81 resultados para food quality


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The number and the main groups of microorganisms present in samples of different nonalcoholic carbonated beverages (lemon, orange and guaraná soft drinks) obtained from a small factory were analyzed. The samples were obtained at the end of the processing line. They were then divided into two lots: one was sent to immediate analysis, the other was stored at environmental temperature for 90 d thereafter it was submitted to the same analysis. Aliquots of 1 mL were drawn from the various samples and the corresponding decimal dilutions were prepared. They were then grown in culture media and counts of mesophilic aerobic bacteria, molds and yeasts, acid-producing bacteria, total and fecal coliforms were taken. It was observed that, of all the analyzed samples, at time 0 or after storage sample C (orange) was the best, since it conformed to the microbiological standards established by legislation. The guaraná type could also be consumed on day zero; the lemon type was inadequate for consumption of all the analyzed samples, the orange type was the only one that could be consumed within 3 months of storage.

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Late-season grapefruits (Citrus paradisi Macf. cv. Marsh seedless) were dipped in water at 50°C for 3 min with and without 200 ppm imazalil (IMZ) or 1000 ppm IMZ at 19°C and were subsequently stored at 7°C and 90-95% relative humidity (RH) for 11 weeks plus one week at 21°C and approximately 75% RH to simulate a marketing period (SMP). Residue concentrations in fruit after treatment with 200 ppm IMZ at 50°C were 3.46 ppm, about twice the level (1.80 ppm) found in fruit treated with 1000 ppm IMZ at 19°C. Fungicide degradation rates during storage showed similar patterns resulting in an approximately 50% decrease. Both fungicide treatments significantly reduced decay and chilling injury (CI) during storage and SMP. Hot water reduced CI and decay but not as effectively as the IMZ treatments. Soluble solids concentrations were not affected by treatments, IMZ treatments resulted in significantly lower values of titratable acidity and higher concentrations of ethanol in the juice after SMP. Weight loss was significantly higher in fruit dipped in water at 50°C after SMP. No visible damage occurred to the fruit as a result of any of the treatments.

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A recent theory suggests that economic considerations are more important than genetic ones in the emergence and maintenance of social behavior. Evolution of social behavior in wasps, thus, could be based on the development of worker castes, which increase the efficiency of brood care and energy use of the colony. If so, social wasps should collect a larger range of prey, favoring polyethism, as social behavior should increase the adaptive value of social species among wasps by increasing the range of prey accessible. We explored the literature and showed that the Eumeninae, which are mostly solitary, draw prey from significantly fewer orders of arthropods than wasps in the subfamily Vespinae and Polistinae, which are mainly social, supporting the hypothesis that social behavior may have emerged as a more efficient way to feed and care for the young by opening a wider range of food sources, increasing the amount of food and quality of care provided to the young. Two alternative explanations of this data are also discussed.

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Ice used for human consumption or to refrigerate foods can be contaminated with pathogenic microorganisms and may become a vehicle for human infection. To evaluate the microbiological content of commercial ice and ice used to refrigerate fish and seafood, 60 ice samples collected at six different retail points in the city of Araraquara, SP, Brazil, were studied. The following parameters were determined: total plate counts (37° C and 4° C), most probable number (MPN) for total coliforms, fecal coliforms and Escherichia coli, presence of Salmonella spp., Shigella spp., Yersinia spp., E. coli, Vibrio cholerae and Aeromonas spp.. Results suggested poor hygienic conditions of ice production due to the presence of indicator micro-organisms. Fifty strains of E. coli of different serotypes, as well as one Y. enterocolitica biotype 1, serogroup 0:5, 27 and phage type Xz (Ye 1/05,27/Xz) and one Salmonella Enteritidis phage type 1 (PT1) were isolated. Aeromonas spp., Shigella spp. and V. cholerae were not detected. The presence of high numbers of coliforms, heterotrophic indicator micro-organisms and pathogenic strains suggested that commercial ice and ice used to refrigerate fish and seafood may rep resent a potential hazard to the consumer in our community. © 2002 Elsevier Science Ltd. All rights reserved.

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Male juveniles of Nile tilapia, Oreochromis niloticus, were stocked in 12, 300-m 2 ponds at a density of 1.7 fish/m 2 to evaluate the effects of different food management methods (natural foods and diets in pellet, floating or minced form) on fish production and carcass characteristics. Water quality variables monitored during the period were within acceptable levels for the species. Total fish production was significantly different (P < 0.05) and the highest values were obtained with diets in pellet (5,997 kg/ha) and floating (5,441 kg/ha) form. The fish fed diets had higher contents of body fat (1.57 to 1.98%) and visceral fat (12.64 to 25.04%) than fish fed natural food, which had levels between 0.17 and 0%, respectively. Natural food treatment yielded lower fish production and fish with lower body fat, while treatments that yielded higher fish production (rations) higher percentage of visceral fat. © 2004 by The Haworth Press, Inc. All rights reserved.

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This study evaluated selected limnological variables in inlet water in six sequentially distributed semi-intensive fishponds. Data were collected during 15 consecutive days in three distinct grow-out periods (May, October and January). Only phosphorus and pH varied among sites and periods (p < 0.01); the opposite (p > 0.05) occurred in the cases of nitrite and dissolved oxygen. No variation was reported with regard to dissolved oxygen, conductivity, alkalinity, free CO2, bicarbonate, chlorophyll-a, nitrite and ammonia did not vary throughout the period (p > 0.05). In May, or rather, the final grow-out period, the fishponds displayed high concentrations, mainly in nitrogen compounds. As from fishpond 3, the inlet water contained high levels of nutrients. The water is passed from pond to pond, evidencing the need for management practices adequate to the specific conditions of each pond. Water quality should be monitored more frequently during high grow-out period when food addition is more intense. Thereafter, more care should be taken, as highest phosphorus concentrations occurred in May.

