Czech Journal of Food Sciences, 2010 (vol. 28), issue 3
Quality of rabbit meat and phyto-additives
Monika Pogány Simonová, Ąubica Chrastinová, Jozef Mojto, Andrea Lauková, Renáta Szabóová, Ján Rafay
Czech J. Food Sci., 2010, 28(3):161-167 | DOI: 10.17221/49/2008-CJFS 
The consumption of healthy and nutritive food (rich in proteins and low in cholesterol and lipid contents) is a preferred factor with the contemporary consumers. In addition, natural alternatives are requested to replace the additives used up to now but recently banned. To reach the above given condition, phyto-additives represent a good alternative. The aim of this study was to examine the physicochemical properties and amino acid composition of rabbit meat after the enrichment of rabbit diet with oregano, sage, and Eleutherococcus senticosus extracts, and to make a comparison with the commercial product XTRACT and control samples (without...
Application of different sterilising modes and the effects on processed cheese quality
Zuzana Lazárková, Frantiąek Buňka, Leona Buňková, Pavel Valáąek, Stanislav Kráčmar, Jan Hrabě
Czech J. Food Sci., 2010, 28(3):168-176 | DOI: 10.17221/44/2008-CJFS
The aim of the present work is to evaluate the impacts of four different sterilising modes (110°C 100 min, 115°C 32 min, 120°C 10 min, and 125°C 3.2 min - with a constant lethal effect on microorganisms) on some chemical (pH, total and bio-available lysine, and ammonia content), microbiological, and sensory (shade and acceptability) properties of processed cheese depending on the lactose additions (0.0-2.0% w/w). All sterilising modes used were sufficient to inactivate the microorganism groups observed (total number of microorganisms, colony forming units of yeasts and/or moulds, number of spore-forming microorganisms). The falling sterilisation temperature...
Trans fatty acid contents in chocolates and chocolate wafers in Turkey
Yavuz Selim Çakmak, Gökalp Özmen Güler, Abdurrahman Aktümsek
Czech J. Food Sci., 2010, 28(3):177-184 | DOI: 10.17221/48/2009-CJFS
Fatty acid compositions and trans fatty acid contents of chocolate and chocolate wafers collected from Turkish markets were determined by GC. Total 62 samples, being all chocolates and chocolate wafers sold in Turkey, were investigated. 35 samples of chocolate which were categorised as milk chocolate, bitter chocolate, chocolate with nuts, chocolate with pistachio, chocolate with almond, other chocolates, and 27 samples of chocolate wafer which were categorised as pure chocolate wafers and chocolate wafers with nuts belonging to 12 different national chocolate brands, were analysed. Generally, C16:0 palmitic acid, C18:0 stearic acid, and C18:1...
Mixolab versus Alveograph and Falling Number
Georgiana Gabriela Codină, Silvia Mironeasa, Despina Bordei, Ana Leahu
Czech J. Food Sci., 2010, 28(3):185-191 | DOI: 10.17221/169/2008-CJFS
Recently, in 2005, a new method for monitoring the rheological properties of the dough on the entire technological process of bread making became available through Mixolab at an international level. This laboratory equipment has amazing possibilities for the research and development, enabling a complex analysis of flour. It allows the analysis of flour proteins quality (water absorption, stability, elasticity, weakening), the analysis of starch behaviour (gelatinisation, gelatinisation temperature, the modification of its consistency on additives addition) and the analysis of enzymatic activities (proteolytic, amylolytic). The objective of this study...
Effect of pressure on the Maillard reaction between ribose and cysteine in supercritical carbon dioxide
Honggao Xu, Wenhao He, Xuan Liu, Yanxiang Gao
Czech J. Food Sci., 2010, 28(3):192-201 | DOI: 10.17221/189/2008-CJFS
An aqueous ribose-cysteine model system, heated at 140°C under supercritical carbon dioxide (SC-CO2) and supercritical nitrogen (SC-N2), was investigated with emphasis on the formation of volatile compounds. In general, SC-CO2 facilitated the overall intermediates accumulation while suppressing the advanced stage of browning. 3-Methyl-1, 2-dithian-4-one increased with increasing SC-CO2 pressure, and was always more concentrated than in the case of SC-N2-treatment. The formation of thiols, disulfides, and formyl substituted thiophenes was also promoted in SC-CO2-treated reaction products,...
Determination of organic acids in olive fruit by HPLC
Pelin Günç Ergönül, Cevdet Nergiz
Czech J. Food Sci., 2010, 28(3):202-205 | DOI: 10.17221/1379-CJFS
Organic acids (oxalic, citric, malic, and succinic) contents of Domat, Memecik and Uslu varieties of olives grown in Turkey were investigated using HPLC method. Organic acids were extracted from olives with water-methanol mixture solution 75:25 (v/v) and were analysed through KC-118 ion-exchange column using UV absorbance detector at 214 nm. The mobile phase was phosphoric acid (0.1%, w/v). The recovery values of the organic acids added into olive fruit samples were 92.8%, 98.75%, 110%, and 86% for oxalic, citric, malic, and succinic acids, respectively.
