|
|
Development of cereal products for specific nutrition with the addition of legumes, algae and yeasts
Pavlištíková, Nela ; Mikulíková, Renata (referee) ; Márová, Ivana (advisor)
This diploma thesis is focused on the development of cereal products for special nutrition with the addition of legumes, algae and yeast. In the theoretical part, expert knowledge about gluten-free cereals, their chemical composition, gluten and food fortification is developed. Then an overview of the legumes, algae and yeasts tested in this work was elaborated. As a part of the literature review, emphasis was placed on the chemical composition of the analysed products. In the experimental part, the characterization of selected gluten-free cereals and legumes was carried out. The tested cereals were buckwheat, quinoa and gluten-free oatmeal. Pea, red lentil and Beluga black lentil were selected from among legumes. Furthermore, various types of algae and yeast extracts were prepared, which were subsequently optimized. Algae of the genera Dulse, Chlorella and Spirulina were selected for enrichment of pseudocereals. Dried baker's yeast and Saccharomyces cerevisiae were chosen as yeast representatives. Phenolics, flavonoids, antioxidant activity, carbohydrates, proteins, fatty acids, lipids and lipophilic pigments were determined in gluten-free cereals and legumes. The content of -glucans and gluten were determined for in cereals as well. Some content of phenolic substances, flavonoids, antioxidants, total fatty acids, lipophilic substances, pigments and -glucans were found in extracts from algae and yeast. Selected samples were also subjected to antimicrobial and cytotoxicity tests. Finally, mixed cereal products were prepared from selected gluten-free cereals, legumes, selected algae and yeast extracts and algae biomass. Extracts were selected based on obtained results and subjected to MTT cytotoxicity tests. It was found that the addition of pea, extracts from algae and yeast or the algae biomass itself increased the protein content of the prepared mixtures. Furthermore, in hexane:ethanol extracts from Chlorella and Spirulina or their biomass, the amount of antioxidants has been increased. The obtained results show that the combination of cereals with addition of algae and yeast extracts is suitable for increasing the protein content in gluten-free products. It was also found that selected microalgae and yeast have the potential to enrich gluten-free products with bioactive substances, when using biomass or extracts produced from them.
|
|
|
Possibilities of processing the fruit of lesser-known fruit tree species
Vachta, Jonáš ; Hudečková, Helena (referee) ; Mikulíková, Renata (advisor)
This diploma thesis deals with the possibilities of using the fruits of common quince (Cydonia oblonga), common medlar (Mespillus germanica) and flowering quince (Chaenomeles speciosa) for food purposes, specifically for the production of jellies and jams. The goal was to create a product that would capture the character of the fruit used, preserve its beneficial properties, such as aromas and the content of bioactive substances, and at the same time be pleasant for consumers. A total of three types of products were prepared, namely gelatin jelly, agar jelly and jam for each type of fruit used. The product samples were subjected to sensory analyses, the aim of which was to determine the optimal addition of sugar to the product, to determine the overall consumer acceptability of the individual samples, and in the case of jelly, also to compare the sensory properties of the gelatin and agar variants. For chemical analyses, model samples were prepared, the composition corresponding to the best sensorially evaluated samples from each type of product. The total content of polyphenols, the total content of flavonoids, the content of vitamin C, the content of lipophilic pigments, ubiquinone and phytosterols and the profile of volatile compounds in individual samples were studied. The analysis results showed that the jams, as heat-processed products, generally retained a greater amount of bioactive substances compared to the jelly samples, and in certain cases even a greater amount than the fruit samples. The jelly samples, on the other hand, retained a greater amount of the original fruit aroma.
