Browsing by Subject "ekstruusio"

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  • Rytkönen, Laura (Helsingfors universitet, 2017)
    Liquorice is a confection which is manufactured by cooking. Main ingredients in the liquorice usually are extract from the root of the liquorice plant, sugar, wheat flour, molasses and water. The literature review focused on the raw materials and the manufacturing process of liquorice, starch and starch gelatinization as well as quinoa. The aim of this study was to find out whether liquorice confection can be produced by organic quinoa flour instead of wheat flour. Also the effects of processing parameters (water content of the feed, mass flow and screw speed) on the water content, water activity, hardness and diameter of the liquorice was investigated. Reference sample was made from organic whole-grain speltflour. In the experimental research, liquorices were manufactured on a laboratory scale with a twin-screw extruder according to Box-Behnken design, where the variables were water content of the mass (21, 23.5, 26%) mass flow (70, 100, 130 g/min) and screw speed (40, 55, 70 rpm). The results were analysed by using PLSR (Partial Least Square Regression). Organic quinoa liquorice succeeded at all water contents used. Instead the liquorice manufactured from whole-grain speltflour succeeded only at water content of 26%. Probably the spelt flour would have needed bigger water content and higher temperature for the gelatinization of starch. Water content of the mass was the only variable which was affecting statistically significantly to the moisture content and water activity of the organic quinoa liquorice. After storage for four months water content of the mass was affecting statistically significantly to the hardness and diameter of the organic quinoa liquorice. In the PLSR model for organic quinoa liquorice, the coefficient of determination R2 was 41.9% and the coefficient of prediction Q2 was 13.8%. After four months storage the coefficient of determination R2 was 36.1% and the coefficient of prediction Q2 was 15.7%. PLSR-analysis was not made for organic spelt liquorice because there were not enough samples from different experiment points. The present study showed that liquorice can be produced from organic quinoa flour with a twin-screw extruder.
  • Rauta, Janne (Helsingin yliopisto, 2019)
    Extrusion is a versatile thermomechanical food processing technology, and cereal based snack products made with extrusion are one of the most significant ready-to-eat products. The literature review covered extrusion process in general while the effect of different components of grain and milk powders in extrusion was examined more closely, and also different methods to evaluate the properties and the quality of extrusion products were examined. The objective of the experimental study was to study the effects of sugar content and composition as well as the effects of different milk protein and water contents of the mass on the properties (water content, expansion and hardness) and organoleptic quality of extrudates. Experiments were carried out by using twin-screw extruder and the main component of extrudates was a mixture of oat flour and waxy maize starch. Three different milk powders were used (one lactose-containing and two lactose-free skimmed milk powders) in experiments, so that the milk protein content of mass was 8, 10 and 12 % (from solids) and water content 14, 16 and 18 %. The effect of sugar composition (lactose vs. glucose/galactose mixture) and sugar content (lowering the milk sugar content to about 60 % from solids) in extrusion was also examined. The water content, hardness and expansion of extrudates were measured. In sensory analysis (n=6) the effect of different milk powders and water contents on extrudates were evaluated. More expanded and less hard extrudates were obtained by adding milk powder that contained lactose compared to lactose-free milk powders. Lowering the sugar content did not affect the properties of extrudates significantly. Increasing the milk protein content of the mass increased the typical positive features of extrudates when lactose-containing milk powder was used, but when lactose-free milk powders were used the effect was the opposite. Increasing the water content of the mass decreased the expansion and increased the hardness of extrudates. In sensory analysis the major differences were observed in the darkness of color and the diameter of the extrudates. According to the results of the present study it is possible to obtain extrudates with good structure using lactose-containing milk powder as well as lactose-free milk powder. However, lactose-containing milk powder may be a better alternative in extrusion compared to the lactose-free milk powder. It may be possible, to some extent, to lower the sugar content of the extrudates that contain lactose-free milk powders without compromising the structural and organoleptical quality of the extrudates.
  • Oksa, Vilma (Helsingin yliopisto, 2019)
    Abstract Licorice is traditionally made from sugar, molasses, water, wheat flour, and licorice extract. In the literature review, the focus was on the properties of quinoa, licorice extrusion, sensory and physical properties of licorice and the basis behind sensory evaluation and instrumental testing in product development. In the experimental part, gluten-free quinoa and rice licorice were made and their properties were studied with multiple sensory and instrumental measurements, and the self-made samples were also compared to commercial samples to see the possible differences between them. The hypothesis was that the changes in the recipes and process parameters would result in significant differences between the products. The sensory evaluations included a generic descriptive analysis with the first batch and two separate consumer tests with the two batches. The instrumental testing conducted of compression and extension tests with Instron and the determination of water activity. The data were analyzed with one- and three-way analyses of variance, as well as principal component analysis for the descriptive analysis. The manufacturing of the quinoa and rice licorice with the twin-screw extrusion was achieved. The generic descriptive analysis revealed that all the self-made samples were described similarly to each other, while the commercial gluten-free samples differed significantly from these. The quinoa licorice was seen sticky and not homogenous in appearance or texture, while the commercial samples were described as more homogenous and more intense in their taste. The consumer tests showed that both panels preferred the commercial samples over the self-made ones and that the quinoa licorice was preferred over the rice licorice. Commercial samples were seen as soft and chewy, while all the self-made samples from both tests were described as hard and grainy. The hypothesis was overruled since the quinoa licorice samples did not have significantly different properties despite the variation in the process parameters and ingredients. The study revealed that at least with these parameters there are no noticeable, significant differences in the sensory or physical properties of quinoa licorice. The commercial samples, however, remain significantly different from the self-made samples.