Presented diploma thesis deals with the analysis of juices of selected red and white currant varieties. The theoretical part is dedicated to the characteristics of a currant, biologically active substances of its fruits, its growing proces and the utilization of currants in the food industry. The analyzed parameters of currants - phenolics, anthocyanins and vitamin C are also characterized in the theoretical part with possibůe methods of their determination. The experimental part is devoted to the preparation of samples and the working practices of individual analysis. Six selected varieties of white and eleven varieties of red currant from Research and Breeding Institute of Pomology Holovousy Ltd. and six varieties of white and ten varieties of red currant from private grower were used for the analysis. Total phenolics and anthocyanins were determined spectrophotometrically, the content of vitamin C was determined by HPLC. Higher values of these compounds were measured mainly in the varieties of Research and Breeding Institute of Pomology Holovousy Ltd. Varieties of red currants contained higher amounts of total phenolics and anthocyanins while white currants contained higher amounts of vitamin C.

This diploma´s thesis deals with the determination of total antioxidant activity of red and white gooseberries and red, white and black currants. There are available information about small fruits, an overview of natural and synthetic antioxidants and a summary of the methods to determine the total antioxidant activity in the theoretical part. Frozen fruit samples were provided by Research and Breeding Institute of Pomology Holovousy Ltd. in the project QI111A141 – Research of new technologies in the cultivation of gooseberries and currants with a focus on quality and use of fetuses (Ministry of Agriculture). The total antioxidant activity of red and white gooseberries and currants was measured by spectrophotometric methods using free radicals ABTS•+ and DPPH and was expressed as a Trolox equivalent. The total antioxidant activity of black currants was measured by electron paramagnetic resonance using free radicals ABTS•+ and DPPH and expressed as a TEACABTS and a TEACDPPH. There were measured 8 species of red gooseberries, 6 species of white gooseberries, 12 species of red currants, 6 species of white currants and 8 species of black currants in this thesis. The highest values of total antioxidant activity showed species of red and white gooseberries Alan, Karmen, Pax and Invicta and species of red and white currants Rovada, Orion and Olin. Among black currants, species Ometa and Ruben had the highest values of total antioxidant activity.

Presented diploma thesis is dedicated to the determination of selected chemical parameters of fruits of new currant varieties. The theoretical part is focused on the characteristics of currant, the biologically active substances of its fruits and also the utilization of current in the food industry. Further part of the theory deals with the main chemical parameters which were examined: polyphenols, anthocyanins, ascorbic acid and antioxidant activity. In the practical part there were determined selected chemical parameters in six white, twelve red and thirteen black varieties of currant. Anthocyanins and polyphenols have been determined spectrophotometrically. The content of ascorbic acid in selected varieties of currant was determined by HPLC. As a technique for the determinationof the antioxidant activity was selected the method of free radical DPPH.

