Overall beverages B, A and F were the most accepted, with scores of 7.7, 6.4 and 6.2, respectively. Internal Preference Mapping showed that most of the consumers were located near beverages A, B and F, confirming the acceptance results. The consumers indicated appearance and flavor as the most appreciated characteristics in beverages A, B and F. Beverages A, B and F presented higher total soluble solids contents and viscosities than the other beverages. Consumer segmentation did not depend on the different levels of familiarity with the cajá flavor. Thus the preparation of mixed flavor beverages of cajá-strawberry and cajá-cashew is an excellent proposal because it presents flavors with good potential for marketing in different regions of Brazil.

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AbstractThe Atlantic Forest has species of native fruits, consumed fresh and processed, which have an important contribution to food sovereignty of families that consume it. This study examined the physical and physicochemical characteristics, proximate composition, concentration of carotenoids, vitamin C, vitamin E and minerals in the pulp and kernels of fruits of licuri (Syagrus coronata (Mart.) Becc.). Titratable acidity was analyzed by volumetric neutralization, soluble solids by refractometry, proteins by the micro-Kjeldahl method, lipids by gravimetry using soxhlet, dietary fiber by non-enzymatic gravimetry, carotenoids and vitamin C by HPLC-DAD, vitamin E by HPLC-fluorescence, and minerals by ICP-AES. Pulp were a source of Zn (0.95 mg 100–1), a good source of fiber (6.15 g 100–1), excellent source of provitamin A (758.75 RAE 100–1), Cu (0.69 mg 100–1), Fe (3.81 mg 100–1), Mn (3.40 mg 100–1) and Mo (0.06 mg 100–1). The kernel were a source of Fe (3.36 mg 100–1) and excellent source of Mn (6.14 mg 100–1), Cu (0.97 mg 100–1) and Mo (0.07 mg 100–1). The nutritional value and wide availability of licuri fruit make it an important resource for reducing food insecurity and improving nutrition of the rural population and other individuals who have access to it.

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Abstract In search for renewable energy sources, the Brazilian residual biomasses stand out due to their favorable physical and chemical properties, low cost, and their being less pollutant. Therefore, they are likely to be used in biorefineries in the production of chemical inputs to substitute fossil fuels. This substitution is possible due to the high contents of carbohydrates (>40%), low contents of extractives (<20%), ashes (<8%) and moisture (<8%) found in these residual biomasses. High calorific values of all residues also offer them the chance to be used in combustion. A principal components analysis (PCA) was performed for better understanding of the samples and their hysic-chemical properties. Thus, this study aimed to characterize biomasses from the north (babassu residues, such as mesocarp and endocarp; pequi and Brazil nut) and northeast (agave and coconut) regions of Brazil, in order to contribute to the preservation of the environment and strengthen the economy of the region.