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Bacvonkralj M.,Agricultural Institute of Slovenia | Jug T.,Agricultural Institute of Slovenia | Komel E.,Agricultural Institute of Slovenia | Fajt N.,Agricultural Institute of Slovenia | And 4 more authors.
Turkish Journal of Agriculture and Forestry | Year: 2014

Peaches are consumed worldwide and have great market demand. Compared to apricots, the volatiles defining the typical peach aroma are still poorly analytically characterized. The aim of our study was to determine the impact of the stage of ripening, sample storage conditions, and type of fiber coating and extraction glassware on peach aroma compounds. The peach aroma components were extracted by headspace solid-phase microextraction (HS-SPME) and with the application of a specific fiber (DVB/CAR/PDMS fiber) that retained the main group of volatiles present in peaches. Artisan-made glassware that enabled bigger sample loads was used. It was found that its application provided a 3-fold higher extraction of aromatic compounds on average. Significant differences were also found when the same peach pulp was analyzed fresh or frozen (in liquid nitrogen or in the freezer at -16 °C). In fresh peaches, a higher amount of some alcohols and important esters was determined. Liquid nitrogen had a positive impact on hexanal and (E)-2-hexenal, whereas the storage of samples in the freezer had a major impact on most other aldehydes, as well as limonene. The study revealed the importance of sample preparation and storage on the overall aromatic profile of peaches. © TÜBİTAK.

Kralj M.B.,Agricultural Institute of Slovenia | Jug T.,Agricultural Institute of Slovenia | Komel E.,Agricultural Institute of Slovenia | Fajt N.,Agricultural Institute of Slovenia | And 3 more authors.
Hemijska Industrija | Year: 2014

Four yellow-fleshed peach cultivars („Royal Glory“, „Redhaven“, „Maria Marta“and „Norman“) were used during two-year period in this study. The characterization of aromatic constituents of investigated cultivars was done using headspace solid phase microextraction (HS-SPME). The intention was to make implicit discrimination between cultivars by analysis of components present in all cultivars during two-year period. Also, the impact of added preservatives (Na-benzoate and citric acid) on the final aroma of cooked peaches was studied. The cultivars' differences and the impact of preservatives (Na-benzoate and citric acid) were statistically evaluated. Multiple discriminant analysis of peaches’ aromatic profile was used to segregate investigated peach cultivars. Although they were very similar, the cultivars were segregated by two discriminant functions, function 1 (which accounted for 56.9% of this peach model) and function 2 (31.7%). The use of preservatives had also an important impact on the aromatic profile of cooked peaches. The statistical analysis indicated that from 57 identified volatiles, 40 volatiles showed statistically significant difference regarding the way of preservation. The main negative impact had Na-benzoate compared to control or samples preserved with citric acid. © 2014, Association of Chemists and Chemical Engineers of Serbia. All Rights Reserved.

Prgomet I.,Skink d.o.o. | Torello Marinoni D.,University of Turin | Donno D.,University of Turin | Prgomet Z.,Collegium Fluminense Polytechnic of Rijeka | And 3 more authors.
Acta Horticulturae | Year: 2014

European chestnut (Castanea sativa Mill.) is widespread in Croatia at medium-high altitudes and in sites with acidic soils that are not suitable for growing other fruit species. Chestnut mostly grows in forest with Fagales species, as beech and oak trees. Croatia is one of the few countries in the Mediterranean area without commercial chestnut orchards. Most of the plants are placed in small private germplasm repositories, and it is unknown which plant material was used for grafting, or how many different genotypes are present. The aim of this research was to characterize by microsatellite markers (Simple Sequence Repeats, SSRs) the genetic diversity of chestnut trees grown in the Istria County and the Primorskogoranska County. The study was performed on leaf samples picked up in 17 different sites and using 10 nuclear microsatellite markers. DNA analysis was successfully used in this study for the genetic identification of the genotypes. The results showed a significant genetic variability of Croatian germplasm. These preliminary data are very important for further research steps in order to avoid loss of potentially useful germplasm and preserve the local biodiversity resources, starting with genetic identification of Croatian germplasm.

