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Determination of sweeteners and preservatives in energy drinks by HPLC
Zídková, Anežka ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This master´s thesis is focused on simultaneous determination of sweeteners and preservatives in energy drinks by liquid chromatography coupled with DAD and ELSD detection. The method was optimized for determination of aspartame, acesulfame K, saccharin, sucralose, steviol glycosides, benzoic acid and sorbic acid. Analyses were carried out on the Poroshell 120 EC-C18 column (4.6 x 150 mm, 2.7 m, Agilent) using mixture of methanol, acetone and water with formic acid and trimethylamine as a gradient mobile phase at a flow rate 0,5 mL•min-1. Validation parameters were determined (limit of detection, limit of quantification, repeatability and recovery). The validated method was applied on real samples.
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Determination of propionic acid in bakery products by liquid chromatography
Benkovská, Dagmar ; Vítová, Eva (referee) ; Kučera, Pavel (advisor)
This thesis deals with the development of high performance liquid chromatography method (HPLC) for the determination of propionic acid in bakery products. This work is resulting from the requirements and conditions of Czech Agriculture and Food Inspection Authority (CAFIA) laboratory in Brno. The theoretical part of the thesis describes properties, production, metabolism, toxicity and preservative effect of propionic acid. Furthermore it is treating about HPLC, validation of some analytical method and methods of propionic acid determination. Experimental part is focused on the propionic acid determination in the major part of available products with this preservative on the Czech market. Propionic acid was extracted from the sample with water, filtered and the filtrate was analyzed directly by HPLC. Separation was performed on a XBridge C18 column (3 x 150 mm, 3,5 µm) with a mobile phase of phosphate buffer (pH adjusted to 2,8) and UV detection at 210 nm. Used method of propionic acid isolation was compared with repeated extraction method, extraction in the mobile phase solution and steam destilation both in commercial samples and in laboratory baked breads with known addition of propionic acid. HPLC with water extraction technique was evaluated as a suitable method for propionic acid determination in bakery products.
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Effect of preservatives on the sensory properties of ham
Bělohoubková, Tereza ; Hudečková, Helena (referee) ; Mikulíková, Renata (advisor)
The Master’s thesis contemplates the effect of additives on sensory properties of ham. The theoretical part incorporates history of meat product preservation and characterization of ham from legislative and compositional point of view. Technological ham making process in the Czech republic as well as worldwide and nutritional value of cooked ham are described. Further on the thesis contains a description of traditional and new sensory evaluation methods. Discussion of current solution of the issue concludes the theoretical part. In the practical part technological highest standard ham making process was optimalized, without the use of industrial manufacturing devices. Samples of ham containing nitrite salting mix and sodium nitrate along with a ham sample without the additon of preservatives were prepared. Total content of moisture, proteins, ash and fats was determined in these samples by regular standardized methods, that were statistically compared by paired test or analysis of variance (ANOVA) with results obtained by FoodScanTM instrument. Fatty acids content was determined by gas chromatography with FID detector in samples containing additives and a sample without additives. Effect of additive adittion in ham on nutritional characteristics, fatty acids content and on concentration of TBARS (lipid oxidation products) was investigated. Within sensory analysis effect of additives on sensory properties of ham was studied by CATA method. Sensory panel consisted of consumers. In the first sensory analysis of ham samples with addition of preservatives (nitrite salting mix, sodium nitrate, sodium acetate and sodium lactate) consumers picked ham containing nitrite salting mix as the most acceptable. The chosen sample served as a base for the second sensory analysis of samples containing antioxidants (sodium erythorbate, butylhydroxyanisole, butylhydroxytoluene, sodium ascorbate) and stabilizers (sodium hydrogen phosphate and potassium phosphate). In the second sensory analysis the consumers had difficulty distinguishing the samples. Part of the sensory analysis was a marketing research and a study of ham additives perception from a consumer’s point of view.
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Quality of selected meat products produced in standard and organic quality
JAROŠOVÁ, Martina
The aim of this Master thesis was to compare the presence of used preservation substances and basic ingredients in meat products made in regular and bio-quality. In practical part of the thesis, a polarization measurement was done with the aim to determine whether there is a quality difference between these two production qualities. The obtained data were subsequently processed and statistically evaluated. The statistical evaluation showed that the basic composition of meat products in regular and bio-quality is basically identical in percentage. Furthermore, the frequency of used preservation additives in different foods was statistically evaluated as well. In conclusion, food products in bio-quality showed 0.7 less additive content compared to regular food product, however, the difference was still weighed as statistically insignificant.
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Význam a výskyt konzervantů ve výrobcích z ovoce a zeleniny
Kotrlová, Adéla
The bachelor thesis on the sujbect Occurrence and Importance of Preservatives in Products of Fruits and Vegetables was elaborated between years 2017 and 2019 at the Institute of Postharvest Technology of Horticulture Products at the Faculty of Horticulture at the Mendel University in Brno. Preservation methods are divided into conservation by physics methods used in the production of fruits and vegetables products. Conservation by chemical preservatives where are desribed particular preservatives used in production of fruits and vegetables products. Legal restrictions and specifications preservatives used in products of furits and vegetables. Enclude limits of the quantity in certain types of products.
