Pawelzik, Elke

[["dc.bibliographiccitation.firstpage","10"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Postharvest Biology and Technology"],["dc.bibliographiccitation.lastpage","18"],["dc.bibliographiccitation.volume","49"],["dc.contributor.author","Keutgen, Anna J."],["dc.contributor.author","Pawelzik, Elke"],["dc.date.accessioned","2018-09-10T08:43:43Z"],["dc.date.available","2018-09-10T08:43:43Z"],["dc.date.issued","2008"],["dc.description.abstract","Strawberries (Fragaria × ananassa Duch.) were grown under an ozone-enriched atmosphere, and fruit yield, quality, and postharvest behavior under simulated retail storage conditions were investigated. The more ozone sensitive cv. Korona and the less sensitive cv. Elsanta, according to previous studies, were exposed for 2 months to 156 μg m−3 ozone on average, or air without ozone, in controlled-environment chambers. The influence of ozone depended significantly on the cultivar and its susceptibility to oxidative stress. Generally, ozone decreased the contents of ascorbic acid, caused higher lipid peroxidation and lowered sweetness of the fruit. In the case of lipid peroxidation, the effect was strengthened under retail conditions. The ozone stress did not influence yield, size, antioxidative capacity, anthocyanins, or phenolic compounds of fruit. In the more sensitive cv. Elsanta, ozone-induced sepal injuries were detected and the appearance of fruit was thus impaired; glutathione content of fruit also decreased. In contrast, fruit quality of the less sensitive cv. Korona remained almost constant. In general, retail conditions impaired quality of strawberry fruit and in the case of an effect on quality by ozone during fruit development, quality was slightly worse after storage due to the high perishability of the strawberry fruit."],["dc.identifier.doi","10.1016/j.postharvbio.2007.12.003"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/15685"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.title","Influence of pre-harvest ozone exposure on quality of strawberry fruit under simulated retail conditions"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","868"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Journal of plant physiology"],["dc.bibliographiccitation.lastpage","875"],["dc.bibliographiccitation.volume","165"],["dc.contributor.author","Keutgen, Anna J."],["dc.contributor.author","Pawelzik, Elke"],["dc.date.accessioned","2018-09-04T09:21:31Z"],["dc.date.available","2018-09-04T09:21:31Z"],["dc.date.issued","2008"],["dc.description.abstract","Cell wall polysaccharides, pectin composition, as well as apoplastic superoxide dismutase and peroxidase activities were investigated in strawberry (Fragaria x ananassa) cultivars (cvs) Korona and Elsanta differing in their ozone sensitivity. Plants were exposed to 140-170 microg m(-3) ozone either short-term for 7 days or long-term for 2 months in order to investigate whether differences in ozone sensitivity were due to differences in the apoplastic antioxidative systems. Cell wall polysaccharides were increased after 7 days and 2 months of ozone stress. While water-soluble pectins, low methoxy pectinates and NaOH-soluble pectinates were elevated after 7 days, their contents were unaffected (water-soluble pectins) or lower (low methoxy pectinates, NaOH-soluble pectinates) after 2 months. In cv. Elsanta, ozone treatment resulted in a significant reduction of superoxide dismutase activity after 7 days and 2 months, while it remained similar in cv. Korona. After 7 days, peroxidase activity was significantly higher in ozone-exposed leaves of cv. Korona, whereas after 2 months it was similar to or higher than in controls. Superoxide dismutase in cv. Korona detoxified ozone and its products in the apoplast, and the resulting elevated levels of H(2)O(2) were balanced within 7 days by an increase in peroxidase activity. Long-term peroxidase activity may not play a comparably significant role in ozone defence, but the increase in cell wall polysaccharides and cell wall thickness measured after 2 months, resulting in a decrease in specific leaf area, reflected structural modifications that limited activities of reactive oxygen species efficiently. In contrast, the reduction of superoxide dismutase activity in cv. Elsanta indicated a less efficient apoplastic radical scavenging system, at least during the first 7 days of ozone stress, which was accompanied by membrane leakage and contributed to accelerated leaf senescence. Long-term, the