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Preparation and stability of core-shell type organic micro- and nanoparticles
Byrtusová, Dana ; Benešová, Pavla (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on possibilities of encapsulation polyphenolic compounds in core-shell type organic micro- and nanoparticles. The theoretical part is aimed at characterization of polyphenolic compounds, their biological effects and their possibilities of encapsulation into various types of particles. The experimental part deals with the content of polyphenolic compounds, flavonoids and anthocyanins in guarana, ginseng ang goji. Extracts from these samples were packed into liposomes and polysaccharide particles. Encapsulation´s effectiveness was determined spectrophotometrically. The stability of particles was monitored for size and stability by dynamic light scattering. The particles were exposed to the model body fluids and model food.
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Honeysuckle Lonicera camtschatica - unconventional fruit of Czech republic
Rybníčková, Eva ; Šalplachta, Jan (referee) ; Vespalcová, Milena (advisor)
This work speaks about the possibilities of using fruits of the blue honeysuckle (Lonicera camtschatica) in the food industry. The first part describes the properties of this plant and methods of its cultivation. The second chapter deals with the chemical composition of the fruits and the importance of nutritionally valuable substances contained in them. The third chapter assesses the current appearance of the fruits in the world in the commercial point of view and the possibilities of processing the fruits into products. The last part deals with the methods of isolation and determination of important substances in the fruits, namely anthocyanins.
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Basic chemical properties of fruits of selected cherry varieties
Chmil, Vojtěch ; Vítová, Eva (referee) ; Diviš, Pavel (advisor)
Diploma thesis is focused on chemical characteristics of nine selected sweet cherry varieties in nine parameters. Total and soluble solids were analyzed with these results 13.07–16.58 % for total and 14.67–19.50 °Brix for soluble solids, ash content 0,31–0,39 %, titratable acidity 5.44–9.91 g of malic acid per 1 kg of fresh cherries and formol number 14.45–23.73 ml of 0.1 M NaOH per 100 g of cherries. Then there were analyzed crude proteins content calculated from total nitrogen content determined by Kjeldahl method with results 0.41–0.68 % of crude proteins. Molecular absorption UV/VIS spectrophotometry was used for determination of total phenolic substances 0.30–0.89 g of gallic acid per 1 kg of cherries and total content of anthocyanins 128–848 mg of cyanidine-3-glucoside in 1 kg of cherries. Saccharides were determined by high performance liquid chromatography (HPLC) with ELSD detector. Content of glucose was 45.45–59.49 g/kg and fructose 46.88–60.01 g/kg. All results are compiled using tables and graphs and discussed. Experimental part of the thesis also describes principles and procedures of every analysis, so it can be reproduced. In theoretical part there is described botanical characteristic of cherry tree (Prunus avium L.), active substances contained in its fruits and their use in food industry. At the end of the theoretical part there is described instrumentation of high-performance liquid chromatography.
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Anthocyan pigments in selected fruits
Peprná, Tereza ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
This diploma thesis is concerned with determination anthocyanins dyes in elderberry (Sambucus nigra L.). In theoretical part there is described general characterization of the plant, its chemical composition, short view of elderberry breeding and possibilities of usage in food and medical industry. Bigger attention is paid to anthocyanins dyes. There is described their characterization, occurrence, factors that have an impact on their stability. Biosynhesis of the pigments and metabolism, benefit effects and their usage in food chemistry are then shortly sumarized. Methods of determination of anthocyanins are discused too. Next chapter deals with high performance liquid chromatography. At the end of theoretical part, there is sumarized findings of anthocyan dyes analysis by expert scientists in various matrix. In experimental part, total of 16 species of elderberry were analyzed. These species are from research and breeding institute of pomology in Holovousy. The dyes were identification and quantification by high performace liquid chromatography coupled with a diode array detector. Detection wavelenght was 520 nm. Gradient of mobile phase was optimilized because of shortening analyses time and resolution improvement. Four dyes were identified by HPLC: cyanidin-3-sambubioside, cyanidin-3-glukoside, cyanidin-3,5-diglukoside a cyanidin-3-sambubioside-5-glukoside. Total amount of anthocyanins ranged from 33627167,0 to 5525284,0 mAU•min-1. The most anthocyanins dyes were determined in Mammut species (33627167,0 mAU•min-1), the lowest amount was measured in Aurea species (5525284,0 mAU•min-1). The most abundant anthocyanin in all species of eldeberry fruit except Haschebrg and Aurea species was cyanidin-3-sambubioside. The concentrations of cynidin-3-glucoside in all of the berries were quantified using regression equation of calibration curve. Mammut species had the most amount of this anthocyan (0,486 mg•ml-1) and the lowest amount had Aurea species (0,033 mg•ml-1).
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Representative of small fruit - currant and its nutritional characteristics
Marková, Leona ; Vránová, Dana (referee) ; Vespalcová, Milena (advisor)
This bachelor thesis deals with representative of small fruit – currant (Ribes L.). Basic information about plant is described in theoretical part. Next there are described varieties, diseases and pests of currant. Attention is given also to production and consumption of these fruit in the Czech Republic. The following chapters include a list of active substances which the fruit contains and also the list of some possibilities of processing and utilization of currant especially in the food industry. In conclusion, the theoretical part describes the most common methods for the determination of anthocyanins. Main result of experimental part is comparison of the content of anthocyanin pigments in juices of red and black currant. Content of monomeric and polymeric pigments was evaluated depending on time and temperature of storage of currant juice and also after heating of this juice. pH differential method was used as the main method.
