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The effect of heat treatment on the antioxidant activity of sour cherry jams
121-126Views:451Sour cherry (Prunus cerasus) is a valuable fruit known for its high antioxidant content. Its bioactive substances contribute to health maintenance, as they have strong anti-inflammatory and free radical scavenging properties. Jams made from sour cherries provide a concentrated form of the antioxidant content of fruit, thus can play an important role in a balanced diet. Heat treatment is an essential part of the jam-making process, as it ensures the microbiological stability and longer shelf life of the product. At the same time, heat can significantly affect the antioxidant content of the fruit. In this study, the authors compared the antioxidant content of six different sour cherry jams. Based on the obtained results, it was concluded that the fruit content of sour cherry jams alone is not sufficient to estimate their antioxidant capacity, but the extent of the effect of heat treatment on it is generally independent of the nature of the products. This result highlights that the fruit content and the applied technology play an important role in preserving the antioxidant content of fruits during product processing.
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The parameters of homemade jams after storage
39-42Views:284Nowadays producing jams is considered a traditional way of plum processing in Hungary. Plum jams without added sugar can be stored
This research aimed to analytically determine which quality parameters of the jams and to what extent they change during storage. Furthermore, this study intended to find out whether a concious consumer can presume any difference between varieties or the year of harvest, or wheather a one-time customer should suspect differences in quality parameters of the different products. This study focused on those differences or alterations in the parameters that occur in the jams made from several different plum varieties produced in different years.
I analyzed the classic chemical parameters (dry matter content and ash content) and physiologically important nutritional components (phenolic and flavonoids antioxidants and vitamin C). In this research I used jams which were produced from 6 varieties grown in 2009 (President, Tophit, Bluefre, Elena, Presenta, Stanley), 4 varieties from 2010 (President, Bluefre, Elena, Presenta) and 6 varieties from 2011 (President, Tophit, Bluefre, Elena, Presenta, Stanley). Jams were produced with traditional technology in cauldrons without added sugar. Jars were placed into a relatively dark and cool place and were stored there until the analysis.
Having regard to the results, when consumers choose between the different products they also choose quality since the processed plum variety, and the year of production/processing determine the nutritional value of the specific product. This could be used for market positioning and promotion of the product, however further research is needed to gain more information from the differences that derive from the varieties, year of harvest or other factors. This way fruit and jam producers could turn these informations into market advantage.
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Contributions to the 2014 and 2015 flight pattern and damages of Carpomyia schineri Loew.
96-99Views:193The fly Carpomyia schineri Loew is a pest of the berries of the feral Rosa canina group but is can also be found in the berries of grown rose cultivars. The larva damages the flesh of the berry, several larvae can develop inside a single berry. It can decrease the quantity and ascorbic acid content of the tea and jam, which are important human ascorbic acid sources during winter. At the same time in trapping experiments the adult can be confounded with adults of the walnut husk fly (Rhagoletis completa Cresson). In collections of berries at several sites in Hungary damage levels ranged from 0.88% to 65.08 %. Based on these damage levels we had the impression that the yellow sticky traps CSALOMON® PALz or PALs baited with the synthetic Rhagoletis lure caught moderate numbers of adults and were not satisfactory for detection, consequently improving trapping methods is necessary in the future.