93 resultados para Food processing machinery
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Effects of cold storage and three common cooking practices, blanching, sauteing, and microwave cooking at different time intervals, on the content of glucosinolate (GSL) anticancer components in six Brassica vegetables were investigated. Eleven GSLs including progoitrin, glucoraphanin, sinigrin, glucoalyssin, gluconapin, glucobrassicanapin, glucoerucin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, and neoglucobrassicin were quantified using LC-MS and HPLC. Storage at 4 ºC indicated no significant loss of GSLs in broccoli, kohlrabi, and cabbage, and approximately 90-100% of the total concentration of aliphatic and indolyl GSLs were detected. Interestingly, glucoraphanin and glucobrassicin, known as a cancer prevention agents, increased approximately above 50% in broccoli, kohlrabi, and cabbage, while the amount of glucobrassicin decreased by 5% in cauliflower for 5 days at 4 ºC. Blanching of broccoli at 120 sec significantly (36%) decreased total GSLs; however, sautéing and microwaving decreased by13-26%. Individual GSLs have different response at blanching. These findings suggest that different processing methods for each vegetable would be preferred to preserve the nutritional qualities.
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The aim of this study was to extract and identify volatile compounds from pineapple residues generated during concentrated juice processing. Distillates of pineapple residues were obtained using the following techniques: simple hydrodistillation and hydrodistillation by passing nitrogen gas. The volatile compounds present in the distillates were captured by the solid-phase microextraction technique. The volatile compounds were identified in a system of high resolution gas chromatography system coupled with mass spectrometry using a polyethylene glycol polar capillary column as stationary phase. The pineapple residues constituted mostly of esters (35%), followed by ketones (26%), alcohols (18%), aldehydes (9%), acids (3%) and other compounds (9%). Odor-active volatile compounds were mainly identified in the distillate obtained using hydrodistillation by passing nitrogen gas, namely decanal, ethyl octanoate, acetic acid, 1-hexanol, and ketones such as γ-hexalactone, γ-octalactone, δ-octalactone, γ-decalactone, and γ-dodecalactone. This suggests that the use of an inert gas and lower temperatures helped maintain higher amounts of flavor compounds. These data indicate that pineapple processing residue contained important volatile compounds which can be extracted and used as aroma enhancing products and have high potential for the production of value-added natural essences.
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Sugarcane juice with passion fruit pulp was clarified using microfiltration under different T (temperature), P (pressure), and V (tangential velocity). The effects of these processing parameters were evaluated applying a rotational central composite experimental design (RCCD) and response surface methodology (RSM). The tests were performed at a filtration pilot plant using a polyamide hollow-fiber membrane with an average pore diameter of 0.4 µm and filtration area of 0.723 m². In addition, the resistances to the permeate flux during the microfiltration were investigated according to the series resistance. The final permeate flux ranged from 7.05 to 17.84 L·h- 1·m- 2. There was a rapid decline in flux (50%) in the initial stages of microfiltration. T and V were the major variables responsible for the flux increase. The concentration polarization showed the greatest influence on the flux decline, and highest values for the flux decline rate (λ) were found when low pressures were used. In the clarified juice there was a reduction in the contents of total solids, proteins, vitamin C, and acidity, while the soluble solids, pH, and ash contents did not change. Finally, membrane process could produce high quality filtered sugarcane juice with substantial flux and increased luminosity improving organoleptical properties.
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In this work, a protocol for the formulation of an enzyme concentrated product to be applied in fruit juice treatment is described. Downstream processing conditions for the recovery and concentration of pectinases produced by the new strain Aspergillus niger LB-02-SF in solid state cultivation were assessed. The solid-liquid ratio in the extraction step of pectinases recovery from the cultivated media was evaluated and the highest activity was obtained with a solid-liquid ratio of 1:10. The crude extract was concentrated by ultrafiltration and the total pectinase (TP) activity was 73.6-fold concentrated in relation to the crude extract, and a final TP titer of 663 U mL–1 was obtained with 73.7% of recovery yield. KCl and different glycerol concentrations were added to the concentrated extract and the stability of pectinases during the storage at 5°C for 59 weeks was tested. The formulation with 50% w/w glycerol was applied to the treatment of apple and grape juices and the results of these tests were statistically comparable to those obtained with two high-quality commercial preparations.