|
|
|
Use of citrus fruits in the food industry
Havlíková, Michaela ; Hudečková, Helena (referee) ; Mikulíková, Renata (advisor)
The main objective of the thesis was to prepare marmalades, jellies, and dried slices of citrus fruits. Three types of citrus fruits: orange, grapefruit, and pomelo, were chosen for this thesis. The nutritional characteristics of the prepared products were determined including volatile matter content, dry matter content, pigment content, lipophilic content, and vitamin C content. The aforementioned products were also subjected to sensory analysis to assess their taste, aroma, texture, colour, and overall acceptability. The theoretical part describes the legislation dealing with citrus processing, marmalades, dried fruit and jelly confectionery. Further, the characteristics of the aforementioned food products and the characteristics of citrus fruits are also given. The theoretical part also deals with the theory of the methods used, i.e. sensory analysis, gas chromatography with mass spectrometry, and high-performance liquid chromatography. The experimental part describes the preparation of samples and the performance of individual determinations. In the sensory analysis, marmalades, jellies, and dried sheets were evaluated separately. The evaluators assessed their acceptability depending on the citrus used. The volatile substances were also determined by gas chromatography-mass spectrometry. The moisture and dry matter of the products were determined by drying and the pigments and lipophilic substances contained in the products were determined by high-performance liquid chromatography.
|
|
|
Possibilities of using spices in the production of ham salami
Vershinina, Alina ; Szotkowski, Martin (referee) ; Mikulíková, Renata (advisor)
This bachelor's thesis focuses on the possibilities of using different spices, specifically cumin, nutmeg, allspice and marjoram, in the production of ham cuts. The aim of the work is to investigate the effect of these spices on the taste, aroma and other sensory properties of the ham cut and to assess their contribution to improving the overall quality of the product. The methodology includes the collection of samples of ham cut with various additions of spices, the performance of sensory analysis and chemical analysis for the identification and quantification of phenolic substances present in individual spices. Subsequently, the results will be evaluated and their significance for the production of ham cuts will be discussed. The results of this work could contribute to a better understanding of the use of spices in the production of meat products and provide data for the optimization of recipes and processes in the food industry.
|
|
|
Possibilities of using plant protein sources in the production of pâtés
Kmeť, Jan ; Svoboda, Zdeněk (referee) ; Mikulíková, Renata (advisor)
The main purpose of this thesis is to evaluate the options of adding high-protein plant-based substitutes of meat to liver pâtés. The aim of this research was to optimize recipes and prepare liver pâtés, in which certain part of meat component (25 % of total amount) was substituted by peanuts, chickpeas or barley groats. Pâté samples were prepared in two sets – a seasoned one and an unseasoned one. The effect of plant substitute on the final product was assessed by sensory evaluation and analysis of selected nutritional characteristics. Crude protein content was determined by Kjeldahl method, fat content and fatty acid profile were analyzed with the use of GC FID. The data obtained by sensory evaluation were statistically assessed. The most widely acceptable sample for assessors turned out to be the standard sample, followed closely by the sample of spiced pâté with addition of chickpeas. Both the seasoned and unseasoned version with groats were found as noticeably less appetizing. Pâtés with the addition of peanuts were determined to have similar contents of crude protein and fat as the standard sample. The samples containing peanuts or chickpeas were proven to serve as a decent substitute for meat from a nutritional point of view, due to their high content of unsaturated fatty acids. Final results of the research clearly show that the spiced samples with the addition of peanuts or chickpeas, as well as the unseasoned sample solely with chickpeas, happen to be an attractive alternative to pure meat pâtés.
