|
|
Technologický postup výroby pařených sýrů
Skýpalová, Veronika
This bachelor thesis deals with pasta filata cheese. In the introduction, it is briefly outlined the history of cheese including the group of pasta filata cheese since ancient times. Then there is also described milk and its characteristic component which is important for the production of cheese. The fundamental part of the thesis is the description of the production of cheese itself and used technological procedures, both in general and with focusing on pasta filata cheese. As a part of the thesis there are also requirements for raw materials, without which it could not be possible to produce high-quality cheese. In the conclusion, it is described the assortment of pasta filata cheese available both in the Czech Republic and in other European countries.
|
|
|
Senzorická analýza holandských sýrů skladovaných pod různými nátěry
Přesličková, Barbora
This thesis deals with sensory analysis of Dutch cheeses stored under different coatings. The aim of this study was to investigate changes in the chemical and sensory characteristics of Dutch-type cheese wrapped in two types of ripening rinds (polymer coating - Plasticoat and curd wax) during the extended period of maturation. The results of chemical and sensory analysis show that the use of different types of ripening packaging affects the selected indicators of Dutch-type cheeses. The selected chemical indicators evaluated the biggest changes in dry matter content. The largest increase in dry matter content, which increased with aging period, was recorded in cheeses, packaged in to polymer coating. From the sensory properties of the biggest changes were observed in hardness, and were evaluated as the hardest cheeses wrapped in ripening, made of polymeric materials. When evaluating hardness with cheese packed into the curd wax was found rather the opposite trend. Significant changes were also observed in the intensity of bitter taste. During ripening, the intensity of bitter taste increased and thus, more radical changes occurred in cheeses treated with curd wax.
|
|
|
Změny látkových složek během zrání hroznů révy vinné
Prát, Oto
In the presented work are the results of evaluation of four cultivars of grape in the period from veraison phase of the over ripening. Sampling of berries were in the three times over that period and were marked as unripen, ripe and over ripe berries. In this work a content of compound are divided as volatiles and non volatiles. As an evaluation criterion of non volatiles are soluble solid, titratable acid and impact firmness during the whole ripening. From formulated ripening index as soluble solids multiplied by impact firmness and divided by titratable acid were obtained values from 11 to 18 and the cultivars was in order -- Frankovka, Tramín červený, Chardonnay and Müller Thurgau. Volatiles in berries were analysed by gas chromatograph with mass spectroscopy. From the all compounds were quantified terpene lactons, a hexanols, hexanals a their esters. The concentrations values of terpene are in the level about nanograms per kilogram.
|
|
|
Podnícení zralosti jablek účinkem exogenního etylenu
Valachová, Zuzana
The theoretical part was described by Golden Delicious variety. This part of the thesis describes the material composition of apple, ripe apples qualitative disaggregation into individual groups. Attention was paid to the effect of ethylene on ripening apples and development.It has also described the climacteric types of fruit and the process of their maturation. In the first experimental part, I followed the harvest maturity fruit varieties Golden Delicious. In the second part of the experiment I followed the criteria specified I during storage in the two different temperatures and at 2 ° C and 20 ° C for treatment with exogenous ethylene. During storage were observed in terms of maturity, which was based on objective measurement. Measurements included pulp strength, the starch content, total acidity and soluble solids, as well as the production of ethylene and carbon dioxide.
|
|
|
Látkové složení odrůd broskví v období dozrávání
Nekužová, Nikola
They were evaluated for the degree of maturity of three varieties of peaches. They were select varieties of peach Royal glory, Redhaven, and Flamingo. Fruits were collected at three intervals and in an immature stage, perfectly ripe and overripe in the period from 10.7. to 1.9. 2014 in orchard Horticultural faculty, in Lednice. Ripening peaches on the tree took place spontaneously. At the plant material was determined by the weight, the proportion of the wallop and pulp, firmness fruit, content titratable acidic, soluble solids content and sensory evaluation was carried out. Subsequently, was performed correlation analysis of measured parameters.
