Wyniki wyszukiwania - AGRO

1

Solid phase extraction in food analysis

100%

Majewska M., Krosowiak K., Raj A., Smigielski K.

Zeszyty Naukowe. Politechnika Łódzka. Chemia Spożywcza i Biotechnologia

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2008

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tom 72

2

Conjugated linoleic acid (CLA) and trans isomers of C18:1 and C18:2 acids in mould cheeses

88%

Paszczyk B., Borejszo Z., Luczynska J.

Polish Journal of Natural Sciences

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2012

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tom 27

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nr 1

This study was aimed at determining the content of cis9transll C18:2 (CLA) acid and of trans isomers of C18:l and C18:2 acids in fat of mould cheeses originating from various producers (from different countries) available on the market in the city of Olsztyn. Analyses were carried out for 20 types of mould cheeses originating from different EU Member States, i.e. Poland (8 types) as well as Denmark, Germany, France and Italy (3 types from each country). The content of cis9transll C18:2 acid in fat of the analyzed mould cheese originating from Polish producers ranged from 0.25 to 0.64% and did not differ significantly (p>0.05) from that noted in fat extracted from cheeses originating from the other EU Member States. The content of this acid in cheeses from Denmark ranged from 0.50 to 0.54%, in those from Germany - from 0.44 to 0.81%, in those from Italy - from 0.48 to 0.51%, and in those from France - from 0.41 to 0.54% of the total fatty acid composition. Contents of trans isomers of C18:l acid in cheeses from Poland accounted for 1.94 to 2.64% of the total fatty acid composition. A similar content of those isomers was reported in the French cheeses. In turn, in the cheeses originating from Denmark, Germany and Italy the total content of C18:l trans isomers was found to be significantly (p≤0.05) higher. Trans isomers of C18:2 acid analyzed in the Polish cheeses constituted from 0.57 to 0.73%. In the cheeses from Denmark and France they were at a similar level, whereas in the cheeses from Germany and Italy the total content of those isomers was significantly (p ≤ 0.05) higher than in the Polish cheeses. The study demonstrated that the investigated mould cheeses originating from various producers and from various countries, and available on the Olsztyn market, were characterized by similar contents of CLA and diversified contents of trans isomers of C18:1 and C18:2 acids.

3

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Food quality control by hyphenated separation techniques

88%

Walczak J., Pomastowski P., Buszewski B.

Health Problems of Civilization

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2015

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tom 09

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nr 1

Food as complex mixture of proteins, lipids, vitamins, etc. cannot be separated and identified by using in only one method. This article presents a revision on the hyphenated chromatographic techniques and methods used in food analysis and described main application in food science research, and determination of xenobiotics and their metabolites in environmental. Also article discusses applications of “omics” in food analysis (proteomics, transcriptomics, genomics, metabolomis) and new discipline of – foodomics.

4

Copper content of milk fat

88%

Rafalowski R., Zegarska Z.

Polish Journal of Food and Nutrition Sciences

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2006

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tom 15/56

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nr Spec.Issue 1

The study was aimed at determining the content of copper in milk fat. Analyses were carried out on fat extracted from non-pasteurised sweet cream obtained from bulk milk. Copper was extracted from fat samples with nitric acid and its content was determined with the method of flameless atomic absorption spectrophotometry. The results obtained indicate that the content of copper in milk fat ranged from 0.010 to 0.089 mg/kg. The average copper content of fat from the summer feeding accounted for 0.037±0.020 mg/kg, and that of fat from the winter feeding was significantly higher (α=0.05) and reached 0.054±0.021 mg/kg.

5

Multi-element composition of honey as a suitable tool for its authenticity analysis

75%

Oroian M., Amariei S., Leahu A., Gutt G.

