As yields are already at a quite high level in the European vegetable industry, nowadays the main emphasis is on the nutritive value of the vegetable products. Our objective was to investigate the effects of irrigation and increased potassium supply on the nutritive composition and yield of carrot. The experiment was conducted in 2010 in central Hungary on a sandy soil. Sprinkler irrigated stand and rainfed control, and potassium supply of 150 and 300 kg K2O ha(-1) were compared. Dry matter, fructose, glucose, saccharose, six different carotenes, polyphenol and nitrate concentrations were measured as nutritive constituents. Because of the unusually high amount of precipitation just three irrigations were necessary to apply with a total amount of 69 mm during a rainless period in July. Irrigation has significantly increased the marketable carrot root yield (by 59%, 108 t ha(-1) opposed to 68 t ha(-1)), due to higher average root weight (124 g opposed to 79 g). Contents of nutritive components were not negatively affected by the irrigation. Moreover, dry matter, alpha-carotene and nitrate contents were significantly better for the irrigated treatment. This result can be explained by the fact that during the last two months of the experiment the water supply was the same for every treatment through the natural precipitation, but in July at the beginning of photosynthate accumulation water supply was higher in the irrigated stand. The similar nutrient content and the higher root yield resulted in significantly higher nutrient yield in case of every investigated nutritive compound. Potassium supply of 300 kg K2O ha(-1) did not improve the yield and the nutritive value compared to the 150 kg K2O ha(-1) rate.

Anti-nutritive components in multi resistant potato cultivars were investigated in relation to conventional and organic farming for three years. Glycoalkaloids, nitrate, nitrite, asparagine, and glutamine contents of tubers were examined. Farming technology was found not to have an effect on the level of glycoalkaloids, which was influenced mostly by the genotype and season. Nitrogen fertilisation caused significant increase in nitrate, asparagine, and glutamine contents as compared to organic farming. Nitrite content was found to be more independent of farming technologies than nitrate. Tubers of cultivar Rioja had the lowest nitrate content irrespective of season or technology. In conclusion, the absolute amount and changes of different anti-nutritive components of potato tubers were influenced differently by the technology, genotype, and season in a complex manner. Organic farming had no effect on the glycoalkaloid content, but the nitrate levels had a tendency to be lower compared to conventional farming. This can be seen as a positive effect of organic farming.

The composition of five pear varieties (‘Abate Fètel’, ‘Bosc’, ‘Williams’, ‘Conference’, ‘Packham’s Triumph’) grown in Nagykanizsa was investigated in three consecutive years (2008, 2009, 2010). A storage experiment was performed in 2008. Four winter pear cultivars were kept in an ULO store for four months and their parameters measured after two and four months. The parameters tested were: size, weight, water soluble solids, titratable acidity, glucose, fructose, sucrose, water soluble pectin, total polyphenols, free radical scavenging capacity, copper and zinc content. The fruits of ‘Conference’ and ‘Bosc’ varieties were found to contain the highest sucrose and total sugar content, while ‘Abate Fétel’ had the lowest sucrose and highest glucose levels among cultivars tested. ‘Williams’ pear was the most acidic. Brix, total sugar, sucrose and water soluble pectin were decreased during storage. Titratable acidity slightly decreased in fruits of Conference pear. Polyphenols and free radical scavenging capacity did not show a significant change during storage.

Fruits of different sour cherry varieties cultivated, in 2008 and 2009, under organic farming and integrated cultivation conditions were analysed for their quality attributes, antioxidant activity and subjected to sensory evaluation.. Average size, weight, soluble solids, titratable acidity, total polyphenols, free radical scavenging capacity expressed as Trolox equivalent (TEAC), copper and zinc were determined in freshly harvested fruits. The obtained results indicated that, the principal component analysis can separate and distinguish the seasons of fruit production. The farming system seemed to have slight effect on quality the fruit as compared to varietal factors (genotypes). However, the total polyphenol content was uniformly less in 2009. Total polyphenols and free radical scavenging activity were significantly higher in Bosnian type sour cherries, and outstanding in Amarelle type cultivar ‘Pipacs’. There was no statistically significant difference between the sensory properties of cultivars tested by panels, except the case of ‘Pipacs’. The organolaptic investigation showed marked preference to the fruits of Eva and Petri cultivars.

Prima’, ‘Gala’, ‘Remo’, ‘Topáz’, ‘Idared’, ‘Releika’, ‘Resi’, ‘Rubinola’, ‘Rajka’, ‘Rewena’ and ‘Florina’ apple cultivars, both from organic and integrated farming, from Pallag and Újfehértó, were compared. Average size, weight, soluble solids, titratable acidity, total polyphenols, free radical scavenging capacity expressed as Trolox equivalent (TEAC), copper and zinc were determined at harvest and after cool storage. Organic apples were more acidic, while integrated fruits had mostly higher copper and zinc content. Total polyphenols and TEAC values did not show a significant difference as a function of farming technology. A principal component analysis shows the separation of provenances as well as stored and fresh apples. Results are considered as preliminary.

