Authors:D. Horvat, V. Spanic, K. Dvojkovic, G. Simic, D. Magdic, and A. Nevistic
Under artificial Fusarium infection the total glutenin content determined by chromatographic (RP-HPLC) method was significantly reduced in comparison to gliadins which were increased. Among protein types, α-GLI and HMW-GS were the highest affected. Artificial Fusarium infection significantly increased GLI/GLU ratio when compared with the natural infected samples. Artificial Fusarium infection dramatically decreased the dough mixing tolerance and had a considerable negative effect on dough energy, maximum resistance, and resistance/extensibility ratio. Disturbed GLI/GLU ratio and an increased amount of mycotoxin DON under artificial Fusarium infection showed a strong negative impact on affected functional properties of dough and bread. Total and γ-GLI as well as GLI/GLU ratio were significantly positively affected by mycotoxin DON in contrast to total GLU, HMW-GS and LMW-GS which were negatively affected. Results indicated that the stability of baking quality parameters of cultivars more tolerance to the Fusarium infection can be well define by lower accumulation of mycotoxin DON.
Authors:G. Šimić, R. Sudar, A. Lalić, Z. Jurković, D. Horvat, and D. Babić
The hordein proteins of ten barley (
L.) cultivars grown in region of eastern Croatia were studied for their contribution to the malting quality, particularly relating hordein influence on malt extract yield. The analysis of hordein proteins was carried out by reversed-phase high-performance liquid chromatography (RP-HPLC). The micromalting of investigated barley cultivars and malt analyses were done according to the EBC official methods. The quantitative analysis of hordein proteins has showed that B-hordein was major component, followed by C- and D-hordeins. Among investigated cultivars the malt extract yield varied from 76.8% (cv. Angora) to 82.6% (cv. Scarlett). Spring barleys had on the average higher malt extract yield in contrast to winter barleys. The significant negative correlation between the total hordein content and malt extract yield was found. Among hordein fractions the B-hordein and D-hordein significantly contributed to lower malt extract yield. RP-HPLC analysis of malt hordeins revealed that the amount of hordein degraded during malting significantly correlated with Kolbach index.
Authors:D. Horvat, N. Ðukić, D. Magdić, J. Mastilović, G. Šimić, A. Torbica, and D. Živančev
Glutenin polymers composed of HMW and LMW subunits are important contributors to the wheat end-use properties. Twenty-six winter wheat cultivars differing in bread processing quality were collected at the experimental fields of the Agricultural Institute Osijek, Croatia and Institute of the Field and Vegetable Crops Novi Sad, Serbia, in 2008/2009 season. The HMW glutenins composition and glutenin proteins content were determined by SDS-PAGE and RP-HPLC, respectively, with aim to determine the relationship between glutenin protein fractions and wheat quality properties. Significant differences were found between Croatian and Serbian cultivars in several quality attributes (GI, WA, DDT, DS and R/EXT) as well as in the content of total glutenins and LMW glutenins and GLI/GLU ratio. The dominant HMW subunits in analyzed cultivars were 2*, 7 + 9/7 + 8 and 5 + 10. Principal component analysis (PCA) confirmed the presence of association between HMW glutenins composition and GI, dough E, R and R/EXT, while the glutenins quantitative data showed pronounced relation with P, DDT, DS, E, R and R/EXT. GLI/GLU ratio had the opposite effect on these parameters.
Authors:D. Horvat, Z. Jurković, G. Drezner, G. Šimić, D. Novoselović, and K. Dvojković
The gluten proteins of 15 winter wheat cultivars grown in eastern Croatia were studied for their contribution to the bread-making quality. Composition of high-molecular-weight glutenin subunits (HMW-GS) was analyzed by SDS-PAGE, while the quantity of gluten proteins was determined by combined extraction/RP-HPLC procedure. The results of the linear correlation analysis carried out on the particular gluten proteins and technological properties showed that the amount of total gluten content highly correlates with protein content. Among gluten proteins, the glutenins showed higher correlation with protein content, with pronounced influence of HMW-GS, than gliadins. Wet gluten content was significantly correlated to total gliadin quantity. Gluten index as gluten quality parameter was positively influenced by total glutenins and low-molecular-weight glutenin subunits (LMW-GS), and negatively, by the ratios of gliadin to glutenin (Gli/Glu), whereas the amount of gliadins was not important. Dough development time was strongly correlated with total gluten content, total glutenins and the Gli/Glu ratio. Dough mixing resistance was strongly affected by total glutenin content with pronounced influence of HMW-GS. Degree of dough softening is mainly negative influenced by total glutenins and ratio of Gli/Glu. Farinograph quality number as flour quality index was highly positively correlated with total glutenins, with emphasized influence of HMW-GS. The Gli/Glu ratio had the highest influence on dough maximum resistance. Dough extensibility showed moderate correlation with total gliadins. The results of the linear correlation indicated that loaves volumes were significantly influenced by total gluten proteins, HMW-GS and LMW-GS.
