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Optimization of sample preparation for determination of antioxidant parameters from one grape berry
93-97.Views:184Berry quality is an important issue in wineprocessing, however evaluating characteristics in a single berry level is very complex. The Phenolic compound analysis is more challenging because of the limited amount of material and a mixture of skin, pulp and seed. No clear protocol exists for evaluating these compounds from single berries. The aim of our investigation was to develop such a protocol. Single whole grape berries samples were homogenized in 20 replicates by 5 different methods. The most effective method was when berry was placed in a mortar and was crushed with a pestle under liquid nitrogen until seeds were clearly visible. Seeds were then taken from the mortar and crushed between two stainless steel plates with a hammer, and returned to the mortar without residues. Homogenization continued until the sample had a powdery appearance. The homogenized samples were taken for further analysis such as total polyphenols, total anthocyanin contents and total antioxidant capacity. Our results demonstrate that single berries could be processed and that the homogenates were suitable for taking chemically uniform subsamples.
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Effect of the terroir and the harvest time on the Kékfrankos grape berries visual and physical parameters in Eger (Hungary)
81-85.Views:152In this research, the effects of the “terroir” and the harvest time on the most important physical properties of the berries of Kékfrankos (Blaufrankish) grape variety were examined in 2010 and 2011. The results of the experimentation shown, that the maturation processes can be well described by different physical parameters of the grape berry. The terroir and harvest time effects were investigated in two different vintages and four different territories. It can be concluded, that these physical parameters change significantly during the ripening period, but trends differ between vintages and regions.
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Rheological evaluation of industrial tomato in raw and processed condition
60-64.Views:205Tomato (Lycopersicon esculentum Mill.) is the second most important vegetable with one of the biggest producing areas worldwide, and an increasing tendency in Hungary as well. To fulfil the growing demands of the industry the producers must use the most suitable genotypes for the given conditions. In the experiment six genotypes (‘Heinz 1015 F1‘,‘Heinz 9478 F1‘,‘Kecskeméti 407‘,‘NUN254 F1‘,‘Prestomech F1‘ and ‘Rustico F1‘) were evaluated for different quality parameters: fruit shape index (length/diameter), firmness (g cm-2), force needed to tear the skin (kg-1) and consistency of tomato puree (g*sec). According to the results, the ‘Heinz 1015 F1‘ and ‘Heinz 9478 F1‘ were the most suitable genotypes for industrial processing in the mean of fruit quality. Strong positive correlation between consistency of juice and fruit shape index (r=0.891) and firmness of berry (r=0.882) was confirmed. The results have proved the necessity of these quality parameter measurements, which are important for the evaluation of raw material.
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Effect of the terroir and the harvest time on the Kékfrankos grape berries sensorial properties in Eger (Hungary)
87-92.Views:158In this research the effects of the production site “terroir” and the harvest time on the most important organoleptic properties of the berries of Kékfrankos (Blaufrankish) grape variety were observed. The follow-up of the maturation process in a given parcel can effectively supplemented by the results of sensorial evaluations of the grape berries. In most cases, the tasters found significant differences in sensorial characteristics of the berries due to the harvest time, although the trends of each parcels were different. Significant differences were frequently found in the result of the observed terroirs.