Projects of 2014

Results of main activities 2014
The results achieved in various projects, in research suported by grants and by the work under the research plan are presented in the form of research or technical papers, patents, or papers read at workshops and conferences.

Most important results achieved in 2014
authors from other organizations are marked by an asterisk (*)

Balík* J., Híc* P., Soural* I., Tománková* E., Houška M., Strohalm J., Tříska* J., Vrcholová* N., Moos* M., Marešová* I.: Mošt, víno nebo nápoj na bázi vína se zvýšeným obsahem přírodní lignanů. [Must, wine or beverage based on wine with increased content of natural lignans.] Užitný vzor reg. č. 27 508.
The typical content of lignans in musts is less than 0.1 mg/liter, in wines it amounts around 1 mg/ liter. The recommended dose of lignans in human nutrition ranges from 10 to 30 mg HMR/day. Lignans contained in knots (in wood substance) of European spruce are little soluble in water and simple maceration of wood substance with water or must is insufficient to increase their content. Must, wine or wine-based drinks contain at least 10 mg, preferably 15 to 50 mg of lignans per liter of beverage. Must, wine or wine-based drinks with the increased content of natural lignans also contain sucrose or concentrated grape must in the amount of 50–300 grams of sugar per liter. Wine or wine-based drinks with the increased content of natural lignans further contain 15 to 20 vol% of alcohol in the form of fine or superfine alcohol or wine distillate. The increase of must or wine temperature can improve the efficiency of maceration of lignans from wood substance. Wine, due to the natural content of alcohol, extracts lignans more efficiently as compared to water. Further addition of 15 to 20 vol% of alcohol in the form of fine or superfine food alcohol or wine distillate can further enhance the solubility of lignans.

Balík* J., Soural* I., Híc* P., Tříska* J., Vrcholová* N., Moos* M., Houška, M., Landfeld A., Strohalm J., Novotná P.: Grape juices with an increased content of lignans.[Hroznové mošty se zvýšeným obsahem lignanů.] XXXVIth World Congress of Vine and Wine of the International Organization of Vine and Wine in Mendoza, Argentina, 9.–14. 11. 2014, In Book of Abstracts 784–785.
Lignans belong to a wide group of plant phenols which have attracted our attention within the last two decades not only due to their multiple biological effects but also because of their structural abundance. From the structural viewpoint, plant lignans are formed by joining the two phenylpropanoid precursors at beta-carbon atoms of both propyl side chains. Most frequently, they are dimers but some higher oligolignans were also described in recent years. As secondary metabolites of vascular plants, lignans show also effects of antioxidants, antitumour protectants, antiviral and antibacterial substances, insecticides, fungicides, estrogens, antiestrogens and, last but not least, substances protecting against cardiovascular diseases. High levels of lignans were found out in wood of conifers and in some food plants (above all flax, hemp and sesame). In grape juices their common level is lower than 0.1 mg/l. In human nutrition the recommended dose of lignans ranges from 10 to 30 mg of hydroxymatairesinol per day. Within the framework of the research project no. QJ1210258 of the Agency of the Ministry of Agriculture of the Czech Republic, some technologies of the manufacture grape juices were suggested that enabled to increase the content of natural lignans. Crushed grapes were mixed with various amounts of wood chips made of spruce (Picea abies) knots and, after the thermomaceration at 80 °C, the grape juice was made by pressing. Simultaneously, ethanol extracts of wood chips made of spruce knots were also applied to grape juice. Sensory properties, contents of lignans and antioxidant activity of these enriched juices were evaluated after their pasteurization. The antioxidant activity was evaluated by DPPH and FRAPS methods. 7-hydroxymatairesinol (HMR) concentrations were determined by HPLC with a diode array detector. From the sensory point of view, thermomacerated grapevine juices containing 12.9–52.7 mg/l of hydroxymatairesinol and showing the Trolox antioxidant activity rangingfrom 0.53 to 15.80 mmol/l were evaluated as the best ones.

