Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 28

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Jubileusz 85-lecia urodzin profesora Zdzisława Edmunda Sikorskiego

100%
Kolodziejska I.
Żywność Nauka Technologia Jakość
|
2015
|
tom 22
|
nr 6
2

Zmiany w komorkach mikroorganizmow pod wplywem wysokiego cisnienia

63%
Malinowska-Panczyk E., Kolodziejska I.
Medycyna Weterynaryjna
|
2007
|
tom 63
|
nr 11
1285-1290
The mechanisms responsible for microorganisms' death under high pressure conditions are still not clear. Pressure in the range of 5-40 MPa does not usually lead to death of cells, but causes changes in their shape, dimensions and motility. In the case of some microorganisms, mainly of moulds and yeast, elongation of the cell may cause injury in the cell wall and therefore lead to their death. Changes in the cytoplasmic membrane permeability are considered to be the main reason for pressure-induced inactivation of microorganisms. According to some authors, inactivation of key enzymes leads to the inhibition of metabolic processes and the death of microorganisms. Pressure influences ribosomes and the biosynthesis of proteins. Some bacteria may be adapted to elevated pressure by regulation of protein expression. Among the new proteins, so-called PIPs (pressure-induced proteins), are identified heat-shock proteins and cold-shock proteins.
3
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Proteolytic activity of the viscera and partial purification of acid proteases of squid Illex argentinus hepatopancreas

63%
Kolodziejska I., Mazurek A.
Polish Journal of Food and Nutrition Sciences
|
1995
|
tom 04
|
nr 3
63-70
The squid hepatopancreas, containing 20-60% lipids, is not suitable on board vessel for producing fodder meal and is often discarded, although it constitutes the major part of the viscera and is a rich source of proteolytic enzymes. The proteolytic activity against hemoglobin at pH 3.0 of the extract of the he pato pan ere a s of frozen stored squid, calculated per mg of protein, is about 20 times higher than that of the extract of the rest of the viscera. Due to incubation of the homogenate at pH 3.0 at 30 and 40°C in 2 days a clear watery phase was formed, well separated from the oily fraction containing floating solid particles of the autolysate. In 2 days about 35 and 50% of the protein was hydrolysed at 20°C and 30-40°C, respectively, to degradation products not precipitated by TCA. The proteolytic activity of the autolyzed homogenate after 2 days at pH 3.0 is about 80 % of that of the original homogenate. Incubation at 40°C at pH 3.0 decreased the activity after 6 days by about 50%. In the autolysate of squid hepatopancreas the proteolytic activity at pH 3.0 in the absence of reducing compounds was almost totally due to aspartic proteases. In the presence of dithiothreitol the activity increased by about 50%, but the increase was only partly due to the presence of thiol proteases.
4

Elektroforetyczna charakterystyka kolagenu miesni bydlecych

63%
Sadowska M., Kolodziejska I.
Przemysł Spożywczy
|
1994
|
tom 48
|
nr 11
356-358
W artykule przedstawiono elektroforetyczne rozdziały kolagenu mięśni bydlęcych z zastosowaniem PAGE-SDS. Dominował kolagen typu I. W wyniku hydrolizy pepsyną uzyskiwano zwiększenie rozpuszczalności kolagenu.
5

Enzymy wystepujace w miesie i ich wrazliwosc na wysokie cisnienie

63%
Malinowska-Panczyk E., Kolodziejska I.
Medycyna Weterynaryjna
|
2009
|
tom 65
|
nr 12
817-822
Changes in the structure enzyme proteins occurring under high pressure can in some cases limit the usefulness of the high pressure technique in the preservation or mild processing of food. However, other changes can be advantageous in forming functional properties of food products. High pressure can affect the activity of proteolytic enzymes of meat by changing their conformation or releasing organelles from the cell and through the increase in concentration of activators or inhibitors in a reaction medium. Changes in enzyme activity, mainly of cathepsins and calpains, caused by high pressure affect the texture of meat. The final effect depends on many factors, primarily on the parameters of pressurization and the post mortem state of meat. The enzymes of coldwater fish are more sensitive to high pressure than their counterparts present in mammal meat or fish living in warm waters. The high pressure causing partial inactivation of oxydoreductases and lipolytic enzymes prevents the deterioration of the sensory quality of the product.
6

Możliwości wykorzystania wysokiego cisnienia w przemyśle mleczarskim

63%
Malinowska-Panczyk E., Kolodziejska I.
Medycyna Weterynaryjna
|
2010
|
tom 66
|
nr 07
s.470-474,bibliogr.
High pressure affects the structure, conformation, and functional properties of milk proteins. It may inactive some enzymes and change the size of casein micelles and milk fat globules. High pressure technique may prove useful in cheese manufacturing, making it possible to shorten the rennet coagulation time and to increase the yield of the product. Yogurts obtained from pressure-treated milk show better rheological properties. However, some changes of milk components under the influence of high pressure may lead to the deterioration of the sensory qualities of milk, e.g. the development of a bitter taste and a rancid flavor as an effect of increasing lipoprotein lipase activity. These unfavorable changes of sensory attributes may limit the use of high pressure in milk processing.
7
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Changes in enzymatic activity of fish and slaughter animals meat after high pressure treatment at subzero temperatures

