Taste, smell and the flavour are the most important attributes determining the quality of bread or baked cereal products in general. Bread flavour is composed of hundreds of volatile and non-volatile compounds, i.e. many alcohols, ketones, aldehydes, acids, esters and other compounds. Many researchers have been studying volatile compounds in different breads worldwide, but in Latvia only few studies are conducted on volatile compounds in bread and its production stages. The aim of this research was to analyse the composition of volatile compounds during wheat dough fermentation. Experiments were done in 2011 and carried out in the Laboratory of Bread Technology and Laboratory of Packing Material Investigations at the Department of Food Technology in the Latvia University of Agriculture. An investigation of volatile compounds was done using solid-phase microextraction (SPME) and gas-chromatography mass-spectrometry (GC-MS). Volatile compounds were analyzed on the 10th, 20th and 30th minutes of wheat dough fermentation. In a fermentation process of wheat dough totally 15 volatile compounds were detected. Eight of them were alcohols, two aldehydes, two ketones, one ester, one acid and one terpene. Three volatile compounds – 1-octanol, caryophyllene and acetophenone, were detected in the dough samples only after 30 minutes of fermentation – those were not detected at the earlier stages of fermentation. The peak areas of 11 volatile compounds increased, but peak area of one volatile compound decreased along the fermentation time. The study proved that solid-phase microextraction can be used for detection of volatile compounds in wheat dough fermentation process.

Aroma forming volatiles are important components of fermented beverages. The aim of current research is to evaluate the influence of different yeast strains on the volatile compounds of fermented apple juice of the variety ‘Lietuvas Pepins’. Apples were harvested in the Latvia State Institute of Fruit Growing. Apple variety ‘Lietuvas Pepins’ juice was fermented with four different commercial yeast strains - Saccharomyces bayanis yeasts ‘EC-1118’, ‘Cider yeast’, Saccharomyces cerevisiae yeasts ‘71B-1122’ and ‘K1V- 1116’. Fermentation was performed in laboratories of Latvia University of Agriculture, Faculty of Food Technology. Volatile aroma compounds of apple juice, yeasts and fermented juice were determined. Extraction of aroma compounds was performed using solid phase microextraction (DVB/Car/PDMS fibre). Analysis of volatile aroma compounds was made using a Perkin Elmer Clarus 500 GC/ MS. The data obtained in the present study shows the influence of the yeast strain on the final chemical and volatile composition. The main group of volatiles in juice was esters, whereas in fermented juices – alcohols. The highest percentage of esters was determined in juice fermented with ‘Cider yeast’ whereas the highest percentages of alcohols – in juice fermented with yeast K1V-1116 and also free terpenes, associated with the floral note. The 71B-1122 strain produced the highest amount of identified volatile compounds. The strains potentially producing a higher number of volatile compounds could contribute to a more complex aroma of the final product, due to their potential ability to utilize and transform numerous apple must precursors.

Computer models of bioprocesses have become an essential tool in biotechnology. This paper describes various bioprocess scaleup releated problems. The problems at different scales are explained. In this paper the use of computer model in E.coli fermentation scale-up from shake flask to laboratory scale bioreactor is discussed. A black box modelling approach was used. Fermentation results have been visualized and discussed. The computer model created in Matlab environment was used for bioprocess behaviour prediction. Possible bioprocess scale-up software improvements and bioprocess optimization are discussed.

Fermentation of milk with probiotics and prebiotics has been shown to increase the concentration of B group vitamins in fermented milk products. The task of the study was to investigate the influence of prebiotics on the increasing of thiamin and riboflavin concentrations in milk during fermentation by Bifidobacterium lactis. Lactulose (Duphilac, Netherlands) and inulin (Raftiline, Belgium) were added (1, 2, 3, 4 and 5%) into 100 g of milk. The milk samples were inoculated with Bifidobacterium lactis (BB-12, Chr. Hansen, Denmark) and incubated at 38 deg C for 16 hours. The amount of thiamine and riboflavin was determined by fluorometric method. Laboratory studies have shown that the increasing of thiamin and riboflavin concentrations in milk depends on the concentration of lactulose and inulin. Data on the final thiamin and riboflavin concentrations in fermented milk indicates that increasing the lactulose concentration from 1% to 3% enhanced the production of thiamin and riboflavin. The similar data was obtained with inulin. Increasing of inulin concentration from 1% to 4% enhanced the production of vitamins thiamin and riboflavin. The present results furthermore indicate that finding optimal combination of prebiotics and probiotic pairs where the prebiotic would benefit the specific probiotic strain, e.g. during production and formulation into foods, is one of the research priority for functional foods.

Sambucus nigra has garnered attention in the food industry for its natural colouring and antioxidant properties, mainly due to its high content of anthocyanins, other polyphenols, and vitamins. These bioactive compounds not only contribute to the nutritional impact of food products, but also make it possible to replace synthetic additives that meet the current consumer demand for natural and functional foods. This study provides an overview of the bioactive compounds in Sambucus nigra (black elder) fruits, highlighting their potential health benefits and toxicity concerns. It examines the effect of different processing technologies on the phenolic and cyanogenic glycoside composition of elderberry, emphasizing the need to balance microbial decontamination with the sensory quality and nutritional value of food products. The study also reviews the mechanism of ultrasonic inactivation of microorganisms and the potential of fermentation to reduce toxic compounds in Sambucus nigra fruits, thus contributing to the improvement of food safety and nutritional quality, emphasizing the importance of considering the potential limitations of ultrasound and the use of combined methods to increase efficiency while minimizing the negative impact on both the product and the consumer. Additionally, the study discusses the significance of selecting appropriate processing methods to ensure the safety of elderberry products, given the presence of potentially harmful cyanogenic glycosides and lectins, which can be mitigated through heat treatment and fermentation.

The aim of the experiment reported here was to evaluate the effects of an inoculant SIL-ALL**4x4 on the fermentation quality and chemical composition of silage made from meadow-fescue and meadow-foxtail. Inoculant SIL-ALL**4x4 provided the good quality of silage in all stages of maturity. Lactic acid fermentation of inoculated silage was very extensive, especially in the stages of ear formation of meadow-fescue. The results indicated that the use of inoculant improved fermentation and silage hygienic quality.