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Sensory evaluation of sweets
Boboková, Alexandra ; Burdějová, Lenka (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with a sensory analysis of a selected type of non-chocolate sweets – gummy jellies with sour coating. The theoretical part describes raw materials needed for the production of non-chocolate sweets, a list of non-chocolate sweets and their technological production are also mentioned. Sensory analysis and sensory evaluation methods are briefly described. The experimental part is focused on sensory analysis of selected yellow-coloured/lemon flavoured samples from five different producers. The samples were evaluated using a scale based on their appearance, colour, flavour, aroma and texture. Furthermore, the sensory profile and evaluation of aftertaste using time intensity methods were applied. Common consumers were represented by 20 untrained assessors from the Faculty of Chemistry of BUT. Bright colour contributed positively, while hard texture negatively to the overall evaluation of samples.
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Sensory evaluation of drinks enriched with extracts of herbs
Scholzová, Kristýna ; Pořízka, Jaromír (referee) ; Vítová, Eva (advisor)
This diploma thesis deals with sensory evaluation of herbal non-alcoholic beverages, being a part of a new product development. The theoretical part provides information concerning chemical composition, health effects, food applications and aroma compounds of the herbs of interest (peppermint (Mentha piperita), sage (Salvia officinalis), St. John’s wort (Hypericum perforatum) and lemon balm (Melissa officinalis). Another topic is a description of sensory methods, requirements and arrangement of the analysis, statistical methods, and also technological processes leading to herbal syrups and beverages production. The practical part comprises sensory analysis of a few, newly designed, formulas of one-component and two-component alcohol free herbal beverages. The sensory panel consisted of 40 students of master's and also doctoral study programme at Faculty of chemistry, University of Technology Brno. Four subsequent experiments are introduced, each of them consisting of a few sensory tests and including corresponding sensory forms attached. The sensory tests arrangement was based on currently valid Czech Technical Standards, using a ranking, descriptive, paired comparison, sensory profile testing and scaling methods. For the purpose of statistical evaluation, Friedman, Kruskal-Wallis, PCA and Faktor analysis were used. Level of abilities and sensory experience of panelists were found comparable to consumer testing. The results include sensory characteristics of all of the beverages tested. In general, the one-component beverages were preferred to the two-component beverages and the additive colouring with aronia concentrate wasn´t found any benefitial, from the sensory point of view. The consumer questionnaire proved all of the samples to be very promising, but based on the sensory results, we would consider the mint and the sage-mint beverages being the most potentialy applicable samples.
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Influence of aroma compounds on sensory quality of sweets
Motúzová, Eliška ; Zemanová, Jana (referee) ; Vítová, Eva (advisor)
This master´s thesis is focused on determination of aroma active compounds in non-chocolate sweets and their influence on sensory quality/flavour. The theoretical part describes production of non-chocolate sweets, characterizes aroma active compounds including allergenic ones, method for their determination by solid-phase microextraction and gas chromatography with mass detection. For experimental part were used as model samples gummy candies purchrased in regular market. Four flavors were used, specifically yellow (lemon), green (apple), red (strawberry) and orange (orange). The HS-SPME-GC-MS method was used to identify volatile aroma active compounds. To evalutate the sensory quality were used scales, a profile test, and a time course evaluation. Owerall 120 volatille compounds were identified including 8 allergens.
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Sensory properties of yogurt depending on various fruit composition
BOHDALOVÁ, Tereza
Diploma thesis is divided into two parts: theoretical and practical. The literary review is related to classification and chemical composition of yogurts and technological procedures in yogurt production. There is also a chapter on methods and application of sensory analysis in food industry. The aim of thesis was to evaluate three samples of yogurts differing in composition of strawberry mixture using the sensory profile and preference test. Questionnaire survey on consumer habits was a part of the research. The evaluators were students of the Faculty of Agriculture at the University of South Bohemia in České Budějovice and schoolchildren of Elementary School in Velešín.
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Porovnání senzorických vlastností džemů slazených steviol-glykosidy a dalšími sladidly
KÜFFNEROVÁ, Nela
The aim of the diploma thesis was evaluation of sensoric attributes of blueberry and current jams sweetened by selected Steviol glycosides and their comparing with other sweeteners. For evaluation of sensoric attributes were used rebaudioside A, stevioside, aspartame, erythritol and sugar beet. Stevia rebaudiana var. Bertoni is a persistent plant, which contains sweetening Steviol glycosides, which have a use in food processing. They are available in the area of EU indicated as E960 since 2011. The most used Steviol glycosides are stevioside and rebaudioside A, which are demarcated with a high sweetness, which could be 200-400 times higher than saccharose. The usage of sweeteners is legislatively allowed, which means it is also allowed to do sensoric analyse and detect perception of added substances in food. These analyses evaluate food with the help of sense - perception. Methodical part of the work contains procedure, used methods for gaining evaluation of data from a sensoric analyse after the degustation of jams, which has taken place with the presence of ten judges - an academic students in the working compartment of University of South Bohemia. Respondents entered their evaluation into protocols, which were prepared in advance. The results of diploma thesis are evaluated by the method of Kramer, which is used for this kind of analyse. The critical scale between 20 and 40 with the value of probability P = 95% was defined according to this method. Evaluation is described with the help of graphs and tables, added with a wordily describtion. Conclusion of analyse of diploma thesis is, that the usage of Steviol glycosides is not most suitable way of sweetening jams. Acceptable valuations of jams containing Steviol glycosides were proven in parameters of colour and aroma. The reasons for less successful evaluation of Steviol glycosides could be due to bad pH of food or badly chosen dosing, without combination of other kinds of sweeteners. The best sensory characteristics traditionally showed sugar beet and aspartame followed by rebaudioside A and stevioside, which were placed on the third and forth place from five used sweeteners. The part of the diploma thesis was an evaluation of questionnaire, where the result was, that asked people preferred fruit ingredient of jams (type of fruit, amount) not their way of sweetening while choosing a jam.