reduction of intercellular air space volume in leaves contributed to ozone tolerance of cv. Elsanta as in cv. Korona."],["dc.identifier.doi","10.1016/j.jplph.2007.06.012"],["dc.identifier.pmid","17913290"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/15638"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.eissn","1618-1328"],["dc.title","Apoplastic antioxidative system responses to ozone stress in strawberry leaves"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","7580"],["dc.bibliographiccitation.issue","18"],["dc.bibliographiccitation.journal","Journal of Agricultural and Food Chemistry"],["dc.bibliographiccitation.lastpage","7585"],["dc.bibliographiccitation.volume","55"],["dc.contributor.author","Keutgen, Anna J."],["dc.contributor.author","Pawelzik, Elke"],["dc.date.accessioned","2018-11-07T10:58:39Z"],["dc.date.available","2018-11-07T10:58:39Z"],["dc.date.issued","2007"],["dc.description.abstract","Strawberry cultivars differ in their sensitivity to NaCl; fruits of cv. Elsanta suffer from softening, whereas those of cv. Korona retain their firmness. The mean fruit fresh weight is reduced in cv. Elsanta up to 46% and in cv. Korona up to 26%. Cell walls of fruits grown under 0, 40, or 80 mmol/L NaCl were extracted and analyzed. In fruits of cv. Korona, the content of the alcohol-insoluble residue remained comparatively stable as salt levels increased but was reduced in cv. Elsanta. The water-soluble pectin fraction was not affected in cv. Korona, but the content of low methoxy pectinates increased significantly, indicative of the generation of calcium and magnesium bridges that stabilize pectin polysaccharicles of cell walls. In cv. Elsanta, the content of water-soluble pectin rose, indicating pectin solubilization. For both cultivars, the significant negative correlation of fruit Cl- contents with the contents of NaOH-soluble pectinates, when expressed per fruit fresh mass, indicated that covalently bound pectic substances were degraded. Especially the response of cv. Elsanta is in line with the general observation that severe osmotic stress results in slower cell expansion and weaker cell walls."],["dc.identifier.doi","10.1021/jf071216o"],["dc.identifier.isi","000249150900049"],["dc.identifier.pmid","17676869"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50511"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","0021-8561"],["dc.title","Cultivar-dependent cell wall modification of strawberry fruit under NaCl salinity stress"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","642"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Food Chemistry"],["dc.bibliographiccitation.lastpage","647"],["dc.bibliographiccitation.volume","111"],["dc.contributor.author","Keutgen, Anna J."],["dc.contributor.author","Pawelzik, Elke"],["dc.date.accessioned","2018-09-10T08:42:37Z"],["dc.date.available","2018-09-10T08:42:37Z"],["dc.date.issued","2008"],["dc.description.abstract","Strawberry cvs Korona and Elsanta, differing in their sensitivity to salt stress, were exposed to 0, 40, or 80 mM NaCl in the root medium from the end of April to mid-August. Although fruits of both cultivars contained comparable amounts of Na+ and Cl−, fruit quality was more impaired in cv. Elsanta, as indicated by the larger reductions of fruit size and sugar/acid ratios. Malondialdehyde levels started to rise significantly at 40 mM NaCl in the more sensitive cv. Elsanta, but at 80 mM in cv. Korona. Total amino acid levels, especially contents of essential amino acids, rose significantly in both cvs. Salt stress also increased contents of free proline, asparagine, and glutamine. Their increases may contribute to osmotic adjustment. The results of the present study favour the interpretation that elevated levels of proline, asparagine and glutamine are indicative of salt stress damage."],["dc.identifier.doi","10.1016/j.foodchem.2008.04.032"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/15684"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.title","Contribution of amino acids to strawberry fruit quality and their relevance as stress indicators under NaCl salinity"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1487"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Food Chemistry"],["dc.bibliographiccitation.lastpage","1494"],["dc.bibliographiccitation.volume","105"],["dc.contributor.author","Keutgen, Anna J."],["dc.contributor.author","Pawelzik, Elke"],["dc.date.accessioned","2018-11-07T11:06:35Z"],["dc.date.available","2018-11-07T11:06:35Z"],["dc.date.issued","2007"],["dc.description.abstract","Two