|
|
|
Possibilities of using rose hips in the food industry
Maráčková, Adéla ; Kovalčík, Adriána (referee) ; Mikulíková, Renata (advisor)
This thesis focuses on the possibilities of using rose hips in the food industry. The aim of this thesis was to design and create sensory acceptable food products which are made from rose hips. A recipe was created for rosehip jams, chutneys and jellies. During the development of the recipe, individual flavors of rosehip products were evaluated. Freshly ground spices combined with fruits and vegetables were used to flavor the products. According to the optimized recipe for chutney, 1 standard and 3 types with spices were produced: chili, allspice and ginger. A recipe for jams was also prepared - 1 standard and 3 types: cardamom, cinnamon and rosehip jam in combination with apple jam in a ratio of 1:1. Finally, a jelly recipe was created - 1 standard and 3 types with spices: cinnamon, allspice and anise. Individual rosehip products were subjected to sensory analysis and their organoleptic properties were evaluated. The sensory analysis was divided into three parts – for jellies, jams and chutneys. The best rated was a sample of rosehip jelly without the addition of spices. Among the jams, the best rated sample was the jam with the addition of cardamom, which was popular with the respondents because of its pleasant and non-traditional taste. For rosehip chutney, the sample without the addition of spices was the best rated. The mass spectrometry method was used to determine the presence of ionones in the samples, the presence of which is typical for rose hips. The presence and concentration of vitamin C, lipophilic substances and total pigments were determined in the respective rosehip products using the high-performance liquid chromatography method. It was verified by the method of high-performance liquid chromatography that a considerable amount of vitamins was preserved even after the preparation of the resulting products, which were heated. The results of the work pointed to the potential of rosehips, which can be used in the food industry.
|
|
|
Production of pates with the addition of mushrooms
Tóthová, Martina ; Holub, Jiří (referee) ; Mikulíková, Renata (advisor)
This bachelor thesis deals with the sensory evaluation of pâté with mushrooms. First the 3 samples of pâtés were made to select the right concentration of mushrooms for sensory evaluation. Then the 7 samples of pâtés which contained different texture and types of mushrooms were produced. In the theoretical part pâtés are characterised, their manufacturing and types of pâtés are described. The part of literature search is description of mushrooms in general, their composition and description of mushrooms which were used for production of pâtés. Another topic is description of conditionals and methods of sensory analysis. The experimental part is focused on the production of pâtés for two sensory analyses, evaluating the heat treatment and sensory analysis. The content of vitamin D in the samples of pâtés was analysed by liquid chromatography. Processing of results of sensory analysis of pâtés was determined that the best samples were pâtés with milled champignons and champignons which were add in blender.
|
|
|
Phloridzin content in selected apple varieties
Křehlíková, Jana ; Mikulíková, Renata (referee) ; Diviš, Pavel (advisor)
Phloridzin, a phenolic compound found in Malus genus, was targeted in this study for detection in apples and apple-based foods via HPLC. The research aimed to assess phlorizin’s potential as a marker for confirming apple presence in food, addressing food authenticity concerns. The methodology encompassed method optimization for sample preparation, considering solvent selection and oxygen impact on stability. Analysis revealed significant phloridzin distribution among apple varieties (Golden Delicious, Red Delicious, Granny Smith, Gala, Champion, Jonagold), averaging 17 ± 10 mgkg1. Further, 15 fruit products were surveyed for phloridzin content, with 5 non-apple-labelled foods also analysed. Phloridzin proved effective in detecting undeclared apple presence in jams, fillings, and fruit purees, highlighting potential for authenticity verification. However, fruit drinks and juices exhibited inconclusive results, suggesting a need for improved sample preparation and analysis methods.
