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Pollen analysis is a method used for verification of the botanical and geographical honey origin. Currently, much effort is being made to introduce automated systems with the use of image analysis programs. The automatic analysis is impeded by the insufficient depth of field of objects when using a light microscope, however, this can be avoided by using image reconstruction from images obtained from different focal planes. In this method, testing was performed on the normal focus (NF) and extended-depth-of-focus (EDF) images. These two methods were compared and statistically evaluated. The number of pollen grains and selected morphometric characteristics were compared. For EDF images, a higher number of pollen grains was obtained for the analysis, and except for the length/width ratio, a statistically significant difference was observed in the characteristics of pollen grains between the compared NF and EDF methods.

Honeybees are important pollinators. As a side product of pollination, honeybees produce honey, as a natural sweetener. The source of honey depends on the hive location. In specific conditions honeybees produce monofloral honey, but more common are polyfloral kinds of honey. In this study honey from the Czech Republic in the 2019 season was evaluated by melissopalynology analysis. The common botanical taxa in the Czech Republic were determined and season impact to pollen taxa was compared for dominant pollen taxa. The taxonomic distribution of pollen in Czech honey was stable during the year. The average number of species was 11.52 taxa per sample. The dominant pollen source in Czech honey was the Brassicaceae family. The high pollen content in honey was confirmed also in the Rosacea family (fruit tree), Ubelliferacae family and Myosotis genus. During the year the pollen taxa were equally distributed in honey. Seasonal effects were confirmed only in Salix genus, Ubelliferacae family and Phacelia genus. Seasonal effects correspond with the blooming season and honeybee handling in the hive was also confirmed. High variability during the season and hive location was confirmed for other taxa.

One of the options to determine botanical origin of trees or honey is the analysis of pollen grains. The characteristics of pollen grains in Czech flora has not been sufficiently described yet. Within this work, fruit trees pollen of Czech origin was characterized on the basis of morphological and spectral description of pollen grains produced by fruit species of M. domestica, P. armenica, P. persica, P. domestica, P. avium and P. cerasus. The morphological characterization results of the studied fruit species are consistent with results by other authors, but certain differences between the pollen grains of some fruit trees were confirmed. Most morphological differences were confirmed among the Malus and Prunus genera. Results of morphological and spectral analyzes further confirmed the differences between some types of fruit trees, but homogeneity remained for individual species even in mixed samples. Morphological and spectral analysis can therefore be used for botanical identification of pollen. If this knowledge is applied to pollen analysis in honey, these methods can also be used to verify the botanical origin of honey.

Fat is an irreplacable ingredient in the production of sausages and it determines the appearance of the resulting cut to a significant extent. When shopping, consumers choose a traditional product mostly according to its appearance, based onwhat they are used to. Chemical analysis is capable to determine the total fat content in the product, but it cannot accurately describe the shape and size of fat grains which the consumer observes when looking at the product. The size of fat grains considered acceptable by consumers can be determined using sensory analysis or image analysis. In recent years, image analysis has become widely used when examining meat and meat products. Compared to the human eye, image analysis using a computer system is highly effective, since a correctly adjusted computer program is able to evaluate results with lower error rate. The most commonly monitored parameter in meat products is the aforementioned fat. The fat is located in the cut surface of the product in the form of dispersed particles which can be fairly reliably identified based on color differences in the individual parts of the product matrix. The size of the fat grains depends on the input raw material used as well as on the production technology. The present article describes the application of image analysis when evaluating fat grains in the appearance of cut of the Gothaj sausage whose sensory requirements are set by Czech legislation, namely by Decree No. 326/2001 Coll., as amended. The paper evaluates the size of fat mosaic grains in Gothaj sausages from different manufacturers. Fat grains were divided into ten size classes according to various size limits; specifically, 0.25, 0.5, 0.75, 1.0, 1.5, 2.0, 2.5, 5.0, 8.0 and over 8 mm. The upper limit of up to 8 mm in diameter was chosen based on the limit for the size of individual fat grains set by the legislation. This upper limit was not exceeded by any of the products. On the other side the mosaic had the hightest representation of 0.25 mm fat grains.

