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Use of meal from Jerusalem artichoke tubers in production of products from minced meat
MUŽÍKOVÁ, Monika
Jerusalem artichoke is a root vegetable containing glucofructan inulin in its tubers that is valued for its positive effect on the human organism. The aim of thesis was to evaluate use of meal made from Jerusalem artichoke tubers in production of products from minced meat. The experiment was divided into two parts. In the first part, the differences in water-holding capacity of semi-rough wheat flour and Jerusalem artichoke powder (JAP) in various types of solvents were determined. The statistically significant difference in water-holding capacity between the flours was found solely in the saline solution. Furthermore, the results showed that type of solvent had the main effect on water-holding capacity. In the second part of the experiment, 4 types of meat products were made - sausages, meatloaf, liver pate and meat hash. Wheat flour, which is commonly added to these products, has been completely replaced by (JAP). Subsequently, the sensory analysis was evaluated by experts (n = 16) for an estimation sensory quality and sensory changes of new product with JAP compared to standard meat products. The results of the study showed that the addition JAP to sausages had a negative effect on its sensory quality, namely its overall appearance of the product, texture and taste. On the contrary, there were improved functional properties in meatloaf (juiciness) and pate (taste). According to the results of the sequence test, the liver pate was found the most delicious product.
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Technologie pěstování Stévie sladké (Stevia rebaudiana) ve vztahu ke kvalitě produktu a jeho využití v potravinářství, medicíně a kosmetice.
KÁBELOVÁ, Lenka
The theoretical part of the diploma thesis deals with cultivation of the plant Stevia rebaudiana. This plant is 300x sweeter than sucrose. It is often used as a compensation for sugar sweetener, suitable for diabetics and people who suffer from overweight. There is processed the characteristics of the plant, botanical description, conditions of cultivation and chemical composition. There are described the methods of determination of steviol glycosides. The practical part elaborates on a sensorical analysis. This analysis has two parts. The first part is the evaluation of stevia concentrates with the flavour of aronia, sour cherry and beetroot and stevia powder in 10 milk products bought in supermarkets. The second part deals with the evaluation of black tea sweetened with few different easily available sorts of sweetening products. The currently valid legislative in the area of the Czech Republic allows the food industry to use steviol glycosides of high purity under the name E960. The use of the plant stevia or its parts as food isn't enabled.
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Effect of used sweeteners on sensory properties of fruit drinks
PRAYER, Radek
The object of the study was a sensory evaluation of used sweetners in beverages from selected fruits. Within the sensory analysis apple juice and also pear, apricot, cherry and blackcurrant nectar were used. These drinks were subsequently diluted at two concentrations with drinking water: 1) in a ratio of 50 % of the original beverage and 50 % of drinking water; 2) in a ratio of 25 % of the original beverage and 75% of drinking water. Each of the concentrations were then divided into groups which were sweetened with white sugar, cane sugar, aspartame, sucralose or rebaudioside A. The performed sensory analyses show that rebaudioside A would have great potential to replace the commonly used white sugar in apple juice. Sucralose would have this potential in pear and cherry drinks. However, the use of other sweeteners in other types of beverages is also not excluded, because to prove a preference for white sugar failed in most cases.
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Effect of different descaling/skin removing methods on sensory properties and shelf life of common carp
VÁGNER, Martin
The present bachelor thesis studied microbiological quality, sensory attributes and customer preferences of common carp filet (Cyprinus carpio) descaled by different methods under two storage conditions. Fillets were processed by four descaling methods, namely: without skin, without scales, undercut scales and fillets of mirror carp (with skin). Moreover two types of storage conditions, air packed and vacuum packaged, were tested at 3.8 +- 0.5 ° C. Microbiological analyses were determined by total viable counts in logarithm of colony-forming units per gram (log CFU.g) on storage days 0, 3, 6 and 9. Furthermore, sensory analyses of fillets was classified and customer preferences were evaluated by using an anonymous questionnaire. In microbiological analyses, an increase of the total number of microorganisms with increasing storage time was observed. Microbial communities grew to between 2.3 - 2.69 log CFU.g-1 on the first day of fish processing (day 0) and 6.35 - 8.28 log CFU.g-1 on the last day of storage (day 9). Microbiological analysis showed that skinless fillets reached the lowest total number of microorganisms, regardless the type of packaging (air / vacuum packaged). Also sensory analyses showed that consistency and odour of carp fillets were influenced by packaging conditions as well as descaling methods. The best results in sensory evaluation achieved fillets without skin and undercut scales. The survey on consumer preferences of carp found out that 58.9 % of customers preferred scaly carp with undercut scales and processed to fillets. The results of present study show that different types of descaling methods combined with air / vacuum packaging can significantly prolong the shelf life of carp fillets.
