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Production of enzyme hydrolysates from flaxseed proteins and evaluation of their properties
HAŠKOVÁ, Kateřina
This thesis focuses on effect on antioxidant properties and chosen functional properties: solubility, water and fat holding capacity, emulsification activity and stability caused by hydrolysis of protein isolates (PI) made from three different flax varieties (Libra, Agriol and Raciol). Part of this work was production of PI from flax seed. For hydrolysis trypsin, alcalase and papain were used - hydrolysis by trypsin was the mildest, while hydrolysis by papain was the most intensive one. Dynamics and degree of hydrolysis were also observed. Solubility of PI and hydrolysates was discovered to be very high (almost 100%). On the contrary water holding capacity was lower (3,93 g/g and less) than fat holding capacity (4,34 g/g), which increased upon hydrolysis for most enzymes, while water holding capacity decreased. Emulsification activity rised (1,47×) under the effect of hydrolysis, however stability dropped (1,3×). The best emulsifiction properties were found out in trypsin hydrolysates. Hydrolysis caused great impact on content of polyphenols which were in alcalase hydrolysates up to 3× higher and on antioxidant activity which grew in papain hydrolysates up to 2,5×.
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Optimization of artificial spawning of pikeperch (Sander lucioperca) using HCG and new ways of removing artificial stickiness of eggs before incubation.
BLECHA, Miroslav
The object of the thesis is to experimentally find the most suitable method of artificial spawning of pikeprech, using hormonal stimulation of ovulation in females hormonal medication containing HCG. After scraping of the broodstock and after artificial fertilization of eggs obtained experimentally test new methods of artificial stickiness removing of eggs and then evaluate the success of artificial incubation of stripped, fertilized and unstickeness eggs of pikeprech. Experiments that are part of the thesis have been divided into several sub-experiments. In the first experiment was observed effect of different doses of hormonal Chorulon, containing the active substance HCG, the basic indicators of reproductive females. Was evaluated as spawning synchronization, spawning success, the number of spontaneous spawnings, fertility of females and hatching rate of eggs. The used HCG doses were 250, 500, 700 and 1000 IU per kilogram of body weight. All eggs were deprived of stickiness using a mixture of talc and milk. In the second experiment was carried out comparing different types of removes stickiness solutions. Here was evaluated especially time and labor intensity and the influence of various solutions on fertilization and hatching rate of eggs. In this trial was all pikeperch females injected the same amount of HCG hormone 500 IU per kilogram of body weight. Tested solutions was a mixture of talc and milk, just eggs wash water and the solution of various concentrations alkalase. The amount alkalase was 0,5; 1; 1,5; 2 and 5 ml, which are mixed with distilled water, so that the total volume of the solution was 1000 ml. The third experiment was supposed to simulate the pilot plant mass propagation of pikeperch females. All females received the same amount of hormone 500 IU of HCG per kilogram of body weight. All eggs were deprived of stickiness using a mixture of talc and milk. In the last experiment was one of the methods tested, which could limit the number of spontaneous spawning during the artificial spawning of pikeperch. To prevent spontaneous spawning were selected females (all were injected with 500 IU of HCG per kilogram of body weight) sewing genitourinary papilla. The incubation of eggs collected during all the experiments were used Zugské bottle.
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