Computational fluid dynamics evaluation of liquid food thermal process in a brick shaped package

Food processes must ensure safety and high-quality products for a growing demand consumer creating the need for better knowledge of its unit operations. The Computational Fluid Dynamics (CFD) has been widely used for better understanding the food thermal processes, and it is one of the safest and most frequently used methods for food preservation. However, there is no single study in the literature describing thermal process of liquid foods in a brick shaped package. The present study evaluated such process and the influence of its orientation on the process lethality. It demonstrated the potential of using CFD to evaluate thermal processes of liquid foods and the importance of rheological characterization and convection in thermal processing of liquid foods. It also showed that packaging orientation does not result in different sterilization values during thermal process of the evaluated fluids in the brick shaped package.

Influence of different sanitizers on food contaminant bacteria: effect of exposure temperature, contact time, and product concentration

The efficiency of four Sanitizers - peracetic acid, chlorhexidine, quaternary ammonium, and organic acids - was tested in this work using different bacteria recognized as a problem to meat industry, Salmonella sp., S. aureus, E. coli and L. monocytogenes. The effects of sanitizer concentration (0.2, 0.5, 0.6, 1.0, 1.1 and 1.4%), at different temperatures (10 and 45 °C) and contact time (2, 10, 15, 18 and 25 minutes) were evaluated. Tests in an industrial plant were also carried out considering previously obtained results. In a general way, peracetic acid presented higher efficiencies using low concentration (0.2%) and contact time (2 minutes) at 10 °C. The tests performed in industrial scale showed that peracetic acid presented a good performance in concentration and contact time lower than that suggested by the suppliers. The use of chlorhexidine and quaternary ammonium led to reasonable results at the indicated conditions, and organic acids were ineffective under concentration and contact time higher than those indicated by the suppliers in relation to Staphylococcus aureus. The results, in general, show that the choice for the most adequate sanitizer depends on the microorganism contaminant, the time available for sanitizer application, and also on the process cost.

Modeling of allergen proteins found in sea food products

Shellfish are a source of food allergens, and their consumption is the cause of severe allergic reactions in humans. Tropomyosins, a family of muscle proteins, have been identified as the major allergens in shellfish and mollusks species. Nevertheless, few experimentally determined three-dimensional structures are available in the Protein Data Base (PDB). In this study, 3D models of several homologous of tropomyosins present in marine shellfish and mollusk species (Chaf 1, Met e1, Hom a1, Per v1, and Pen a1) were constructed, validated, and their immunoglobulin E binding epitopes were identified using bioinformatics tools. All protein models for these allergens consisted of long alpha-helices. Chaf 1, Met e1, and Hom a1 had six conserved regions with sequence similarities to known epitopes, whereas Per v1 and Pen a1 contained only one. Lipophilic potentials of identified epitopes revealed a high propensity of hydrophobic amino acids in the immunoglobulin E binding site. This information could be useful to design tropomyosin-specific immunotherapy for sea food allergies.

Processing, physicochemical, and sensory analyses of ostrich meat hamburger

The objective of this study was to assess the potential utilization of ostrich meat trimming in hamburger preparation, as well as its physicochemical and sensory characterization. Using ostrich meat trimmings from the legs and neck, four different formulations were prepared with varied amounts of bacon and textured soybean protein. Physical analysis of yield, shrinkage percentage, and water retention capacity and chemical analysis of proximate composition, cholesterol levels, and calories were performed. The formulations underwent sensory analysis by 52 potential ostrich meat consumers, who evaluated tenderness, juiciness, flavor, and purchase intent. The formulations containing textured soybean protein showed the highest yield, lowest shrinkage percentage, and highest water retention capacity. Lipid content varied from 0.58 to 4.99%; protein from 17.08 to 21.37%; ash from 3.00 to 3.62%; moisture from 73.87 to 76.27%; cholesterol from 22.54 to 32.11 mg.100 g-1; and calorie from 87.22 to 163.42 kcal.100 g-1. All formulations showed low cholesterol and calorie levels, even that containing 10% bacon and 3.5% textured soybean protein, which achieved the best scores and acceptance by the panelists.

Consumer attitudes toward information displayed at food buffets in commercial restaurants

This study aimed to evaluate the attitude of consumers towards information about dishes in a commercial restaurant. This research was conducted from January to April 2009 in a restaurant in the city of Santa Maria (RS), Brazil. Food information including the name of the dish, ingredients, health benefits and warnings, and calorie value was displayed. After providing this nutritional information, a questionnaire was applied to 300 consumers at the restaurant to observe their attitudes towards the food information. It was found that 10.57% of the respondents reported allergy or intolerance to some kinds of food and that 10.98% of the respondents reported having diseases that require moderate consumption and/or total restriction on the consumption of those foods. However, 84.96% of the respondents did not restrict consumption of any food, even though those foods may have posed a risk to their health, and 58.54% of the respondents consumed some food due to the potential benefits to their health. With regard to the respondents' level of satisfaction concerning the food information provided, 72.76% considered the information provided as very good. The respondents had a tendency to change their behavior towards consumption after having access to information about the dishes displayed.

