Synytsya A., Míčková K., Jablonský I., Sluková M., Čopíková J. (2008): Mushrooms of genus Pleurotus as a source of dietary fibres and glucans for food supplements. Czech J. Food Sci., 26: 441-446.Fruit bodies (separately pilei and stems) of mushrooms Pleurotus ostreatus (four strains) and Pleurotus eryngii were characterised as a source of polysaccharides. The contents of glucans and dietary fibres were determined with using the respective Megazyme enzymatic kits. Enzymatic analysis of the fruit bodies confirmed significant differences in the contents of these components among the species and strains. The stems contained more insoluble dietary fibres than the pilei in all the cases and more β-glucans in most cases. However, relatively high contents of β-glucan (20-50% of dry matter) could be a result of incomplete enzymatic hydrolysis of insoluble α-1,3-glucans. Nevertheless, low food quality stems of mushrooms Pleurotus sp. could be a valuable source of cell wall glucans for the preparation of food supplements.Keywords: mushrooms Pleurotus; glucans; dietary fibres; food supplements For millennia, humankind has been valued mushrooms as an important edible and medical resource (Chang 1980;Breene 1990;Wasser 2002). The dry matter of mushroom fruit bodies is about 5-15%, they have a very low fat content and contain 19-35% proteins. Mushroom fruit bodies are rich in vitamins, mainly B 1 , B 2 , C, and D 2 (Manzi et al. 1999;Mattila et al. 2000), and contain some important elements such as K and P (Vetter 2007). The content of carbohydrates, which are mainly present as polysaccharides or glycoproteins, ranges 50-90%; the most abundant polysaccharides are chitin, α-and β-glucans and other hemicelluloses (e.g. mannans, xylans and galactans). 442Vol. 26, No. 6: 441-446 Czech J. Food Sci. 1988). Their solubility in water strongly depends on the molecular structure and conformation. Glucans bound to proteins or to chitin are usually insoluble in water. Mushroom-derived substances with antitumour, immunomodulating, and antioxidative properties are currently used as dietary supplements. Mushroom polysaccharides with antitumour action differ greatly in their chemical compositions and configurations, as well as in their physical properties. Immunomodulatory and antitumour activities are exhibited by a wide range of glycans extending from homopolymers to highly complex heteropolymers; the differences in their activities can be correlated with the solubility in water,molecular size, branching rate and form (Augustín 1998; Ooi & Lui 1999;Wasser 2002;Novak & Vetvicka 2008). Besides the well-known antitumour β-(1→3),(1→6)-glucans (Kuniak et al. 1992(Kuniak et al. , 1998, a wide range of biologically active glucans of different structures have been described. Linear or branched polysaccharides chains occur with a backbone composed of α-or β-linked glucose units, and their various side chains can be attached in different ways. The main source of biologically active polysaccharides appears to be fungal cell walls consisti...

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The aim of the bioassay-guided fractionation was the selection of the most potent group of compounds responsible for the protection of sunflower bee pollen grains. Synthesis of prospective antifungal polyamides of hydroxycinnamic acids was based on previous structural elucidation of ethanol soluble fraction by 1H,1H-PFG-COSY, 1H,13C-HSQC, FT-IR, FT-Raman, and LC–MS experiments. The main compounds found were tri-p-coumaroylspermidines accompanied by other HCAA of spermidine and putrescine. Several model HCAA derivatives were prepared to test their antifungal activity against widespread spoilage fungi (A. niger 42 CCM 8189, F. culmorum DMF 0103, and P. verrucosum DMF 0023). A. niger CCM 8189 and F. culmorum DMF 0103 exhibited higher resistance to the antifungal effects of hydroxycinnamic acid amides, whereas P. verrucosum DMF 0023 was the most sensitive strain. It has been discovered the effect of HCAA polarity on the role of secondary metabolites in the microbial protection of pollen grains. The combination of bioassay-guided fractionation, structural elucidation, selection of prospective compounds, and their synthesis to determine their antifungal properties could be considered as an original approach.