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Encapsulation of natural antioxidants
Štindlová, Jitka ; Obruča, Stanislav (referee) ; Márová, Ivana (advisor)
In theoretical part of this diploma thesis the basic properties of antioxidants, especially anthocyanins and phenolic compounds are described, as well as the basic features and principles of free radicals formation. The theoretical part also describes some possible ways of encapsulation of antioxidants into polysaccharide and lipid particles. In the experimental part basic characteristics of extracts from selected lyophilized fruits and vegetables (carrots, apples and mixed berries) are described. As group parameters of plant extracts the total antioxidant activity, content of flavonoids and phenolics, carotenoids, anthocyanins and ascorbic acid were determined. In experimental part also various encapsulation techniques were tested, encapsulation effectiveness of each technique was evaluated and the stability and size of the created particles were determined. As the best encapsulation method in terms of encapsulation efficiency in most of samples/parameters ethanol injection was found. On the other hand the particles prepared by ethanol injection are relatively unstable in terms of zeta potential, which is followed by their tendency to aggregate. As the most stable particles prepared by thin layer evaporation (TLE) and reverse phase thin layer evaporation (RP-TLE) were evaluated. Particles prepared by TLE, RP-TLE and chitosan-alginate particles exhibited a negative charge, while particles prepared by ethanol injection stayed uncharged and chitosan particles have a positive charge.
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Comparison of some new currant varieties based on the content of selected biologically active compounds
Marková, Leona ; Diviš, Pavel (referee) ; Vespalcová, Milena (advisor)
Diploma thesis deals with currant (Ribes L.) and substances which currants contain especially anthocyanin pigments, vitamin C and antioxidants. In theoretical part is described basic characteristic about plant, including varieties of currants. The following chapters include a list of active substances which the fruit contains and also the list of some possibilities of processing and utilization of currant especially in the food industry. Big attention is given to anthocyanins, their characteristics, utilization in the food industry, factors that affect their stability and especially methods of determination. In conclusion, the theoretical part describes importance and methods of determination of vitamin C and antioxidant capacity. Selected nutritional parameters were determined in fifteen known and in three unknown varieties of currants. Anthocyanins were measured spectrophotometrically and determined by HPLC in color samples. By pH differential method was evaluated a content of monomeric and polymeric pigments. By HPLC method were identified individual anthocyanin pigments contained in fruits. Also, content of ascorbic acid was determined by HPLC in all varieties. Antioxidant capacity of white currants measured by DPPH was compared.
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Disposable pH sensor
Dvořáčková, Sabina ; Kovalčík, Adriána (referee) ; Veselá, Mária (advisor)
This bachelor thesis deals with thin polymer layers containing substances capable of reacting to changes in the pH. In theory are processed informations of smart packaging including legislation of general food packaging. Natural substances forming the basis for the production of edible films are also described. An indicator of ammonia in composition of PVA and red cabbage anthocyanins was studied here. The prepared layers were tested for gaseous NH3. Layers containing anthocyanins responded with a very intense color transition from purple and blue to turquoise.
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Printed indicator of pH value designed for food packaging
Valíková, Michaela ; Kovalčík, Adriána (referee) ; Veselá, Mária (advisor)
The aim of this diploma thesis was to design an intelligent indicator of pH value for food packaging. Intelligent packaging is a new group of packaging that is able to provide costumers real-time information on the quality of packaged food through various indicators. In the theoretical part, a search was made on the topic of intelligent packaging with emphasis on freshness indicators. A smaller part was devoted to the issue of food spoilage. Emphasis was also placed on the description of the main components of the functional layer, and on the issue of chitosan crosslinking. In the experimental part, the crosslinking of chitosan with the addition of polyvinylalcohol using vanilin was studied. Prepared layers were monitored for their solubility and degree of crosslinking, which was determined using the ninhydrin method. To create a colorimetric pH indicator, an anthocyanin extract obtained by extraction from red cabbage was incorporated into the composition. A total of 3 anthocyanin extracts were prepared, for which the total anthocyanin concentration was determined by the difference method. The color of the prepared layers was evaluated spectrophotometrically under the action of various concentrations of the ammonia gas. The stability of the layers over time was also monitored. The last part of the experiment was the application of the prepared layers in a package with real meat.
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Determination of selected chemical parameters of fruits of cultivated elderberry varieties
Hamalová, Veronika ; Vránová, Dana (referee) ; Vespalcová, Milena (advisor)
In this thesis was determinated selected chemical and nutritional parameters in the wild elderberry and 17 cultivated varieties of elderberry. The fruits was provided by the Research and Breeding Institute of Pomology Holovousy Ltd. The theoretical part deals describes elderberry, chemical composition of elderberry, especially biological active substances and its using not only food industry. Closer attention has been focused on effect of saccharides, anthocyanins and methods of their determination, specially determination by HPLC. The experimental part describes the various methods of determination of selected chemical and nutritional parameters. Total dry matter, content of total polyphenolic compounds, monomeric anthocyanin pigment and antioxidant activity was defined in all varieties of elderberry fruits. For some varieties was defined total soluble dry matter, content of organic acids and saccharides by various methods. In the end was compared the values from different methods varieties.
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