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Smart food polymer layers
Valíková, Michaela ; Kovalčík, Adriána (referee) ; Veselá, Mária (advisor)
Smart packaging represents a group of packaging with great potential when used in the food industry. Active packaging can have a positive effect on the condition of stored food and smart packaging can inform consumers about the condition of stored food. In the theoretical part, a search was made on the topic of packaging in the food industry, with emphasis on active and intelligent packaging, including the legislative framework. The substances from which smart packaging is made have been described. In the experimental part, partially water¬insoluble polymer layers were prepared from gelatin, glycerol, crosslinking agent and anthocyanin extract. Glutaraldehyde or tannic acid was used as a crosslinking agent. Anthocyanins were obtained by extraction from red cabbage. The total concentration of anthocyanins in the extract was determined by the difference method. For prepared layers, their water solubility was measured and the colour response to the pH environment was evaluated spectrophotometrically. The stability of the layers over time was also monitored. It was found that the prepared layers are able respond to changes in pH.
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Smart edible films sensitive to pH
Jarošová, Gabriela ; Kovalčík, Adriána (referee) ; Veselá, Mária (advisor)
This bachelor thesis is focused on smart edible films sensitive to pH. The theoretical part deals with smart packaging including legislation. The main compound for the film preparation is chitosan, which is described and anthocyanins serving as the color indicator. At first, the anthocyanins were isolated from red cabbage using extraction. The edible films were prepared from chitosan, corn starch and anthocyanins. Pentasodium triphosphate was used as a crosslinking agent. The layers were subjected to the solubility test, which showed smallest decrease in case of fast drying in the dryer, namely 14,5 %. The color reaction on the pH change was studied. It was found that the prepared layers reacted to every pH change, the most significant reaction was to pH 1 and 3.
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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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Natural dyes for smart packaging
Nyklesová, Ludmila ; Dzik, Petr (referee) ; Veselá, Mária (advisor)
This thesis focuses on the use of natural dyes in smart food packaging as pH change indicators. The theoretical part of the thesis describes smart packaging, which can be divided into active and intelligent packaging. Within intelligent packaging, the thesis focuses mainly on pH indicators, including their composition, i.e., the polymer used and the dyes, with an emphasis on anthocyanin dyes. The theoretical part also includes a description of the methods used to measure the color changes of prepared indicators. In the experimental part of the thesis, anthocyanin dye is extracted from Aronia melanocarpa berries and thin films containing the anthocyanin extract are prepared. The color change of the prepared thin layers is further studied in an environment with a low concentration of ammonia. Layers that showed a reaction to the ammonia environment were subsequently overprinted with white UV varnish, and their reaction to an environment with low ammonia content was observed.
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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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Smart edible films sensitive to pH
Jarošová, Gabriela ; Kovalčík, Adriána (referee) ; Veselá, Mária (advisor)
This bachelor thesis is focused on smart edible films sensitive to pH. The theoretical part deals with smart packaging including legislation. The main compound for the film preparation is chitosan, which is described and anthocyanins serving as the color indicator. At first, the anthocyanins were isolated from red cabbage using extraction. The edible films were prepared from chitosan, corn starch and anthocyanins. Pentasodium triphosphate was used as a crosslinking agent. The layers were subjected to the solubility test, which showed smallest decrease in case of fast drying in the dryer, namely 14,5 %. The color reaction on the pH change was studied. It was found that the prepared layers reacted to every pH change, the most significant reaction was to pH 1 and 3.
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Smart food polymer layers
Valíková, Michaela ; Kovalčík, Adriána (referee) ; Veselá, Mária (advisor)
Smart packaging represents a group of packaging with great potential when used in the food industry. Active packaging can have a positive effect on the condition of stored food and smart packaging can inform consumers about the condition of stored food. In the theoretical part, a search was made on the topic of packaging in the food industry, with emphasis on active and intelligent packaging, including the legislative framework. The substances from which smart packaging is made have been described. In the experimental part, partially water¬insoluble polymer layers were prepared from gelatin, glycerol, crosslinking agent and anthocyanin extract. Glutaraldehyde or tannic acid was used as a crosslinking agent. Anthocyanins were obtained by extraction from red cabbage. The total concentration of anthocyanins in the extract was determined by the difference method. For prepared layers, their water solubility was measured and the colour response to the pH environment was evaluated spectrophotometrically. The stability of the layers over time was also monitored. It was found that the prepared layers are able respond to changes in pH.
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