Using Computational Fluid-Dynamics (CFD) for the evaluation of beer pasteurization: effect of orientation of cans

In-package pasteurization is the most used method for beer microbiological stabilization. The search for safer and better quality food has created a need to better understand the processes involved in producing it. However, little is known about the temperature and velocity profiles during the thermal processes of liquid foods in commercial packaging, which results in over-dimensioned processes to guarantee safety, decreasing the sensorial and nutritional characteristics of the product and increasing process costs. Simulations using Computational Fluid-Dynamics (CFD) have been used by various authors to evaluate those processes. The objective of the present paper was to evaluate the effect of packaging orientation in the pasteurization of beer in a commercial aluminum can using CFD. A heating process was simulated at 60 ºC up to 15 PUs (a conventional beer process, in which 1 Pasteurization Unit (PU) is equivalent to 1minute at 60 ºC). The temperature profile and convection current velocity along the process and the variation of the PUs were evaluated in relation to time considering the cans in the conventional, inverted, and horizontal positions. The temperature and velocity profiles were similar to those presented in the literature. The package position did not result in process improvement.

Hygienic-sanitary quality of vegetables and evaluation of treatments for the elimination of indigenous E. coli and E. coli O157:H7 from the surface of leaves of lettuce (Lactuca sativa L.)

The purpose of this study is to evaluate the hygienic-sanitary quality of vegetables and irrigation water and assess the effectiveness of lemon juice and vinegar in reducing E. coli strains inoculated on lettuce. One hundred and forty samples of vegetables and 45 samples of irrigation water were investigated for thermotolerant coliforms and Salmonella spp. In order to verify the effectiveness of natural household sanitizers in reducing E. coli in inoculated lettuce, four treatment solutions were tested: fresh lemon juice, alcohol vinegar, lemon juice-vinegar mixture, and lemon juice-vinegar-water mixture. The microbiological analysis revealed high rates of contamination by thermotolerant coliforms and identified the presence of E. coli in 32% of the tested vegetable samples and 56% of the water samples. While no significant statistical difference (p < 0, 05) was identified in the tested solutions, the treatment with a combination of lemon juice and vinegar resulted in the highest Decimal Reductions (DR) of E. coli O157: H7 while the treatment with vinegar alone was the most effective against the indigenous E. coli strain

Evaluation of process parameters in the industrial scale production of fish nuggets

This work reports the use of experimental design for the assessment of the effects of process parameters on the production of fish nuggets in an industrial scale environment. The effect of independent factors on the physicochemical and microbiological parameters was investigated through a full 24 experimental design. The studied factors included the temperature of fish fillet and pulp in the mixer, the temperature of the added fat, the temperature of water and the ratio of protein extraction time to emulsion time. The physicochemical analyses showed that the higher temperature of the pulp and fillet of fish, the lower the protein in the final product. Microbiological analyses revealed that the counting of Staphylococcus coagulase positive, total and thermo-tolerant coliforms were in accordance with the current legislation.

Evaluation of the potential use of rebaudioside-A as sweetener for diet jam

Sweeteners based on stevia extract contain a series of diterpene glycosides derivatives from steviol, standing out the rebaudioside-A. There is no tabletop sweeteners in the market formulated purely with rebaudioside-A yet, so its use in foods depends on the development of new products followed by physicochemical and sensory evaluations. This work presents the formulation of a diet strawberry jam dyed with cranberry juice and sweetened with rebaudioside-A purified from stevia plants of the lineage UEM-320 developed in the Centro de Estudos de Produtos Naturais da Universidade Estadual de Maringá. Evaluations of physicochemical properties, microbiological and sensory characteristics were carried out for the product in comparison with a control sweetened with equal amount of sucralose. The results showed that the physicochemical characteristics of the sample and the control are not significantly different and the supplementation with cranberry juice increased both color and total phenolic content in both samples. The sensory acceptability indicated a significant preference for the formulation sweetened with 100% of rebaudioside-A, only in the items flavor and purchase intent. We concluded that rebaudioside-A has a better sensory performance than sucralose, even this last one being 1.33 fold sweeter than rebaudioside-A.

Evaluation of quality factors of bovine and chicken meat marinated with reduced sodium content

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.

Evaluation of the PetrifilmTM and TEMPO® systems and the conventional method for counting microorganisms in pasteurized milk

New microbiological methods have been developed and commercialized, but their performance must be guaranteed. The aim of the present study was to evaluate the PetrifilmTM and TEMPO® systems compared to the conventional method for counting microorganisms in pasteurized milk. A total of 141 samples of pasteurized milk were analyzed by counting mesophilic aerobic, Coliforms at 35 ºC, Coliforms at 45 ºC, and Escherichia coli microorganisms. High correlation was found between the methods for counting Coliforms at 35 ºC, but low correlation was found for counting mesophilic aerobic, Coliforms at 45 ºC, and Escherichia coli. No significant statistical difference was found among the three methods for counting Coliforms at 35 ºC; however, the mean counts of mesophilic aerobic, Coliforms at 45 ºC, and Escherichia coli showed significant statistical difference. PetrifilmTM and TEMPO® systems had satisfactory results for Coliforms at 35 ºC in pasteurized milk but low performance for mesophilic aerobic, Coliforms at 45 ºC and Escherichia coli.