Study of adsorption isotherms of green coconut pulp

Brazil is considered one of the largest producers and consumers of tropical fruits. Green coconut (Cocos nucifera L.) stands out not only for its production and consumption, but also for the high amount of waste produced by coconut water industry and in natura consumption. Therefore, there is a need for utilization of this by-product. This study aims to study the adsorption isotherms of green coconut pulp and determine its isosteric heat of sorption. The adsorption isotherms at temperatures of 30, 40, 50, 60, and 70 °C were analyzed, and they exhibit type III behavior, typical of sugar rich foods. The experimental results of equilibrium moisture content were correlated by models present in the literature. The Guggenheim, Anderson and De Boer (GAB) model proved particularly good overall agreement with the experimental data. The heat of sorption determined from the adsorption isotherms increased with the decrease in moisture content. The heat of sorption is considered as indicative of intermolecular attractive forces between the sorption sites and water vapor, which is an important factor to predict the shelf life of dried products.

Stability of cassava flour-based food bars

The consumption of Brazilian cassava has been reduced due to a lack of adjustment to the modern lifestyle. To reverse this trend, new products could be developed specifically targeted to high-value niche markets. Cereal bars stand out as fast food high in nutritional value. A bar formula mimicking cereal bars was prepared using a mixture of Brazilian cassava flour, hydrogenated vegetable fat, dried bananas, ground cashew nuts, and glucose syrup. After being pressed, the bars were dried for 1 hour at 65 °C, packaged in films, and stored under ambient conditions. Its stability was continuously monitored for 210 days in order to ensure its safety and enable its introduction to the market. Texture loss was observed in the packed bars after 90 days of storage, but the sensory characteristics allowed the testers to perceive this tendency after only 30 days of storage. However, chemical, physical, and microbial analyses confirmed that the bars were safe for consumption for 180 days. The results showed that a 45 g cassava flour-based bar enriched with nuts and dried fruits can meet 6% of the recommended daily fiber intake with a caloric value between that of the common cereal bar and that of an energy bar. Adapting the formula with ingredients (fruits, nuts) from different regions of Brazil may add value to this traditional product as a fast food.

Citotoxicity of food dyes sunset yellow (E-110), bordeaux red (E-123), and tatrazine yellow (E-102) on Allium cepa L. root meristematic cells

The objective of this study was to evaluate the cytotoxic effect of the food dyes sunset yellow, bordeaux red, and tartrazine yellow on the cellular cycle of Allium cepa L. Each dye was evaluated at the doses of 0.4 and 4.0 mL, at the exposure times of 24 and 48 hours in root tip cells of Allium cepa L. Slides were prepared and cells were analyzed during the whole cell cycle for cellular aberrations totaling 5,000 total cells for each dose evaluated. The mitotic index was calculated, and statistical analysis was performed using the Chi-squared test (p < 0.05). The results showed that the three dyes used under the evaluated doses and exposure times were cytotoxic to the cells of the system-test used. Further cytotoxicity studies should be conducted for additional results and a proper evaluation of the effect of these three dyes on a cellular level.

Isolation and characterization of bacterial strains with a hydrolytic profile with potential use in bioconversion of agroindustial by-products and waste

There is a trend towards the use of novel technologies nowadays, mainly focused on biological processes, for recycling and the efficient utilization of organic residues that can be metabolized by different microorganisms as a source of energy. In the present study the isolation of bacterial strains from six different agro-industrial by-products and waste was performed with the objective of evaluating their hydrolytic capacities and suitability for use in bioconversion of specific substrates. The 34 isolated strains were screened in specific culture media for the production of various hydrolytic enzymes (lipase, protease, cellulase, and amylase). It was found that 28 strains exhibited proteolytic activity, 18 had lipolytic activity, 13 had caseinolytic activity, 15 had amylolytic activity, and 11 strains exhibited cellulolytic activity. The strains that showed the highest hydrolytic capacities with biotechnological potential were selected, characterized genotipically, and identified as Bacillus, Serratia, Enterococcus, Klebsiella, Stenotrophomonas, Lactococcus, and Escherichia genera. It was concluded that the strain isolates have a high potential for use in the bioconversion of agro-industrial waste, both as a pure culture and as a microbial consortium.