Supercritical carbon dioxide (SC-CO2) was used to produce oleoresin from dried onion by pilot-scale extraction. The results showed that the extraction pressure and temperature affected the yield and sulphur concentration of onion oleoresin. Increase of the temperature from 45 to 65 degrees C at 300 bar resulted in an increase of the yield and the sulphur concentration of oleoresin. At the same temperature (45 degrees C) the yield was also higher at 300 bar than 100 bar while sulphur concentration of oleoresin got smaller at 300 bar than at 100 bar. The volatile composition of oleoresin displayed practically no differences as a function of extraction parameters, Comparison of different extraction methods showed that the yield after SC-CO2 extraction was 22 times higher than that after steam distillation, but it was 14 or 39 times less than that after alcohol extraction, shaking at 25 degrees C or in Soxhlet apparatus, respectively. The concentration of sulphur was the highest in steam distilled onion oil while it was the lowest in the extract of hexane and alcohol (at 25 degrees C). The results of sensory evaluation showed that oleoresin extracted by SC-CO2 was the first in ranking (at level of significance 0.05), before steam distilled oil and alcoholic extract. There was no significant difference between steam distilled oil and alcoholic extract in ranking, but the alcoholic extract was the least desirable, since the intensity of its off odour attribute was the highest. (C) 1998 SCI.

Supercritical carbon dioxide (SC-CO,) extraction on a laboratory-scale, was applied to produce oleoresin from dried onion (Allium cepa L). The goal of this work was to determine the optimal conditions of extraction for producing oleoresin with the highest yield and the best quality. A polynomial model was developed on the data. The square of correlation coefficient was R-2 = 0.9022 (at P less than or equal to 0.05). The statistical analysis showed that the extraction pressure, temperature, and time have significant influence on the yield of the oleoresin. Increasing these parameters resulted in an increase in the yield. Maximum yield was obtained when the extraction pressure and temperature were above 350 bar and 57 degrees C, respectively. At the lowest pressure (150 bar) applied the highest concentration of sulphur was produced in the oleoresin. The concentration of sulphur increased as a function of temperature when the pressure was maintained at 300 and 400 bar. The composition of volatile compounds of oleoresin differed from that of distilled onion oil. (C) 1998 SCI.

Sensory qualification of 26 Hungarian fruit juices and nectars was performed by experts and consumers firstly to establish the congruency of their results. For the sake of comparison the relevant versions of ranking and scoring methods were used. The favourable similarity was also proven by rank correlation method according to Spearman as well as by linear correlation and regression calculations. The assessing ability of experts was estimated on the basis of three factors. Repeating ability needs further development, while the evaluation accuracy and scoring deviation were proven to be satisfactory.

For qualitative determination of lipoic acid (6,8-thio-octanoic acid) a multi-stepwise, two-dimensional thin-layer chromatographic method has been elaborated. Because the large quantity of similar type compounds - mainly fatty acids - interfered, we have developed capillary gas chromatographic methods too. In both processes lipoic acid - mainly bound to proteins - was liberated by acidic hydrolysis, followed by extraction. Thin-layer chromatography was carried out with samples taken directly from the lipoic acid containing extract. For gas chromatography the solvent was removed from the extract and its methyl ester derivative was used for analysis. A Supelcowax 10 (of 10-mu-m thickness) coated glass capillary column of 30 m length, 0,75 mm inner diameter, was used at 240-degrees-C (isotherm conditions), applying H-2 as carrier gas (tCH4 = = 1.25 min). The apparatus used was Hewlett-Packard type 5720 GLC provided with flame ionization detector. Quantitative evaluation was carried out by a HP 3392 Reporting Integrator, calibrated with a known quantity of lipoic acid. The gas chromatographic method was suitable for the estimation of lipoic acid quantities in ppm amounts present in brewers' yeast. Of the known amount of added lipoic acid the total recovery was found to be 30%. The lipoic acid content as determined from different brewers' yeasts (fresh, spray-dried, autolysate) amounted to 1-2.5-mu-g per g; taking into account the mere 30% recovery, the values come up to 3.3-8.3-mu-g per g.

AbstractAroma content and composition of different Hungarian and foreign apricot cultivars were studied. Volatile flavour substances were isolated by simultaneous steam distillation‐extraction. GC and GC/MS analysis of the aroma extracts revealed 40 components, 12 of them have been reported for the first time in apricots. The changes in the aroma composition of the cultivar “Hungarian kajszi” during ripening were also studied.

AbstractAs a part of a selection study, the aroma of the most common Hungarian and several foreign cultivars was investigated. Four cultivars were studied during three consecutive years, three others only once. The cultivars contained the same main components in different ratios. The quantity of 30 components identified earlier was measured. Statistical evaluation of the results is also given. Sensory descriptive analysis coupled with gas chromatographic separation of aroma extracts was performed, the odour values of individual components were calculated.