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Addition of probiotics to baby food products
Dudrová, Markéta ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
This Diploma thesis deals with preparation of probiotic cultures Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium breve enriched with prebiotics meant for application in baby food products. Natural extracts from matcha, moringa, young beat, young barley, chlorella and spirulina were selected as prebiotics. The theoretical part is focused on probiotic bacteria, their biological effects and their effects on the child´s body. The experimental part deals with the cultivation of probiotic bacteria with plant extracts, monitoring their viability and stabilization in an encapsulated form. Mixtures of probiotic cells with prebiotics were encapsulated into alginate particles to increase stability. Some of the alginate particles were processed by freeze drying. Mixtures of probiotic cultures with plant extracts were subjected to model human digestion by the action of model digestive juices in unencapsulated, encapsulated and lyophilized form. Selected extracts of plant materials were characterized in terms of amount of total and reducing sugars, total phenolic substances, individual phenolic substances and antioxidant activity. Further, two baby commercial dietary supplements containing probiotics were selected, which were characterized in terms of cell number and viability. Probiotic products were also subjected to model digestion.
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Viability of probiotic bacteria in some foods
Pokorná, Martina ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on viability od probiotic bacteria in some foods and looking for optimal food and beverages, that exhibited a minimal negative effect on the growth and viability of probiotic bacteria. Lactobacillus acidophilus, Bifidobacterium breve and commercially complex of probiotics were tested. In the practical part, probiotics were incubated in the environment of selected types of model and real foods. Further, incubation in model gastrointestinal juices to simulate human digestion was performed. Model foods with a moderate value of concentrations of sugar, protein and alcohol were shown the best alternative for growth of bacteria and their lowest mortality. For salt, the smallest concentration was shown as the most suitable. The chicken broth, chicken and beef meat were evaluated as the best environment for the capsule with complex probiotics. The vegetables and vegetable broth were stated like the best for Lactobacillus acidophilus and Bifidobacterium breve. According to the preliminary results we can conclude that the probiotics should be preferably consumed during meals and with the sufficient amount of liquids for the activation of all cells.
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Encapsulation of lactic acid bacteria
Vrtná, Monika ; Lichnová, Andrea (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on encapsulation of two strains of probiotic bacteria. Lactic acid bacteria were encapsulated into several types of materials, mostly polysaccharides. The theoretical part describes the techniques of encapsulation applicable in the food industry. During the experimental part alginate and chitosan microparticles were prepared. These particles exhibited different sizes and some of them were modified by starch and carboxymethyl cellulose. Particles were used for encapsulation of two strains - Bifidobacterium breve and Lactobacillus acidophilus. Using flow cytometry cell viability was measured after 24-hours cultivation of bacteria. Particles were observed immediately after encapsulation by optical microscopy and then long-term stability in model foods was evaluated after two days, a week and after four weeks of incubation. Using the Bürker chamber the alived and death bacteria were counted inside and outside the capsule. The stability and viability of the cells were studied also in the artificial intestinal, stomach and bile juices. As the best material for encapsulation of lactic acid bacteria 2% alginate modified by carboxymethyl cellulose was found. The highest viability of bacteria was observed in milk as the real model food. Prepared particles are suitable for use in the food industry.
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Optimalizace procesu triploidizace u candáta obecného (Sander lucioperca)
TRNKA, Kamil
This thesis was aimed on optimization of induction of triploidization of pikeperch (Sander lucioperca) using cold, hot and pressure shocks. To induce the triploid status of the larvae using cold shock fertilized eggs of pikeperch were dropped into the cold bath of temperature 0,5-1°C in 2, 4, 8, 12 and 16 minutes post fertilization with shock duration of 20, 40, 60, 90 and 120 minutes. Hot shock was induced by 30°C bath 2, 4, 8, 12 and 16 minutes post fertilization with duration of shock 5, 10, 20, 30 and 40 minutes. Pressure shock was also tested for induction of triploidization using pressure of 70 MPa 5, 10 and 20 minutes post fertilization with duration of shock 5 minutes. Ploidy level was then determineted using flow cytometry. As a result hatchability (%), share of malformed larvae (%), share of triploid individuals (%) and yield of triploids (%) were determined. None of the experiemental shocks have led to a 100% share of triploids concerning the samples examined by flow cytometry. Best result was reached via pressure shock with duration of 20minutes which resulted with share of triploid individuals of 95% and yield of triploids 12.2+-2.5%. It must be noticed that increasing duration of pressure shock resulted in decreased hatchability and increased share of malformed larvae. Second best result was achieved via cold shock. Worst results were obtained via hot shock.