Modelling of solid-liquid extraction process of total polyphenols from soybeans
Stela Jokić, Darko Velić, Mate Bilić, Ana Bucić-Kojić, Mirela Planinić, Srećko Tomas
Czech J. Food Sci., 2010, 28(3):206-212 | DOI: 10.17221/200/2009-CJFS
The influence of the solvent, temperature, and extraction time on the extractability of total polyphenols from milled soybeans variety Ika was investigated. The study was performed in order to select the most suitable solvent (water; 50, 60, 70, and 80% aqueous ethanol) for achieving the highest yield of total polyphenols. The most effective solvent (50% aqueous ethanol solution) was used for monitoring the kinetics and modelling of solid-liquid extraction of total polyphenols from soybeans, average particle size 0.459 mm, at solid-liquid ratio of 20 ml/g (ratio of the solvent volume per g of raw material). The total polyphenols content in the soybean...
Determination of some heavy metal levels in soft drinks from Turkey using ICP/OES method
Mehmet Bingöl, Gülderen Yentür, Buket Er, Aysel Bayhan Öktem
Czech J. Food Sci., 2010, 28(3):213-216 | DOI: 10.17221/158/2008-CJFS
Total number of 104 canned soft drinks collected from several regions in Turkey were analysed. The purpose of this study was to determine the levels of heavy metals in the drinks commonly consumed in Turkey. Quantitative determination of heavy metals: arsenic, copper, zinc, cadmium, and lead in all samples was carried out by ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry) method. The mean levels (± SE) of arsenic, copper, zinc, cadmium, and lead were found to be 0.037 ± 0.002 mg/kg, 0.070 ± 0.009 mg/kg, 0.143 ± 0.012 mg/kg, 0.005 ± 0.0003 mg/kg, and 0.029 ± 0.002 mg/kg, respectively, in soft drinks....
The activities of amylases and α-amylase inhibitor in wide-range herbicide resistant wheat lines
Magdolna Nagy-Gasztonyi, András Nagy, Emőke Németh-Szerdahelyi, János Pauk, Éva Gelencsér
Czech J. Food Sci., 2010, 28(3):217-224 | DOI: 10.17221/125/2009-CJFS
The activities of total amylase, α-amylase, and α-amylase inhibitor in the albumin-globulin fractions of isogenic non transgenic control (CY 45) and ppt (phosphinothrichin) resistant transgenic spring wheat (Triticum aestivum L.) lines (T106, T116, T117, T124, T128, T129) were studied in two subsequent years. The plants were either sprayed with a selective herbicide Granstar (G), a wide range herbicide Finale 14 SL (F), or were grown without spraying (Q). Samples were obtained from field trial experiments of the Cereal Research Non Profit Co (Szeged, Hungary). Our results showed an increased trend in total amylase activity of untreated...
Exopolysaccharide from Lactobacillus helveticus: identification of chemical structure and effect on biscuit duality
Ahmed Said Hussein, Ghada Saber Ibrahim, Mohsen Mohamed Selim Asker, Manal Gomaa Mahmoud
Czech J. Food Sci., 2010, 28(3):225-232 | DOI: 10.17221/97/2009-CJFS
Exopolysaccharide (LB-gum) was produced from Lactobacillus helveticus by ethanol precipitation and gel-permeation chromatography. The structures of LB1 and LB2 were estimated by sugar composition analysis, methylation, and FT-IR analysis. The results proved the contents of glucose and galactose in molar ratio of 2:1 and 2.3:1, and molecular weights ~5.4 × 105 Da and ~20.3 × 105 Da, respectively. Xanthan and LB-gum were added to wheat flour during biscuits making at levels of 0, 0.5, 1.0, 1.5, and 2.0%. Rheological properties and chemical quality attributes of the biscuits during storage for six months were evaluated....
Comparison of two clean up techniques in isolation of ochratoxin A from red wine
Elena Belajová, Drahomíra Rauová
Czech J. Food Sci., 2010, 28(3):233-241 | DOI: 10.17221/101/2008-CJFS
Two procedures for the extraction of ochratoxin A (OTA) from red wine - the reference clean up procedure using specific immunoaffinity column (IAC), and solid phase extraction (SPE) in which an active carbon was employed, was compared. In SPE procedure, various mixtures of dichloromethane (D), toluene (T), acetonitrile (AC), methanol (M), and acetic acid (A) were used as OTA desorption agents. Two types of SPE carbonaceous columns were tested - commercial SPE columns (SupelcleanTM Envi-Carb) with a nonporous graphitised carbon, and SPE columns prepared in our laboratory (further specified as Lab-Carb) that were filled with a micro particular...
Influence of the preservative material HOLDBACTM on the growth and proliferation of Listeria on the surfaces of cheeses
Jarmila Vytřasová, Jana Fousová, Petra ©névajsová, Marcela Pejchalová
Czech J. Food Sci., 2010, 28(3):242-248 | DOI: 10.17221/185/2009-CJFS
Three varieties of cheese were selected for the experiment: Genuine Olomouc-brand soft ripened cheese, Loose-brand acid curd cheese, and Slovak-style string cheese. Their surfaces were inoculated with Listeria cells of a defined density and then treated with the preservative material HOLDBACTM at its optimal concentration. The cheeses were stored at two different temperatures for the periods of 2, 5, 9, and 14 days, after which the effectiveness of the treatment with the preservative material was determined. The results were compared with the effectiveness of the material on the growth and proliferation of Listeria when...