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AbstractThermal processing and production practices used in vegetables can cause changes in their phytochemical contents. Eggplant is characterized by its high antioxidant content. The objective of this work was to determine levels of anthocyanins, polyphenols, and flavonoids and antioxidant capacity in organically and conventionally grown eggplant prepared fresh or subjected to one of three thermal preparation methods: boiling, baking or steaming. The soluble and hydrolyzable polyphenols and flavonoids content were quantified by Folin-Ciocalteu and Aluminum chloride methods, respectively. Anthocyanins were quantified according to the pH differential method. Antioxidant capacity was determined by DPPH and ORAC methods. The results showed differences between organic and conventional eggplant for some variables although cultivation method did not have a consistent effect. Hydrolysable polyphenol content was greater, and soluble and hydrolysable antioxidant capacities were higher in organically grown eggplant, while anthocyanin content was greater in conventionally grown eggplant. Fresh eggplant produced under conventional cultivation had a much greater content of anthocyanins compared to that of other cultivation method-thermal treatment combination. In general, steamed eggplant contained higher total polyphenol and flavonoid levels as well as greater antioxidant capacity. Steamed eggplant from both conventional and organic systems also had high amounts of anthocyanins compared to other thermal treatments.
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Abstract Chopped mussel meat packaged in retort pouches was processed in a laboratory-scale water immersion retort, adapted for processing under overpressure conditions. Retort temperature effects on product yield and on cook value were evaluated by setting the F0 at 7 min. The effects of different pre-treatments (salting and marination) on the characteristics of mussels were evaluated after processing at retort temperature of 118 °C and during a whole year of storage at 25 °C. The salted samples showed better yield during storage, while no differences were found for the other physicochemical parameters.
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Phenolic compounds have been extensively studied in recent years. The presence of these compounds in various foods has been associated with sensory and health promoting properties. These products from the secondary metabolism of plants act as defense mechanisms against environmental stress and attack by other organisms. They are divided into different classes according to their chemical structures. The objective of this study was to describe the different classes of phenolic compounds, the main food sources and factors of variation, besides methods for the identification and quantification commonly used to analyze these compounds. Moreover, the role of phenolic compounds in scavenging oxidative stress and the techniques of in vitro antioxidant evaluation are discussed. In vivo studies to evaluate the biological effects of these compounds and their impact on chronic disease prevention are presented as well. Finally, it was discussed the role of these compounds on the sensory quality of foods.
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O presente trabalho analisa a estratégia de entrada de firmas da indústria de fast-food brasileira em novos mercados. Investigamos quais os atributos de uma cidade que atrai firmas dessa indústria e como firmas de diferentes cadeias interagem nas suas decisões de entrada. Os resultados indicam que as firmas adotam uma estratégia do tipo me-too: uma vez que uma firma entra em um mercado inexplorado, as demais tendem a também entrar nesse mercado. A hipótese do artigo é que há uma incerteza quanto ao potencial de um mercado, e a entrada de uma firma sinaliza para as demais que esse potencial é elevado Os ganhos da descoberta e da entrada em um novo mercado com alto potencial dissipam-se rapidamente com a entrada das firmas seguidoras, concedendo uma vantagem temporária para a firma pioneira.
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In the past thirty years, a series of plans have been developed by successive Brazilian governments in a continuing effort to maximize the nation's resources for economic and social growth. This planning history has been quantitatively rich but qualitatively poor. The disjunction has stimulated Professor Mello e Souza to address himself to the problem of national planning and to offer some criticisms of Brazilian planning experience. Though political instability has obviously been a factor promoting discontinuity, his criticisms are aimed at the attitudes and strategic concepts which have sought to link planning to national goals and administration. He criticizes the fascination with techniques and plans to the exclusion of proper diagnosis of the socio-political reality, developing instruments to coordinate and carry out objectives, and creating an administrative structure centralized enough to make national decisions and decentralized enough to perform on the basis of those decisions. Thus, fixed, quantified objectives abound while the problem of functioning mechanisms for the coordinated, rational use of resources has been left unattended. Although his interest and criticism are focused on the process and experience of national planning, he recognized variation in the level and results of Brazilian planning. National plans have failed due to faulty conception of the function of planning. Sectorial plans, save in the sector of the petroleum industry under government responsibility, ha e not succeeded in overcoming the problems of formulation and execution thereby repeating old technical errors. Planning for the private sector has a somewhat brighter history due to the use of Grupos Executivos which has enabled the planning process to transcend the formalism and tradition-bound attitudes of the regular