Czech Journal of Food Sciences, 2008 (vol. 26), issue 1
Perspectives and applications of immobilised β-galactosidase in food industry - a review
Zuzana Grosová, Michal Rosenberg, Martin Rebroš
Czech J. Food Sci., 2008, 26(1):1-14 | DOI: 10.17221/1134-CJFS 
β-Galactosidase is an important industrial enzyme in the hydrolysis of milk and whey lactose. The enzymatic hydrolysis of lactose allows to avoid health and environmental problems posed by this disaccharide. In addition, this enzyme catalyses the formation of galacto-oligosaccharides, which are prebiotic additives for the so-called "healthy foods". β-Galactosidase is one of the relatively few enzymes that have been used in large-scale processes in both free and immobilised forms. This article presents a review of recent trends in immobilisation of β-galactosidase and their application in food industry.
Influence of Alcalase and transglutaminase on immunoreactivity of cow milk whey proteins
Barbara WRÓBLEWSKA, Lucjan JĘDRYCHOWSKI, Gyongyi HAJÓS, Erzsebet SZABÓ
Czech J. Food Sci., 2008, 26(1):15-23 | DOI: 10.17221/1141-CJFS
The aim of the research was to determine the changes in the immunoreactivity of whey protein concentrate (WPC) modified by two enzymes: proteinase, Alcalase 2.4L FG (Novo Nordisk), and cross-linked transglutaminase (EC 2.3.2.13, ActivaTM P, m-TG, Ajinomoto). The new products were characterised by 2D electrophoresis, immunoblotting, and ELISA methods. The WPC hydrolysate obtained with Alcalase contained proteins and peptides characterised mostly by low molecular weight peptides (MW < 14.4 kDa) in the pH range of 3-10. Immunoblotting showed strong immunoreactive properties of the hydrolysate with α-la and β-lg polyclonal rabbit...
The usefulness of rabbit anti-QQQPP peptide antibodies to wheat flour antigenicity studies
Joanna Leszczyńska, Agata Łącka, Malgorzata Bryszewska, Ewa Brzezińska-Błaszczyk
Czech J. Food Sci., 2008, 26(1):24-30 | DOI: 10.17221/1124-CJFS
The aim of our work was to estimate the usefulness of rabbit polyclonal anti-QQQPP peptide antibodies to determination of gluten proteins and the usage of these antibodies to estimate the changes of allergenicity of wheat flour after enzymatic modification. For enzymatic modification of wheat flour trypsin, subtilisin and transglutaminase were used. By the use of rabbit antibodies against QQQPP peptide we have stated that the products of subtilisin and transglutaminase degradation exert strongly decreased immunoreactivity.
Determination of folates in vegetables and their retention during boiling
Marie HOLASOVÁ, Vlasta FIEDLEROVÁ, Slavomíra VAVREINOVÁ
Czech J. Food Sci., 2008, 26(1):31-37 | DOI: 10.17221/1137-CJFS
HPLC method for 5-methyltetrahydrofolate (5-MTHF) determination in vegetables was optimised for the folate release from the food matrix. Enzymatic hydrolyses using the subsequent addition of α-amylase, protease, and conjugase from hog kidney, or their combinations, were tested. The highest release values were obtained with the application of enzymes α-amylase and conjugase, amounting to 112.4-127.0% of the values obtained in the processing with sole conjugase. The simultaneous addition of both enzymes and the incubation at pH 4.9 did not suppress the release of folates. Spinach, Chinese cabbage, lettuce, cauliflower, and broccoli contained...
Preparation of high Fischer ratio oligopeptide by proteolysis of corn gluten meal
Ying MA, Li LIN, Da-Wen SUN
Czech J. Food Sci., 2008, 26(1):38-47 | DOI: 10.17221/1138-CJFS
A method to obtain an oligopeptide with high Fischer ratio is described. Corn gluten meal (CGM) was hydrolysed with Alcalase 2.4L using a two-step hydrolysis. In the first-step hydrolysis, the enzyme reaction conditions for hydrolysing CGM were optimised by using the orthogonal experimental design, while pH = 8.0, temperature = 55°C, enzyme to substrate ratio (3:97, w/w), and the substrate concentration = 5% were identified as the optimum conditions, under which up to 11.62% degree of hydrolysis (DH) could be obtained. The hydrolysate was then fractionated by ultrafiltration using a membrane with the molecular cutoff of over 10 kD at 20 kPa. For the...
Sloughing in potatoes induced by tuber density and affected by variety
Anna Hejlová, Jiří Blahovec
Czech J. Food Sci., 2008, 26(1):48-57 | DOI: 10.17221/1136-CJFS
Two cultivars (Nicola and Saturna) largely distinguishing from each other in cooking behaviour and one cultivar (Agria) grown in six different cultivation regimes were tested by the CPEM (cooked potato effective mass) method for the potato sloughing assessment. The sloughing process is characterised by two cooking and disintegration stages, from which two basic CPEM parameters are derived: cooking time as the starting point of disintegration and the rate of the disintegration. Both parameters are analysed as functions of the tuber density in linear models of both stages. Significant differences in CPEM parameters and in the linear models were observed...
Fractionation and identification of some phenolics extracted from evening primrose seed meal
Lucia Zahradníková, Štefan Schmidt, Zuzana Sékelyová, Stanislav Sekretár
Czech J. Food Sci., 2008, 26(1):58-64 | DOI: 10.17221/1135-CJFS
Crude ethanol and ethyl acetate extracts of evening primrose (Oenothera biennis L.) seed meal were separated into fractions using Silicagel L 100/200 column chromatography and methanol as the mobile phase. Six fractions were obtained from the ethanol extract and five fractions from the ethyl acetate extract and their contents of total phenolics were determined. By means of HPLC, the active compounds were identified as catechin, gallic acid, caffeic acid, syringic acid, and ferulic acid.
Mercury and methylmercury in muscle tissue of chub from the Elbe River main tributaries
Kamila KRUŽÍKOVÁ, Zdeňka SVOBODOVÁ, Olga VALENTOVÁ, Tomáš RANDÁK, Josef VELÍŠEK
Czech J. Food Sci., 2008, 26(1):65-70 | DOI: 10.17221/1140-CJFS
The aim of the present study was to investigate the concentrations of total mercury and methylmercury in muscle of 55 chub (Leuciscus cephalus) from seven main tributaries (Orlice, Chrudimka, Cidlina, Jizera, Vltava, Ohře, Bílina) of the Elbe River and to evaluate the health risks of eating fish from the tributaries monitored. Mercury was determined by means of cold vapour atomic absorption spectrometry using AMA-254, methylmercury in the form of CH3HgCl by gas chromatography. The highest mean concentrations of total mercury and methylmercury were found in the Jizera (0.27 ± 0.19 mg/kg and 0.23 ± 0.15 mg/kg, respectively)...
Prof. Dr. Ing. Vladimír Kyzlink, DrSc., Dr.h.c. deceased
P. Pipek
Czech J. Food Sci., 2008, 26(1):71 | DOI: 10.17221/1139-CJFS