With the growing popularity of various plant proteins used as raw materials for meat production, interest of manufacturers to extend the range of such raw materials is increasing as well. Manufacturers are trying to minimize the cost of manufacturing their products with simultaneous preserving the nutritional value of their products to the maximum extent possible. Such cheaper raw materials, which are also nutritionally rich, include pea protein. Another advantage for manufacturers is the fact that legislation does not order them to indicate pea protein presence in case of its addition, as it does for other allergenic ingredients, although this legume contains storage proteins which can cause a variety of allergic reactions, just like other legumes. Currently no method used for its qualitative determination has been described in literature, let alone its quantitative determination. Our work describes a possible method that can be applied for its quantification. It is a stereological method applied to microscopic sections stained by immunohistochemical staining based on the avidin-biotin complex using monoclonal legumin (1H9) as the primary antibody. The stereological method is based on geometry, it applies knowledge of geometry to analyze a sample of diverse origin, size and internal structure. Despite potential shortcomings in staining microscopic preparations, stereology allows us to perform quantification based on knowledge of morphology of the observed structures. This work describes a procedure of a known pea protein addition quantification in model meat products by means of Ellipse software. Pea protein quantification was performed in two ways. In the first case ten microimages of all sections prepared were examined, while in the second case one scan of the entire section was analyzed. Based on the results, Spearman's correlation coefficient was calculated, which confirmed our assumption of correlation between the protein added into the product and the measured area in microimages. In both ways Spearman's correlation coefficient was rSp = 1000. We obtained regression equations in MS Excel, which can be used for calculation of pea protein addition based on measured area of this protein in microscopic section.

In recent years, various protein additives intended for manufacture of meat products have increasing importance in the food industry. These ingredients include both, plant-origin as well as animal-origin proteins. Among animal proteins, blood plasma, milk protein or collagen are used most commonly. Collagen is obtained from pork, beef, and poultry or fish skin. Collagen does not contain all the essential amino acids, thus it is not a full protein in terms of essential amino acids supply for one's organism. However, it is rather rich in amino acids of glycine, hydroxyproline and proline which are almost absent in other proteins and their synthesis is very energy intensive. Collagen, which is added to the soft and small meat products in the form of isolated porcine protein, significantly affects the organoleptic properties of these products. This work focused on detection of isolated porcine protein in model meat products where detection of isolated porcine protein was verified by histological staining and light microscopy. Seven model meat products from poultry meat and 7 model meat products from beef and pork in the ratio of 1:1, which contained 2.5% concentration of various commercially produced isolated porcine proteins, were examined. These model meat products were histologically processed by means of cryosections and stained with hematoxylin-eosin staining, toluidine blue staining and Calleja. For the validation phase, Calleja was utilized. To determine the sensitivity and specificity, five model meat products containing the addition of isolated porcine protein and five model meat products free of it were used. The sensitivity was determined for isolated porcine protein at 1.00 and specificity was determined at 1.00. The detection limit of the method was at the level of 0.001% addition. Repeatability of the method was carried out using products with addition as well as without addition of isolated porcine protein and detection was repeated 10 times. Repeatability in both, positive and negative samples, for isolated porcine protein was determined at 100%. The results show that the histological processing of cryosections stained using Calleja is suitable for detecting isolated porcine protein in meat products.

Nowadays there are various vegetable protein additives intended for the manufacture of meat products in the food industry. These ingredients include both, plant-origin as well as animal-origin proteins. The most common vegetable additives include various types of flour, starch, fiber and plant protein. Among animal proteins, the most commonly used are plasma, collagen or milk protein. Milk protein is added to meat products due to its functional properties, such as emulsifying fats, improving the holding capacity of meat, improving juiciness, gel-forming capacity and affecting the taste of the product. Usage of these proteins, however, is currently limited by the effective legislation, not only in order to prevent consumer deception, but also because of their potential impact on consumers' health of. Thus, this issue has received considerable attention not only in the Czech Republic, but also globally. The main risk is the impossibility of selecting a suitable foodstuff for individuals with potential allergic reactions. The only option for allergic consumers to protect themselves is to strictly exclude the given allergen from their diet. Although the number of studies dealing with the reduction or loss of allergenicity is increasing, yet these practices are not common. Most of the population suffering from food allergies is thus still dependent on strict exclusion of foodstuffs causing adverse allergic reactions from their diet. Detection of allergens in foodstuffs is unfortunately quite difficult due to the fact that they occur in trace amounts and are often masked by different parts of the foodstuff. This research dealt with the detection of milk protein in meat products purchased in the market network of the Czech Republic, whereas declaration given by the manufacturer on the packaging for the small meat products purchased from the market was used to verify the detection of milk protein by the immunofluorescence method. 20 products were examined, these were selected with regard to the presence of milk protein that was declared by the manufacturer on the packaging. Method validation was performed by comparing the positive results from the investigated method with information on the packaging of the meat product. Milk protein was detected in 84.62 per cent of samples where the manufacturer declared the presence of milk or cheese on the package and additionally in 85.71 per cent of samples where the manufacturer declared the presence of milk protein. The results show that the immunofluorescence method is suitable for the detection of milk protein in meat products.

