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Utilisation of plant origin waste
Habáníková, Kamila ; Šťavíková, Lenka (referee) ; Omelková, Jiřina (advisor)
This thesis describes properties and utilization and specifies the composition of organic plant waste produced during industrial processing. By cultivation of specific micro-organisms from this waste material it is possible to produce enzymes that have further beneficial industrial utilization. The experimental part of this thesis deals with the production of enzymes from the applied waste material grape pomace with the help of chosen micro-organisms. Waste, its processing and utilization is and always will be a key issue in our society.
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Multi-experimental Characterization of Grape Skins' Extracts
Šťavíková, Lenka ; Brezová, Vlasta (referee) ; Šilhar,, Stanislav (referee) ; Omelková, Jiřina (advisor)
The determination of anthocyanins in red grapes and wines has been of increasing interest in the last years, as they play an important role in colour quality of red wines revealing also many human health beneficial effects. They contribute e.g. to the reduction of coronary heart disease, but exhibit also antimutagenic, anti-inflammatory, anti-carcinogenic and antioxidant properties. In this doctoral thesis, the complex study of grape skin alcoholic and water extracts, prepared from Alibernet and St. Laurent wine grape varieties is presented. Extracts were prepared from three different amounts (0,5; 1,0 and 1,5 g) of lyophilized grape skin powder using the Pressurized fluid extraction (PFE) and the Pressurized Hot Water Extraction (PHWE) at different temperatures ranging from 40 up to 120°C and pressure of 15 MPa. Methanol, ethanol and water were used as a solvents. Total phenolic compound content (TPC) of individual extracts was determined using the Folin-Ciocalteau assay and their tristimulus color values (CIE Lab) were estimated, using the UV-VIS spectrophotometer. The identification and quantification of anthocyanins by high-performance liquid chromatography with diode array detection (HPLC-DAD) was performed. In addition, pH values of all extracts were also measured using the combinated glass electrode. Antioxidant activity of extracts was tested by EPR spectroscopy in Fenton system (H2O2/Fe2+) generating reactive radicals (•OH, O2-•, •CH3) followed by spin trapping technique, using 5,5-dimethylpyrroline-N-oxide (DMPO) as spin trap. In addition, radical scavenging activity of extracts was assessed applying 2,2-diphenyl-1-picrylhydrazyl (•DPPH) free radical and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) cation radical (ABTS•+) assays. All the experimental data were processed with principal component analysis (PCA) and canonical discriminant analysis (CDA) to specify the optimum extraction conditions for extract preparation from the perspective of the potential further application of the extracts as food supplements or food colour enhancers. The results indicated that grape skins of both varieties are a promising source of anthocyanins with prospective application in food industry.
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Multi-experimental Characterization of Grape Skins' Extracts
Šťavíková, Lenka ; Brezová, Vlasta (referee) ; Šilhar,, Stanislav (referee) ; Omelková, Jiřina (advisor)
The determination of anthocyanins in red grapes and wines has been of increasing interest in the last years, as they play an important role in colour quality of red wines revealing also many human health beneficial effects. They contribute e.g. to the reduction of coronary heart disease, but exhibit also antimutagenic, anti-inflammatory, anti-carcinogenic and antioxidant properties. In this doctoral thesis, the complex study of grape skin alcoholic and water extracts, prepared from Alibernet and St. Laurent wine grape varieties is presented. Extracts were prepared from three different amounts (0,5; 1,0 and 1,5 g) of lyophilized grape skin powder using the Pressurized fluid extraction (PFE) and the Pressurized Hot Water Extraction (PHWE) at different temperatures ranging from 40 up to 120°C and pressure of 15 MPa. Methanol, ethanol and water were used as a solvents. Total phenolic compound content (TPC) of individual extracts was determined using the Folin-Ciocalteau assay and their tristimulus color values (CIE Lab) were estimated, using the UV-VIS spectrophotometer. The identification and quantification of anthocyanins by high-performance liquid chromatography with diode array detection (HPLC-DAD) was performed. In addition, pH values of all extracts were also measured using the combinated glass electrode. Antioxidant activity of extracts was tested by EPR spectroscopy in Fenton system (H2O2/Fe2+) generating reactive radicals (•OH, O2-•, •CH3) followed by spin trapping technique, using 5,5-dimethylpyrroline-N-oxide (DMPO) as spin trap. In addition, radical scavenging activity of extracts was assessed applying 2,2-diphenyl-1-picrylhydrazyl (•DPPH) free radical and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) cation radical (ABTS•+) assays. All the experimental data were processed with principal component analysis (PCA) and canonical discriminant analysis (CDA) to specify the optimum extraction conditions for extract preparation from the perspective of the potential further application of the extracts as food supplements or food colour enhancers. The results indicated that grape skins of both varieties are a promising source of anthocyanins with prospective application in food industry.
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Utilisation of plant origin waste
Habáníková, Kamila ; Šťavíková, Lenka (referee) ; Omelková, Jiřina (advisor)
This thesis describes properties and utilization and specifies the composition of organic plant waste produced during industrial processing. By cultivation of specific micro-organisms from this waste material it is possible to produce enzymes that have further beneficial industrial utilization. The experimental part of this thesis deals with the production of enzymes from the applied waste material grape pomace with the help of chosen micro-organisms. Waste, its processing and utilization is and always will be a key issue in our society.
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