Jukic H.,University of Bihac | Mujic I.,Collegium Fluminense Polytechnic of Rijeka | Vladimir-Knezevic S.,University of Zagreb | Rudic D.,Collegium Fluminense Polytechnic of Rijeka | And 3 more authors.
Acta Horticulturae | Year: 2014

Bioactive plant polyphenols are well known for their antioxidant, antimutagenic, anti-cancer, anti-inflammatory, anti-angiogenic, antiulcer and antimicrobial properties. Food intake of phenolic compounds is associated with reduced risk of a variety of diseases. In addition, epidemiological studies have established a connection between food intake rich in natural antioxidants, i.e. specifically-foods rich in polyphenols, and lower risk of cardiovascular disease. For many herbal ingredients, it has been determined to prevent mold growth and accumulation of mycotoxins. With multiple biological activities, extracts rich in phenols are of special importance for the food industry because they slow down the oxidative degradation of lipids and improve the quality and nutritional value of food. Plant polyphenols affect the sensory properties of food, functional and nutritional value of the protein present in the food, and the texture of the food. As a good example of such a plant species that contains a variety of bioactive compounds with potential antioxidant properties can serve Castanea sativa Mill., whose extracts are poorly scientifically tested. Until now this plant species was primarily used for nutrition and getting tannin extract.

Vidovic S.,University of Novi Sad | Zekovic Z.,University of Novi Sad | Mujic I.,Collegium Fluminense Polytechnic of Rijeka | Lepojevic Z.,University of Novi Sad | And 2 more authors.
Central European Journal of Biology | Year: 2011

Daedaleopsis confragosa belong to a large and remarkable group of mushrooms called polypores.This type of mushroom could be easily said to be quite unexplored and unused when it comes to its antioxidant properties. Thus, in order to evaluate its antioxidant activity, the investigation had to include the total phenolics and flavonoide content, the content of Selenium, the content of Zinc, the scavenging capacity on DPPH· and OH· radicals, reducing power and capacity to remove lipid peroxidation. The investigated mushroom extract contained 54.17 mg GAE/g of total phenols and 48.46 mg CE/g of total flavonoides. Zinc and Selenium were detected and quantified by using inductively coupled plasma mass spectroscopy. The scavenging activity of the radicals was found to exhibit 50% of the inhibition value (IC50 value) at the extract concentration of 0.015±0.007 mg/ml for the investigated D. confragosa extract. By using electron paramagnetic resonant spectroscopy it was found that the investigated extract does not have a significant role in the prevention of lipid peroxidation. It was effective in scavenging on ·OH radical, RI was 56±2%. © 2011 Versita Warsaw and Springer-Verlag Wien.

Mujic I.,Collegium Fluminense Polytechnic of Rijeka | Rudic D.,Collegium Fluminense Polytechnic of Rijeka | Zivkovic J.,University of Niš | Jukic H.,University of Bihac | And 3 more authors.
Acta Horticulturae | Year: 2014

Recently the role of phenolic compounds as protective dietary constituents has become an increasingly important area of human nutrition research. So far the application of extract of sweet chesnut in diet and therapy was poorly studied. Samples of catkins of sweet chestnut and grafted Italian marrone cultivar have been collected in Bosnia and Herzegovina. The samples were milled for further analysis. After the addition of 250 ml of 50% ethanol to 50 g of each sample, extraction of the ethanol dissolving compounds was performed by ultrasound (30 min). The samples were filtrated and dried by evaporation under vacuum at 313 K. The extracts were kept at 193 K. With intention to simulate metabolism of tannins in human intestine and to simplify the analysis, chestnut extracts were submitted to methanolysis. The identification of the constituents of the extracts after methanolysis was performed by LC/MS and HPLC/DAD. The antioxidative properties of extracts was invetigated by application of electron paramagnetic resonance (EPR) technique. In the other hand, the disc-diffusion method was used as a test for antimicrobial activity. The identified compounds in examinated extracts could be classified as ellagic acid or its derivatives, gallic acid derivates, flavonoids (quercetin, kaempferol, isorhamnetin) and coumaric acid methyl ester. The highest content of gallic acid derivates was obtained in extract of grafted Italian marrone cultivar 136.8 mg/g, experessed as gallic acid per g of dry extract. Condensed and hydrolysable tannins are potentially more potent antioxidants than simple monomeric phenolics. The most prominent antioxidant activity against superoxide radical was detected for the extract of catkins of grafted Italian marrone (RI=85%). Total level of derivatives of ellagitannins showed statistically significant positive correlation with antioxidative activity of extracts against superoxide. The test extracts demonstrated significant antimicrobial activity, especially against both Gram-negative (Salmonella typhimurium) and Gram-positive (Micrococcus pyogenes var. albus and Staphylococcus aureus) bacteria. The growing interest in the substitution of synthetic food antioxidants by natural ones has fostered research on vegetable sources and the screening of raw materials for identifying new antioxidants. We found that Castanea sativa Mill. catkins extracts could be one with promising characteristics. Also, analysing extracts possesses great antimicrobial activity.

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