Exploring the use of currant pomace in foods is favourable due to its nutritional profile but also for economic and sustainability aspects. This by-product of fruit juice processing contains in addition to the dominating dietary fibre fraction considerable amounts of fat, protein, and polyphenols that are lost when the pomace is disposed of. Regardless of the intended use, the perishable material must be dried immediately or alternatively preserved. Three processing strategies (A, B, C) with different energy input and impact were outlined and related applications were implemented. The minimal (A) and intensive scenario (B) were examined comprehensively, whereas the complex processing (C) was considered only theoretically. For a prospective use in low-cost products (A), whole dry pomace was ground using various technologies. Ready-to-use powders were obtained by impact milling below 1 mm or simultaneous drying and grinding in a turbo rotor mill. A wide range of applications is possible, especially in baked products. The powder was used to partially replace flour in bread by considering its high water-binding capacity. In the example of wheat bread, 10% flour were simply replaced with pomace and dough handling properties (reduced stickiness) as well as bread quality parameters (lower baking loss, moister crumb) were improved by pre-hydration of the pomace in hot water. To expand the applicability of the pomace in the intensive scenario (B), the seeds were separated prior to milling and the remaining fibre fraction was treated thermomechanically either by planetary ball milling or extrusion cooking. This processing resulted in high fibre material with increased swelling capacity and water solubility. Based on the micronised seedless pomace, sweet creamy spreads were designed as an application example and the effects on rheology and physical stability were characterised. The pomace below 30 μm performed very well in spreads where it decreased oil separation. When it comes to zero-waste concepts, the seeds can be used for oil extraction whereas the stabilising effects of the fibre fraction may also be exploited to counteract sedimentation in aqueous suspensions and emulsions after pressure homogenisation.:1 Motivation 2 Literature review 2.1 Cultivation and processing of currants 2.2 Composition of currant pomace 2.2.1 Dietary fibre 2.2.2 Lipophilic components 2.2.3 Proteins, sugars, and minerals 2.2.4 Polyphenols and antioxidant capacity 2.3 Residues of toxicological importance 2.4 Preservation and comminution of food processing by-products 2.4.1 Drying 2.4.2 Particle size reduction 2.5 Extraction and fractionation of selected pomace components 2.5.1 Soluble and insoluble dietary fibre 2.5.2 Seed oil 2.5.3 Proteins 2.5.4 Anthocyanins 3 Objectives of the thesis 4 Materials and Methods 4.1 Origin of currant pomace 4.2 Processing of pomace 4.2.1 Minimal processing: Drying and milling 4.2.2 Intensive processing: Thermo-mechanical treatment of dried pomace 4.3 Pomace analysis 4.3.1 Proximate composition 4.3.2 Contamination analysis 4.3.3 Physical properties 4.3.4 Techno-functional properties 4.4 Food applications: Preparation and analysis 4.4.1 Preparation of wheat bread 4.4.2 Dough expansion, pH, and rheology 4.4.3 Bread appearance and texture 4.4.4 Preparation of sweet spreads 4.4.5 Spread analysis 4.5 Statistics 5 Results and discussion 5.1 Natural variation of currant pomace composition 5.2 Minimal processing scenario 5.2.1 Preservation of fresh pomace by convection drying 5.2.2 Milling techniques to obtain ready-to-use pomace powder 5.2.3 Hydration properties of pomace powders 5.3 Application of minimally processed pomace powder in wheat bread 5.3.1 Hydration properties and rheology during simulated baking 5.3.2 Changes in dough properties during proofing 5.3.3 Effects on bread characteristics 5.4 Intensive processing scenario 5.4.1 Composition of seedless currant pomace 5.4.2 Impact of HTST-extrusion 5.4.3 Influence of planetary ball milling on particle size 5.4.4 Modified functionality after thermo-mechanical treatments 5.5 Application of intensively processed pomace in fat-based spreads 5.5.1 Wet ball milling in oil-suspension 5.5.2 Rheological properties and physical stability of sweet spreads 5.5.3 Sensory attributes of pomace spreads 5.6 Concepts for the implementation of zero-waste strategies 6 Conclusions Bibliography List of figures List of tables Appendix List of publications / Die Verwertung von Johannisbeertrester in Lebensmitteln bietet sich