Beran M., Urban M., Drahorád J., Adámek L., Rutová E.: Substrát pro pěstování hub. [Mushroom growing substrate.] Patent č.304 304.
The present invention relates to a mushroom growing substrate, wherein the invention is characterized in that 1 kg of the common mushroom growing substrate contains linseed cake in an amount rangingfrom 0.1 to 100 percent by weight and the substrate can be used particularly for growing mushrooms.

Beran M., Urban M., Drahorád J., Adámek L., Rutová E.: Odhořčený koncentrát amarantových bílkovin se zvýšeným obsahem vápníku a hořčíku a způsob jeho výroby. [Debittered concentrate of amaranth proteins with increased amount of calcium and magnesium as well as process for preparing thereof.] Patent č.304 782.
According to the present invention the debittered concentrate of amaranth proteins with increased amount of calcium and magnesium contains 50 to 85 wt% dry matter of proteins, 0.2 to 3 wt% of calcium or magnesium in organic bond and is neutral in taste, without any bitter or other aftertaste. The preparation process of the invented concentrate is characterized in that hot drinking water and sodium chloride are added to amaranth flour defatted by supercritical extraction and containing at least 16.3 wt% of proteins. Subsequently potassium hydroxide is added into the resulting suspension under constant agitation until the pH value stabilizes on 11 and the suspension temperature is maintainedunder constant agitation at 50 °C for 30 minutes. When the extraction is completed, the suspension is centrifuged. The sediment containing mainly fibre and the residue of the starch fraction is dried for further use. The supernatant is then purified by separation of the solid residues of the starch fraction and fibre by additional centrifuging to obtain a clear purified liquid. A portion of this, containing at least 10 wt% of dry matter, is separated and 0.5 to 30 wt% of calcium or magnesium salt in the form of pre-prepared water suspension is added to it, the resulting suspension is heated to boiling in a duplicator vessel with steam heating and the resulting crude precipitate is separated by sedimentation, thickened and dried after resuspension in drinking water using a pilot-scale spray dryer to form a dry powdered product having a minimum of 90 wt% of dry matter and containing at least 60 wt% dry matter of protein and 0.2 to 3 wt% of calcium in organic bond, when the coagulated amaranth protein before and after drying has a neutral taste without any traces of bitterness or another aftertaste.

Beran M., Drahorád J., Hušek* Z, Toman * F.: Immobilization of Microorganisms in Fibers. Sborník 6. ročníku mezinárodní konference Nanocon 2014, 5.–7. 11. 2014, hotel Voroněž I, Brno. ISBN 978-80-87294-55-0.
Probiotics have been defined as live microorganisms that pass through the gastrointestinal tract and by doing so benefit the health of the consumer. They must be resistant to gastric acidity and bile salts in the small
intestine. This is why a method for encapsulation and stabilization of probiotic yeasts (Saccharomyces boulardii) or bacterial strains (Lactobacillus and Bifidobacterium spp.) in polymeric or biopolymeric fibres has been developed. Centrifugal methods using a rotating bell have been employed to produce a mixture of nanoand microfibers. An aqueous solution of polyvinylalcohol and gelatine with prebiotic fibre inulin and
suspended microbial preparations has been used to produce the fibres. The centrifugal fibre spinning is a simple, cheap and eco-friendly process. It can be carried out at laboratory temperature without any heating. The survivability of probiotics in fibrous preparations was tested in vitro in a simulated environment of bile salts solution and gastric juice with subsequent incubation.

Evans* J.A., Foster* A.M., Huet* J-M., Reinholdt* L., Fikiin* K., Zilio* C., Houska M., Landfeld A., Bond* C., Scheurs* M., van Sambeeck* T.W.M.: Specific energy consumption values for various refrigerated food cold stores. Energy and Buildings Journal. (2014) 74 (1): 141–151, ISSN 0378-7788.
Two benchmarking surveys were created to collect data on the performance of chilled, frozen and mixed (chilled and frozen stores operated from a single refrigeration system) food cold stores with the aim of identifying the major factors influencing energy consumption. The volume of the cold store was found to have the greatest relationship with energy use with none of the other factors collected having any significant impact on energy use. For chilled cold stores, 93% of the variation in energy was related to store volume. For frozen stores, 56% and for mixed stores, 67% of the variation in energy consumption was related to store volume. The results also demonstrated the large variability in performance of cold stores. This was investigated using a mathematical model to predict energy use under typical cold store construction, usage and efficiency scenarios. The model demonstrated that the store shape factor (whichhad a major impact on surface area of the stores), usage and to a lesser degree ambient temperature all had an impact on energy consumption. The work provides an initial basis to compare energy performance of cold stores and indicates the areas where considerable energy savings are achievable in food cold stores.