Horáčková Š., Mühlhansová A., Sluková M., Schulzová V., Plocková M. (2015): Fermentation of soymilk by yoghurt and bifidobacteria strains. Czech J. Food Sci., 33: 313-319.Soy and milk based products fermented by yoghurt culture YC-381 alone or in combination with two probiotic cultures (Bifidobacterium animalis subsp. lactis BB 12 and Bifidobacterium bifidum CCDM 94) were prepared. Bacteria growth, the amounts of lactic acid, acetic acid, and acetaldehyde were compared after 16 h of fermentation at 37°C. The changes of isoflavones concentrations were also monitored in soy products. The growth of Streptococcus thermophilus and bifidobacteria was similar in both media, but Lactobacillus delbrueckii subsp. bulgaricus showed a better growth in milk. Titratable acidity and the concentrations of acids were consistently higher in cow milk than in soymilk at the end of fermentation. Bifidobacteria, compared to the yoghurt culture, were only able to acidify the media to the half values. Comparing the bifidobacteria strains, Bifidobacterium animalis subsp. lactis BB 12 exhibited a better ability to acidify milk. The strain Bifidobacterium bifidum CCDM 94 was able to release 6.90 mg/100 ml of isoflavone aglycones in soymilk.

Research groups have put significant emphasis on the evaluation of nutritional, health-promoting, and other biological activities of secondary metabolites from buckwheat. Among these phytochemicals, phenolic and lipophilic antioxidants, particularly, phenolic acids, flavonoids, and tocopherols, have been the focus of the latest studies since antioxidant activity has recently been associated with the possibility of inhibiting fungal growth and mycotoxin biosynthesis. The mycotoxin contamination of cereal and pseudocereal grains caused primarily by Fusarium, Penicillium, and Aspergillus species poses a significant hazard to human health. Therefore, efforts to examine the involvement of plant antioxidants in the biosynthesis of mycotoxins at the transcriptional level have emerged. In addition, hydrophobic interactions of buckwheat phenolics with cell membranes could also explain their capacity to reduce fungal development. Eventually, possibilities of enhancing the biological activity of cereal and pseudocereal phytochemicals have been studied, and sourdough fermentation has been proposed as an efficient method to increase antioxidant activities. This effect could result in an increased antifungal effects of sourdough and bakery products. This review reports the main advances in research on buckwheat phenolics and other antioxidant phytochemicals, highlighting possible mechanisms of action and processes that could improve their biological activities.

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Horáčková Š., Sedláčková P., Sluková M., Plocková M. (2014): Influence of whey, whey component and malt on the growth and acids production of lactobacilli in milk. Czech J. Food Sci., 32: 526-531.The effect of whey powder, whey protein concentrate, caseinomacropeptide, and malt addition into milk on the growth and acid production of lactobacilli (Lactobacillus casei Lafti L-26, Lactobacillus acidophilus CCDM 151, and Lactobacillus casei CCDM 198) was evaluated. The ability of these strains to use different types of saccharides from milk and plant sources was also tested. Glucose, galactose, fructose and maltose were utilised by all tested strains. The results showed that the addition of malt positively affected the growth of lactobacilli strains compared to the growth in milk enriched by whey ingredients. The addition of malt increased significantly the production of d(-) isomer of lactic acid by Lactobacillus acidophilus CCDM 151 and Lactobacillus casei CCDM 198 and the production of acetic acid by Lactobacillus casei CCDM 198.

The aim of this work was to characterize three Czech spring and one German winter barley cultivars specifically cultivated for use in the food industry. Two hull-less and two waxy barleys were roller-milled and separated into ten milling fractions. Additionally one wholemeal flour was prepared. The chemical composition of flour fractions from all cultivars was compared individually. The starch content was very similar in white flour fraction C1 and coarse bran flour from both waxy genotypes. The highest b-glucan content was determined in bran fractions in all barley materials. The similar trend was also found for the arabinoxylan content. Czech spring breeding line KM 1057 showed higher arabinoxylan content in all milling fractions than the other varieties. A strong positive correlation between b-glucan and protein content, as well as b-glucan and dietary fibre was found. By choosing the suitable milling fractions (flour separated from bran or bran, especially in hull-less cultivars), as high fibre to starch ratio as 1:0.8 can be achieved. Furthermore these fractions contained a high content of b-glucan, protein and ash.