Czech Journal of Food Sciences, 2005 (vol. 23), issue 1
Optimum conditions of rice puffing - review
Karel Hoke, Jiřina Houšová, Milan Houška
Czech J. Food Sci., 2005, 23(1):1-11 | DOI: 10.17221/3365-CJFS 
The presented paper reviews the existing literature dealing with rice puffing and optimum conditions of this process. The rice pre-treatment procedures and puffing conditions (dry heat, microwave, gun-puffing) are considered. The optimum composition of the raw material is also mentioned.
Anti-yeast effects of some plant extracts on yeasts contaminating processed poultry products in Egypt
Abdel-Aziz Hemly Brr, Yehia Abdel-Galele Mahmoud
Czech J. Food Sci., 2005, 23(1):12-19 | DOI: 10.17221/3366-CJFS
A total of 60 random samples of fresh chicken burger, fillet, and luncheon (20 of each) were collected from markets at Tanta city. The average total yeast counts (cfu/g) in burger, fillet, and luncheon samples were 2.7 × 106 ± 1.1 × 106, 2.1 × 105 ± 0.9 × 105, and 1.4 × 107 ± 0.7 × 107, respectively. A total of 158 yeast isolates of 23 species were isolated and identified. Candida, Cryptococcus, Debaromyces, Issatchenkia, Pichia, Rhodotorula, Saccharomyces, Trichosporon and Yarrowia species were recovered from the examined samples of fresh chicken...
Determination of fumonisins B1 and B2 in beer
Ľubomír Daško, Drahomíra Rauová, Elena Belajová, Milan Kováč
Czech J. Food Sci., 2005, 23(1):20-26 | DOI: 10.17221/3367-CJFS
The aim of this study was to investigate the contamination of beer of Slovak origin with fumonisins. A suitable analytical procedure was suggested - the limit of detection at the level close to 1 µg/l was achieved for both fumonisins B1 and B2. The recovery was determined at 93% for fumonisin B1 and at 78% for fumonisin B2. Fluorescence detection was used after derivatisation with a mixture of o-phthaldialdehyde and 2-mercaptoethanol. Phosphate buffer usually applied resulted in a poor separation of derivatised fumonisins. Peak splitting was observed depending on the pH of the eluent. The pH...
Chocolate authenticity control concerning compliance with the conditions for adding cocoa butter equivalents as laid down by Directive 2000/36 EC
Ivan Bohačenko, Zdenka Kopicová, Jitka Pinkrová
Czech J. Food Sci., 2005, 23(1):27-35 | DOI: 10.17221/3368-CJFS
Chocolate samples (22 in total, including 11 samples of milk chocolate) were bought from retail store in Prague and tested for their CBEs contents in relation to the declaration of CBE addition on the product labels. The modified method of Padley and Timms was employed for determining selected triglycerides (C50, C52 and C54). The presence of CBEs in chocolate was evaluated using the following relationship: %C50 < 44.095 - (0.737 × %C54). The content of CBE in chocolate was determined using the method of Young, modified by the replacement of the original graphical procedure with the numerical processing of the results. 19 samples i.e. 90% of the...
TLC separation of methylated (-)-epigallocatechin-3-gallate
Ryszard Amarowicz, Anna Maryniak, Fereidoon Shahidi
Czech J. Food Sci., 2005, 23(1):36-39 | DOI: 10.17221/3369-CJFS
Methylated EGCG was separated from the crude extract using Sephadex LH-20 column chromatography with methanol as the mobile phase, and a semi-preparative HPLC method with water-dimethylformamide-methanol-acetic acid (157:40:2:1, v/v/v/v) as the mobile phase. The chemical structure of the separated catechin was confirmed by ESI-MS in the negative-ion mode. Three different mobile phases were used for silica gel and reversed phase TLC of EGCG and methylated EGCG. Rf values of both catechins were calculated and are reported. In the normal phase, the best condition of separation was with chloroform-methanol-water (65:35:10; v/v/v; lower phase)...