Fucikova* J., Moserova* I., Trusová* I., Hermanova* I., Vancurova* I., Partlova* S., Fialova* A., Sojka* L., Cartron* P.F., Houska M., Rob* L., Bartunkova* J., Spisek* R.:High hydrostatic pressure induces immunogenic cell death in human tumour cells. International Journal of Cancer. (2014), 135 (5): 1 165–1 177, ISSN 0020-7136.
Recent studies have identified molecular events characteristic of immunogenic cell death (ICD), including surface exposure of calreticulin (CRT), the heat shock proteins HSP70 and HSP90, the release of high-mobility group box protein 1 (HMGB1) and the release of ATP from dying cells. We investigated the potential of high hydrostatic pressure (HHP) to induce ICD in human tumour cells. HHP induced the rapid expression of HSP70, HSP90 and CRT on the cell surface. HHP also induced the release of HMGB1 and ATP. The interaction of dendritic cells (DCs) with HHP-treated tumour cells led to a more rapid rate of DC phagocytosis, upregulation of CD83, CD86 and HLA-DR and the release of interleukin IL-6, IL-12p70 and TNF-a. DCs pulsed with tumour cells killed by HHP induced high numbers of tumour-specific T cells. DCs pulsed with HHP-treated tumour cells also induced the lowest number of regulatory T cells. In addition, we found that the key features of the endoplasmic reticulum stressmediated apoptotic pathway, such as reactive oxygen species production, phosphorylation of the translation initiation factor eIF2a and activation of caspase-8, were activated by HHP treatment. Therefore, HHP acts as a reliable and potent inducer of ICD in human tumour cells.

Gabrovská D., Ouhrabková J., Rysová J., Holasová M., Fiedlerová V., Laknerová I., Winterová R., Eichlerová E., Erban V., Strohalm J., Němečková I., Houška M.: Mixed vegetable juices acidified with sauerkraut juice and preserved using high pressure or heat pasteurization treatments – nutritional and sensory evaluation. Czech J. Food Sci. (2014), 32(2), s.182–187, ISSN1212-1800.
The goal of this work was to design mixed vegetable (vegetable-fruit) juices treated with high pressure, which have an increased content of bioactive substances. These juices are made from local raw materials and offer excellent nutritional and taste qualities. The new products were prepared with help of laboratory scale units and underwent nutritional, microbiological, and sensory evaluations. The basic composition, total polyphenol content, ascorbic acid content, and total antioxidant activity were determined.

Houška M., Tříska* J., Balík* J., Landfeld A., Novotná P., Vrcholová* N., Híc* P.: Sledování změn obsahu resveratrolu ve slupkách bobulí a moštech z vybraných druhů révy vinné ošetřené UV zářením. [Influence of UV radiation treatment of freshly harvested grapes of selected sorts of wine on the resveratrol content in skins and musts.] Výživa a potraviny. (2014), 4: 104–108, ISSN 1211-846X.
This work deals with the influence of UV radiation treatment of freshly harvested grapes of two sorts of wine on the resveratrol content in skins and musts. The results presented show that this procedure provides tools to increase resveratrol content in grape skins and musts. The obtained results show the parameters that have the statistically significant influence on the process.

Houška M., Tříska* J., Balík* J., Landfeld A., Novotná P., Vrcholová* N., Híc* P.: Hodnocení obsahu resveratrolu ve slupkách bobulí a moštech z vybraných druhů révy vinné máčených v ozonizované vodě. [Resveratrol content evaluation in grape skins and musts from selected sorts of wine grapes dipped in ozonized water.] Výživa a potraviny. (2014) 5: 131–135, ISSN 1211-846X.
This work deals with the influence of dipping freshly harvested grapes of two sorts of wine in ozonized water. Main parameters of the method and their influence on the increase of trans-resveratrol content in grape ball skins or musts prepared from those grapes were determined. The obtained results showed the statistically significant process parameters influencing the content of resveratrol.