Quality evaluation of parmesan-type cheese: a chemometric approach

Parmesan-type cheeses are the most consumed special cheeses in Brazil. It is generally sold in retail shops, either grated or in wedge-shaped pieces, and its quality varies considerably, which is reflected directly in its price. There is lack of processing standardization and, since the ripening period is fundamental for the quality of this hard, semi-fat cooked cheese, this stage seems to be the thin line between low and high quality products. It is important to note that the Italian Parmegiano Reggiano is matured for a period of twelve months, as well as its rival Grana Padano, and this long ripening period causes changes making them gourmet, highly-valued cheeses. In the present study, twelve different Parmesan-type cheeses were purchased from the Brazilian retail market and evaluated for microbiological, physicochemical, and instrumental parameters. Heterogeneous quality was confirmed by microbiological problems detected in the samples and physicochemical composition that did not meet current Brazilian specifications. The use of principal component analysis and hierarchical cluster analysis made it possible to separate the samples into three distinct groups, mainly due to different acidity and moisture levels, water activity, and hardness values. The price per kg was also considered and was correlated with moisture, acidity, and texture.

Labneh with probiotic properties produced from kefir: development and sensory evaluation

The labneh or labaneh is a popular fermented milk in the Middle East. Another fermented product that deserves special mention is kefir since it has probiotic activity and unique sensory, nutritional, and therapeutic properties. The aim of the present study was to develop a functional probiotic labneh using kefir as a fermenting agent and to perform a sensory analysis of the obtained product. Kefir was obtained by growing grains in pasteurized milk. Samples of skimmed and whole labneh were prepared from the inoculation of 5% kefir milk (skimmed/whole) at 28 ºC for 24h, followed by cooling (12-18h) and whey drainage (12-24h), both at 4 ºC. Sensory analysis was performed with 70 untrained panelists using a 9-point scale hedonic in the acceptance tests. The paired t-test was used to compare the differences between the means of the scores obtained, with the significance level of 5%. The labneh prepared showed good acceptance by the judges, and the whole labneh samples had the highest scores in the acceptance test. Further studies on the analysis of microbiological viability, nutritional composition, and determination of shelf life, also to improve acceptability of the low-fat version of the product, are needed.

Evaluation of Petrifilm™ system compared with traditional methodology in count of indicators of sanitary-hygienic quality and pathogenic microorganisms in sheep milk

The objective of this study was to evaluate the applicability of the Petrifilm™ plates to enumerate microbial groups in sheep milk. Samples of sheep milk (n = 30) were plated simultaneously, to enumerate mesophilic aerobes, total coliforms, lactic acid bacteria, Staphylococcus aureus and Escherichia coli, using convencional reference protocols and Petrifilm™ plates. The results were compared using McNemar's test, linear regression and ANOVA (p < 0,05). The results demonstrated good significant between conventional methodologies and Petrifilm™ plates. Further, the Petrifim™ STX for counting S. aureus had higher recoverability of bacteria compared with the conventional methodology. Based on the results obtained and in view of the ease and rapidity procedures results, Petrifim ™ plates may be considered as alternatives for microbiological testing in sheep milk.

Development and evaluation of iron-rich meatloaves containing pork liver for schoolchildren

AbstractIron deficiency is a highly prevalent nutritional problem worldwide and it impacts on the cognitive development of children. Therefore, the aim of this research was to develop meatloaf with high iron content by using in their formulations pork liver. Meatloaves were prepared with additions of 9.98% and 13.31% (formulations A and B) of pork liver in order to meet 15% and 20% of the daily requirement of iron (10 mg/day) for children. Samples were evaluated regarding their physicochemical, microbiological and sensory characteristics. The results were subjected to Analysis of Variance (ANOVA) followed by Tukey test. Results of physicochemical analyses showed an increase in protein and mineral contents and a decrease in fat content. The iron and zinc contents were respectively 100.0% and 70.83% (formulation A) and 152.73% and 97.92% (formulation B) higher than that of the standard formulation. Regarding fat content, the reduction of 31.5% in formulation B makes it a light product. As for the microbiological aspect, all meatloaves were adequate for consumption. Regarding sensory analysis, all the attributes considered were not statistically different, but for purchase intention test formulation B was better accepted. Therefore, formulations A and B are good sources of iron and zinc.