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Quality of smoked products of economically important fish species
KORYŤÁK, Lukáš
The objective of this thesis was to test the environmental friendly additive substance, in particular sodium caseinate, which is not subject to designation "E" on the label of the product, which is unpopular among the consumers, and which would provide so-called a "higher value" to a product of economically important fish species in the Czech Republic, specifically the common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix) and the rainbow trout (Oncorhynchus mykiss).Determination of the influence of this additive on microbial and biochemical processes, and also on organoleptic properties of the selected smoked fish was another goal of the work. Three concentrations of this product were used for application in total, in particular 25, 50 and 100 g×kg-1. The results of this work confirmed that, due to caseinate (concentration of 100 g×kg-1) such losses of water were avoided, as observed in case of the control group, to which no additive product was applied, and which served for comparison with the groups treated with caseinate. General carp had an average loss of 12.9 % for the samples treated with sodium caseinate and 14 % for the control group. The silver carp white showed similar results. The group treated with caseinate lost 12.4 % in average, and the control group of approximately 14 %. The best results were recorded with the rainbow trout, which, due to caseinate withheld the largest amount of water, respectively, it did not lose so much of weight, in particular 15.9 % for sodium caseinate compared to 19.3 % measured in the control group, however these differences were not confirmed as statistically conclusive. As for the texture of the meat, tougher samples came out for the ones treated with sodium caseinate compared to the more brittle control group. In carp and trout no statistically noteworthy dissimilarity in stiffness of meat was proved between the control group and the group with the applied additive product. While these differences were significant in silver carp. While for silver carp were these differences significant. The control group showed clearly (p<0.05) lower stiffness compared to the group, to which the additive product was applied. Microbiological analysis was performed on the 7th day after smoking, and the values were in the range of 2×10 to 1.9×10^2 CFU×g-1. In the experiment, groups of test fish species did not show any statistically significant difference (p>0.05). Tests for the possible presence of Listeria monocytogenes in all of the smoked fish samples and the control group were negative. Nutrient composition was mainly focused on the basic nutrient components, which were the proteins, fats and carbohydrates. The control group did not show any significant differences compared to the group to which sodium caseinate was applied. The results from the consumers and sensory analysis by a panel of trained persons were very similar. No statistically significant differences between the group treated with caseinate sodium, and the untreated so called control group of smoked species of fish.
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Characterization of goat milk
Pospíchalová, Alžběta ; Burdějová, Lenka (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the sensory evaluation of goat milk. The differences in the sensory properties of goat and cow milk samples were followed. In the theoretical part goat milk is characterized, its composition, physical and chemical properties as well as its sensory properties are described. After that the methods of sensory evaluation are described. In the experimental part three samples were subjected to sensory evaluation, two samples of goat milk and one sample of cow milk, by the untrained assessors, which means common consumers. The observed properties, evaluated using a seven-point scale, were appearance, colour, texture, odour, flavour, off-flavour and the overall acceptability of samples. The results were graphically and statistically processed. The sample of cow milk was evaluated as the best; the acceptability of goat milk was negatively influenced by bitterish taste with the goat off-flavour.
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Sensory quality of selected types of sweets
Michalíková, Veronika ; Němcová, Andrea (referee) ; Vítová, Eva (advisor)
This diploma thesis deals with the sensory evaluation of selected types of non-chocolate sweets. In the theoretical part the production technology of non-chocolate sweets is described, including raw materials needed. Furthermore, basics of sensory analysis with characteristics of sensory evaluation and selected sensory methods are mentioned. The experimental part deals with the sensory evaluation itself; the selected sensory methods were applied on samples of gummy sweets. Four colours/flavours (strawberry, orange, lemon, apple) from five producers were chosen for evaluation, together 20 samples. The aim was to assess the differences in sensory quality of samples of the same type from different producers. Untrained assessors, from Faculty of Chemistry BUT, were invited for sensory evaluations. Significant differences were found among the samples, glossy appearance and pleasant characteristic taste contributed to the positive evaluation, on the contrary the rigid texture, bland taste and odour and possible off-flavour contributed to the negative evaluation.