strawberry (Fragaria x ananassa Duch.) cultivars differing in their sensitivity to NaCl stress, cv. Elsanta (sensitive) and cv. Korona (less sensitive), were cultivated under 0, 40 and 80 mmol NaCl/l for two months during flowering and fruiting until final fruit harvest. Modifications of sensory quality parameters and selected chemical properties of the non-climacteric fruit were evaluated. Generally, NaCl salinity decreased quality of strawberry fruit, especially in cv. Elsanta. Fruits of stressed plants contained lower amounts of sugars, organic acids and soluble solids, were less sweet and did not meet consumers' requirements. Overall appearance of fruits decreased significantly. The reduced acceptance to consumers was closely correlated with the decline of sugar contents, especially sucrose content, as well as with the increase of organic acids, such as acetic acid. Sensory changes were revised on the basis of a dose to threshold relationship. Decreasing contributions of sugars to taste and a rising importance of sodium, acetic and citric acids as the most taste-relevant compounds were the main causes of the limited acceptance of salt-stressed fruits. (c) 2007 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.foodchem.2007.05.033"],["dc.identifier.isi","000249078200022"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/52348"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Sci Ltd"],["dc.relation.issn","0308-8146"],["dc.title","Modifications of taste-relevant compounds in strawberry fruit under NaCl salinity"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1413"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Food Chemistry"],["dc.bibliographiccitation.lastpage","1420"],["dc.bibliographiccitation.volume","107"],["dc.contributor.author","Keutgen, Anna J."],["dc.contributor.author","Pawelzik, Elke"],["dc.date.accessioned","2018-09-10T08:44:43Z"],["dc.date.available","2018-09-10T08:44:43Z"],["dc.date.issued","2008"],["dc.description.abstract","Modifications of fruit quality, in response to a long-term salt stress of four months, were studied in two strawberry cultivars differing in their sensitivity to salinity. The sensitive cv. Elsanta and the less sensitive cv. Korona were treated during two vegetation seasons with 0, 40 or 80 mmol NaCl/l in the nutrient solution. While mean fruit weight decreased, dry matter and contents of total soluble carbohydrates, as well as sweetness index of fruits, remained constant. Salt stress in both cultivars increased the antioxidant capacity, antioxidants pools (ascorbic acid, anthocyanins, superoxide dismutase) and selected minerals such as Na+, Cl−, K+, N, P and Zn2+, as well as lipid peroxidation. Furthermore, salt stress increased the contents of free and essential amino acids, especially in cv. Elsanta. The more tolerant cv. Korona was characterized by an increase of reduced glutathione and a better fruit taste. In salt-stressed fruits of cv. Elsanta, taste was significantly impaired."],["dc.identifier.doi","10.1016/j.foodchem.2007.09.071"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/15686"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.title","Quality and nutritional value of strawberry fruit under long term salt stress"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","170"],["dc.bibliographiccitation.issue","2-3"],["dc.bibliographiccitation.journal","Environmental and Experimental Botany"],["dc.bibliographiccitation.lastpage","176"],["dc.bibliographiccitation.volume","65"],["dc.contributor.author","Keutgen, Anna J."],["dc.contributor.author","Pawelzik, Elke"],["dc.date.accessioned","2018-11-07T08:31:56Z"],["dc.date.available","2018-11-07T08:31:56Z"],["dc.date.issued","2009"],["dc.description.abstract","Two strawberry (Fragaria x ananassa Duch.) cvs Korona and Elsanta differing in their tolerance to NaCl salinity were exposed to 40 and 80 mmol NaCl L-1 for over 4 months in the growing seasons of 2002 and 2003, respectively. However, the osmotic potential, i.e. the NaCl concentration of the root medium, varied during the experiments, because Hoagland solution and demineralized water were added usually once a week in order to push NaCl uptake on the one hand, but to allow leaching the soil after application of demineralized water on the other. Leaching the soil should quickly improve the water relations of the plant, but not affect salt levels within the plant. This strategy was