Authors:Adrien Fónagy, Heather Marco, Simone König, and G. Gäde
The need for more environmentally sound strategies of plant protection has become a driving force in physiological entomology to combat insect pests more efficiently. Since neuropeptides regulate key biological processes, these “special agents” or their synthetic analogues, mimetics, agonists or antagonists may be useful tools. We examined brain-suboesophageal ganglia and corpora cardiaca-corpora allata complexes of the cabbage moth,
, in order to obtain clues about possible peptide candidates which may be appropriate for the biological control of this pest. With the aid of bioassays, reversed phase high performance liquid chromatography, and mass spectrometry, five neuropeptides were unequivocally identified and the presence of a further three were inferred solely by comparing mass spectra with known peptides. Only one neuropeptide with adipokinetic capability was identified in
. Data from the established homologous bioassay indicated that the cabbage moths rely on a lipid-based metabolism which is aided by an adipokinetic hormone (viz. Manse-AKH) that had previously been isolated in many different lepidopterans. Other groups of neuropeptides identified in this study are: FLRFamides, corazonin, allatostatin and pheromonotropic peptide.
Authors:Eszter Laczkó-Zöld, Péter Forgó, István Zupkó, Eşianu Sigrid, and Judit Hohmann
Physalin D was isolated from the methanol extract of Physalis alkekengi L. fruits by combination of different chromatographic methods (CPC, TLC, HPLC). The structure was elucidated based on 1H and 13C NMR spectral analysis with the aid of 2D-correlation spectroscopy (1H, 1H-COSY, HSQC and HMBC) and comparison with literature data. The quantity of physalin D in mature and immature fruits and calyces was determined by RP-HPLC-UV method. Among the studied samples, immature calyx showed the highest content of physalin D (0.7880 ± 0.0612%), while mature calyx contained 4 times less amount (0.2028 ± 0.016%). The physalin D content of the fruit was much lower; immature fruits contained 0.0992 ± 0.0083% physalin D and mature fruits 0.0259 ± 0.0021%. The antiproliferative activity of the CHCl3 extract and its fractions was tested on three cancer cell lines (HeLa, MCF-7 and A431). The antiproliferative activity of physalin D is discussed with regard the published data.
Ultracentrifugation was used as a non-destructive method to separate dough into liquid, gel, gluten, starch and bottom phases. The protein composition in the different phases was investigated for dough prepared from spring wheat (Triticum aestivum L.). The SDS-PAGE, SE-HPLC and RP-HPLC methods were used for the analysis. The wheat protein composition of the liquid and gel phases consisted of albumins, globulins and traces of gliadins and glutenins. The gluten phase contained proteins extractable with all the extraction buffers used. A similar protein composition was found in the starch and bottom phases, but in considerably lower amounts. Specific LMW glutenin subunits were identified in the gluten phase by RP-HPLC. The albumin composition differed in the gel phase compared to the gluten and bottom phases. Differences in protein composition due to mixing methods were detected only for the albumin composition in the liquid phases.
Authors:Tibor Bartók, András Szekeres, Árpád Szécsi, Mihály Bartók, and Ákos Mesterházy
Fumonisins were extracted from a rice culture which had been inoculated with
isolated from maize stalk. The culture extracts were analysed by a hyphenated technique: reversed-phase high-performance liquid chromatography/electrospray ionization ion-trap mass spectrometry (RP-HPLC/ESI-IT MS
). Besides already known fumonisins, a new type of fumonisin series (PHFB4OSA belonging to the formerly described FBX)-containing four new compounds-was detected. At these compounds, one of the OH groups attached to the fumonisin backbone was esterified by carboxylic acid (oxalylsuccinic acid, OSA) other than tricarballylic acid (TCA). The masses of the protonated molecules and of the characteristic product ions and the characteristic neutral mass losses from the protonated molecules suggested their structure. The relative quantities of the new minor compounds were expressed as percentages of FB1 toxin.