|
|
|
Hodnocení zralosti odrůd meruněk podle fyzikálně chemických ukazatelů
Kochová, Eliška
This bachelor thesis on the topic of "Evaluation of maturity of apricot varieties based on physicochemical parameters" describes the theoretical part of history and characteristics of apricots, as well as the ripening and storage and the changes during ripening and storage. The thesis deals with the changes in the material composition during ripening and storage for 7 days at 18 ° C in two stages of ripeness (ripe and overripe). In the practical part three varieties of apricots were monitored. The observed changes regarded fetal body weights, weight stones fruits, soluble solids content, titratable acids content and the fruit's peel strength. The following varieties of apricots were observed: 'Adriana', 'Betinka' and 'Marlen'. The source of the fruits of the varieties was the school orchard at the Faculty of Horticulture in Lednice. The determination of soluble solids content was performed by using the PALETTE digital refractometer ATAGO. For the determination of titratable acids the visual indication of equivalence point to phenolphthalein was used. The measured values were presented in the form of spreadsheets and graphs and evaluated. The achieved results apply to a given piece of land and year. It was confirmed that there is a decrease of fetal weight, the content of titratable acids and firmness of the fruits' peel during the ripening and storage. The increase of the degree of ripeness of soluble solids content during storage was confirmed as well.
|
|
|
Study of fruit ripening and storage
Langová, Jiřina ; Zemanová, Jana (referee) ; Babák, Libor (advisor)
There are many changes in fruit quality during its ripening and storage. The following four apple varieties were studied: Champion, Glostr, Golden Delicious and Idaret. Amount of reducing sugars, total amount of sugars, quantities of acids, refractive solids and loss of starch were monitored. The changes of parameters, the differences between the varieties and differences in storage were compared. Parameters were monitored from mid-August 2008, when the apples ripened. After the harvest, apples were stored in a cool box at 2 - 3 ° C and at room temperature 20 - 23 ° C. Apples stored in the cool box were analyzed till the end of March 2009, and apples stored at room temperature until the beginning of January 2009. Total quantity of sugars in all varieties increases before harvest, while it decreases after picking the apples. The quantity of reducing sugars in apples rises gradually and after their picking it falls significantly in apples stored at 20 - 23 ° C. In apples stored in the cool box it continues rising until the end of November, and then it also decreases. Losses of starch are considerable and they are accelerated after the harvest. The quantity of acids also decreases throughout and amounts of refractive solids increases. For all varieties there are significant changes in storage at 20 - 23 ° C. Temperature, therefore, significantly affects processing of sugars and acids in fruit respiration.
|
|
|
Úloha osmotických a iontových činidel ve fyziologii rybích spermií
BONDARENKO, Olga
The present study focused on clarification of the roles of environmental osmolality and ion composition in the initiation of spermatozoa motility in different freshwater fish species. Additionally, the role of osmotic and ionic agents in sturgeon spermatozoa maturation was investigated. A first aim of the present study focused on studies of osmotic regulation of spermatozoa volume alterations in different fish species. This led to the discovery that spermatozoa swelling are species-specific: fish sperm with ionic mode of motility activation (sturgeon, trout) has no capacity for swelling, In contrast to carp sperm (osmotic mode of activation) for which volume correlates with environmental osmolality. A second aim was to apply the capacity for swelling in carp spermatozoa to improve the cryopreservation procedure relative to post-thaw sperm quality. Post-thaw motility parameters and ability to fertilize eggs were measured and compared with non-treated sperm. As a result, higher post-thaw motility rate, spermatozoa velocity, and fertilization rate were observed in sperm pretreated with hypotonic solutions compared to non-treated sperm. Thus, our results demonstrate for the first time, that spermatozoa ability for hypotonic changes could be used for improvement of cryopreservation procedure. A third aim of this study was the investigation of the role of environmental osmolality and ion composition in fish sperm motility. Sturgeons and salmonids sperm was activated in media of differing ionic and osmotic composition. Even though environmental Ca2+ concentration is not crucial in conditions of Na+ presence, a