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Addition of probiotics to baby food products
Dudrová, Markéta ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
This Diploma thesis deals with preparation of probiotic cultures Lactobacillus acidophilus, Lactobacillus casei and Bifidobacterium breve enriched with prebiotics meant for application in baby food products. Natural extracts from matcha, moringa, young beat, young barley, chlorella and spirulina were selected as prebiotics. The theoretical part is focused on probiotic bacteria, their biological effects and their effects on the child´s body. The experimental part deals with the cultivation of probiotic bacteria with plant extracts, monitoring their viability and stabilization in an encapsulated form. Mixtures of probiotic cells with prebiotics were encapsulated into alginate particles to increase stability. Some of the alginate particles were processed by freeze drying. Mixtures of probiotic cultures with plant extracts were subjected to model human digestion by the action of model digestive juices in unencapsulated, encapsulated and lyophilized form. Selected extracts of plant materials were characterized in terms of amount of total and reducing sugars, total phenolic substances, individual phenolic substances and antioxidant activity. Further, two baby commercial dietary supplements containing probiotics were selected, which were characterized in terms of cell number and viability. Probiotic products were also subjected to model digestion.
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Indukce triploidie u candáta obecného (Sander lucioperca)
RŮŽEK, Martin
The aim of this study was to induce the triploidy in pikeperch (Sander lucioperca) with use of a cold shock. To induce the triploidy, fertilised egg were (spawning temperature 14,5 °C) submerged in a cold bath at the temperature of 2 °C. Time of initiation was 1; 3; 5; 7 and 10 minutes post activation. The exposure time was 20 and 40 minutes. Ploidy level of freshly hatched larvae was assessed with use of the flow cytometry. In both exposure times, the hatching rate was getting lower with later time of initiation (20 minutes exposure, hatching rate: 58,4-13,4 %; 40 minutes exposure, hatching rate: 28- 9,6 %). Number of malformed larvae increased with later time of initiation and longer exposure time (20 minutes exposure, malformed larvae 0-47,2 %; 40 minutes exposure, malformed larvae 0-58,8 %). None of the tested combination of exposure time and time of initiation led to a population containing 100 % triploid larvae. However, percentage of triploid larvae grew up with longer exposure time and later time of initiation. The best cold shock combination with highest yield of triploids were after 20 minutes long treatment initiated 10 minutes post activation (57,1 +- 14,2 %) and after 40 minutes long treatment initiated 10 minutes post activation (61,9 +- 8,2 %). The most important finding of this study is that cold shock treatment leads to triploidy in pikeperch. To obtain 100% triploid larvae, shorter exposure time and different shock temperature might be applied. It may also eliminate low hatching rate and high appearance of malformed larvae.
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Viability of probiotic bacteria in some foods
Pokorná, Martina ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on viability od probiotic bacteria in some foods and looking for optimal food and beverages, that exhibited a minimal negative effect on the growth and viability of probiotic bacteria. Lactobacillus acidophilus, Bifidobacterium breve and commercially complex of probiotics were tested. In the practical part, probiotics were incubated in the environment of selected types of model and real foods. Further, incubation in model gastrointestinal juices to simulate human digestion was performed. Model foods with a moderate value of concentrations of sugar, protein and alcohol were shown the best alternative for growth of bacteria and their lowest mortality. For salt, the smallest concentration was shown as the most suitable. The chicken broth, chicken and beef meat were evaluated as the best environment for the capsule with complex probiotics. The vegetables and vegetable broth were stated like the best for Lactobacillus acidophilus and Bifidobacterium breve. According to the preliminary results we can conclude that the probiotics should be preferably consumed during meals and with the sufficient amount of liquids for the activation of all cells.
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Encapsulation of lactic acid bacteria
Vrtná, Monika ; Lichnová, Andrea (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on encapsulation of two strains of probiotic bacteria. Lactic acid bacteria were encapsulated into several types of materials, mostly polysaccharides. The theoretical part describes the techniques of encapsulation applicable in the food industry. During the experimental part alginate and chitosan microparticles were prepared. These particles exhibited different sizes and some of them were modified by starch and carboxymethyl cellulose. Particles were used for encapsulation of two strains - Bifidobacterium breve and Lactobacillus acidophilus. Using flow cytometry cell viability was measured after 24-hours cultivation of bacteria. Particles were observed immediately after encapsulation by optical microscopy and then long-term stability in model foods was evaluated after two days, a week and after four weeks of incubation. Using the Bürker chamber the alived and death bacteria were counted inside and outside the capsule. The stability and viability of the cells were studied also in the artificial intestinal, stomach and bile juices. As the best material for encapsulation of lactic acid bacteria 2% alginate modified by carboxymethyl cellulose was found. The highest viability of bacteria was observed in milk as the real model food. Prepared particles are suitable for use in the food industry.
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The verification of the mass induction of triploidy in brook charr in operating conditions.
ŠVAGROVÁ, Kateřina
This bachelor thesis deals with the induction of triploidy in brook trout, Salvelinus fontinalis under farm conditions using a heat- and /or hydrostatic pressure shock. The first part involves the issues of polyploidy in fish, its induction, detection methods of polyploidy and its contribution to aquaculture. The second part deals with the technological process of induction of triploidy and subsequently, with evaluation of the effectiveness of both types of the shock upon ploidy level determine by flow cytometry. In this experiment, heat shock induced 80% of triploids in contrary to the hydrostatic pressure shock inducing triploidy in 100%. The pressure shock induced triploidy in brook trout more effectively than the heat shock and provided better operational results. Moreover, pressure shock displayed better fertilization of eggs, higher hatchability, and also higher percentage of triploids.
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