nicht nur aufgrund seines Nährstoffprofils an, sondern ist auch im Sinne der Nachhaltigkeit und unter wirtschaftlichen Aspekten vorteilhaft. Das bei der Fruchtsaftherstellung anfallende Nebenprodukt besteht überwiegend aus Ballaststoffen sowie nennenswerten Mengen an Fett, Protein und Polyphenolen, welche im Falle einer Entsorgung für die menschliche Ernährung verloren gehen. Ganz unabhängig von der weiteren Nutzung muss der leicht verderbliche Trester zunächst getrocknet oder alternativ haltbar gemacht werden. Es wurden drei Aufarbeitungsstrategien (A, B, C) entworfen, welche sich in Energieaufwand und Intensität unterscheiden. Davon wurden das sogenannte minimale (A) und das intensive Szenario (B) inklusive entsprechender Anwendungen umfassend untersucht, während eine komplexe Verarbeitung (C) nur theoretisch betrachtet wurde. Für den Einsatz in niedrigpreisigen Lebensmitteln wurde getrockneter Trester im Gesamten (A) unter Anwendung verschiedener Technologien vermahlen. Direkt verwendbare Tresterpulver unter 1 mm wurden durch Vermahlung in einer Prallmühle oder mittels Mahltrocknung hergestellt. Es bieten sich eine ganze Reihe von Anwendungen, vor allem im Bereich der Backwaren, an. Unter Berücksichtigung der hohen Wasserbindekapazität erfolgte der Einsatz des Pulvers als Mehlsubstituent in Brot. Im Fall von Weizenbrot konnten 10% Mehl problemlos durch Trester ersetzt werden, wobei die Verarbeitungseigenschaften des Teigs (verminderte Klebrigkeit) und qualitätsbestimmende Broteigenschaften (geringerer Backverlust, feuchtere Krume) durch Vorquellen in heißem Wasser verbessert werden konnten. Um die Einsatzmöglichkeiten des Tresters zu erweitern, wurden im intensiven Verarbeitungsszenario (B) die Samen abgetrennt und die verbleibende Faserfraktion thermo-mechanisch behandelt, zum einen in einer Planetenkugelmühle, zum anderen durch Extrusion. Die intensive Aufarbeitung resultierte in einer ballaststoffreichen Faserfraktion mit erhöhtem Quellvermögen sowie höherer Wasserlöslichkeit. Als Einsatzbeispiel wurden ausgehend von der feinstvermahlenen Faserfraktion süße Streichcremes entwickelt, und die Auswirkungen des Tresters auf Rheologie und physikalische Stabilität charakterisiert. Der Trester unter 30 μm eignete sich hervorragend in der Herstellung von fettreichen Aufstrichen, da die Ölseparation vermindert wurde. Eine möglichst umfassende, reststofffreie Verwertung des Tresters (zero-waste) kann durch Nutzung der Samen zur Ölgewinnung erfolgen, wohingegen die stabilisierenden Eigenschaften der Faserfraktion nach Hochdruckhomogenisierung auch in wässrigen Suspensionen und Emulsionen ausgeschöpft werden könnten.:1 Motivation 2 Literature review 2.1 Cultivation and processing of currants 2.2 Composition of currant pomace 2.2.1 Dietary fibre 2.2.2 Lipophilic components 2.2.3 Proteins, sugars, and minerals 2.2.4 Polyphenols and antioxidant capacity 2.3 Residues of toxicological importance 2.4 Preservation and comminution of food processing by-products 2.4.1 Drying 2.4.2 Particle size reduction 2.5 Extraction and fractionation of selected pomace components 2.5.1 Soluble and insoluble dietary fibre 2.5.2 Seed oil 2.5.3 Proteins 2.5.4 Anthocyanins 3 Objectives of the thesis 4 Materials and Methods 4.1 Origin of currant pomace 4.2 Processing of pomace 4.2.1 Minimal processing: Drying and milling 4.2.2 Intensive processing: Thermo-mechanical treatment of dried pomace 4.3 Pomace analysis 4.3.1 Proximate composition 4.3.2 Contamination analysis 4.3.3 Physical properties 4.3.4 Techno-functional properties 4.4 Food applications: Preparation and analysis 4.4.1 Preparation of wheat bread 4.4.2 Dough expansion, pH, and rheology 4.4.3 Bread appearance and texture 4.4.4 Preparation of sweet spreads 4.4.5 Spread analysis 4.5 Statistics 5 Results and discussion 5.1 Natural variation of currant pomace composition 5.2 Minimal processing scenario 5.2.1 Preservation of fresh pomace by convection drying 5.2.2 Milling techniques to obtain ready-to-use pomace powder 5.2.3 Hydration properties of pomace powders 5.3 Application of minimally processed pomace powder in wheat bread 5.3.1 Hydration properties and rheology during simulated baking 5.3.2 Changes in dough properties during proofing 5.3.3 Effects on bread characteristics 5.4 Intensive processing scenario 5.4.1 Composition of seedless currant pomace 5.4.2 Impact of HTST-extrusion 5.4.3 Influence of planetary ball milling on particle size 5.4.4 Modified functionality after thermo-mechanical treatments 5.5 Application of intensively processed pomace in fat-based spreads 5.5.1 Wet ball milling in oil-suspension 5.5.2 Rheological properties and physical stability of sweet spreads 5.5.3 Sensory attributes of pomace spreads 5.6 Concepts for the implementation of zero-waste strategies 6 Conclusions Bibliography List of figures List of tables Appendix List of publications

