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Apple is one of the most important fruit grown and consumed in the temperate climate region. About 2% of the European population suffers from several allergenic reactions after consumption. Presence of 7 members of Mal d 1 gene family occurring in some apples was examined by PCR. The Mal d 1.01 and 1.02 genes could be detected from 91% and 79% of apple cultivars, respectively, due to the high degree of conservative regions. The Mal d 1.04 gene has 4 functional varieties and 2 pseudo-alleles, so it is highly variable. The PCR amplifi cation with Mal d 1.06 primers gave one or two fragments with different sizes. The electrophoretic pattern is a suitable means to select apple cultivars according to their low, medium, or high Mal d 1 allergen content. Florina apple showed the single 154 bp allele, which is responsible for the small Mal d 1 allergen content in homozygote form..

Several samples gave weak signal or did not give any fragment-band on the gel, so Mal d 1.07 and 1.08 genes might have more varieties. Regarding the Mal d 1.09 gene we have found that it has conservative sequences in different apple cultivars and does not have too many varieties.

Open access

Reliable determination of microbial or transgenic Cry toxins is an essential issue in food and feed analyses, and enzyme-linked immunosorbent assays (ELISAs) are the method of choice for quantifying these toxins currently in food and environmental analysis. Internal Quality Control (IQC) is an indispensable method to assess accuracy, precision, and reproducibility of analytical measurements. To assess the utility of the ELISA method, IQC was performed on EnviroLogix Cry1Ab/Cry1Ac QualiPlate ELISA with manufacturer supplied analytical standards. Applicability of negative and positive controls (C− and C+) was examined by Shewhart Control Charts for bias and Control Chart of the Range of Duplicates for precision. Linear regression (up to 5 ng ml−1 Cry1Ab concentration) of the commercial ELISA kit was compared to sigmoid calibration (up to 60 ng ml−1 Cry1Ab concentration). For immunoassay optimization process, possible matrix effects in different liquid and solid vertebrate tissues were examined by determination of the limit of detection values in these matrices.

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Successful applications of toxins derived from Bacillus thuringiensis (Bt) strains in Bt-based bioinsecticides and more recently in Bt-plants in crop protection have enhanced the importance of analytical quantification of Cry toxin dosages for studies on various topics including environmental risk assessment (ERA), resistance management, quality control and regulatory compliance. It is essential to follow-up distribution and environmental degradation of these lectin type, crystalline (Cry) toxin proteins showing insect specificity at order level. Thus, Cry1Ab toxin produced by Bt-maize of genetic event MON 810 is specific to lepidopteran species. Widely used analytical methods for detection of Cry toxins are enzyme-linked immunosorbent assay (ELISA) systems. Reported Cry1Ab toxin concentrations in MON 810 maize show high variability: order of magnitude differences have been observed among various plant parts from different varieties, cultivated at different locations, and sometimes even within the same plant variety at a single location. Besides biological sources of variability, numerous analytical problems have been identified and are reported in this report, influencing the results of quantitative determination of Cry1Ab toxin and explaining the high variability among documented data on toxin content. Conclusions in every case refer to genetic event MON 810, but can be extended to other genetic events producing Cry1Ab toxin.

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Abstract

Enzymatic hydrolysates of mechanically deboned meat (MDM) for a long time have been used as flavouring and functional food ingredients in the food industry and also as the bases of formula foods for special dietary uses.

The aim of the present study was to produce MDM hypo-antigenic products with improved digestibility and high biological value to be used as a milk protein alternative. turkey MDM was treated with digestive enzymes (trypsin and/or α-chymotrypsin, or pancreatin), followed by freeze drying. The optimised reaction conditions of hydrolysis were at 6% (w/v) of meat protein in 0.1% NaHCO3 buffer, pH 7.5; pancreatin enzyme with 50 TAME units/g meat protein substrate, 37 °C and 60 min). Hydrolysates (MDMH) were assessed for degree of hydrolyses (DH, %) by using trinitrobenzenesulphonic acid method and MW distribution by SDS-PAGE. Modification of immune reactive binding sites in MDMHs was monitored by immunoblot with cow’s milk, chicken egg or meat allergic human patients’ sera. Biological value indices (True Digestibility (TD), Net Protein Utilisation (NPU), Biological Value (BV)) were determined using rat feeding trials. Among the MDMH products, the pancreatic hydrolysate proved to be the most favourable in terms of biological value and digestibility as well as hypoallergenic property.

Open access

Yellow pea flour contains very low quantity of prolamins, thus it could be a good alternative dietary source for individuals suffering from celiac disease or wheat allergy. Beside emulsifiers, enzymes can be used for developing noodle structure with high quality. Transglutaminase (TG) enzyme was tested in model systems for improving noodle structure by using beneficial cross-linking property of the enzyme. Sensory-and cooking properties and biochemical attributes of proteins were evaluated to characterize structure-function relationships in accordance with the concentration of the applied enzyme. The amount of water and salt soluble protein fractions was reduced meaningfully and the molecular weight distributions assessed by SDS PAGE were changed by addition of 50–200 mg kg −1 TG enzyme. At the same time, sensory properties were improved and high water uptake and low cooking loss were also observed. Forasmuch an increase has been expected in the amount of the cross-linked molecules, the cross-reactivity of prolamins with anti-gliadin antibody was also tested to reduce the risk related to gluten sensitivity. Finally, the possible contamination with wheat was controlled by DNA-based PCR.