Kučerová* Z., Kýhos K., Aulický* R., Lukáš* J., Stejskal* V: Laboratory experiments of vacuum treatment in combination with an O2 absorber for the suppression of Sitophilus granarius infestations in stored grain samples. Crop Protection (2014), 61: 79–83, ISSN 0261-2194.
The effectiveness of vacuum (V) treatment alone and in combination with an oxygen absorber (V + A) for suppression of grain infestation by Sitophilus granarius L. were compared under laboratory  conditions. The effectiveness of the treatment methods was evaluated at different temperatures (15, 25 °C) and exposure times (7, 14, 21, 28 days). We evaluated both the effects on adults present in grain interspaces and hidden infestations within the kernels in terms of treatment times separately. Adults of S. granarius present in grain interspaces were more susceptible to both treatments than hidden infestations developing within kernels. At 25 °C, total mortality of adults in grain interspaces was achieved after 10 days of exposure whereas total suppression of hidden infestations was achieved after 3 weeks. Higher temperature and longer exposure correlated with a greater effectiveness of the tested treatments. The addition of an oxygen absorber to the vacuum treatment (V + A) showed the general tendency of improving the effectiveness of the vacuum treatment on suppression of hidden infestations; significant differences between the V + A and V treatments were prominent primarily at the lower temperature tested. Reduction of hidden infestation was achieved after 3 weeks of exposure to V + A treatment (99.8%) and after 4 weeks of V treatment (95.8%) at 15 °C.

Kýhos K.: Koncovka pro netoxické ekologické ošetření zrnin před hmyzími škůdci. [End piece for nontoxic, environment-friendly treatment of grain against insect pests.] Patent reg. č. 304 947. The end piece for non-toxic, environment-friendly treatment of grain against insect pest according to the present invention consists of a large-area suction plate, made of incompressible porous material. A seal pad of a plastic package fits tightly to the plate. A pipe to connect a control gauge passes through an opening in the plastic package. At one end of the control gauge piping is a valve connected to a vacuum meter, whereas the other end of the pipe is joined to a valve leading to a vacuum pump. The end piece of the present invention can have a suction plate made of a compressible material that is permeable for air even after compression.

Kýhos K., Novotná P., Strohalm J., Landfeld A., Houška M.: Krekry z naklíčených sójových bobů se sníženou hladinou galaktosidů. [Crackers of germinated soybeans with reduced level of galactosides.] Užitný vzor reg. č. 27 210.
The basic paste for the production of crackers contains whole sprouted beans including the germs. The only component removed is 80 wt% of bean husks, which contain the majority of a-galactosides. Fats, crushed vegetables, fruits and other additives and flavouring / aromatic substances are added to this paste following various formulas. Finished shaped crackers are dried for 10 minutes in an oven preheated to 160 °C. Subsequently crackers are only dried at 80 °C for 3 hours.

Kýhos K., Ouhrabková J.: Nízkokalorická doplňková potravina s obsahem proteinů a způsob její výroby. [Protein-containing low-calorie supplementary food and process for producing thereof.] Patent reg. č.304 491.
The protein-containing low-calorie supplementary food according to the present invention contains egg white with crushed root vegetables and/or Brassica vegetables and/or bulbous vegetables and/or fruit added thereto. The low-calorie supplementary food further includes minerals and vitamins, unsaturated fatty acids, salt, artificial sweetener, whey protein, solid and liquid fibre. The present invention also provides for a process for preparing the above-described low-caloric supplementary food. Said process comprises mixing dry egg white with crushed vegetables left after squeezing juice from these. The obtained mixture is then pressed to the required shapes and dried by hot air at a temperature ranging from 80 to 105 °C.

