Wyniki wyszukiwania

1

Zwiazki zapachowe zywnosci wyzwanie dla analityka

100%

Jelen H. H.

Przemysł Spożywczy

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2004

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tom 58

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nr 05

18-22

Omówiono problem analizy związków tworzących aromat żywności. Przedstawiono skrótowo specyfikę substancji zapachowych, ich powstawanie i wpływ budowy na zapach. Opisano najczęściej stosowaną w analizie związków zapachowych technikę analityczną - chromatografię gazową, specyfikę przygotowania próby i detekcji jej składników, także za pomocą olfaktometrii. Opisano wykorzystanie dwóch technik - enancjoselektywnej chromatografii gazowej i spektrometrii mas stosunku izotopów (IRMS) w ocenie zafałszowań aromatu. Przedstawiono także niektóre trendy w nowoczesnej analizie związków zapachowych żywności - szybką chromatografię, spektrometrię mas oraz elektroniczne nosy.

2

Nitrogen atmosphere and natural antioxidants effect on muesli oxidation during long-time storage

63%

Klensport-Pawlik D., Jelen H. H.

Acta Scientiarum Polonorum. Technologia Alimentaria

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2009

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tom 08

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nr 1

5-15

The effects of natural antioxidants from raspberry and black currant seeds and modified atmosphere packaging on muesli oxidative stability measured by monitoring volatile lipid oxidation products were evaluated. The effectiveness toward lipid oxidation was investigated during 10 months storage at ambient temperature. Both ethanolic ex-tracts as well as nitrogen atmosphere influenced lipid oxidation rate in muesli measured by volatile compounds content. The most abundant lipid derived volatile compounds was hexanal. After storage, its concentration changed from 802 μg/kg to 9.8 mg/kg in muesli stored in air atmosphere, whereas in muesli stored in nitrogen atmosphere with raspberry seed extract addition it raised to 3.1 mg/kg. Although, both natural antioxidants rich in phenolic compounds, were effective towards lipid oxidation, the strongest inhibiting effect had modified atmosphere packaging. The addition of ethanolic extracts did not for-tify its positive effect. Total concentration of volatile compounds in muesli after 10 months of storage was 19.6 mg/kg when stored in air and 13.7 and 11.8 mg/kg when stored with raspberry and black currant seeds extract addition respectively, while 9.8 mg/kg when stored in nitrogen atmosphere without antioxidants, and 9.7 and 9.9 mg/kg when stored with antioxidants mentioned above.

3

Solid phase microextraction for profiling volatile compounds in liquered white wines

63%

Jelen H. H., Szczurek A.

Acta Scientiarum Polonorum. Technologia Alimentaria

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2010

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tom 09

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nr 1

23-32

Background. Profile of volatile compounds is a distinct feature of wine, which is dependent on the type of wine, grapes, fermentation and ageing processes. Profiling volatile compounds in wine using fast method provides information on major groups of compounds and can be used for classification/differentiation purposes. Solid phase microextraction (SPME) was used for the profiling of volatile compounds in liquered white wines in this study. Material and methods. Different fibers were tested for this purpose: PDMS, Carboxene/ PDMS, Carboxene/DVB/PDMS, Polyacrylate, Divinylbenzene/PDMS. Different times were compared to optimize extraction process. Profile and amount of volatile compounds extracted by SPME fiber was compared for eight liquered white wines. Results. Carboxene/DVB/PDMS showed the highest efficiency in extracting higher alcohols, esters, carbonyls and terpenes. Of tested extraction times ranging from 5 to 30 min. 20 minutes was chosen providing sufficient peak responses. Using SPME total amount of volatile compounds in eight liquered wines was compared - Riversaltes, Offley Porto and Jutrzenka having the highest amount of adsorbed volatiles. Profiles of volatiles of analysed wines revealed that dominating compounds in 6 wines were esters, followed by higher alcohols, two analysed Muscat wines had high terpene contents compared to remaining wines. Conclusion. SPME can be used for relatively fast profiling of wine volatiles, that can be used for wines classification.

4

Analysis of volatile aldehydes in oat flakes by SPME-GC/MS

63%

Klensporf D., Jelen H. H.

Polish Journal of Food and Nutrition Sciences

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2005

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tom 14/55

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nr 4

5

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A comparison of human and electronic nose responses to flavour of various food products of different degree of lipids oxidation

51%

Mildner-Szkudlarz S., Zawirska-Wojtasiak R., Korczak J., Jelen H. H.

Polish Journal of Food and Nutrition Sciences

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2007

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tom 57

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nr 2

195-202

This paper investigates the effectiveness of electronic nose with subsequent principal component analysis (PCA) treatment of data for differentiation of food samples of varied odour quality caused by lipid oxidation. Samples were evaluated for off-flavours with an electronic nose and a sensory analysis and for Totox value. Volatile compounds of fresh samples and samples subjected to storage test at 60°C were isolated with a static headspace technique. The results suggest that the electronic nose could help to supplement the sensory analysis. Models based on partial least-squares analysis were able to predict the oxidized flavour attribute of samples, with correlation coefficients ranging from 0.66 to 0.99. Based on elaborated methods and data treatment with PCA it was possible to distinguish between different food samples and monitor the formation of off-flavours associated with lipid oxidation.

6

Determination of volatile carboxylic acids in some Polish cheese by solid phase microextraction and gas chromatography

51%

Kieronczyk A., Jelen H. H., Kaminski E.

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

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1999

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tom 03

Ograniczanie wyników

2 Acta Scientiarum Polonorum. Technologia Alimentaria

2 Polish Journal of Food and Nutrition Sciences

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

1 Przemysł Spożywczy

6 Jelen H. H.

1 Kaminski E.

1 Kieronczyk A.

1 Klensporf D.

1 Klensport-Pawlik D.

1 Korczak J.

1 Mildner-Szkudlarz S.

1 Szczurek A.

1 Zawirska-Wojtasiak R.

1 2010

1 2009

1 2007

1 2005