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The expression levels of two marker proteins (phosphinotrichin acetyltransferase, PAT and wheat germ agglutinin, WGA) in the transgenic wheat lines and their resistance to digestion in small intestine of rats were studied in comparison with their non-transgenic counterpart obtained from green house and field experiments of two subsequent years. The marker proteins were quantified by ELISA. It was found that the expression of PAT and WGA markedly increased when the wheat was grown in the field compared to that in the greenhouse. There were no significant differences between the WGA contents of the parent and transgenic wheat lines, but a broad range of expression of PAT and WGA was observed in the transgenic lines. PAT did not survive in the small intestine of the rats, while WGA was resistant to digestion in different ratios and was bound to the intestinal epithelium.

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Acta Alimentaria
Authors:
E. Szabó
,
É. Gelencsér
,
E. Kovács
,
A. Jánosi
,
K. Takács
, and
E. Kiss

In our research we studied the occurrence of the main apple allergen coding gene-families (Mal d 1, Mal d 2, Mal d 3, Mal d 4) in 16 different and most preferably consumed apple varieties. After the DNA isolation by Wizard method the simple PCR reaction was used to examine the apple allergen-coding genes. To identify the presence of the four allergenic protein-coding genes two primer pairs were chosen. The presence of these allergens in most apple varieties could be confirmed. According to our results two varieties — Jonathan and Granny Smith — were found to contain the lowest amount of the coding genes of the allergenic apple proteins studied by us. Besides this, polymorph pattern was obtained by the use of Mal d 1 primer, which may lead to determine apple varieties with small amount of Mal d 1 allergens.The confirmation study of the presence of potential apple allergens by RNA and protein techniques is our plan in the near future.

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Acta Alimentaria
Authors:
É. Sárdi
,
É. Stefanovits-Bányai
,
I. Kocsis
,
M. Takács-Hájos
,
H. Fébel
, and
A. Blázovics

Of the twenty table beet ( Beta vulgaris L. ssp. esculenta convar. crassa provar. conditiva ALEF.) cultivars investigated for several nutritionally important components (betaine, betanin, phenol, glucose, fructose, sucrose) formerly (Hájos et al., 2004), cultivar Ditroit having average quality parameters was chosen for in vitro animal experiments. The hyperlipidemic rat model is suitable to study the physiological effect of table beet on the metabolic alterations and the redox homeostasis in the liver. In fatty liver, as a consequence of hyperlipidemy, the redox homeostasis is strongly injured. General biologically active compounds of table beet have indirect lipid lowering effect and antioxidant properties. Therefore, the effect of lyophilised table beet powder was studied on altered lipid metabolism and redox parameters in hyperlipidemic rats. Hyperlipidemy was induced by a fat-rich diet, and both in the control group and in the hyperlipidemic group, animals were treated with the lyophilised table beet powder (2 g bwkg −1 ) added into rat chow for 10 days parallel with the feeding. Significant antioxidant activity of table beet was recorded in the hyperlipidemic liver. This phenomenon was expected because of the significant amount of betanin and the high total polyphenol content of the beet. Significant beneficial changes were also observed in the serum cholesterol level, alkaline phosphatase and alanine-aminotransferase activities, although a non-expected elevation was observed in the serum bilirubin level in hyperlipidemy. Non-specific H-donor activity was not changed, but protein related free SH-group concentration was decreased in the plasma. Serum triglyceride level was better after table beet treatment in normolipidemy, only. Change of redox-homeostasis was more favourable in the liver during the treatment. Diene conjugate content and the level of induced free radicals decreased during the table beet treatment in case of fatty liver. These changes were due to the bioactive components of the commercially available table beet. Consequently, table beet due to its specific qualities beneficially influences several metabolic pathways, therefore it can be considered as a functional food.

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Tomato spotted wild virus (TSWV) has become an important plant pathogen during the past 10 years in Hungary. This virus belongs to the family of Bunyaviridae, genus Tospovirus. According to the latest studies, this virus has about 1090 host plant species, including crops and weeds. In the autumn of 2009, some Aristolochia clematitis plants were collected showing symptoms of TSWV infection. On the basis of electron microscopic and molecular studies, leaf samples of Aristolochia clematitis L. found in a vineyard proved to be infected with Tomato spotted wilt virus (TSWV). This is the first report on the occurrence of TSWV in Aristolochia in Hungary.

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The main objective of the DOSoReMI.hu (Digital, Optimized, Soil Related Maps and Information in Hungary) project is to significantly extend the potential, how demands on spatial soil related information could be satisfied in Hungary. Although a great amount of soil information is available due to former mappings and surveys, there are more and more frequently emerging discrepancies between the available and the expected data. The gaps are planned to be filled with optimized digital soil mapping (DSM) products heavily based on legacy soil data, which still represent a valuable treasure of soil information at the present time. The paper presents three approaches for the application of Hungarian legacy soil data in object oriented digital soil mapping.

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