In Latvia the spontaneous sourdough is used in traditional rye bread baking whose microflora is determined in flour and in microorganism cultures presented in external environment. Almost all spontaneous sourdough cultures, especially those that have been maintained for a long time, contain both lactic acid bacteria (LAB) and yeasts. The main purpose of the current research was to analyze growth dynamics of LAB in spontaneous rye flour sourdough and to isolate some of its representatives. Experiments were carried out in the Department of Food Technology of the Faculty of Food Technology of Latvia University of Agriculture in January and February 2008. Considering differences in constituents, two types of flour were used in the research - peeled and crude rye flour. There were three stages of spontaneous sourdough preparation in 72 hours totally; the renewal of sourdough was realized each 24 hours. The dynamics of LAB plate count in every stage of fermentation was investigated as well as changes of pH was observed using standard methods. The results of experiments show substantial increase in amount of LAB in both sourdoughs, particularly in sourdough from peeled flour, reaching 6.06 log10 cfu mlE-1. A significant decrease of pH value from pH 6.7 to pH 3.8 during fermentation process was observed. As a result, the sourdough from peeled flour had desirable properties for preparation of sourdough starter. LAB cultures isolated and identified from current sourdoughs using API tests: Lactobacillus brevis and Lactobacillus fermentum are also typical members of sourdoughs found in other countries.

Nowadays one of most urgent problems is the production of healthy food which ensures normal maintenance of the human body. Rye bread is one of the bases of wholesome food. Every year scientists in Europe and other countries carry out investigations on the nutritional impact of processing rye. Interesting questions arise regarding changes in the biologically active compounds in rye bread as a result of processed. Connate antiradical activity (ARA) of rye bread affects free radicals by scavenging or donating electrons, which suggests that the ARA of rye bread averts attacks of free radicals on human cells. Therefore it is important to use antioxidants containing products with antiradical activity in human diets. The aim of this study was to analyse the impact of baking processing on rye bread antiradical activity. The object of the study was Latvian traditional rye bread baked in a commercial bakery, made with scald, and baked in a clay-floor firewood oven. The antiradical activity of rye bread crumb and crust was measured by using free radical 2.2-diphenyl-1-picrylhydrazyl (DPPH). It was concluded in the research that rye flour type 1740 has antiradical activity by scavenging 67 μmol·100gE-1 DM of the stable free radical DPPH, which is 13% more than the dough antiradical activity of the same flour. The antiradical activity of the crust is 49.6% more than the antiradical activity of the crumb. Baking time has no significant impact on changes in the antiradical activity of rye bread crumb.

This work deals with the baking quality of the spelt wheat grain (Triticum spelta L.) compared with bread wheat (Triticum aestivum L.). Mixed flours were made of different share of spelt wheat and bread wheat (in total 11 mixtures) in 2016 in the Česke Budejovice in the laboratories of the Faculty of Agriculture. The technological quality of these mixtures was analysed, focusing on standard evaluation methods (protein content, characteristic of gluten or swellability of protein). The analysis was supplemented by complete rheological analysis made by Mixolab II. Bread was used as a model product. Subsequently, sensory evaluation of baked bread from the previously prepared mixtures was done. Part of the analysis was to estimate the economic basic bread recipe with different proportions of bread wheat and spelt wheat. The results were statistically analysed via STATISTICA 9.1 (StatSoft, Inc., USA). It was proved that the flour made of spelt can give cereal products with a higher nutritional value. The results have shown that the spelt grain is much more suitable for baking. Its advantage is the higher protein content and higher resistance of kneading of the dough and starch gelatinization rate, which was statistically confirmed. The main disadvantage is the higher price of spelt. According to the results, the ideal utilization of spelt wheat based on sensory analysis and economic calculations seems to be the mixture of spelt wheat and bread wheat, which results in an undeniable decrease of the product cost, and hence effects the common customer choice and taste preferences.

Germinated grains are added to wheat dough with the purpose to promote the biological value of bread. As a result, a new product was obtained with a higher content of protein, fibre, B group vitamins; and vitamins C and E. The task was to investigate gluten quality changes at grain germination time, wheat dough rheological properties changes with various wheat, rye and barley amount additions, germinated for a different time. With the purpose to save maximum stability value of gluten, it was ascertained that the germination time of wheat grain could not be more than 24 hours. The best dough quality was obtained with germinated wheat grain additive. Germinated rye and barley grain additive (more than the experimentally ascertained amount) increases dough softening, decreases dough development time and dough stability. Only adding experimentally determined optimal amount of germinated grain, which promotes high quality bread, could produce dough with accepted rheological properties.

The major wheat flour constituent, which determines the dough quality, is gluten. Oatmeal has higher biological value due to amino acid composition and content if compared to other cereals, but the technological properties of proteins are not as good as the ones of wheat flour. Oat products can be used in bread making although the increased amount of additives shows negative influence on bread texture, elasticity, volume, taste, and flavour. The method is developed for hydrolysed oatmeal separation in soluble and insoluble fractions, thus extending the oatmeal application possibilities. The aim of the current research was the investigation of influence of hydrolysed oats insoluble fraction on wheat dough rheological properties. The obtained results proved that in case hydrolysed oats insoluble fraction additive was used, water adsorption was increased by 63.8%-66.4% and dough stability time was changed from 4.8 to 10.0 min. The negative influence on dough development time and dough softening degree was observed. The farinograpgh quality index was within acceptable limits (less than 120 FU), if the oat additive of 10% and 15% was used. It is possible to obtain dough with better rheological properties if the hydrolysed oats insoluble fraction additive is 15% from flour mass.

More and more people looking for healthy foods. Because researchers in nourishment to look for new possibilities in breadmaking. One of the possibilities is to substitute wheat flour by oat or buckwheat flour in bread products. Bread quality is characterized by sensory properties: taste, smell, flavour and texture. Hardiness, elasticity and gumminess are important indices of bread texture. The purpose of our work is to determine the changes in the bread texture of mix flour sample. Samples were prepared to substitute wheat at 10% and 15% or by at 10% and 25%. The wheat flour was used as a control. The experiments were made in the pilot Laboratory of I.A.T.A. in Spain, using AACC methods. Output data show that substitution buckwheat flour has improved the texture of bread, but substitution of oat flour has impaired the properties of texture.