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Acta Alimentaria
Authors:
M. Nagy-Gasztonyi
,
E. Biekman
, and
B. Krebbers

The combination of lactofermentation and enzyme-treatment (Rohament-PL as endo-polygalacturonase and the mixture of Rohament-PL and Rohalase 7069 as cellulase) of sliced carrot and orange juice resulted in a homogeneous product, with pleasant organoleptic features, after 18 h fermentation period. Two ways of inoculation were applied with Lactobacillus plantarum. The addition of Rohament-PL, even at 150 mg kg-1 concentration, simultaneous inoculation with Lactobacillus plantarum (circumstances: 28 °C, 80 r.p.m. shaking) promoted the growth of lactobacilli. By 42 h fermentation time LAB count increased up to 3.2-4.8´109 cm-3. Furthermore the surface colour of the samples was more intensive (higher L-, a- and b-values) than without Lactobacillus plantarum inoculation. The application of Rohament-PL (50-100 mg kg-1) resulted in a homogeneous carrot puree, the combination of Rohament-PL (150 mg kg-1) and Rohalase 7069 (150 mg kg-1) in the process gave a more fluid product, as proved by the lower specific viscosity values.

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The aim of the paper is primarily to evaluate the heating energy demand of an industrial hall. In the study, we have made multidimensional dynamic whole building simulations for describing coupled heat and moisture behaviour and energy consumption of the building with different internal loads and compared to the calculated energy consumption of the building according to the Hungarian and Austrian regulations. The walls and roof structure of the industrial building were made with insulated panel systems, the plinth wall was built with monolithic reinforced concrete with 12 cm of XPS insulation. The floor is made of steel fibre reinforced concrete, where 10 cm XPS perimeter insulation was applied. After the calculations, we insulated the floor on the whole surface with 10 cm XPS and investigated the modified structure’s heating energy demand too. In the paper, we analyse the energy consumption of the original and modified industrial building according to the monthly and seasonal calculations and the whole building dynamic simulations and evaluated the differences. Furthermore, we assessed the effect of internal loads, thermal bridges on the simulations.

Open access

During the ageing in barrels, the contact with the fine lees triggers several processes in wine. Lees has a reductive effect by absorbing dissolved oxygen and reducing the amount, which will remain in the wine. At present, minimizing the addition of sulphur dioxide is the trend in all viticultural areas. In this study, the effect of various sulphur dioxide levels was monitored in presence of the lees to determine which dose is appropriate to provide the protection of susceptible white wine against oxidation.

Without SO2 protection, the rH and redox potential changed slightly, so the level of dissolved oxygen seemed to be controlled during the ageing period by the lees, though the antioxidant effect of lees in itself was not appropriate to protect the polyphenol content from chemical oxidation, which led to considerable browning. With the addition of a lower amount of SO2 — 40 mg l2, the lees is already able to protect the white wine samples in all aspects.

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In recent years, research related to studying the effect of gut microflora on the human health has become of major economic importance. The main objective of our study was to examine whether or not the orally administered Lactobacillusstrains (LB) as an oral adjuvant can improve the mucosal immune protectionviaan enhanced IgA secretion to a co-administered marker antigen ovalbumin (OVA). We adapted a murine (BALB/c) model to demonstrate beneficial adjuvant effects of probiotic LB strains. Orally sensitised mice with OVA, which were prefed with native or heat denatured (HD) Lactobacillus salivarius (Ls) or Lactobacillus casei (Lc) responded better or with the same efficiency to a vaccination with antigen (OVA) than mice that had been sensitised only with OVA or not sensitised at all. Antibody (IgA) responses in the gut were increased in response to vaccination with OVA in mice that had been prefed with native or heat denatured Ls or Lc followed by Ls or Lc and OVA feeding. In prefed groups, the OVA feeding alone primed for specific immune response, while adjuvanted OVA has increased the immune exclusion potential of the gut.

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The aim of this study was to develop simple, rapid and reliable methods for the selective determination of Bifidus essensis from ACTIVIA (Danone) yogurts. The methods are based on a modified MRS medium (B-broth), which does not contain inhibitory additives. The sugar source of the medium is maltose, which is metabolized by the bifidobacteria applied in the probiotic products, and not by the normal microflora of yogurt ( Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus ). The redox potential of the medium was reduced with cysteine-HCl. Due to its reduced redox potential, the new bouillon is suitable for aerobic cultivation of bifidobacteria, while in agar form it needs anaerobic incubation. In bouillon form (MPN method) the incubation time is only 2 days compared to the 5-day requirement of the classical anaerobic plate counting methods. The B-broth in diluted form was successfully used in a RABIT (Don Whitley) equipment for selective impedimetric determination of bifidobacteria in Danone yogurts. The exact detection time of the Bifidobacterium counts in a good quality probiotic yogurt, containing bifidobacteria at a concentration of 10 7 to 10 8 CFU ml −1 is not more than 10 to 12 h (in contrast to the 5 days of classical anaerobic plate counting methods).

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In the microflora of sunflower seeds stored in domestic stores the, Alternaria species dominate, while those of Penicillium, Trichoderma, Stemphylium and Absidia spp. are present in lower numbers. During model tests (cca 20% seed moisture content, 25 °C, 4 weeks storage) the Alternaria species were almost completely eliminated and on the seeds mainly Aspergillus species, characteristic of stores, propagated. The moulds significantly deteriorated the quality of the seed and that of the produced oil and meal (reproductive ability, germinating power, oil content, lipoxygenase enzyme activity, acid value, peroxide value, fatty acid composition, UV absorbance, colour, sensorial properties, as well as the protein content, amino acid composition, colour and the smell of the meal), but no aflatoxin production occurred. The findings offer a comprehensive picture on the multiple destructive effects of incorrect storage.

