Efeito da utilização de substitutos de gordura em queijos light

Cheeses are known to be sources of calcium, phosphorus and protein, important nutrients for a suitable nutrition. However, certain cheeses imply the ingestion of large amounts of fats, which can cause the development of coronary heart and carcinogenic diseases. Although consumers are aware of the necessity of reducing the fats intake, they are still not pleased with the quality of light cheeses available on the market, because the partial or total fat removal provides some undesirable changes, especially regarding to the product texture and flavor. In order to offer products nutritionally adequate and palatable, alternatives have been developed to improve the characteristics of light cheeses. Such alternatives include the use of fat substitutes, those additives that improve the functional and sensory characteristics of cheeses with reduced fat. Fat substitutes composed of proteins, carbohydrates and lipids, or a combination of them, help the retention of moisture and eliminate the undesirable characteristics of fat reduced-cheeses. In this context, this review aims at reporting the innovations and trends on the use of fat substitutes to produce light cheeses.

Avaliação da composição química, proteólise e propriedades funcionais do queijo mussarela comercial com teor reduzido de gordura

Chemical composition, proteolysis and functional properties of commercial Mozzarella cheese with reduced fat content found in the market of Londrina – PR were evaluated. The cheeses were analyzed for chemical composition, meltability, free oil formation, and the indexes of extension and depth of proteolysis during 30, 45 and 60 days of storage at 5°C. The samples showed no significant difference in chemical composition. The fat content of all samples complied with current legislation regarding the minimum percentage (25%) of fat reduction. Among the three brands tested, the cheeses of brand C showed the highest depth index of proteolysis. In all chesses, the meltability has increased during storage period. The, the brand C had significantly higher (p <0.05) free oil content when compared to other brands tested.

Efeito de colágeno hidrolisado sobre a qualidade tecnológica de queijo Minas frescal light

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Efeito de substitutos de gordura na qualidade de queijo Prato com reduzido teor de gordura

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Improving daylighting performance of mirrored light pipes

This paper assesses and compares the performances of two daylight collection strategies, one passive and one active, for large-scale mirrored light pipes (MLP) illuminating deep plan buildings. Both strategies use laser cut panels (LCP) as the main component of the collection system. The passive system comprises LCPs in pyramid form, whereas the active system uses a tiled LCP on a simple rotation mechanism that rotates 360° in 24 hours. Performance is assessed using scale model testing under sunny sky conditions and mathematical modelling. Results show average illuminance levels for the pyramid LCP ranging from 50 to 250 lux and 150 to 200 lux for the rotating LCPs. Both systems improve the performance of a MLP. The pyramid LCP increases the performance of a MLP by 2.5 times and the rotating LCP by 5 times, when compared to an open pipe particularly for low sun elevation angles.

Experimental study of the mechanical properties of light gauge cold-formed steels at elevated temperatures

In recent times, light gauge cold-formed steel sections have been used extensively as primary load bearing structural members in many applications in the building industry. Fire safety design of structures using such sections has therefore become more important. Deterioration of mechanical properties of yield stress and elasticity modulus is considered the most important factor affecting the performance of steel structures in fires. Hence there is a need to fully understand the mechanical properties of light gauge cold-formed steels at elevated temperatures. A research project based on experimental studies was therefore undertaken to investigate the deterioration of mechanical properties of light gauge cold-formed steels. Tensile coupon tests were undertaken to determine the mechanical properties of these steels made of both low and high strength steels and thicknesses of 0.60, 0.80 and 0.95 mm at temperatures ranging from 20 to 800ºC. Test results showed that the currently available reduction factors are unsafe to use in the fire safety design of cold-formed steel structures. Therefore new predictive equations were developed for the mechanical properties of yield strength and elasticity modulus at elevated temperatures. This paper presents the details of the experimental study, and the results including the developed equations. It also includes details of a stress-strain model for light gauge cold-formed steels at elevated temperatures.