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Influence of humic substances on the broiler chicken´s meat
Novák, Tomáš ; Bušová, Milena (advisor) ; Daniel, Daniel (referee)
Due to great popularity of the chicken meat, the breeders try to improve yield of meat and its quality parameters, which leads to the application of various food additives such as those based on humic compounds. Those humic matters are used for their positive influence over the immunity system, metabolic functions and adaptability of the livestock organisms.
Literature review sums up the experience with broiler chicken breeding and feeding. Further it deals with meat composition and its characteristics. The last part contains information of humic compounds and their influence over the live organism and compares the findings about the application of humic preparation into the livestock food portion.
Practical part of this thesis researches the influence of humic preparation Humafit over the qualitative and quantitative parameters of the broiler chicken meat. Two groups of chicken were observed, experimental one and control one. Feeding of these two groups was held at the same time, whereas the experimental group was being fed with 200 ml of Humafit per 1000 l of supply water from 10th to 20th day of feeding. The research did not prove statistically important differences (p > 0.05) in chicken corpse weight such as in weight of each parts of the corpses.
Differences in the protein content in the breast muscle were also not statisticaly demonstrative such as pH value of the breast and thigh muscle. Total amount of heme pigments in breast muscle of the experimental group was higher and this difference was statistically important (p = 0.049). The breast muscle of chicken in the control group showed up higher binding capacity for water, this difference was statistically important (p = 0.041). This finding correlates with sensory analysis results (|r| = 0.691), when the panelists rated the meat of the control group chicken as more flavorous.
There is disunion among scientific studies in the opinion of humic compounds influence over the livestock organism. It is not possible to make a definite evaluation of humic compounds influence over the meat quality, because qualitative and quantitative parameters of the livestock meat depend on the number of intravital and external factors which can affect the experiment results.
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Organoleptic characteristics of the venison and venison products
Henrychová, Marie ; Kouřimská, Lenka (advisor) ; Daniel, Daniel (referee)
This thesis is focused on the organoleptic properties of game and farm animals meat. Some attention is dedicated to the game meat products too. Hypotesis Organoleptic properties of game meat are statistically different from meat of farm animals was evaluated. Comparison of the scientific publications concering this topic was made. Organoleptic properties are dependent on physical and chemical attributes, thus some of these important attributes are discussed in this thesis.
Results of this thesis show, that there are significant differences between organoleptic properties of game and farm animals meat and the hypotesis is valid. Within chemical and physical properties of compared kinds of meat there are significant difference especially in fat content and fatty acids profile. Game species presented in this thesis have lower fat content and also more favourable fatty acids profile and especially content of unsaturated fatty acid is higher. Significant differences were also in nitrogen compounds content, amino acids composition and haem pigments content. Higher moisture content was often presented in game meat. Differences in protein content were not significant, but several differences were found in the protein composition. During sensory evaluation significant differences were found in intensity and pleasantness of flavour, tenderness and juiciness of meat. Further differences were also found in color.
Specific properties of game meat are transfered also to the game meat products. But in products differences are soften by the use of other components, such as other kinds of meat or food additives.
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Influence frozen dough on the quality and on the durability of bakery products
Hliněnská, Veronika ; Faměra, Oldřich (advisor) ; Jaroslava, Jaroslava (referee)
Bakery products are one of the most important parts ot the people diet. For the simplification of the bakery production and the most effective sale was started manufacturing process involving freezing.
The aim of this bachelor s work was writting a literature review about freezing technology in bakery production. There was described a technology of controlled proofing that can interrupt a production for several hours. Another way of baking is freezing of fully baked dough pieces. In this work there was described storaging, thawing and proofing. There are two etaps of baking. The first one is pre-baking and the second is fully-baking. Very important part of freezing is refrigeration equipment.
In the second part there was described influence of freezing dough on the quality and on the durability of bakery products. In several thesis there was find out that semi-frozen pastry are growing-old more quickly than fresh pastry. This is caused by negative impact on yeast and dough structure. Quality is assessed rheologically and sensory by experts.
Assortment of frozen bakery products in stores is different. There are more fresh bakery products from nearby bakeries in small stores. There are local bakeries for baking a fresh pastry in large supermarkets. There are also a lot of semi-frozen pastry in large supermarkets. There are more semi-frozen pastry than the fresh pastry in some of these supermarkets.
For more comfortable orientation in pastries selection there are legislative laws which correct labeling of fresh and frozen bakery products.
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