Anna Prescha |
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Wroclaw Medical University
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Department of Food Science and Nutrition
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Skills (2)
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62 Questions1657 Followers
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15 Questions207 Followers
Publications (22) View all
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Article: Instant food products as a source of silicon.
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ABSTRACT: Silicon is a trace element for humans, and is absorbed from food in the form of orthosilicic acid. Instant food products are part of a constantly growing market of convenience foods, which have not been evaluated yet as sources of silicon. In this study the total and soluble silicon contents in different instant food products were determined by using graphite furnace atomic absorption spectrometry (GF-AAS). A selection of instant products commercially available in Wroclaw were analyzed: soups, main courses, coffee drinks, jellies and puddings. Total silicon contents in soups, main courses and coffee drinks ranged widely and reached the values: 0.10-30.20, 0.63-37.91 and 0.21-13.37mg/serving, respectively. These products contained 0.05-1.26mg of soluble silicon per serving. The total silicon content in jellies and puddings did not exceed 0.36mg and 2.42mg/serving, respectively. Among the analyzed desserts the highest level of soluble silicon was found in chocolate puddings: 0.36-0.41mg/serving. The silicon level in servings of the studied instant products when prepared with the appropriate amount of water was also estimated. The mean content of silicon determined in samples of drinking water from Wrocław and the vicinity, which was used for the estimation, amounted to 7.09mg/l. The total silicon content in ready-to-eat products ranged from 1.32 to 39.21mg/serving. In conclusion, some of the analyzed instant foods contained very high amounts of silicon, however the content of the soluble, and hence available, form of this element was low.Food Chemistry 12/2012; 135(3):1756-61. · 3.65 Impact Factor -
Article: Engineering flax plants to increase their antioxidant capacity and improve oil composition and stability.
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ABSTRACT: The composition of polyunsaturated fatty acids in the tissues is very important to human health and strongly depends on dietary intake. Since flax seeds are the richest source of polyunsaturated acids, their consumption might be beneficial for human health. Unfortunately, they are highly susceptible to auto-oxidation, which generates toxic derivatives. The main goal of this study was the generation of genetically modified flax plants with increased antioxidant potential and stable and healthy oil production. Since among phenylpropanoid compounds those belonging to the flavonoid route have the lowest antioxidant capacity, the approach was to inhibit this route of the pathway, which might result in accumulation of other compounds more effective in antioxidation. The suppression of the chalcone synthase gene resulted in hydrolyzable tannin accumulation and thus increased antioxidant status of seeds of the transgenic plant. This was due to the partial redirecting of substrates for flavonoid biosynthesis to the other routes of the phenylpropanoid pathway. Consequently, transgenic plants produced more (20-45%) polyunsaturated fatty acids than the control and mainly α-linolenic acid. Thus, increasing the antioxidant potential of flax plants has benefits in terms of the yield of suitable oil for human dietary consumption.Journal of Agricultural and Food Chemistry 04/2012; 60(19):5003-12. · 2.82 Impact Factor -
SourceAvailable from: Karel Sigler
Article: Viability and formation of conjugated dienes in plasma membrane lipids ofSaccharomyces cerevisiae, schizosaccharomyces pombe, rhodotorula glutinis andCandida albicans exposed to hydrophilic, amphiphilic and hydrophobic pro-oxidants
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ABSTRACT: Effects of four lipid peroxidation-inducing pro-oxidants-amphiphilictert-butyl hydroperoxide (TBHP), hydrophobic 1,1′-azobis(4-cyclohexanecarbonitrile) (ACHN), hydrophilic Fe11 and 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH)-on cell growth and on generation of peroxidation products in isolated plasma membrane lipids were determined in four yeast species (S. cerevisiae, S. pombe, R. glutinis andC. albicans) differing in their plasma membrane lipid composition. TBHP and ACHN inhibited cell growth most strongly, Fe11 and AAPH exerted inhibitory action for about 2 h, with subsequent cell growth resumption.S. cerevisiae strain SP4 was doped during growth with unsaturated linoleic (18∶2) and linolenic (18∶3) acids to change its resistance to lipid peroxidation. Its plasma membranes then contained some 30% of these acids as compared with some 1.3% of 18∶2 acid found in undopedS. cerevisiae, while the content of (16∶1) and (18∶1) acids was lower than in undopedS. cerevisiae. The presence of linoleic and linolenic acids inS. cerevisiae cells lowered cell survival and increased the sensitivity to pro-oxidants. Peroxidationgenerated conjugated dienes (CD) were measured in pure TBHP- and ACHN-exposed fatty acids used as standards. The CD level depended on the extent of unsaturation and the pro-oxidant used. The TBHP-induced CD production in a mixture of oleic acid and its ester was somewhat lower than in free acid and ester alone. In lipids isolated from the yeast plasma membranes, the CD production was time-dependent and decreased after a 5–15-min pro-oxidant exposure. ACHN was less active than TBHP. The most oxidizable were lipids fromS. cerevisiae plasma membranes doped with linoleic and linolenic acids and fromC. albicans with indigenous linolenic acid.Folia Microbiologica 04/2012; 47(2):145-151. · 0.68 Impact Factor -
Article: IR and Raman studies of oil and seedcake extracts from natural and genetically modified flax seeds.
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ABSTRACT: Flax plant of the third generation (F3) overexpressing key genes of flavonoid pathway cultivated in field in 2008 season was used as the plant material throughout this study. The biochemical properties of seed, oil and seedcake extracts from natural and transgenic flax plants were compared. Overproduction of flavonoids (kaempferol), phenolic acids (coumaric, ferulic/synapic) and lignan-secoisolariciresinol diglucoside (SDG) in oil and extracts from transgenic seeds has been revealed providing a valuable source of these compounds for biotechnological application. The changes in fatty acids composition and increase in their stability against oxidation along three plant generations were also detected. The analysis of oil and seedcake extracts was performed using Raman and IR spectroscopy. The wavenumbers and integral intensities of Raman and IR bands were used to identify the components of phenylpropanoid pathway in oil and seedcake extracts from control and transgenic flax seeds. The spectroscopic data were compared to those obtained from biochemical analysis.Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 03/2011; 78(3):1080-9. · 2.10 Impact Factor -
Article: Chromium content in selected convenience and fast foods in Poland
Monika Krzysik, Halina Grajeta, Anna Prescha[show abstract] [hide abstract]
ABSTRACT: The chromium content in selected convenience and fast foods was determined. Samples were wet digested with HNO3 (69%) in a microwave digestion system. Chromium was determined by graphite furnace atomic absorption spectroscopy (GF-AAS). The chromium content in convenience food ranged on average from 2.22 to 18.2 μg/100 g, in fast food from 3.76 to 28.6 μg/100 g, and in instant food from 0.34 to 4.75 μg/100 g.Food Chemistry 03/2008; 107(1):208-212. · 3.65 Impact Factor