Polish Journal of Food and Nutrition Sciences

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2015

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tom 65

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nr 2

The aim of this study was to evaluate the composition of 36 honey samples of 4 different botanical origins (acacia, sun flower, tilia and honeydew) from the North East region of Romania. An inductively coupled plasma-mass spectrometry (ICP-MS) method was used to determine 27 elements in honey (Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, K, Li, Mg, Mn, Na, Ni, Pb, Rb, Se, Sr, Tl, U, V and Zn). We would like to achieve the following goal: to demonstrate that the qualitative and quantitative multi-element composition determination of honey can be used as a suitable tool to classify honey according to its botanical origin. The principal component analysis allowed the reduction of the 27 variables to 2 principal components which explained 74% of the total variance. The dominant elements which were strongly associated with the principal component were K, Mg and Ca. Discriminant models obtained for each kind of botanical honey confirmed that the differentiation of honeys according to their botanical origin was mainly based on multi-element composition. A correct classification of all samples was achieved with the exception of 11.1% of honeydew honeys.

6

Application of impedimetry for microbiological risk assessment in food

75%

Kowalik J., Tarczynska A., Ziajka S.

Polish Journal of Natural Sciences. Supplement

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2004

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tom 02

81-89

7

Analysis of selected chemical parameters in Piemontese wines

75%

Stepien A. E., Stawarczyk K., Bilek M., Kedziora K. M.

Roczniki Państwowego Zakładu Higieny

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2015

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tom 66

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nr 3

Background. Piemontese wines are well known and valued all over the world. The most popular of them are Barolo and Barbaresco wines. However, in Poland, they are still little known and only now are being gradually introduced to a wider range of consumers. Objective. The aim of this study was to evaluate the content of inorganic anions, minerals, sugars and glycerol of Piemontese wines from micro-region Langhe, classified as DOCG („Denominazione di Origine Controllata e Garantita”, ie. controlled designation of origin guaranteed) and DOC („Denominazione di Origine Controllata”, ie. controlled designation of origin) products. Material and Methods. Seven types of red wines and one type of white wine were tested. High Performance Ion Chromatography with conductometric detection (HPLC-CD) was used to measure the content of inorganic anions, ie. fluorides, chlorides, sulfates and phosphates. Flame atomic absorption spectrometry (F-AAS) was used to measure the content of minerals, ie. magnesium, calcium, sodium, copper, potassium, zinc and iron, while High Performance Liquid Chromatography with charged aerosol detection (HPLC-CAD) was used to measure the content of glycerol and sugars, ie. fructose, glucose and sucrose. Results. Our studies show that although Piemontese wines are characterized by a relatively low content of minerals in comparison with the wines from other regions, they contain a lot of ingredients that have beneficial effects for human health. Moreover, we observed that the studied wines contain particularly high concentration of inorganic ions – phosphates and fluorides. Furthermore, all tested red wines show far reaching similarities in their chemical properties, which is possibly a direct consequence of using in their production locally cultivated grape varieties. Conclusions. Analysis of the wines from the Piemont region, classified as DOCG, DOC, confirmed that these are dry wines of a high quality.

8

Atomic forms of selenium in selected mineral and well water in Poland

75%

Gawloska-Kamocka A.

Roczniki Państwowego Zakładu Higieny

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2009

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tom 60

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nr 1

The study aimed at application of a high performance liquid chromatography (HPLC) with UV detector for selenium speciation in samples of mineral and well waters in Poland. Basic solutions 1000 μg/l SeO3 2- and SeO4 2- were prepared by dissolving 2.190 g of reagent Na2SeO3 and 2.393 g Na2SeO4 in 1000 ml of deionised water, respectively. Recent standards SeO3 2- and SeO4 2- (single or mixed) were prepared daily. Chromatographic separations were obtained on a column with reversed phase of C18, 250*4 mm, 5 μm ODS. As mobile phase mixture of 5 mmol/l phosphate tetrabutylammonium, 50/50 water/methanol at pH 3.4 was used. Flow rate of mobile phase was1 ml/min and detector was set on λ=210 nm. Injection volumes were 5 μl. The average concentration of Se(IV) was 4.10 μg/l and Se(VI) - 4.27 μg/l and Se(II) - 0.54 μg/l although the differences between water samples originating from various sources were relatively high. The developed method can be therefore recommended for determination of Se in samples of mineral water.

9

Effect of moisture content on textural attributes of dried figs

75%

Ansari S., Maftoon-Azad N., Farahnaky A., Hosseini E., Badii F.