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Acta Alimentaria
Authors:
Á. Tóth
,
E. Baka
,
Sz. Luzics
,
I. Bata-Vidács
,
I. Nagy
,
B. Bálint
,
R. Herczeg
,
F. Olasz
,
T. Wilk
,
T. Nagy
,
B. Kriszt
,
I. Nagy
, and
J. Kukolya

Thermobifidas are thermophilic, aerobic, lignocellulose decomposing actinomycetes. The Thermobifida genus includes four species: T. fusca, T. alba, T. cellulosilytica, and T. halotolerans. T. fusca YX is the far best characterized strain of this taxon and several cellulases and hemicellulases have been cloned from it for industrial purposes targeting paper industry, biofuel, and feed applications. Unfortunately, sequence data of such enzymes are almost exclusively restricted to this single species; however, we demonstrated earlier by zymography that other T. alba and T. cellulosilytica strains encode the same enzyme sets. Recently, the advances in whole genome sequencing by the use of next generation genomics platforms accelerated the selection process of valuable hydrolases from uncharacterized bacterial species for cloning purposes. For this purpose T. cellulosilytica TB100T type strain was chosen for de novo genome sequencing. We have assembled the genome of T. cellulosilytica strain TB100T into 168 contigs and 19 scaffolds, with reference length of 4 327 869 bps, 3 589 putative coding sequences, 53 tRNAs, and 4 rRNAs. The analysis of the annotated genome revealed the existence of 27 putative hydrolases belonging to 14 different glycoside hydrolase (GH) families. The investigation of identified, cloned, and heterologously multiple cellulases, mannanases, xylanases, and amylases may result in industrial applications beside gaining useful basic research related information.

Open access
Acta Alimentaria
Authors:
L. Biró
,
B. Rabin
,
A. Regöly-Mérei
,
K. Nagy
,
B. Pintér
,
E. Beretvás
,
E. Morava
, and
M. Antal

The lack of data regarding dietary and lifestyle habits of Hungarian university students prompted us to undertake a cross-sectional pilot study of students of Semmelweis University, Budapest. A total of 264 students (78 males with mean age of 21.4±2.6 y and 186 females with a mean age of 21.2±2.6 y) were involved in the study. The questionnaires contained inquiries of energy and nutrient intake, use of vitamin and mineral supplements, food frequency, meal frequency and physical activity. Statistical analysis was carried out using SPSS for Windows 9.0. The energy, protein and fat intake was somewhat higher than the Hungarian Recommended Dietary Allowances (HRDA) (BIRÓ & LINDNER, 1999). Sodium intake was alarmingly high. Vitamin D consumption was inadequate. The intake of the members of vitamin B group with exception of B12 and niacin was insufficient. The daily consumption of milk, dairy products, fruits and vegetables was deficient. The meal pattern was unbalanced. Only 66% of males and 52% of females were involved in a regular physical activity. Our results suggest that nutrition should be introduced into the medical curriculum as a separate and full-fledged course of study.

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Abstract

The presented research aimed to confirm that the differences in the lipid peroxidation of three maize (Zea mays L.) hybrids with different genotypes and maturity are due to different nitrogen levels, which was observed based on the amount of malondialdehyde (MDA) measured in the leaves at the main phenological stages of plants. The experiments were performed in a multi-factorial long term fertilisation field trial. In the study, phosphorus and potassium were constantly provided at the optimal level for the plants. The phosphorus and potassium fertilisation were applied in autumn. However, N levels varied from 0 to 300 kg ha−1. Sampling was done at different growth stages 5 times during the growing season (4 leaves, 6 leaves, 8 leaves, 14 leaves, silking). The 300 kg ha−1 N (dose 3) resulted in a significant increase in lipid peroxidation (MDA level), but not a statistically significant difference between the control (dose 1) and the 120 kg ha−1 (dose 2) N doses. The H1 hybrid had the lowest level of lipid peroxidation at the first sampling date. High volume nitrogen fertilisation (dose 3: 300 kg ha−1) increased lipid peroxidation in the hybrids. Averaging the values obtained for the same hybrid at the different sampling times, the medium (dose 2) 120 kg ha−1 N treatment had no significant effect on the lipid peroxidation of the hybrids compared to the values of the control plants. Based on the lipid peroxidation response of the hybrids to N treatment, the exact N dose inflection point can be determined to make the fertiliser utilisation of plants more efficient. Based on our results, we found that inadequate, low (120 kg ha−1) or high (300 kg ha−1) nitrogen fertilisation could affect the MDA levels of plants, thereby affecting the functioning of the lipid peroxidation mechanism.

Open access
Nanopages
Authors:
J. B.Nagy
,
J. N. Coleman
,
A. Fonseca
,
A. Destrée
,
Z. Mekhalif
,
N. Moreau
,
L. Vast
, and
J. Delhalle

Organic polymers - carbon nanotubes nanocomposites are synthesized either by mechanical mixing of the two components or by covalently linking the nanotubes to the matrix. The various procedures will be overviewed and the determining factors will be identified for the best mechanical properties of the composites. On the other hand, it will be shown that for highest electrical conductivity much smaller amounts of carbon nanotubes are needed if the nanotubes can be aligned. The thermal conductivity of the nanocomposites will also be overviewed. Finally, together with nanoclay particles, nanotubes are inducing remarkable flame retardant properties in the nanocomposites materials.

Open access