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Determination of sweeteners and preservatives in energy drinks by HPLC
Zídková, Anežka ; Pořízka, Jaromír (referee) ; Diviš, Pavel (advisor)
This master´s thesis is focused on simultaneous determination of sweeteners and preservatives in energy drinks by liquid chromatography coupled with DAD and ELSD detection. The method was optimized for determination of aspartame, acesulfame K, saccharin, sucralose, steviol glycosides, benzoic acid and sorbic acid. Analyses were carried out on the Poroshell 120 EC-C18 column (4.6 x 150 mm, 2.7 m, Agilent) using mixture of methanol, acetone and water with formic acid and trimethylamine as a gradient mobile phase at a flow rate 0,5 mL•min-1. Validation parameters were determined (limit of detection, limit of quantification, repeatability and recovery). The validated method was applied on real samples.
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Plant-derived food preservatives as alternatives to sulfites
Kmeťová, Martina ; Leuner, Olga (advisor) ; Melnikovová, Ingrid (referee)
In present, fresh-cut foods, dried fruits and processed vegetables are often treated with sulfites against the spoilage and enzymatic browning. However, these additives cause undesirable health risks at a certain portion of the population. In addition, customers demand food without added chemicals. This Bachelor thesis is a literature review of substances with similar properties such as sulfites. These substances should have the ability to inhibit browning and undesirable microorganisms and act as antioxidants; substances of natural origin without health risks unchanging organoleptic properties of food and at the same time available for price allowing them to participate in tests on food models. As a result, sixteen compounds which exhibit very similar properties as sulfites were suggested for further research.
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Food additives of plant origin: analysis of traditional and conventional use
Steiningerová, Kristýna ; Nový, Pavel (advisor) ; Hummelová, Jana (referee)
This bachelor thesis summarizes the knowledge about food preservation including methods of preservation by using food additives of plant and synthetic origin. In order to survive and secure themselves for unfavorable times, it was necessary for people to invent methods of food preservation for extending their shelf-life, but foremost to ensure food safety.
First part of thesis summarizes issues of food preservation. There are mentioned traditionall used methods for preservation since the beginning of preservation and also description of food additives. Concurrently domestic and foreign international organisations, which handle food additives issues, are mentioned. Furthermore there are described possible risks to human health, caused by food additives. Thesis defines preservatives, antioxidants a their main role in food industry. Important point of this thesis is also an attempt to describe substances of natural origin as suitable alternatives to synthetic additives. In the following there is part about medicinal plants including herbs and spices used as preservatives and additives with antioxidant activity.
The aim of this study was to analyse the plants traditionally used for food preservation. However, neither satisfying references about traditionally used plants for preservation were found and nor were confirmed. For this reason was chosen group of plants, which were used as spices in food processing since acient times, for analyses. In scientific browsing databases were found records about chosen plants and their antibacterial and antioxidant activities and about their testing in food models. The result is a list of plants with proven antibacterial and antioxidant effects in vitro studies investigating their potential use in food preservation. Some species, which were not in food models tested, were identified with a potential preservative effect, so it opens the door for possible further investigation.
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Determination of propionic acid in bakery products by liquid chromatography
Benkovská, Dagmar ; Vítová, Eva (referee) ; Kučera, Pavel (advisor)
This thesis deals with the development of high performance liquid chromatography method (HPLC) for the determination of propionic acid in bakery products. This work is resulting from the requirements and conditions of Czech Agriculture and Food Inspection Authority (CAFIA) laboratory in Brno. The theoretical part of the thesis describes properties, production, metabolism, toxicity and preservative effect of propionic acid. Furthermore it is treating about HPLC, validation of some analytical method and methods of propionic acid determination. Experimental part is focused on the propionic acid determination in the major part of available products with this preservative on the Czech market. Propionic acid was extracted from the sample with water, filtered and the filtrate was analyzed directly by HPLC. Separation was performed on a XBridge C18 column (3 x 150 mm, 3,5 µm) with a mobile phase of phosphate buffer (pH adjusted to 2,8) and UV detection at 210 nm. Used method of propionic acid isolation was compared with repeated extraction method, extraction in the mobile phase solution and steam destilation both in commercial samples and in laboratory baked breads with known addition of propionic acid. HPLC with water extraction technique was evaluated as a suitable method for propionic acid determination in bakery products.
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Use of conservation technologies in meat proccesins and produktion of meat products
KUBECOVÁ, Dagmar
This thesis deals with the use of conservation technologies in meat processing and production of meat products. The aim is to gather available information on methods to extend the life of the issue of meat and meat products. In her first retrieval character are generally mentioned meanings conservation technologies and described the principles of conservation, protection and legal requirements associated with it. It further describes the various methods of preserving meat and meat products and their problems including the latest ways that are not yet instance for their high financial demands of commercially exploited. Methods for evaluating the effect of reducing or fully suppressing the activity of microbes. Following the issue of limiting the processing technology and last but not least, there is mention of Additives meat and meat products, antimicrobial substances and antioxidants. Furthermore, there are new trends in contemporary conservation and the conclusion is dedicated to the packaging of meat and meat products, which are monitored by means of long-term storage. The end is explained the principle of vacuum packaging.
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