International Agrophysics

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2014

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tom 28

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nr 4

Due to their soft texture consumers prefer moist figs, which has motivated fig processors to increase the production of this product. However, as water enhances the browning reaction rate, moisture content optimisation of moist figs is very im- portant. Processed figs must have suitable texture softness with browning kept to a minimum. The purpose of this study was to exa- mine the effect of moisture content on the textural attributes of dried figs. Hardness, compression energy, gradient, gumminess and chewiness of fig samples decreased with moisture content exponentially, whereas the trend of springiness and cohesiveness with change of moisture content was nearly constant. Moreover, in the texture profile analysis plot of rehydrated figs, the presence of negative area is an indication of adhesiveness which was zero in control dried figs. The results of the texture profile analysis tests proved the existence of a critical moisture content of about 18.4%, above which no significant effect of moisture content on textural parame- ters was found. The glass-rubber transition results from differential scanning calorimeter may explain the different texture profile analysis attributes of dried figs compared with rehydrated figs.

10

Characterization of flavour profile of blue honeysuckle berries

75%

Chmiel T., Dymerski T., Biernacka P., Wardencki W., Bartoszek A., Mustafa A., Gorecki T.

Polish Journal of Food and Nutrition Sciences

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2011

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tom 61

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nr Suppl.1

11

Speciation analysis of inorganic forms of selenium in confectionery products

75%

Gawloska-Kamocka A.

Journal of Elementology

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2007

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tom 12

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nr 2

Owing to its biological properties the microelement selenium has attracted enormous interest. It has been established that selenium stimulates the human immune system and has anti-carcinogenic effect. The main sources of selenium are high-protein foodstuffs of plant and animal origin, as well as high-protein dairy products. The aim of this study was to detect selenium content in confectionery products using speciation analysis in order to determine inorganic forms of selenium such as Se2- SeO32- and SeO42- anions. The hydride generation method combined with the atomic absorption spectroscopy was used for the final determination of selenium forms. The determination of selenium was conducted using aqueous extraction and digestion of samples with concentrated acids. The speciation determination of selenium was conducted in ten confectionery products. The correlation between the total content of selenium and its individual forms (-II), (IV),(VI) of different oxidation degree was also examined. It was shown that there was no correlation between the total selenium and inorganic forms of selenium. That means that speciation analysis is the only correct analysis of selenium content in foods.

12

Nanomaterials in electrochemical biosensors for food analysis - a review

75%

Viswanathan S., Radecki J.

Polish Journal of Food and Nutrition Sciences

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2008

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tom 58

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nr 2

The interaction of nanotechnology and biosciences opens the possibility for a wide variety of biological research topics and day-to-day applications at the molecular and cellular level. In particular, nanotechnology has been revolutionizing the area of biosensor. Nanobiosensor, an integration of physical sciences, molecular engineering, biology, chemistry and biotechnology holds the possibility of detecting and manipulating atoms and molecules using nanodevices, which have the potential for a wide range of both industrial and domestic applications. The role of electrochemical nanobiosensor in food analysis is an important and interesting area. This review covers the basic principles and types of electrochemical biosensor formats, role of nanomaterials for biosensor and reported food-specific applications of electrochemical nanobiosensors.

13

TEMPO system in microbiological analysis of spices and food additives

75%

Kunicka A.

Polish Journal of Food and Nutrition Sciences

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2007

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tom 57

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nr 3[A]

Thanks to the research it was possible to evaluate how useful is the automated TEMPO® system (bioMerieux) for determining the total number of mesophilic microorganisms in spices and food additives, characterised by a high concentration of dyes. Statistical analysis of the results by linear regression proves the equivalence of the TEMPO® method and the standard count plate method, at a correlation coefficient of 0.99. According to the findings, the dye of the examined matrices does not influence the result of the fluorescent signal at sample dilution of 1/4 000, which results in microbiological matrices contamination, not lower than 1.0 x 103 CFU/g. In the case of colourful food matrices demonstrating a high level of contamination with mesophilic microflora, such as whole black peppercorns (the level of microflora above 4.9 x 106 CFU/g), sample dilutions of 1/40 000 should be applied.