Fiber, a suitable additive to meat products with water-holding capacity, reduces curing losses and maintains juiciness of the meat. The risk is the use of excessive amounts of flour or other ingredients of vegetable origin, in which the fiber is contained. In some cases, sensory characteristics of products can be affected. Detection of fiber may be prevention of adulteration in some meat products. It is therefore very important to regularly detect the amount of fiber in meat products and check its contents. Fiber in meat products can be detected by various methods, applied are for example gravimetric, spectroscopic, histochemical, and microscopic methods. For this reason, a model meat product (Vysočina salami) was prepared in our experiment with the addition of bamboo fiber of selected concentrations of 0%, 2%, and 3%. Subsequently, a series of microscopic sections was made on different days of curing (day no. 7, 14 of the drying phase and 28, 42 of storage). Individual sections were examined and captured using a polarization microscope, the amounts of fiber in individual sections were analyzed by means of image analysis software and the values obtained were compared with each other. Also the influence of drying on the measured area of fiber in sections was monitored. The results indicate a noticeable reduction in the area of fiber until the seventh day of ripening, which is caused by the rapid loss of water in the product. In contrast, sections of products from the following days of drying contained mildly increased concentrations of fiber, which was caused by gradual drying of the products, while the area of fiber refrained form becoming smaller. Between the individual days of drying, a difference that was statistically significant was demonstrated from the 14th day of (storage or drying). Correlation was observed between the date of (storage or drying) and amount of added fiber. Among the tested mean values for the sample with the addition of fiber concentration of 2 % an insignificant difference was found. The difference between test values (day/fiber) in the sample with addition of 3% fiber was, however, statistically significant.

In food industry nowadays, there are various plant-origin protein additives which are meant for production of meat products. Among the most frequent additives of this type there are different kinds of flour, starch, fiber, and plant-origin proteins. Their usage at present is limited by the existing legislation not to prevent consumer deception but also for reasons of possible influence on consumer health. Therefore, this problem is paid a lot of attention not only in the Czech Republic but also all over the world. The main risk is seen in the impossibility to choose a suitable foodstuff for an individual prone to allergic reactions. Potential allergens are also often plant-origin raw materials which are added into foodstuffs for their technological qualities and low price. Wheat is widely cultivated cereal as well as an important source of proteins. After ingestion or inhalation, wheat proteins may cause adverse reactions. These adverse effects include a wide range of disorders which are dependent on the method of contact with wheat protein. These adverse effects can then take the form of various clinical manifestations, such as celiac disease, T-cell mediated inflammatory bowel disease, dermatitis, skin rash, breathing difficulties, allergy to pollen or to wheat flour or food allergy to foodstuffs containing gluten. The only possible protection against adverse immune reactions for those with food allergies is strictly excluding the allergen from their diet. Although the number of studies dealing with the reduction or loss of allergenicity is increasing, yet these practices are not common. Most of the population suffering from food allergies is thus still dependent on strict exclusion of foodstuffs causing adverse allergic reactions from their diet. In order to avoid misleading consumers and also to protect allergic consumers, analytical methods applicable to all types of foodstuffs have been developed. Unfortunately, detection of allergens in foodstuffs is relatively difficult because of the fact that they occur in trace amounts and are often masked by various parts of the product. This paper deals with detection of wheat protein in meat products bought in the retail network of the Czech Republic. Ten cooked meat products, especially types of sausages and soft salami which stated wheat protein in their composition, were examined. The samples were processed using the method of immunofluorescence and stained with Texas Red fluorochrome. The presence of wheat protein was demonstrated in all the examined meat products. From the results it follows that the method of immunofluorescence is suitable for detection of wheat protein in meat products.

Starch has been still used in food industry today as one of the main additives in foodstuffs. The reason for the use of starches in foodstuffs is their ability to bind water and to contribute to the coherent structure of the final product. However, the presence of starch in some foodstuffs is limited by legislation. These are especially meat products where legislation prohibits using starches. This study deals with determination of native starches using histochemical Lugol Calleja staining in meat products. The targeted structures of this successive staining are starches and collagen ligaments. Other structures can also be detected, based on the knowledge of their morphology. Within the scope of this study, the possibility of histochemical proof on the basis of reaction between Lugol's iodine solution and starch amylose was demonstrated. From the samples analyzed, the following criteria for the method were determined: Repeatability and repeatability of intralaboratory results was 100%, selectivity was determined to be 1.03, specificity of the method was determined to be 0.9, limit of detection was established to be 100% for 0.001 g.kg-1 of the addition, and 87.7% for the concentration of 0.0001 g.kg-1 of the starch addition. Based on the results it is obvious that the method is suitable for determination of native starches in meat products, and, in combination with staining of other foodstuffs ingredients, it gives a complex view of the composition and structure of the meat product.