Evaluation of respiratory parameters in minimally processed lettuce grown under organic or conventional system

The increased preference for minimally processed vegetables has been attributed to the health benefits associated with fresh produce and the demand for ready-to-eat salads. In this paper, lettuce (Lactuca sativa L.) was evaluated for the effects of different cropping systems on the respiratory properties. Lettuce was packaged in low density polyethylene bags and stored in a refrigerator at 4 ºC. The concentration of carbon dioxide and oxygen inside the package was monitored during the storage at zero, three, six, eight, ten and twelve days by gas chromatography. Dry matter variation was measured gravimetrically up to day fourteen of storage. Values of respiratory rate for conventional lettuce increased from day 1 to 3 and remained low, while respiratory rate of the organic lettuce increased three-fold up to day 8, stabilizing at a high level. Variation in dry matter during storage also resulted from differences between the two cultivation systems. The highest content of dry matter was achieved by organic lettuce.

Evaluation of polymethylmethacrylate as ocular implant in rabbits subjected to evisceration

Spheres of different types of material are used for the replacement of lost volume after removal of the eye bulb or its content to prevent contraction of the orbital cavity. The aim of this study was to evaluate the scope of polymethylmethacrylate (PMMA) used as intraocular implant in eviscerated rabbit eye. Twelve New Zealand rabbits underwent unilateral evisceration of the left eye, with subsequent implantation of PMMA sphere 12 mm in diameter. Clinical evaluation was performed daily during the first 15 days after surgery and every 15 days until the end of the study period (180 days). For the histopathological analysis, three animals per trial underwent enucleation at 15, 45, 90 and 180 days after evisceration. There was no wound dehiscence, signs of infection or implant extrusion in any animal throughout the study period. Histological examination revealed the formation of fibrovascular tissue around the implants. The PMMA behaved as inert and non-integrable.

Evaluation of collaborative strategies for ecotourism and recreational activities in natural parks of Rio de Janeiro

In the city of Rio de Janeiro, the management agencies of environmental conservation units of the park type have been attempting to meet five primary objectives set by the National System for Conservation Units (NSCU), using participatory management guidelines for these units. Two of these objectives relate to the development of recreation activities that involve contact with nature and ecological tourism. This article presents the analyses and conclusions regarding the implementation of collaborative strategies with businesses to achieve such objectives; it is part of a series of research studies having a broader scope. Case studies were conducted in eight parks by means of dozens of interviews with managers and other interested social actors, as well as by documentary research and direct observation. The results suggest that the ecotourism objective is still far from being reached, and that the collaborative strategies used are not sufficient to compensate for the organizational, material and human limitations that encumber these agencies. It was also concluded for the sample that there lacks a strategic vision on the part of the three branches of government involved in the management of these parks in the sense of viewing ecotourism in the city's conservation units as a powerful means to foster local sustainable development.

Evaluation of organophosphorus and synthetic pyrethroid insecticides against six vector mosquitoe species

Three organophosphorus compounds- malathion, folithion and temephos- and two synthetic pyrethroids- alphamethrin and deltamethrin- were used for monitoring the susceptibility status of larvae and adults of six vector mosquitoe species: Culex quinquefasciatus (Filariasis) and Aedes albopictus (Dengue) (both laboratory and field strains); laboratory strains of Aedes aegypti (Dengue), Anopheles slephensi and Anopheles culicifacies (Malaria), and Culex tritaeniorhynchus (Japanese encephalitis) in India. From the LC50 values obtained for these insecticides, it was found that all mosquito species including the field strains of Cx. quinquefasciatus and Ae. albopictus were highly susceptible Except for Cx. quinquefasciatus (field strain) against malathion, 100% mortality was observed at the discriminating dosages recommended by World Health Organization. The residual effect of alphamethrin, deltamethrin, malathion and folithion at 25 mg (ai)/m² on different surfaces against six species of vector mosquitoes showed that alphamethrin was the most effective on all four treated surfaces (mud, plywood, cement and thatch). Nevertheless, residual efficacy lasted longer on thatch than on the other surfaces. Therefore, synthetic pyrethroids such as alphamethrin can be effectively employed in integrated vector control operations.

Evaluation of dog population in an urban area of Southeastern Brazil

Planning control programs, for diseases such as rabies requires information on the size and structure of the dog and cat population. In order to evaluate the dog population of the urban area of Araçatuba city, S. Paulo State, Brazil, a survey was conducted using a questionnaire to interview members of households. Eighty-eight districts were visited (37,778 houses) and the interview was possible at 77.93% of these. Human population size evaluated was 113,157 inhabitants. Houses that owned animals represented 55.2%, 26,926 of the animals concerned were dogs and 5,755 were cats. Of the dogs, 56.64% were 1-4 year olds and males represented 56.2% of the total population. Dog: person ratio was estimated at 2.8 dogs to every 10 persons, almost 3 times the ratio hitherto estimated and used in the planning of rabies vaccination campaigns.