chosen to reduce the effects of water stress and to focus onto the salt-specific impacts of NaCl stress. The salt stress reduced fresh and dry matter of the whole plants and photosynthetically active leaf area, especially in cv. Elsanta. Typical leaf symptoms of Na and Cl stress were detected in both cvs and the combined effects of both toxic ions resulted in the leaf scorching symptoms. Na uptake of both cvs was similar, but distribution of Na within plants was different. Korona was able to protect leaves more efficiently from Na accumulation. Under NaCl stress Korona plants achieved a significant increase of K content in leaves and crowns, while Elsanta showed an increase of K in fruits and petioles. The accumulation of K under evaluated NaCl levels suggests an efficient K uptake system in strawberry plants. Concentrations of Ca were not significantly affected, with the exception of rising levels in roots of Elsanta plants. Concentrations of Mg, Mn and Fe significantly decreased in leaves, while those of Mg and Mn remarkably rose in crowns of both cvs. N content in leaves, petioles, and roots of both cvs increased. In addition it rose in fruits and crowns in cv. Elsanta. A significant limitation of N uptake by competition with Cl did not occur in these plants. Concentrations of P increased in roots and petioles of both cvs, and in fruits of cv. Elsanta. With respect to Zn and Cu, significant concentration changes related to NaCl stress could not be detected. (C) 2008 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.envexpbot.2008.08.002"],["dc.identifier.isi","000263664100003"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/17233"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Pergamon-elsevier Science Ltd"],["dc.relation.issn","0098-8472"],["dc.title","Impacts of NaCl stress on plant growth and mineral nutrient assimilation in two cultivars of strawberry"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","552"],["dc.bibliographiccitation.issue","5-6"],["dc.bibliographiccitation.journal","European Food Research and Technology"],["dc.bibliographiccitation.lastpage","559"],["dc.bibliographiccitation.volume","220"],["dc.contributor.author","Wang, J."],["dc.contributor.author","Wieser, H."],["dc.contributor.author","Pawelzik, Elke"],["dc.contributor.author","Weinert, Joachim"],["dc.contributor.author","Keutgen, A. J."],["dc.contributor.author","Wolf, G. A."],["dc.date.accessioned","2018-11-07T11:02:51Z"],["dc.date.available","2018-11-07T11:02:51Z"],["dc.date.issued","2005"],["dc.description.abstract","Samples artificially infected by Fusarium culmorum were analyzed to assess the effects of Fusarium infection on the protein quality of winter wheat ( Triticum aestivum L.). The Fusarium infection did not noticeably influence either the crude protein content or the water absorption ability of the wheat flour. The protease activity found in the wheat flour was inversely correlated to the sedimentation value. In contrast, it was positively correlated to both the free amino acid content and the degree of infection as expressed in Fusarium protein equivalents (FPE) quantified by an enzyme-linked immunosorbent assay. A distinct reduction in the content of both total glutenin and high molecular weight glutenin subunits was detected in the seriously infected samples (FPE> 20 μ g g(-1)). The infection with Fusarium impaired the dough quality and led to a deformed loaf shape. The fungal protease was active over both a wide range of temperatures ( from 10 to 100 ° C) and a wide range of pH values ( from 4.5 to 8.5). The maximum protease activity was displayed at 50 ° C in the pH range 6.0-8.0. This property indicates that the protease produced by F. culmorum may impair storage proteins throughout all the processing procedures associated with wheat flour, thereby causing weak dough properties and, consequently, unsatisfactory bread quality."],["dc.identifier.doi","10.1007/s00217-004-1112-1"],["dc.identifier.isi","000229094300018"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/51482"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","1438-2377"],["dc.title","Impact of the fungal protease produced by Fusarium culmorum on the protein quality and breadmaking properties of winter wheat"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","4066"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Journal of Agricultural and Food Chemistry"],["dc.bibliographiccitation.lastpage","4072"],["dc.bibliographiccitation.volume","55"],["dc.contributor.author","Keutgen, Anna