Laknerová I., Hanák P., Zdeňková* K, Purkrtová* S., Piknová* Ľ., Vyroubalová* Š.: Interlaboratory identification of black seabream (Spondyliosoma cantharus) as a model species on basis of PCR targeting the second intron of the parvalbumin gene [Mezilaboratorní identifikace pražmy zpěvné (Spondyliosoma cantharus) jako modelového vzorku na bázi PCR zaměřené na druhý intron parvalbuminového genu.] Journal of Food Quality (2014), 37, s. 429–436, ISSN 1745-4557.
An end-point polymerase chain reaction (PCR) targeting the second intron in the protein-coding region of the parvalbumin gene of black seabream (Spondyliosoma cantharus) was used to identify this fish species. The reproducibility of the method was tested by a collaborative study in which four laboratories participated. Twenty-eight samples of isolated DNA from fish meat were tested in participating laboratories by the presented identification method. Nine samples were from black seabream and the remaining 19 were fish flesh from the reference panel. In parallel, six frozen samples of fish meat, where three were of black seabream and remaining three from the reference panel, were tested in the laboratories by this method after various DNA isolation procedures. The PCR-based method for species determination of black seabream presented in this study proved to be a reliable and independent on method of DNA isolation from meat among the isolation techniques used.

Laknerová I., Holasová M., Fiedlerová V., Rysová J., Vaculová* K., Mašková E., Ehrenbergerová* J., Winterová R., Ouhrabková J., Dvořáček* V., Martinek* P.: Utilisation of Non-Traditional Forms of Cereals in Bakery Production. Czech J. Food Sci.(2014), 32(3), s. 296–301, ISSN 1212-1800.
One form of common wheat with yellow coloured grain, two forms of emmer wheat, and two forms of barley with hulless grain were used for the preparation of bread with enhanced nutritional quality. The following mill products were prepared from the cereal grains: wholemeal flour, break flour, barley grits, and bran. The contents of thiamin, niacin, pyridoxine, total polyphenols, and total dietary fibre were studied in these input raw materials and in bread samples. Furthermore antioxidant activity was assessed in those bread samples and their sensory evaluation was carried out. As a result, the utilisation of the non-traditional forms of cereals improved the nutrient content of bread while maintaining very good sensory characteristics and processing quality.

Landfeld, A., Novotná, P., Strohalm, J., Rysová, J., Houška, M.: Yield stress and sensorial evaluation of soya yoghurts prepared from germinated soybeans. Czech J. Food Sci. (2014), 32 (5): 464–469, ISSN 1213-1800.
The goal of this work was to use germinated soybeans to prepare and evaluate soy yoghurts with substantially reduced alpha-galactosides (AG) content. As a consequence of this reduction, final products do not cause flatulence. To enable us to control the final consistency and other sensory parameters of these yoghurts it was necessary to study the influence of dry matter content on these quality parameters: i.e. yield stress, appearance, flavour, taste, soya off-flavour, consistency and total impression. Establishing relationships between dry matter and qualitative parameters facilitated the prediction of the optimal amount of dry matter to maximize the sensory quality of soy yoghurt. The optimum amount of dry matter was found to be 6.5%.

Vesely *J, Horny* L, Chlup* H, Beran M, Krajicek* M, Zitny* R.: Mechanical properties of polyvinyl alcohol/collagen hydrogel. In: EAN 2014 – Sborník z 52nd International Conference on Experimental Stress Analysis, 2.–5. 6. 2014, hotel Krakonoš, Mariánské Lázně.
The effects of the polyvinyl alcohol (PVA) concentration on mechanical properties of hydrogels based on blends of native or denatured collagen / PVA were examined. Blends of PVA with collagen were obtained by mixing the solutions in different ratios, using glycerol as a plasticizer. The solutions were cast on polystyrene plates and the solvent was allowed to evaporate at room temperature. Uniaxial tensile tests were performed in order to obtain the initial stiffness (up to deformation 0.1), the ultimate tensile stress and the deformation at failure of the material in the water-saturated hydrogel form. It was found that the material was elastic and the addition of PVA helped to enhance both the ultimate tensile stress and the stiffness of the films. Samples prepared from denatured collagen showed the higher ultimate tensile stress and the deformation at failure in comparison with those prepared from native collagen. The results suggest that we could expect successful application of the collagen-PVA biomaterial for tissue engineering.