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Sensory and physicochemical changes of three apple cultivars (‘Golden Delicious’, ‘Idared’ and ‘Gloster’) were monitored during 14 weeks of storage at 6 °C and 70% relative humidity in three following years. The aim was to investigate physicochemical parameters that were best correlated with sensory evaluation of apples during their storage. Sensory quality was assessed using a category point scale and the sensory profile was evaluated using a graphical unstructured scale. Physicochemical changes, such as weight, soluble solids, titratable acidity, and dry matter content, were monitored. All the examined parameters changed during the observed period, with the greatest changes occurring in weight, texture, and taste. There were also differences between the tested cultivars. Statistically significant correlations between sensory and physicochemical data were observed between texture characteristics and weight changes. In case of sweet taste, only a weak correlation between the intensity of sweet flavour and soluble solid content values was found. No statistically significant correlation between the intensity of sour taste and titratable acidity was observed.
Three independent studies were conducted in Chile, Spain and Uruguay to assess the effects of the addition of enzymes on the shelf life of brown pan bread.Four batches of brown bread were prepared in each country: a control batch with no added enzymes, a second batch with amylase, a third batch with xylanase and a fourth batch with a 1:1 mixture of amylase and xylanase. Three sensory texture parameters were evaluated (softness, size of the soft area and cohesiveness) and a consumer study was conducted to determine the acceptability of the samples. In each country, the doses of each enzyme and enzyme mixtures (1:1) added to doughs have to be adapted to obtain good dough handling characteristics and minimise adhesiveness and stickiness of the corresponding flour in the traditional formulation.In all three countries the addition of the enzyme mixture gave the best results, achieving a longer shelf life, while the addition of xylanase accelerated bread staling.
Reliable product characteristics are needed for the prediction of shelf life by mathematical models in the post-harvest sector. Exact knowledge of the nature of changes during ripening and storage in refrigerated storage is essential. Authors investigated physical, chemical and biological changes of field-grown, autumn-harvested food grade potato (cultivar Kondor) as a function of temperature and storage time and the market quality was determined by visual assessment. Most of the investigations were preceded by sampling and methodological examinations. The most appropriate characteristics for the predictive modelling were: water soluble solids content, total starch content, weight loss during storage, marketability of the product (visually assessed) and texture parameters: acoustic firmness factor and bio-yield (by Instron Universal Testing Machine). Components of complex impedance, except for some cases, would be unreliable factors in model creation.
In the research area of healthier meat products a possible trend is to replace high energy density fat in formulations with substances providing less energy than fat. The aim of the producers is to obtain a product having maximum yield with similar or same organoleptic properties and structure like well-known full-fat analogues. Properties of high fat products can be restored with the use of different fat substitutes, non-meat protein, and/or hydrocolloids or starch, owing to their stabilization abilities, fat coating, and water binding, respectively. The review is aimed to summarize the effect of different fat substitutes on the processing quality, textural characteristics, and sensory properties of comminuted meat products with low lipid content.
The n-3 fatty acids advantageously affect human health. Thus, partial substitution of pig backfat with soybean- or flaxseed oils in “Párizsi” (lyoner), with the aim to increase its n-3 fatty acid (FA) content, resulted improved FA profile (n-6/n-3 ratio). Relatively high (9% flaxseed oil) substitution decreased this ratio to the optimum (∼4). This modified FA profile was preserved during 32 storage days. Oil addition influenced fresh surface colour: lightness (L*) increased, redness (a*) decreased in parallel with the increasing oil addition, while only soybean oil increased yellowness (b*). Storage altered the colour slightly. The texture was not systematically altered by oil substitution, while during storage in a vapour permeable casing hardness increased. Considering organoleptic properties, soybean oil improved the extent of spiciness, while the general consumer acceptance was the most favourable (within complemented samples) by 3% flaxseed oil. Increasing vegetable oil levels intensified the taste of spice mixture.
The purpose of this study was to evaluate the effect of rosemary essential oil (250–1000 ppm) or its leaves (0.5–2%) on the quality of turkey sausage. The addition of essential oil had no significant effect on the sausage texture and colour parameters. A high rosemary leaves level resulted in an increase in sausage hardness and chewiness and a decrease in lightness (L*) with respect to the control sausage. Sensory evaluation indicated that rosemary essential oil and its leaves increased the taste and the aroma scores of turkey sausage depending on the concentration. The obtained results also showed that rosemary leaves (0.5%) were more effective than essential oil in reducing total plate counts, TBARS, K232, and K270 values during chill storage, in comparison with the control product. This will contribute to reducing the use of chemical additives, which are badly perceived by consumers, while increasing the sensory properties of such products.
Water content of dry sausages may decrease due to improper ripening and storage as well. As a consequence, an outer crust appears on the surface of the products. The aim of the industry is either to eliminate the presence of outer crust, or decrease its occurrence. The thickness of outer crust can be estimated by non-destructive ultrasound technique. As the propagation time and attenuation of ultrasonic waves vary in the materials with different water content, the thickness of outer crust and the normal texture, respectively, can be estimated on the basis of these characteristics. The propagation and attenuation values are typical for the given layers. Thus, by measuring total attenuation and total width of the product, the thickness of outer crust can be calculated by means of the velocity and attenuation coefficients of ultrasonic waves. Results of this non-destructive measurement may support the proper adjustment of ripening and storage parameters such as temperature and humidity.
This paper presents a brief summary of the main existing shear strength test methods on both intact and fractured rocks, such as the triaxial, half-half notched specimen and direct shear strength tests. A detailed description of how to carry out a direct shear strength test on rocks along discontinuities are provided, supported by test results. The analyses include the interpretation of the tests and the calculation of the maximal and residual shear strength, as well as their angle of friction and apparent cohesion. These parameters depend on the properties of the rock and the discontinuity, such as the joint surface roughness, the rock texture orientation, the filling material, the thickness of the discontinuities, the scale effect and the magnitude of the applied normal force during the test. Their effect is discussed.
Contemporary architectural practical work imposes to architects not only well developed spatial skills but good knowledge of geometry as well. Thus an advanced studying of geometrical forms is necessary for students of architecture. The course entitled Geometry and Visualisations of Free-Forms is introduced to students with adequate knowledge of Descriptive Geometry, Perspectives and basics of CAD modelling. In the course students apply and enhance that knowledge and skills to model, visualise and manipulate both free-forms and forms derived from basic surfaces using various transformations and deformations. Furthermore, options for parameterisation and optimisation of obtained forms are introduced. Finally, patterns and seamless texturing of free-forms are analysed.In general, the course refreshes mental skills, regarding geometry and complex spatial relations, developed in earlier years of architectural study, and enhances the knowledge of CAD software, necessary in today’s architectural practice.This paper also presents the student work, their goals, achieved results and dilemmas on mentioned topics.
The objectives of the paper were to show that the evaporation intensity of water can be increased by the application of appropriate textile materials. The purpose was to determine the dependence of the evaporation intensity on the textile characteristics and the influence weather conditions on the evaporation intensity of different textiles. Five different textile strips of different widths and of single- and multi-layer were tested in definite experimental pots under open air conditions. The results of the experiments showed the total evaporation surface of the textiles depended on the texture material and the capillary volume of the textiles and the capillary volume had a limit at approximately V c = 1000–1200 cm3/m2. Another important result was that the relative air humidity is a main factor of the weather conditions that has principal influence on the evaporation intensity. However, the other parameters — such as temperature, solar radiation and wind speed — have only a secondary effect on the evaporation intensity of textiles.