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Fifty-nine Nellore bulls from low and high residual feed intake (RFI) levels were studied with the objective of evaluating meat quality traits. Animals were slaughtered when ultrasound-measured backfat thickness reached 4. mm, and samples of Longissimus were collected. A mixed model including RFI as fixed effect and herd and diet as random effects was used, and least square means were compared by t-test. More efficient animals consumed 0.730. kg dry matter/day less than less efficient animals, with similar performance. No significant differences in carcass weight, prime meat cuts proportion, chemical composition, pH, sarcomere length, or color were observed between RFI groups. Shear force, myofibrillar fragmentation index and soluble collagen content were influenced by RFI, with a higher shear force and soluble collagen content and a lower fragmentation index in low RFI animals. Feedlot-finished low RFI young Nellore bulls more efficiently convert feed into meat, presenting carcasses within quality standards. © 2012 Elsevier Ltd.

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Thermophilic fungus Thermoascus aurantiacus (CBMAI 756) on solid-state fermentation using corncob as a nutrient source produces an enzyme pool with the potential to be used in bread making. In this paper, the use of this enzyme cocktail as a wheat bread improver was reported. Both products released by flour arabinoxylan degradation and bread quality were investigated. The main product released through enzyme activity after prolonged incubation was xylose indicating the presence of xylanase; however, a small amount of xylobiose and arabinose also confirmed the presence of xylosidase and α-L- arabinofuranosidase, respectively. Enzyme mixture in vitro mainly attacked water-unextractable arabinoxylan contributing to beneficial effect in bread making. The use of an optimal enzyme concentration (35 U xylanase/100 g of flour) increased specific volume (22%), reduced crumb firmness (25%), and reduced amylopectin retrogradation (17%) during bread storage. In conclusion, the enzyme cocktail produced by T. aurantiacus CBMAI 756 can improve wheat bread quality. © 2013 Elsevier Ltd.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The present research was undertaken to explore the influence of fructooligosaccharides (FOS) on the functional and thermal properties of sour cassava starch and the quality characteristics of gluten-free (GF) cheese bread. Fructooligosaccharides were used to replace sour cassava starch at substitution level of 9% (SF1), 17% (SF2), and 29% (SF3). The functional and thermal properties of the starch-FOS mixtures were determined by the water absorption index (WAI), water solubility index (WSI), pasting profile analysis, thermal transition temperatures and enthalpy of gelatinization. Moreover, the GF cheese breads with starch-FOS mixtures were analyzed for height, diameter, weight, specific volume and dough moisture content. The sample with the highest FOS content (SF3) presented the lowest WAI (1.44), peak (62.4 rapid visco units (RVU), breakdown (53.4 RVU), final (13.8 RVU), and setback (4.9 RVU) viscosities, dough moisture content (31.7%), and enthalpy of gelatinization (9.5 J/g) and the highest WSI (29.4%) and pasting temperature (69.1 degrees C). The height, diameter and specific volume of GF cheese bread samples made from sour cassava starch were 3.14 cm, 6.35 cm, and 1.49 cm(3)/g, respectively. The SF1 mixture samples resulted in a 3.01 cm height, 6.34 cm diameter, and 1.55 cm(3)/g specific volume. According to Brazilian food labeling regulations, the latter product cannot be categorized as a good source of fiber because the minimum level of fiber per portion was not reached.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The effect of irradiation doses (0, 125, 250 and 500 Gy) on the nutritional quality of A. bisporus mushrooms (strains ABI-07/06, ABI-05/03 and PB-1) cultivated in composts based on oat straw (Avena sativa) and brachiaria (Brachiaria sp.) was evaluated. The experimental design was 4 x 3 x 2 factorial scheme (irradiation doses x strains x composts), with 24 treatments, consisting of two repetitions each, totaling 48 experimental units (samples of mushrooms). The samples were irradiated in Cobalt-60 irradiator, model Gammacell 220 kGy, with dose rate of 0.740 kGy h(-1), according to the treatments proposed. Subsequently, the control (unirradiated) and the other treatments were maintained at 4 +/- 1 degrees C and 90% RH in a climatic chamber for carrying out the chemical analysis of the mushrooms on the 1st and 14th day of storage. It was found that all A. bisporus strains evaluated were food with excellent nutritional value, because they presented high protein and fiber contents and low ethereal extract content; the chemical characterization of the mushrooms was influenced by the compost type in which they were cultivated; gamma irradiation influenced the chemical composition of mushrooms.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Despite fish being a rich source of animal nutrients and having numerous associated health benefits, it is an extremely perishable food, prone to a wide range of hazards. The bacterial load associated with shelf-whole-fish organs (e.g. digestive tracts and skin) or mishandling of fish may be a vehicle of infection and become a risk to public health. The objective of this paper is to evaluate the microbiological quality of whole ungutted and filleted shelf-tilapia, as well as assess the safety for human consumption. For this purpose, in order to investigate the distribution and occurrence of bacterial populations, the count of total and thermotolerant coliforms, coagulase-positive Staphylococcus and presence of Salmonella spp. was determined. This paper shows that all fish organs were contaminated with thermotolerant coliform. Skin and fillet show higher populations and occurrence of all microorganisms analyzed. Lower bacterial populations were recovered from the gut and muscles of whole tilapia. Two samples of fillet were contaminated with coagulase-positive Staphylococcus. It can be concluded that the skin and filleted tilapia are important carriers of food-borne pathogens. In addition, fish might become an important cross and self-contamination source. (C) 2014 Elsevier B.V. All rights reserved.