minimal intracellular free Ca2+ concentration should be present in sturgeon spermatozoa for initiation of motility. Alteration of osmolality does not seem to play a major regulatory role in trout spermatozoa activation. Alteration of sperm sensitivity to Ca2+ was detected during spawning, according to seasonality. Low motility rate was detected in brook trout spermatozoa at the end of the spawning period. However, a Ca2+ concentration increase up to 10 mM in activating media led to activate motility in at least 85% of the spermatozoa, which suggests a decrease of sperm sensitivity to Ca2+ at the end of the spawning season. The fourth aim was the study of the role of osmotic and ionic agents in sterlet spermatozoa maturation. Our results demonstrate that sturgeon testicular spermatozoa lack capability for motility activation and fertilization. During spawning, sperm is released from testis, pass through the kidney where it is mixed with urine, into the Wolffian duct. We demonstrated for the first time, that testicular sperm incubation with urine controls in vivo maturation, but can be performed in vitro as well (Chapter 6). We detected that sperm maturation does not occur under conditions of Ca2+ deficiency, suggesting that Ca2+ plays an essential role in this process (Chapter 7). During this maturation process, we observed a gradual decrease of spermatozoa sensitivity to environmental Ca2+. We found that testicular spermatozoa motility could be activated only when the Ca2+ concentration is high. Thus, we hypothesize that maturation process might be controlled by Ca2+ influx into the cell with subsequent loading of some Ca2+ stores. To our knowledge, these results provide, for the first time, evidence for the presence of Ca2+ stores in sturgeon spermatozoa. As a conclusion, the results of this study shed light on osmotic and ionic regulation of sperm motility in different fish species. The involvement of specific ions together with osmotic shock in fish spermatozoa maturation and aging were clarified. These findings broaden the possibilities of in vitro sperm manipulation in fisheries practice such as the use of sturgeon testicular spermatozoa, improvement of poor quality sperm in salmonids at the end of spawning season, and increase of carp sperm cryoresistance.
|
|
|
Porovnání analytických a senzorických vlastností vín zrajících v různých skladovacích nádobách
Prátová, Zuzana
The aim of this thesis was to compare the analytical and sensory attributes of wines aged in different storage containers for a certain period of aging . The theoretical section describes wine storage containers from history to the present, their advantages and disadvantages. There are more details of barrique barrels , their processing and burning . The following section discusses the selection of appropriate containers for alcoholic fermentation. There is an important process of biological degradation of acid before red wine maturing, which is described in the next chapter. A large part of the chapter is devoted to wine aging . There are some effects in terms of oxygen, depending on maturation, pH for red wine colours, pH of the acid. An important chapter is the aging of wines in barrique barrels , followed by a change of phenolic compounds, dependence of oak and volatile compounds on physico -chemical characteristics of wines. In subsequent chapters there is explained the concept of wine aging , there are cataracts, diseases and defects of wines that may occur during aging . In the experimental part I used two red wines and one white wine . Wines were divided into inert containers and various barrels of different manufacturers and volumes. Red wines were produced in the same technology manner and the aging conditions (temperature , humidity) were the same as well. The aim was to evaluate the analytical and sensory values of wines for the time of one year . The attempt for white wine was aimed for the time of three months. The main intention was to monitor changes in the content of phenolic compounds : polyphenols, anthocyanins , polyphenols amount of gallic acid, hydroxycinnamic acids and flavonoids. Differences for each wine were observed depending on the container size and the ripening time. The senzory evaluation was an important parameter. Wines matured in barrels showed aromatic complexity and tannin structure with finesse .
|
|
|
Changes in acidity during round-eyed cheese ripening
RANDLOVÁ, Monika
This thesis focused on the factors influencing the ripening of cheese , especially the first phase. The literature review was prepared during maturation of cheese , which is a comprehensive summary of the changes caused syřidlovými enzymes and enzymatic activity of cultures in which the cheese gets the typical appearance, texture, flavor and composition
|
guest ::