bureaucracy. Regional planning offers two relatively successful experiences, Sudene and the strategy of the regionally oriented autarchy. Thus, planning history in Brazil is not entirely black but a certain shade of grey. The major part of the article, however, is devoted to a descriptive analysis of the national planning experience. The plans included in this analysis are: The Works and Equipment Plan (POE); The Health, Food, Transportation and Energy Plan (Salte); The Program of Goals; The Trienal Plan of Economic and Social Development; and the Plan of Governmental Economic Action (Paeg). Using these five plans for his historical experience the author sets out a series of errors of formulation and execution by which he analyzes that experience. With respect to formulation, he speaks of a lack of elaboration of programs and projects, of coordination among diverse goals, and of provision of qualified staff and techniques. He mentions the absence of the definition of resources necessary to the financing of the plan and the inadequate quantification of sectorial and national goals due to the lack of reliable statistical information. Finally, he notes the failure to coordinate the annual budget with the multi-year plans. He sees the problems of execution as beginning in the absence of coordination between the various sectors of the public administration, the failure to develop an operative system of decentralization, the absence of any system of financial and fiscal control over execution, the difficulties imposed by the system of public accounting, and the absence of an adequate program of allocation for the liberation of resources. He ends by pointing to the failure to develop and use an integrated system of political economic tools in a mode compatible with the objective of the plans. The body of the article analyzes national planning experience in Brazil using these lists of errors as rough model of criticism. Several conclusions emerge from this analysis with regard to planning in Brazil and in developing countries, in general. Plans have generally been of little avail in Brazil because of the lack of a continuous, bureaucratized (in the Weberian sense) planning organization set in an instrumentally suitable administrative structure and based on thorough diagnoses of socio-economic conditions and problems. Plans have become the justification for planning. Planning has come to be conceived as a rational method of orienting the process of decisions through the establishment of a precise and quantified relation between means and ends. But this conception has led to a planning history rimmed with frustration, and failure, because of its rigidity in the face of flexible and changing reality. Rather, he suggests a conception of planning which understands it "as a rational process of formulating decisions about the policy, economy, and society whose only demand is that of managing the instrumentarium in a harmonious and integrated form in order to reach explicit, but not quantified ends". He calls this "planning without plans": the establishment of broad-scale tendencies through diagnosis whose implementation is carried out through an adjustable, coherent instrumentarium of political-economic tools. Administration according to a plan of multiple, integrated goals is a sound procedure if the nation's administrative machinery contains the technical development needed to control the multiple variables linked to any situation of socio-economic change. Brazil does not possess this level of refinement and any strategy of planning relevant to its problems must recognize this. The reforms which have been attempted fail to make this recognition as is true of the conception of planning informing the Brazilian experience. Therefore, unworkable plans, ill-diagnosed with little or no supportive instrumentarium or flexibility have been Brazil's legacy. This legacy seems likely to continue until the conception of planning comes to live in the reality of Brazil.
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Nutritional surveys (food consumption, clinical and biochemichal) were conducted in a small institution for homeless children. Results showed that only 30% of the children presented adequate calorie intake. Most of the children presented adequate protein intake, but almost half consumed less than 2/3 of the calcium RDA considered necessary. Food handling, processing, and distribution also proved inadequate and wastage, high. Skinfold measurement showed up one case of obesity. Furthermore, most of the children presented clinical signs of vitamin A deficiency, mostly skin lesions; while about half presented clinical signs of riboflavin deficiency. Biochemical data showed that 63.6% had deficient plasma levels of vitamin A, none showed abnormal results for riboflavin excretion, four showed packed blood cell volume below normal, and all had normal hemoglobin levels. Stool examinations revealed a high rate of pathogenic protozoa (Hymenolepis nana), in fact, one of the highest in Brazilian literature.
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Twelve people became ill with vomiting and diarrhoea approximately four hours after eating cake with a cream filling at a birthday party and on the day following. The cake had been prepared by a food handler who had long experience in preparing foods for such functions. Staphylococcus aureus that produced enterotoxin A was isolated from the nose, the fingernails, and a healed infection on the neck of the food handler, and from the cake. Enterotoxin A was detected in the remaining portion of the cake. The cake, while still warm, had been refrigerated for one hour after it was prepared before it was removed for the party; it was refrigerated after the party. The cake was large (6 kg) and hence it was not adequately cooled in the hour during wich it was refrigerated before the party. The conclusion is that the cake was accidentally contaminated by the food handler and inadequately cooled before it was eaten.