The allergic disease of asthma is characterized by an infiltration of inflammatory cells to the lung, a process co-ordinated by T-helper (TH) cells. The TH2 cytokine Interleukin (IL)-4 promotes infiltration of eosinophils to sites of inflammation. Eosinophil-selective chemoattractant cytokines (eg. eotaxins) are synthesized by lung epithelial cells. Eotaxin-3 is expressed at high levels in the asthmatic lung, predominantly after IL-4 stimulation. Eotaxin-3 is therefore a marker of inappropriate airway inflammation. Polyphenolic (PP) compounds found in high concentrations in berries may have beneficial effects in inflammatory conditions. Plant and Food Research produced high-PP extracts of blackcurrant (BC) cultivars that were tested for inflammation modulating effects. Since high doses of PPs have been shown to cause cell death, we tested two BC cultivars at a range of concentrations in a cell viability (WST-1) assay. While no toxic effects were attributable to the BC extracts (1-50µg/ml), a dose-related trend in cell death was observed and therefore 10µg/ml was chosen for further experiments Ten BC cultivars were compared for efficacy by measuring eotaxin-3 production in IL-4 stimulated human lung epithelial (A549) cells in vitro. Cells were incubated with BC extracts (10µg/ml) and IL-4 (10ng/ml) for 24 hours. The supernatants were then quantified for eotaxin-3 levels by an enzyme-linked immunosorbent assay (ELISA). All ten BC extracts reduced eotaxin-3 levels after stimulation with IL-4, and six BC extracts were effective by statistically significant levels (P<0.05), (BC cultivars -01, -02, -03, -05, -09 & -10). Of those, BC extracts of four cultivars demonstrated a reduction of more than 65% from the IL-4 stimulated control. In addition, a positive trend in inflammation modulation vs. one anthocyanin (ACN) in the BC extracts was shown. This study has demonstrated the beneficial inflammation modulatory effects of polyphenolic BC extracts, which could be related to cyanidin 3-O-rutinoside content. These results may have therapeutic potential for asthma.

The allergic disease of asthma is characterized by an infiltration of inflammatory cells to the lung, a process co-ordinated by T-helper (TH) cells. The TH2 cytokine Interleukin (IL)-4 promotes infiltration of eosinophils to sites of inflammation. Eosinophil-selective chemoattractant cytokines (eg. eotaxins) are synthesized by lung epithelial cells. Eotaxin-3 is expressed at high levels in the asthmatic lung, predominantly after IL-4 stimulation. Eotaxin-3 is therefore a marker of inappropriate airway inflammation. Polyphenolic (PP) compounds found in high concentrations in berries may have beneficial effects in inflammatory conditions. Plant and Food Research produced high-PP extracts of blackcurrant (BC) cultivars that were tested for inflammation modulating effects. Since high doses of PPs have been shown to cause cell death, we tested two BC cultivars at a range of concentrations in a cell viability (WST-1) assay. While no toxic effects were attributable to the BC extracts (1-50µg/ml), a dose-related trend in cell death was observed and therefore 10µg/ml was chosen for further experiments Ten BC cultivars were compared for efficacy by measuring eotaxin-3 production in IL-4 stimulated human lung epithelial (A549) cells in vitro. Cells were incubated with BC extracts (10µg/ml) and IL-4 (10ng/ml) for 24 hours. The supernatants were then quantified for eotaxin-3 levels by an enzyme-linked immunosorbent assay (ELISA). All ten BC extracts reduced eotaxin-3 levels after stimulation with IL-4, and six BC extracts were effective by statistically significant levels (P<0.05), (BC cultivars -01, -02, -03, -05, -09 & -10). Of those, BC extracts of four cultivars demonstrated a reduction of more than 65% from the IL-4 stimulated control. In addition, a positive trend in inflammation modulation vs. one anthocyanin (ACN) in the BC extracts was shown. This study has demonstrated the beneficial inflammation modulatory effects of polyphenolic BC extracts, which could be related to cyanidin 3-O-rutinoside content. These results may have therapeutic potential for asthma.