J."],["dc.contributor.author","Pawelzik, Elke"],["dc.date.accessioned","2018-11-07T11:02:21Z"],["dc.date.available","2018-11-07T11:02:21Z"],["dc.date.issued","2007"],["dc.description.abstract","The responses of fruit antioxidants in two strawberry cultivars differing in their sensitivity to NaCl stress were studied. The sensitive cv. Elsanta and the less sensitive cv. Korona were treated with NaCl solutions of 40 and 80 mmol/L in the nutrient solution. In general, moderate salinity resulted in increases of antioxidant capacity. In cv. Korona, salt stress increased the activity of superoxide dismutase and the contents of glutathione, phenols, and anthocyanins, while that of ascorbic acid decreased. In cv. Elsanta, changes of superoxid dismutase activity and of ascorbic acid concentration were comparable to those of cv. Korona, but the decrease of ascorbic acid was more distinct. The contents of anthocyanins decreased, and those of phenols remained similar. The glutathione content was reduced at the highest NaCl level. The results indicate that less salt-sensitive strawberry cultivars may be grown under moderate salinity stress to optimize fruit quality."],["dc.identifier.doi","10.1021/jf070010k"],["dc.identifier.isi","000246313200046"],["dc.identifier.pmid","17429984"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/51367"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","0021-8561"],["dc.title","Modifications of strawberry fruit antioxidant pools and fruit quality under NaCl stress"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Horticulturae"],["dc.bibliographiccitation.volume","8"],["dc.contributor.affiliation","Rivero, Annia Gonzalez; 1Quality of Plant Products, Department of Crop Sciences, University of Göttingen, Carl-Sprengel Weg 1, 37075 Göttingen, Germany; mariandelagtr@gmail.com (A.G.R.); epawelz@gwdg.de (E.P.)"],["dc.contributor.affiliation","Keutgen, Anna J.; 4Institute of Vegetables and Ornamentals, Department of Crop Sciences, University of Natural Resources and Life Sciences, Gregor-Mendel-Str. 33, 1180 Vienna, Austria"],["dc.contributor.affiliation","Pawelzik, Elke; 1Quality of Plant Products, Department of Crop Sciences, University of Göttingen, Carl-Sprengel Weg 1, 37075 Göttingen, Germany; mariandelagtr@gmail.com (A.G.R.); epawelz@gwdg.de (E.P.)"],["dc.contributor.author","Rivero, Annia Gonzalez"],["dc.contributor.author","Keutgen, Anna J."],["dc.contributor.author","Pawelzik, Elke"],["dc.date.accessioned","2022-07-11T06:53:50Z"],["dc.date.available","2022-07-11T06:53:50Z"],["dc.date.issued","2022-06-18"],["dc.date.updated","2022-07-08T12:20:29Z"],["dc.description.abstract","Tomatoes are the most consumed vegetables worldwide and a valuable source of several antioxidants. The consumption of tomato products from appropriate cultivars after suitable processing methods may significantly improve human diet. The purpose of this study was investigating the variations in the contents of the main antioxidants present in tomato fruits, in the new Cuban breeds and yellow varieties, as well as their changes during the processing to tomato puree and ketchup. The quality evaluation comprised the detection of lycopene, ascorbic acid and total phenolics and the analysis of their contribution to antioxidant capacity in selected tomato genotypes. Heating (90–100 °C/15 min) enhanced the content of lycopene and total phenolics in puree, resulting in an increment in antioxidant capacity, despite the reduction in ascorbic acid as a result of concentration processes. The conducted experiments revealed that cultivars ‘Vyta’ and ‘Cima’ are very suitable for industrial purposes due to their high dry-matter content of more than 9% fresh mass and high biological value. With respect to serving size, the best sources of antioxidants are fresh tomatoes, followed closely by tomato puree, irrespective of cultivar. However, the differences are mainly due to the edible portion size (200 g for fresh tomatoes and 60 mL for puree, respectively)."],["dc.description.sponsorship","German Academic Exchange Service (DAAD) fellowship"],["dc.identifier.doi","10.3390/horticulturae8060547"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/112425"],["dc.language.iso","en"],["dc.relation.eissn","2311-7524"],["dc.rights","CC BY 4.0"],["dc.title","Antioxidant Properties of Tomato Fruit (Lycopersicon esculentum Mill.) as Affected by Cultivar and Processing Method"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]