|
|
|
Study of the Selected Types of Sulphur Compounds in Beer and Brewing Materials
Mikulíková, Renata ; Ventura, Karel (referee) ; Ventura, Karel (referee) ; Čáslavský, Josef (referee) ; Márová, Ivana (advisor)
Much attention has been recently devoted to sensorially active substances affecting beer quality in the Czech Republic and worldwide. Among them, the heterocyclic and sulphur containing compounds play an important role, some of them with high sensorial activity even in extremely low concentrations. Trace amounts of these compounds, which can be frequently found in foods, participate in formation of their aroma and this effect can be generally evaluated as favorable However, in malt or beer it is true only to a limited extent and the presence of heterocyclic and sulphur containing compounds are in this respect assessed rather unfavorably. The aim of the present study was to provide a survey about of problems in the field of sulphur containing compounds in barley, malt and beer, to describe metabolic paths leading to their formation and to verify experimentally possibilities of their determination using modern analytical methods. Sulphur-containing amino acids are a natural part of barley, malt and beer and are precursors of the origin of volatile sulphur substances. The most frequently occurring sulphur amino acids, metionine, cysteine and homocysteine, were selected for analytical monitoring. The method of gas chromatography was used to determine sulphur-containing amino acids in barley, malt and beer. Prior to the analysis, sulphur-containing amino acids were derived and volatile N(O,S)-ethoxycarbonyl propyl esters were formed; they were subsequently analyzed using the gas chromatography with mass detector (GC/ MSD) and the gas chromatography with flame photo detector (GC/ FPD). Direct analysis of sulphur volatile substances is possible only rarely as they are found in the analyzed matrices (malt, beer) only in very low concentrations ( g/kg,l - ng/kg,l). Before the analysis, the analytes must be extracted from the matrix and concentrated. The modern analytical methods SPME (Solid Phase Micro Extraction), SPDE (Solid Phase Dynamic Extraction) and TDAS (Thermal Desorption Autosampler) were experimentally compared for the extraction and subsequent concentration of sulphur volatile substances. The method of gas chromatography with flame photo detector was used to determine sulphur volatile substances. Following volatile sulphur substances were monitored: dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide, carbon disulphide, ethyl sulphide, diethyl disulphide, methionol, 3-methylthiophen, ethyl thioacetate, 2-methyl-1-buthanthiol. Only metionine was detected in significant amounts in the barley samples analyzed. Not only content but also dependence on a variety and locality were studied. Further, changes in methionine, cysteine and PDMS content during malting were followed. Results proved a significant decline in these substances content depending on the kilning temperature. Three types of fibers were tested for the analyses of the selected volatile sulphur substances in beer in the SPME method. PEG - a fiber with stationary phase Carbowax, PDMS - a fiber with stationary phase polydimethylsiloxan and a combined fiber CAR/PDMS - Carboxen and polydimethylsiloxan. Carbon disulphide, methionol, dimethyl sulphide, 3-methylthiophen and diethyl disulphide were detected with this method. Content of the other analyzed volatile sulphur substances was below the limit of detection. Further was tested usage the SPDE and TDAS methods. Both methods appear to be the suitable for the determination of volatile sulphur substances in beer.
|
|
|
Influence of storage on the microbial composition of French Saint-nectaire cheese
Šislerová, Lucie ; Mikulíková, Renata (referee) ; Brázda, Václav (advisor)
The aim of my work is the comparison of microbial composition between farmtype and dairytype of Saint-nectaire cheese and the influence of storage time and temperature on the development of microbial composition, content of fatty acids and aromatic substances. Selected microorganisms were identified by RT-PCR. In addition, Penicillium roqueforti and fuscoglaucum have been identified in the Saint-nectaire farm type compared to the dairy type. In both types of cheese, the highest amount of selected microorganisms was detected in fresh cheese. When stored at 20 °C, an increase over fresh cheese occurred in the following microorganisms: Streptococcus thermophilus, Lactobacillus bulgaricus, Cladosporium herbarum and Penicillium commune and camemberti, and the presence of contaminants and pathogens was noted. After one week of storage at 20 °C, they were Micrococcus luteus, Salmonella enterica and Staphylococcus aureus, and after another two weeks of storage, Listeria monocytogenes was identified. The fatty acid and volatile compounds were compared for five samples: fresh cheese, cheese stored in the refrigerator for one week and three weeks and cheese stored at 20 °C for one week and three weeks. The content of bound and free fatty acids was measured, both by GC-FID. The content of bound fatty acids was comparable in all measured samples. The highest content of free fatty acids was in the cheese after three weeks of storage at 20 °C. The most common fatty acid is palmitic acid. Volatiles were determined by HS-SPME-GC-MS. The most volatiles were identified in the cheese after three weeks at 20 °C and in the cheese after one week in the refrigerator. The most represented groups were alcohols, ketones and acids.
|
guest ::