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OBJECTIVE: To identify the association between food group consumption frequency and serum lipoprotein levels among adults. METHODS: The observations were made during a cross-sectional survey of a representative sample of men and women over 20 years old living in Cotia county, S. Paulo, Brazil. Data on food frequency consumption, serum lipids, and other covariates were available for 1,045 adults. Multivariate analyses adjusted by age, gender, body mass index, waist-to-hip ratio, educational level, family income, physical activity, smoking, and alcohol consumption were performed. RESULTS: Consumption of processed meat, chicken, red meat, eggs and dairy foods were each positively and significantly correlated with LDL-C, whereas the intake of vegetables and fruits showed an inverse correlation. Daily consumption of processed meat, chicken, red meat, eggs, and dairy foods were associated with 16.6 mg/dl, 14.5 mg/dl, 11.1 mg/dl, 5.8 mg/dl, and 4.6 mg/dl increase in blood LDL-C, respectively. Increases of daily consumption of fruit and vegetables were associated with 5.2 mg/dl and 5.5 mg/dl decreases in LDL-C, respectively. Alcohol beverage consumption showed a significant positive correlation with HDL-C. CONCLUSIONS: Dietary habits in the study population seem to contribute substantially to the variation in blood LDL and HDL concentrations. Substantially CHD risk reduction could be achieved with dietary changes.
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OBJECTIVE: Analyze the infectivity and storage resistance of cysts of the ME-49 strain of Toxoplasma gondii in artificially infected bovine milk and homemade fresh cheese. METHODS: Pasteurized bovine milk was infected with 10 cysts/ml of the ME-49 strain of T.gondii and inoculated in different groups of mice, immediately or after storage at 4ºC for 5, 10 and 20 days. Homemade fresh cheese was prepared with artificially infected milk, and also tested in groups of mice, using the same storage process. Infection was identified by the presence of cysts in the brain or serological testing in challenged mice after 5 weeks, confirmed by Western Blot and histology. RESULTS: The infectivity of cysts of the ME-49 strain of T.gondii was maintained in the milk even after storage for 20 days at refrigerator temperatures. Cysts were also able to survive the production process of homemade fresh cheese and storage for a period of 10 days in the same conditions. CONCLUSIONS: These data demonstrated that milk and dairy products could be an important source of T.gondii in human contamination, reinforcing the importance of milk pasteurization before any processing or ingestion.
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OBJECTIVE To propose a short version of the Brazilian Food Insecurity Scale. METHODS Two samples were used to test the results obtained in the analyses in two distinct scenarios. One of the studies was composed of 230 low income families from Pelotas, RS, Southern Brazil, and the other was composed of 15,575 women, whose data were obtained from the 2006 National Survey on Demography and Health. Two models were tested, the first containing seven questions, and the second, the five questions that were considered the most relevant ones in the concordance analysis. The models were compared to the Brazilian Food Insecurity Scale, and the sensitivity, specificity and accuracy parameters were calculated, as well as the kappa agreement test. RESULTS Comparing the prevalence of food insecurity between the Brazilian Food Insecurity Scale and the two models, the differences were around 2 percentage points. In the sensitivity analysis, the short version of seven questions obtained 97.8% and 99.5% in the Pelotas sample and in the National Survey on Demography and Health sample, respectively, while specificity was 100% in both studies. The five-question model showed similar results (sensitivity of 95.7% and 99.5% in the Pelotas sample and in the National Survey on Demography and Health sample, respectively). In the Pelotas sample, the kappa test of the seven-question version totaled 97.0% and that of the five-question version, 95.0%. In the National Survey on Demography and Health sample, the two models presented a 99.0% kappa. CONCLUSIONS We suggest that the model with five questions should be used as the short version of the Brazilian Food Insecurity Scale, as its results were similar to the original scale with a lower number of questions. This version needs to be administered to other populations in Brazil in order to allow for the adequate assessment of the validity parameters.
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OBJECTIVE The objective of this study was to investigate the association between food assistance program participation and overweight/obesity according to poverty level. METHODS A cross-sectional analysis of data from 46,217 non-pregnant and non-lactating women in Lima, Peru was conducted; these data were obtained from nationally representative surveys from the years 2003, 2004, 2006, and 2008-2010. The dependent variable was overweight/obesity, and the independent variable was food assistance program participation. Poisson regression was used to stratify the data by family socioeconomic level, area of residence (Lima versus the rest of the country; urban versus rural), and survey year (2003-2006 versus 2008-2010). The models were adjusted for age, education level, urbanization, and survey year. RESULTS Food assistance program participation was associated with an increased risk of overweight/obesity in women living in homes without poverty indicators [prevalence ratio (PR) = 1.29; 95% confidence interval (CI) 1.06;1.57]. When stratified by area of residence, similar associations were observed for women living in Lima and urban areas; no associations were found between food assistance program participation and overweight/obesity among women living outside of Lima or in rural areas, regardless of the poverty status. CONCLUSIONS Food assistance program participation was associated with overweight/obesity in non-poor women. Additional studies are required in countries facing both aspects of malnutrition.