The allergic disease of asthma is characterized by an infiltration of inflammatory cells to the lung, a process co-ordinated by T-helper (TH) cells. The TH2 cytokine Interleukin (IL)-4 promotes infiltration of eosinophils to sites of inflammation. Eosinophil-selective chemoattractant cytokines (eg. eotaxins) are synthesized by lung epithelial cells. Eotaxin-3 is expressed at high levels in the asthmatic lung, predominantly after IL-4 stimulation. Eotaxin-3 is therefore a marker of inappropriate airway inflammation. Polyphenolic (PP) compounds found in high concentrations in berries may have beneficial effects in inflammatory conditions. Plant and Food Research produced high-PP extracts of blackcurrant (BC) cultivars that were tested for inflammation modulating effects. Since high doses of PPs have been shown to cause cell death, we tested two BC cultivars at a range of concentrations in a cell viability (WST-1) assay. While no toxic effects were attributable to the BC extracts (1-50µg/ml), a dose-related trend in cell death was observed and therefore 10µg/ml was chosen for further experiments Ten BC cultivars were compared for efficacy by measuring eotaxin-3 production in IL-4 stimulated human lung epithelial (A549) cells in vitro. Cells were incubated with BC extracts (10µg/ml) and IL-4 (10ng/ml) for 24 hours. The supernatants were then quantified for eotaxin-3 levels by an enzyme-linked immunosorbent assay (ELISA). All ten BC extracts reduced eotaxin-3 levels after stimulation with IL-4, and six BC extracts were effective by statistically significant levels (P<0.05), (BC cultivars -01, -02, -03, -05, -09 & -10). Of those, BC extracts of four cultivars demonstrated a reduction of more than 65% from the IL-4 stimulated control. In addition, a positive trend in inflammation modulation vs. one anthocyanin (ACN) in the BC extracts was shown. This study has demonstrated the beneficial inflammation modulatory effects of polyphenolic BC extracts, which could be related to cyanidin 3-O-rutinoside content. These results may have therapeutic potential for asthma.

This diploma thesis was focused on study of low-molecular antioxidants present in various kinds of fruits, namely berries. In theoretical part detailed characterization of antioxidants studied in presented work and their biological effects are introduced. Further, principals of processing and storage of specified species of fruits are discussed. Changes observed during storage of specific fruits are described too. In practical part changes in content of selected antioxidants in berries were followed. As studied material strawberries, raspberries, blueberries, red and black currants were used. All kind of these fruits was stored in fridge for six months using several different kind of processing. Berries were stored as whole fruits, whole osmotically processed fruits by sucrose, raw pulp and sweetened pulp. At first, starting values of selected antioxidant parameters were measured in fresh fruits (ascorbate, total antioxidant activity, total phenolics, catechins and individual flavonoids). After freezing the same parameters were measured regularly in two month periods. As the most suitable method of fruit processing, with regard to antioxidant content, storage of the whole fruits or pulp can be recommended. Content of ascorbate decreased in all forms and species of the processed fruits during all the time of storage. Oppositely, the content of other studied antioxidants exhibited fluctuations or increasing trend. Sensory analysis was proved for the whole fruits and also for whole sweetened fruits.

