|
|
Disposable sensor of ammonium for intelligent packaging
Nentvichová, Aneta ; Kořínková, Radka (referee) ; Veselá, Mária (advisor)
This diploma thesis is focused on the problematic of the smart packaging and deals with the preparation of disposable ammonia sensors/indicators and the subsequent color measurement of prepared sensors/indicators using the CIE L* a* b* color space. The theoretical part of the diploma thesis focuses on active and intelligent packaging, using ammonia sensors/indicators. The emphasis is placed on the main components of the sensor/indicator, i.e., chitosan as a polymer and curcumin as a dye. The theoretical part also includes the problematic of meat degradation, which plays a very important role in this thesis. The experimental part was divided into two parts. The first part was to prepare layers that will respond in different colors based on the concentrations of ammonia. Prepared layers were sensitive to ammonia across all concentrations, and based on this result, ascorbic acid was applied to compositions to achieve a calibration retention of the selected amount of ammonia. The second minor part of the experiment was the application of selected layers to packages with real meat.
|
|
|
Bioactive compounds of fennel
Nentvichová, Aneta ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The aim of this bachelor thesis is to study the bioactive substances contained in fennel, to determine the content of polyphenols, flavonoids and to investigate the antioxidant and antimicrobial activity in aqueous and ethanol extracts of fennel. The theoretical part discusses the characteristics of fennel, its classification in the system, its use and especially the bioactive substances contained in it. The experimental part is divided into two sections, where the first part focuses on spectrophotometric determination of polyphenols, flavonoids and antioxidant activities. In the second part the antimicrobial effects of prepared extracts of fennel were examined. Two microorganisms Serratia marcescens and Bacillus cereus were exposed to the said extracts. Antioxidant activity and relatively high content of polyphenols and flavonoids were found in the extracts in the first experimental part. The second experimental part proved that the antimicrobial effect of the extracts was very low, in most cases almost negligible. Ethanol extracts showed higher antimicrobial activity, while hot water extracts found to support the growth of Bacillus cereus.
|
|
|
Disposable sensor of ammonium for intelligent packaging
Nentvichová, Aneta ; Kořínková, Radka (referee) ; Veselá, Mária (advisor)
This diploma thesis is focused on the problematic of the smart packaging and deals with the preparation of disposable ammonia sensors/indicators and the subsequent color measurement of prepared sensors/indicators using the CIE L* a* b* color space. The theoretical part of the diploma thesis focuses on active and intelligent packaging, using ammonia sensors/indicators. The emphasis is placed on the main components of the sensor/indicator, i.e., chitosan as a polymer and curcumin as a dye. The theoretical part also includes the problematic of meat degradation, which plays a very important role in this thesis. The experimental part was divided into two parts. The first part was to prepare layers that will respond in different colors based on the concentrations of ammonia. Prepared layers were sensitive to ammonia across all concentrations, and based on this result, ascorbic acid was applied to compositions to achieve a calibration retention of the selected amount of ammonia. The second minor part of the experiment was the application of selected layers to packages with real meat.
|
|
|
Bioactive compounds of fennel
Nentvichová, Aneta ; Vespalcová, Milena (referee) ; Veselá, Mária (advisor)
The aim of this bachelor thesis is to study the bioactive substances contained in fennel, to determine the content of polyphenols, flavonoids and to investigate the antioxidant and antimicrobial activity in aqueous and ethanol extracts of fennel. The theoretical part discusses the characteristics of fennel, its classification in the system, its use and especially the bioactive substances contained in it. The experimental part is divided into two sections, where the first part focuses on spectrophotometric determination of polyphenols, flavonoids and antioxidant activities. In the second part the antimicrobial effects of prepared extracts of fennel were examined. Two microorganisms Serratia marcescens and Bacillus cereus were exposed to the said extracts. Antioxidant activity and relatively high content of polyphenols and flavonoids were found in the extracts in the first experimental part. The second experimental part proved that the antimicrobial effect of the extracts was very low, in most cases almost negligible. Ethanol extracts showed higher antimicrobial activity, while hot water extracts found to support the growth of Bacillus cereus.
|
guest ::