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Vliv přírodních extraktů na senzorické vlastnosti a prodloužení skladovatelnosti masa pstruha duhového (Oncorhynchus mykiss)
TUNYS, Ondřej
This bachelor thesis evaluates the effects of natural rosemary extract "Inolens 4" on microbiological quality, sensory attributes, colour change and oxidative effect of rainbow trout (Oncorhynchus mykiss). The evaluation is expressed in comparison with the control sample (no additive). Individual analyses took place in different days (0, 3, 6, 10 and 14 days). The microbiological analysis showed values in the range of 1.93 - 2.25; 5.10 - 5.27; 5.12 - 5.80 and 6.34 - 7.66 log CFU*g-1 on days 0, 6, 8 and 10. The limit for freshwater fish consumption (7 log CFU*g-1) was exceeded on 10th day of storage. On the contrary Inolens 0.5 achieved the best result. Sensory analyses also showed that Inolens 0.5 achieved the best results in all sensory attributes (odour, taste, aftertaste, consistency) of cooked fish. Also TBARS analysis evaluating lipid oxidation proved that the application of Inolens 4 extract had a positive effect causing an inhibition of oxidative processes in the muscle. Therefore all the results of this study have shown that the natural extract "Inolens 4" has antioxidant effects extending the storage of rainbow trout meat in combination with suitable storage (vacuum and cooling at 4 +- 1 °C) for up to 10 days. Moreover it has a mild effect on the improvement of sensory properties.
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Technologické parametry a konzervárenské zpracování plodové zeleniny
Pechová, Lenka
The thesis is focused on technological parameters and canning of fruit vegetables. The literary section describes the different kinds of vegetables grown, its material composition, crop changes, storage and conservation options. The practical part of the laboratory and sensory evaluated gherkins variety ZUZANA F1, ORFEUS F1, REGINA F1, KAREN F1, PARTNER F1 and KARLOS F1. Laboratory quality parameters were evaluated different varieties and sizes, weight, color, firmness, soluble solids content, malic acid concentration and all titratable acids. Preservation was chosen sterilization in sweet and sour marinade. The results were statistically evaluated tabular and graphical.
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Technologické parametry a konzervárenské zpracování hrušek asijských odrůd
Jarolík, Ivan
Theoretical part of thesis contains information about importance of sensory analysis for quality evaluation of food. Further described are tools of sensory perception, which are used for sensory analysis. Experimental part consists of laboratory analysis of six varieties of pears in fresh form (Asian varieties Man san gill, Kumt ghant chu, Shinseiki, Chojuro and Pung su, and European variety Conference). These pears were then processed into juice, compote and puree. These products were evaluated in sensory analysis. It was found that the drought of summer 2015 had significant effect on size and weight of pears. Results of sensory analysis tell us that variety Man san gill is most suitable for production of the juice, Shinseiki for production of the compote and Conference for production of the puree. Asian pears are not suitable for the puree production.
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Vliv zkrmování výlisků z technického konopí na senzorickou kvalitu masa brojlerových kuřat
Fernandová, Dominika
This thesis deals with the influence of hempseed cakes in feed mixtures on the sensory meat quality of broiler chickens. During the experiment broiler chickens were fed with feed mixtures containing 5 % and 15 % of hempseed cakes and compared with the control group deprived of hempseed cakes. The total carcass yield, carcass yield of breast and thigh muscle, the amount of dry matter, crude protein and fat were determined. The pH and color of meat were measured and at the end of this experiment sensory evaluation of breast and thigh muscle was performed. For most sensory descriptors statistically significant differences were not demonstrated. Sensory evaluation of breast muscle determined a statistically significant difference (P < 0,05) with descriptors of odour and fibrousness. Sensory evaluation of thigh muscle showed a statistically significant difference (P < 0,05) with descriptors of odour, color, fibrousness and flavour.
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Vliv výlisků ostropestřece mariánského v krmné směsi brojlerových kuřat na sensorickou jakost masa
Sedláčková, Kateřina
The aim of this diploma was evaluate the effect of feeding milk thistle (Silybum marianum L.) seed cakes on sensoric quality of broiler chickens meat. The experimental groups of broiler ROSS 308 received feed mixtures containing 0 % (C - control), 5 % (MT5) and 15 % (MT15) of milk thistle seed cakes. The chickens were fattened on conventional deep litter system. The trial lasted 37 days. Sensory analysis of breast and thigh muscle samples was evaluated in special sensory laboratory (Department of Food Technology, Mendel university in Brno) according ISO 8589. Breast meat was significantly (P < 0,05) rated as the best in parameter flavour in C (control) and MT15 group. The thigh meat was evaluated significantly (P < 0,05) best for colour and fibreness parameters in MT15 group. The addition of milk thistle seed cakes do not worsened sensory characteristic of breast or thigh meat of broilers and reflects standard sensory quality traits.
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