Czech Journal of Food Sciences, 2010 (vol. 28), issue 2
Texture and pasting properties of ultrasonically treated corn starch
Ivana Ljubić Herceg, Anet Režek Jambrak, Drago Šubarić, Mladen Brnčić, Suzana Rimac Brnčić, Marija Badanjak, Branko Tripalo, Damir Ježek, Dubravka Novotni, Zoran Herceg
Czech J. Food Sci., 2010, 28(2):83-93 | DOI: 10.17221/50/2009-CJFS 
The effects of high power ultrasound of 24 kHz and ultrasound bath of 24 kHz frequency on the textural and pasting properties of corn starch suspensions was examined. Suspensions were treated with different intensities and treatment times (15 min and 30 min) using an ultrasound probe set and bath. The treatments with high power ultrasound probes caused a significant lowering of the starting gelatinisation temperatures of corn starch. The ultrasound treatment caused disruption of starch granules by cavitational forces and made the granules more permeable to water. The highest viscosity was observed for the treatment with 300 W probe. Also, a statistically...
New approach to the study of dough mixing processes
Zdenka MUCHOVÁ, Boris ŽITNÝ
Czech J. Food Sci., 2010, 28(2):94-107 | DOI: 10.17221/91/2009-CJFS
The importance of the dough mixing, knowledge of the requirements of individual types of flour in the mixing, and achieving the proper quality with respect to the final dough properties are still actual problems. This study describes the changes in consistency, extensographic energy, and temperature progress in connection with the mechanical energy flow into the dough during mixing on Diosna SP12 kneader. The results of the mixing tests on the first gear indicate that different energy inputs caused different changes in consistency, the development time, and temperature increase of mixed dough. By the alteration of the mixing energy is it probably possible...
Extraction, purification, and characterisation of the flavonoids from Opuntia milpa alta skin
Weirong Cai, Xiaohong Gu, Jian Tang
Czech J. Food Sci., 2010, 28(2):108-116 | DOI: 10.17221/122/2009-CJFS
The flavonoids contained in Opuntia milpa alta skin were extracted, purified, and identified. Based on single factor experimental results, the extraction parameters were optimised by using orthogonal design and variance analysis. The results show that the maximum yield of the flavonoids (5.55 mg/g dry weight) can be obtained with 80% ethanol (v/v), extraction temperature of 90°C, and the solvent to raw material ratio of 25:1. After purification with AB-8 resin, the main components of the extract were characterised as isorhamnetin 3-O-(2, 6-dirhamnosyl)glucoside and isorhamnetin 3-O-d-rutinoside by employing liquid chromatography-mass...
Analysis and characterisation of anthocyanins in mulberry fruit
Chuanguang Qin, Yang Li, Weining Niu, Yan Ding, Ruijie Zhang, Xiaoya Shang
Czech J. Food Sci., 2010, 28(2):117-126 | DOI: 10.17221/228/2008-CJFS
The fruit of mulberry (Morus alba L., Moraceae) has been used as medicinal food in China for a long history. The pigment from the fruit extract is a kind of natural colourant for food processing and has potential medical and commercial values. This study focuses on the analysis and characterisation of anthocyanins from mulberry pigment. The fresh mulberry fruits were extracted with the solvent of 95% alcohol/0.1% HC l (1:1, ratio) at room temperature for 4 h in the dark. After the isolation using C-18 column, the pigment was identified with UV-Visible Spectroscopy, HPLC-PAD, LC-MS, and 1HNMR. The results showed that the abundant anthocyanins...
Major and minor compounds in a Mexican spirit, young Mezcal coming from two Agave species.
