Browsing by Subject "texture"

The use of remote sensing imagery as auxiliary data in forest inventory is based on the correlation between features extracted from the images and the ground truth. The bidirectional reflectance and radial displacement cause variation in image features located in different segments of the image but forest characteristics remaining the same. The variation has so far been diminished by different radiometric corrections. In this study the use of sun azimuth based converted image co-ordinates was examined to supplement auxiliary data extracted from digitised aerial photographs. The method was considered as an alternative for radiometric corrections. Additionally, the usefulness of multi-image interpretation of digitised aerial photographs in regression estimation of forest characteristics was studied. The state owned study area located in Leivonmäki, Central Finland and the study material consisted of five digitised and ortho-rectified colour-infrared (CIR) aerial photographs and field measurements of 388 plots, out of which 194 were relascope (Bitterlich) plots and 194 were concentric circular plots. Both the image data and the field measurements were from the year 1999. When examining the effect of the location of the image point on pixel values and texture features of Finnish forest plots in digitised CIR photographs the clearest differences were found between front-and back-lighted image halves. Inside the image half the differences between different blocks were clearly bigger on the front-lighted half than on the back-lighted half. The strength of the phenomenon varied by forest category. The differences between pixel values extracted from different image blocks were greatest in developed and mature stands and smallest in young stands. The differences between texture features were greatest in developing stands and smallest in young and mature stands. The logarithm of timber volume per hectare and the angular transformation of the proportion of broadleaved trees of the total volume were used as dependent variables in regression models. Five different converted image co-ordinates based trend surfaces were used in models in order to diminish the effect of the bidirectional reflectance. The reference model of total volume, in which the location of the image point had been ignored, resulted in RMSE of 1,268 calculated from test material. The best of the trend surfaces was the complete third order surface, which resulted in RMSE of 1,107. The reference model of the proportion of broadleaved trees resulted in RMSE of 0,4292 and the second order trend surface was the best, resulting in RMSE of 0,4270. The trend surface method is applicable, but it has to be applied by forest category and by variable. The usefulness of multi-image interpretation of digitised aerial photographs was studied by building comparable regression models using either the front-lighted image features, back-lighted image features or both. The two-image model turned out to be slightly better than the one-image models in total volume estimation. The best one-image model resulted in RMSE of 1,098 and the two-image model resulted in RMSE of 1,090. The homologous features did not improve the models of the proportion of broadleaved trees. The overall result gives motivation for further research of multi-image interpretation. The focus may be improving regression estimation and feature selection or examination of stratification used in two-phase sampling inventory techniques.

Sensory evaluation is necessary to understand the specific sensory characteristics of cheese and its influence on eating behavior. This study aimed to create a flavor profile for five cheese samples that were composed of the same ingredients and maturated in temperature-controlled chambers either in silence or in different types of soundscape frequencies for 4 months. Furthermore, the study examined the impact of soundscape ripening conditions on the sensory profile of the cheese samples. The Generic Descriptive Analysis (GDA) sensory profiling method was conducted with trained study participants, (n =10). The experimental phase covered training the panel, creation of lexicon, 4 training, and 3 evaluation sessions. Intensities of sensory properties were evaluated using a line-scale (0 = not at all to 10 = very strong). The quantitative data was collected based on ISO 8589 standard guiding procedure in the sensory laboratory and processed with various statistical methods. Data for each sensory property was analyzed with the one-way ANOVA using IBM SPSS Statistics. Flavor profiles altogether were analyzed with Principal Component Analysis (PCA) using Unscrambler software. The results of this study showed that the sensory profile of the cheese samples was rich in a total of 17 properties that included 6 senses of smell, 5 senses of touch, and 6 senses of taste attributes. The strongest sensory properties were fattiness perceived both via fingers and mouthfeel. The application of soundscape during cheese maturation processes had no significant impact on individual sensory properties. Based on the one-way ANOVA there were no significant differences between the five cheese samples. However, the principal component analysis indicated that cheese samples formed clusters when entire sensory profiles were taken into account. The effect of soundscape during the maturation period of cheese requires further research.

The literature review was concerned with colourful vegetables and the most common pigments in vegetables: carotenoids, anthocyanins, betalaines and chlorophyll. In addition, how thermal treatments affect these pigments and the structure of vegetable was reviewed. The aim of the experimental work was to investigate the effect of thermal treatments on the colour, pigments and texture of carrots and beet-roots. Seven coloured carrot cultivars and four coloured beet-root cultivars were examined. Three different kinds of thermal treatments were applied to the samples: blanching, boiling and steaming. Orange and purple carrots contained the highest amounts of carotenoids. The total carotenoid content of the carrots increased due to the thermal treatments. Purple carrots were the only carrots which contained anthocyanins. Anthocyanin stability is pH dependent: boiling in slightly acidic water had a minor impact on anthocyanin content than boiling in pure water. Red beet was the most betalain-rich beet-root. Other cultivars contained remarkably less betalaines. Betalain content decreased due to the thermal treatments. Betalain degradation due to the thermal treatments was detected as the pigment content and colour changed. Thermal treatments softened the vegetable structure. Thermal treatment improves the extraction of the pigments from the vegetable structure, which was detected as the increase in pigment concentration, leading to an enhancement of bioavailability of pigments. However, long thermal treatments cause pigment degradation and reduce the nutritional value of the vegetables.

The end point chopping temperature influences different properties of the sausage batter and consequently the properties of the final product. If the end point chopping temperature of the sausage batter is either too high or too low the properties of the final product, especially texture, colour, sensory properties, and water-holding capacity (in this context cooking loss) will be affected. However, in the industrial scale, the end point chopping temperatures are hard to alter due to the continuous nature of the processes. The aim of the thesis was to study could marked differences be found from sausage batches that had been chopped to opposite extreme end point chopping temperatures that had been reported by the sausage factory staff. The study was carried out by using following three different meat choppers: standard bowl chopper, two different continuous choppers. Two separate, identically composed preblended meat masses were prepared in such way that their initial temperatures were approximately 0 and 10 °C. The preblended mass with lower initial temperature was made from non-frozen and frozen thawed meat assortments (50 % and 50 %), whereas the other mass was produced from non-frozen meat only. In turn, the chosen values for end point chopping temperatures were 13 and 23 °C. Texture properties, colour and cooking loss were determined from the cooked sausages and the differences were compared statistically.