Toxicity and accumulation of Cd2+ in yeasts were studied in eight different yeast species. The adaptation to toxic concentration of this metal was dependent on the production of extracellular yeast glycoproteins. The highest concentration of Cd2+ ions in the growth medium was tolerated by a Hansenula anomala, strain while the lowest tolerance was found by the strain of species Saccharomyces cerevisiae. Extracellular glycoproteins of Hansenula anomala absorbed nearly 90% of the total content of Cd2+ ions bound by yeast cells, while extracellular glycoproteins of Saccharomyces cerevisiae bound only 6% of the total amount of cadmium. This difference is caused by the variable composition of the saccharide moiety in the extracellular glycoproteins. The composition of extracellular glycoproteins changed during the adaptation of the yeast cells to the presence of Cd2+ ions.

A multistage process was employed to obtain value-added products from brewer's spent grain (BSG). This paper is focused on the production and characterisation of cellulose nano-fibres (CNF) as one of the products obtained during the complete process. In the first stage, protein-rich liquor was separated via the alkaline (NaOH) treatment of dried BSG and stored for further utilisation. In the second stage, bleaching treatments were conducted to separate cellulose, which was later converted to CNF by high-pressure homogenisation. The lignocellulosic product from each step was analysed for its chemical composition by means of alkaline hydrolysis combined with the HPEAC method. The thermal properties were measured using thermogravimetric analysis (TGA). The morphology was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). X-ray diffraction (XRD) was done to observe changes in crystallinity. The nano-cellulose produced can be regarded as a value-added material from the bio-refinery of BSG along with numerous already-reported products.

Carotenoid-producing yeast species such as Rhodotorula glutinis and Sporobolomyces roseus efficiently accumulated selenium from the growth medium. It was observed that incorporation of selenium into yeast cells during the growth inhibited production of beta-carotenoid and other carotenoid precursors (torularhodin and torulene). The yeasts with high content of the carotenoid pigments and selenium may be used for the preparation of a new type of antioxidant formula that could be directly applied for various human and animal diets. We have demonstrated that such a formula can only be produced by separate processes of the cultivation of red yeasts and a subsequent sorption of selenium into the cells.

The positive effect of humic acids on the growth of plant roots is well known, however, the mechanisms and role of their physical structure in these processes have not been fully explained yet. In this work, South-Moravian lignite was oxidized by means of nitric acid and hydrogen peroxide to produce a set of regenerated humic acids. The elemental composition, solid state stability and solution characteristics were determined and correlated in vitro with their biological activity. A modified hydroponic method was applied to determine the effects of their potassium salts on Zea mays seedlings roots with respect to the plant weight, root length, root division, and starch and protein content. The relations between the determined parameters were evaluated through Principal Component Analysis and Pearson’s correlation coefficients. The results indicated that the most important factor determining the biological activity of South-Moravian lignite potassium humates is related to the nature of self-assemblies, while the chemical composition had no direct connection with the root growth of Zea mays seedlings. It was demonstrated a controlled processing that provided humic substances with different chemical and physicochemical properties and variable biological activity.

Chocolate is a semi-solid suspension of fine solid particles of sugar, cocoa, and milk powder (depending on the type), making about 70% total, in a continuous fat phase, consisting mostly of cocoa butter (Afoakwa, 2014). Chocolate shelf-life is limited by the changes in the polymorphic state of cocoa butter or by rancidity development in solid chocolate. The resistance of chocolate to fat bloom is closely related to the crystallization of cocoa butter (Fernandes et al., 2013).At least six crystal forms (I-IV) of cocoa butter can be distinguished, however, form V is most desirable. This form can be achieved by performing proper tempering procedures (Fernandes et al., 2013;Quast et al., 2013). In a traditional tempering process, the chocolate is first heated to about 50℃ to melt all present cocoa butter crystals and then cooled to about 27℃ to start the crystallization process. At this stage, the chocolate contains butter in form V; unstable polymorphs are also present. Unstable crystals melt, leaving only form V crystals in the form of seeds in the tempered chocolate after re-heating to about 29-32℃ (Lonchampt & Hartel, 2004;Quast et al., 2013).Oil from fats or oils within other components (fillings) may migrate and recrystallize on the surface as bloom. The stability of the product is also affected by physical properties of the nonlipid ingredients (size, shape, and surface chemistry of sugar, dairy solids, and cocoa solids). Lipid and ethanol migration from the filling into the chocolate shell is a key factor affecting the shelf-life of composite products (Subramaniam, 2000). Lipids migration is typically observed when the chocolate shell or coating is in direct contact with lipid-rich components like nuts, biscuits, or cream fillings.While lipid migration may result in bloom, the shelf-life is often limited by textural changes, especially softening of the chocolate shell and hardening of the filling (Ziegler, 2009). Ethanol migration may negatively impact chocolate shell stability since ethanol