The thesis deals with one group of small fruits, the genus Ribes, ie currants, and gooseberries. It assesses their physical and chemical parameters with respect to the possibility of use in these properties for the design of a new type of product – beverages. Titration, spectrometric and other methods were used for the evaluation of these properties. A total of fifteen of these methods were available (total juice yield, juice pH, total dry matter, soluble fruit dry matter, titratable acidity, formolic number, reducing carbohydrate content, D-glucose, D-fructose and sucrose content, total polyphenolic substance content, anthocyanins, vitamin C and total antioxidant capacity) and a total of nine analytes (copper, iron, magnesium, phosphorus, zinc, manganese, potassium, calcium and sodium) were selected for the determination of mineral elements. For two years (harvest 2014 and 2015), these parameters were monitored for color variants of currants (white, red and black) and gooseberries (green-fruited, yellow-fruited and red-fruited). A total of six white varieties were tested in the group of currants - Olin, Jantar, Primus, Blanka, Viktoria and Orion, eleven varieties of red currants - Junnifer, Jesan, Detvan, Rovada, Rubigo, J.V.Tets, Tatran, Losan, Kozolupský raný, Stanca, NŠLS 11/6 and eleven varieties of black currant varieties - Ometa, Démon, Triton, Ben Hope, Ruben, Ben Gairm, Ben Lomond, Moravia, Ben Conan, Fokus and Ceres. A total of five varieties of green-fruited gooseberries were tested - Zebín, Mucurines, Rixanta, Rodnik and Prima. Yellow-fruited gooseberries were available in four varieties - Lemon Giant, Invicta, Golden Fig and Darek. The red-fruited gooseberries included varieties - Rolonda, Alan, Karat, Karmen, Krasnoslawjanskij, Himnomacki Rot, Remarka, Tamara and Black Neguš. Using Tukey's test, an analysis was performed and by scoring individual varieties based on the results of individual analyzes, a list of recommended varieties was compiled for further work on the development of a new beverage. Unfortunately, in 2015 there were very few fruits of green-fruited and yellow-fruited gooseberries, so it was decided that the volume of fruit will fall on the testing of bioactive substances. Therefore, at the end of the work, it is not possible to objectively evaluate these varieties of gooseberries in the whole range of analyzes. Therefore, the point evaluation of varieties was based on the averages of individual varieties. The red-fruited varieties were available in full, and therefore a full evaluation could take place. The most significant differences between red gooseberry varieties were in the content of bioactive substances (the content of polyphenolic substances, anthocyanin dyes, and vitamin C) and antioxidant capacity. These results were provided to the food subject, which continued to work with these values. Based on this project, utility model No. PUV 2016-33171 and the resulting combined drink based on wine and fruit juice were developed.

Diploma thesis is focused on the chemical analysis of the juices of black, red and white currant and jostaberry (Ribes a Ribes x culverwellii). The theoretical part is focused to the definition of fruit, fruit importance in human nutrition, description of Ribes and Ribes x culverwellii genuses, active substances in the currants and the jostaberry, description of selected chemical parameters and the determination of some of them. The procedures of determining for the following chemical parameters are described in the experimental section: determination of reducing sugars, determination of total and soluble solids, formol number, pH, titratable acidity, determination of total phenols and anthocyanins and determination of vitamin C in two samples jostaberry, six varieties of black currants, one variety of white currant and two varieties of red currants. Based on the evaluation of the obtained results, the comparison was made with different varieties and the thesis that "overall comparison of the different varieties in the content of phenolic compounds, vitamin C and anthocyanins appears to be the most promising variety of blackcurrant demon. It should however be noted that the highest content of phenolics and anthocyanins were determined in jostaberry„ has been suggested.