Araceli M. Vera-Guzmán, Rosa I. Guzmán-Gerónimo, Mercedes G. López
Czech J. Food Sci., 2010, 28(2):127-132 | DOI: 10.17221/56/2009-CJFS
Major and minor compounds in a traditional Mexican spirit, young mezcal from Agave angustifolia Haw. and Agave potatorum Zucc., were characterised using gas chromatography and solid phase microextraction-gas chromatography-mass spectrometry. A large variability in both mezcal samples was detected in the content of methanol, higher alcohols, acetic acid, and ethyl acetate. However, their values were below the maximum concentration permitted by the Mexican Standards. The minor compounds identified by mass spectrometry included alcohols, esters, ketones, acids, and furanes. The similarities found between mezcal from Agave angustifolia...
Reliability of PCR based screening for identification and quantification of GMOs
Jaroslava Ovesná, Ladislav Kučera, Jan Hodek, Kateřina Demnerová
Czech J. Food Sci., 2010, 28(2):133-138 | DOI: 10.17221/67/2009-CJFS
Handling with genetically modified organisms (GMOs) is regulated namely in EC. Laboratories often use polymerase chain reaction (PCR) based screening methods to monitor the presence of GM particles in food commodities as a cost effective approach. The reliability was tested of such screening using 35S CaMV promoter as the target sequences. Soya grown from non-GM cultivar as declared by a seed company was investigated after the harvest, transport to the silo, and before processing. The results based on PCR and real-time PCR analysis clearly showed that, the contamination with debris of other species, dust during transport, storage, and other kind of...
The influence of feeding diets containing white cheese, produced with prebiotics and the potentially probiotic Lactobacillus plantarum strain, on the gastrointestinal microflora of rats
Monika Modzelewska-Kapituła, Jan Kłobukowski, Lucyna Kłębukowska, Danuta Wiśniewska-Pantak
Czech J. Food Sci., 2010, 28(2):139-145 | DOI: 10.17221/187/2008-CJFS
The effects of inulin HPX and maltodextrins, and also the potentially probiotic Lactobacillus plantarum 14 strain, used separately and in combination in white cheese production, on the gastrointestinal microflora of Wistar rats was investigated. The prebiotic addition to the cheese was 2.5%, whereas probiotic and synbiotic cheeses contained at least 107 CFU/g of live L. plantarum cells. The counts of Bifidobacterium sp., Lactobacillus, coliforms, and the most probable number of anaerobic proteolytic bacteria were evaluated. After a 10-day feeding experiment, significant changes (P < 0.05) were...
Antimicrobial effects of fatty acid fructose esters
Tereza Karlová, Lenka Poláková, Jan Šmidrkal, Vladimír Filip
Czech J. Food Sci., 2010, 28(2):146-149 | DOI: 10.17221/37/2008-CJFS
Antimicrobial effects of various fatty acids and their esters have been extensively studied. Esters with saccharides (glucose, sucrose) have been found to have a broad spectrum of microbicidal activity. The objective of this study was to investigate the susceptibility of four microbial strains (Bacillus cereus, Escherichia coli, Saccharomyces cerevisiae, and Fusarium culmorum) to the antimicrobial properties of fatty acid (capric, lauric, myristic, and palmitic) fructose esters. Microorganisms were cultivated in liquid media supplemented with various concentrations of the tested agents. A spectrophotometric method was used for the quantitative...
The effects of butylated hydroxyanisole, ascorbic acid, and α-tocopherol on some quality characteristics of mechanically deboned chicken patty during freeze storage
Ozgul Ozer, Cemalettin Sariçoban
Czech J. Food Sci., 2010, 28(2):150-160 | DOI: 10.17221/160/2009-CJFS
In this study, the effects were evaluated of butylated hydroxyanisole (BHA), ascorbic acid (AA) and α-tocopherol (TO) on the stability of raw mechanically deboned chicken patties stored at -20°C for 6 months. pH, thiobarbituric acid reactive substance (TBARS), haem iron (mg/kg), metmyoglobin formation (%) and colour (L*, a*, b*, C* and h values) of patties were measured for 0, 2, 4, and 6 months of storage time. pH values were found to be the highest in the initial storage period. TBARS values were observed to range between 0.33 and 2.40 mg malondialdehyde/kg of sample and the L*, a*, and b* values of the patty...