14

Campylobacter jejuni coccoid forms and food safety. PCR and electron microscope study

75%

Popowski J., Korsak D.

Żywienie Człowieka i Metabolizm

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2004

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tom 31

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nr 4

Spiral, native thermotolerant Campylobacter strains transform, into spherical forms (coccoid) in unfavorable conditions. Electron microscopy, PCR and traditional microbiological methods were applied to "perform complex research in order to clarify whether Campylobacter spherical cells are sort of dormant form or rather degenerative form. It was found that during incubation of Campylobacter suspension in saline coccoid cells were formed and soon afterwards became damaged with the rate proportional to the temperature of incubation. Besides, during this process the sensitivity of Campylobacter assay byPCR gradually falls due to DNA degradation. The results indicate that Campylobacter coccoid forms may be recognized as an intermediate form during the death of bacterial population. For this reason such forms cannot be considered as "viable but nonculturable" forms often found in other species.

15

Changes of quantities of tocopherols and their dimers during storage of soya-bean oil under N2 and under air

75%

Gogolewski M., Galuba G., Bartkowiak-Fludra E., Jasinska-Stepniak A.

Food Science and Technology. Scientific Papers of Agricultural University of Poznan

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2000

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tom 04

16

Lead and cadmium levels in raw cow's milk in Lithuania determined by inductively coupled plasma sector field mass spectrometry

75%

Valiukenaite R., Stankeviciene M., Stankevicius H., Skibniewska K. A.

Polish Journal of Food and Nutrition Sciences

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2006

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tom 15/56

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nr Spec.Issue 1

Raw milk from 15 districts in Lithuania was analysed in winter and grazing seasons in 2005. Lead and cadmium were determined by inductively coupled plasma sector field mass spectrometry. Mean cadmium concentrations in winter milk samples amounted to 0.37 μg/kg (0.25-0.49 μg/kg) and in summer ones 0.18 μg/kg (0.11-0.23 μg/kg). The mean concentrations of lead in samples collected in winter and in summer were 0.47 μg/kg (0.17-1.0 μg/kg) and 0.54 μg/kg (0.06-1.76 μg/kg), respectively. No individual sample exceeded the Lithuanian norm value for lead (20 μg/kg). The health quality of Lithuanian milk can be considered as very high in the aspect of cadmium and lead contamination.

17

Determination of iodine content in food products - modification of the Sveikina procedure

75%

Udeh K. O., Targonski Z., Kais-Samborska M.

Polish Journal of Food and Nutrition Sciences

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2001

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tom 10

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nr 3

A simple spectrophotometric method for the determination of total iodine content in foods by modification of Sveikina procedure, based on the works of Moxon and Dixon, is reported. The modified method had about 100-fold higher sensitivity in comparison to the above mentioned methods. The method detection limit (MDL) was 0.01 ng per 100 g of food and a mean recovery test of 92%. This method was used for the analyses of total iodine content in different food products

18

Determination of zinc in dishes from the canteen of Military University in Vyskov in the Czech Republic

63%

Jurikova J.

Polish Journal of Food and Nutrition Sciences

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2011

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tom 61

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nr Suppl.1

19

Oznaczanie azotanow V i III w zywnosci metoda Griessa - uwagi metodyczne

63%

Smiechowska M., Przybylowski P.

Bromatologia i Chemia Toksykologiczna

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2000

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tom 33

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nr 1

67-71

20

Possibilities of using fluorescence in wine research

63%

Gebala S., Przybylowski P.

Polish Journal of Food and Nutrition Sciences

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2007

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tom 57

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nr 3

363-366

Specific structure of fluorescence dye molecules may have an impact on their behavior in water solutions. It is possible that different water affinity of pigment molecules opposite ends (amphophility) may cause the densely packed and ordered, fluorescence layer on the solution free surface. The authors considered the possibility of the occurrence of such a phenomenon in the paper. The paper presents results that can confirm the thesis that flavonoids and anthocyanins contained in wine have a tendency to concentrate on the wine’s surface, thus creating a layer. Clear, stable and repeatable spectra of wine surfaces have been obtained.

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