63%
Malinowska-Panczyk E., Kolodziejska I.
Polish Journal of Food and Nutrition Sciences
|
2018
|
tom 68
|
nr 2
8

Wplyw polaczonego dzialania wysokiego cisnienia i innych czynnikow na mikroorganizmy

63%
Malinowska-Panczyk E., Kolodziejska I.
Medycyna Weterynaryjna
|
2007
|
tom 63
|
nr 05
515-518
High pressure can be used as an alternative for inactivation of microorganisms to traditional, thermal methods. A high pressure technique has been already applied in the food industry, primarily to preserve acidic food products such as fruit juices and jams. However, this method does not guarantee a complete inactivation of microorganisms at moderate temperature in food with pH close to neutral. Therefore the possibility of using high pressure in connection with other antimicrobial factors has been studied, mainly with lysozyme, bacteriocins and CO₂. High pressure increases the bacteriostatic effect of bacteriocins on different vegetative cells of gram-negative and gram-positive bacteria and vice versa, the bacteriocins enhance the sensitivity of microorganisms to high pressure. Such increased inactivation of bacteria occurs also when the cells are treated by high pressure in the presence of pediocin AcH, but the degree of inactivation significantly depends on the species of microoganisms. A synergistic lethal effect in relation to gram-positive bacteria as well as to gram- -negative bacteria has been observed due to the combined action of high pressure and lysozyme; however, the reduction in the number of viable cells was not higher than 1-2 log cycles. For inactivation of bacteria, bacterial spores, and fungi, treatment with CO₂ under pressure can be used. An increase in temperature and pressure favors the penetration of CO₂ through the cell membranes and lowers the internal pH, thereby inactivating the key enzymes participating in cell metabolism and in regulating processes. High pressure and ionizing radiation can be used to reduce the irradiation dose and thus prevent undesirable changes of food components.
9

Mozliwosci wykorzystania wysokiego cisnienia w przemysle miesnym i rybnym

63%
Malinowska-Panczyk E., Kolodziejska I.
Medycyna Weterynaryjna
|
2009
|
tom 65
|
nr 07
455-459
The influence of high pressure on mammal or fish meat components is complex. High pressure induces a denaturation of meat proteins but in a different way than high temperature. Pressure leads to an increase in the solubilization of myofibrillar proteins at a low salt concentration and causes their gelation even at ambient temperature. Such gels have better properties than those obtained by heating. High pressure in a range of 150-500 MPa produces drastic changes in the colour of the red muscles of mammal meat and dark muscles of fish. The colour of meat becomes pink and turns into grey-brown. These changes in the meat colour make it impossible to sell the products as fresh meat. However, high pressure technology can be used to extend the shelf-life and to improve the tenderness of cooked or processed meat. The effects of pressure on the solid-liquid phase transition of water can be applied for pressure-assisted freezing and pressure-assisted thawing of food. Freezing under pressure leads to the formation of ice forms which have grater density than ice I. In these conditions the destruction of meat structure is minimal and therefore the quality of products is better than in the case of standard freezing.
10

Wplyw wysokiego cisnienia na mikroorganizmy

63%
Malinowska-Panczyk E., Kolodziejska I.
Medycyna Weterynaryjna
|
2005
|
tom 61
|
nr 02
150-153
11
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Mozliwosci zastosowania wysokiego cisnienia w przemysle owocowo-warzywnym

63%
Malinowska-Panczyk E., Kolodziejska I.
Żywność Nauka Technologia Jakość
|
2010
|
tom 17
|
nr 2
5-15
Wysokie ciśnienie w umiarkowanej temperaturze może być wykorzystane w przemyśle owocowo-warzywnym do utrwalania produktów takich, jak: soki owocowe, dżemy czy galaretki, gdyż pozwala na zachowanie naturalnej barwy, zapachu i smaku oraz wysokiej wartości odżywczej tych produktów. Chlorofil, karotenoidy i antocyjany występujące w warzywach i owocach są w dużym stopniu stabilne podczas działania ciśnienia w umiarkowanej temperaturze. Również zawartość witamin: A, C, B1, B2, i E nie zmienia się znacząco w owocach i warzywach (oraz ich przetworach) bezpośrednio po zastosowaniu wysokiego ciśnienia. Technika wysokociśnieniowa nie nadaje się jednak do przedłużania trwałości całych owoców i warzyw, gdyż w tych warunkach ma miejsce mechaniczne uszkodzenie tkanek. Prowadzi to do przyspieszenia procesów enzymatycznych i nieenzymatycznych. W wyniku uszkodzenia owoców i warzyw dochodzi do niepożądanych zmian ich tekstury, a niekiedy również zapachu.
12
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Muscle cathepsins of marine fish and invertebrates

63%
Kolodziejska I., Sikorski Z. E.
Polish Journal of Food and Nutrition Sciences
|
1995
|
tom 04
|
nr 3
Muscle proteases are located mainly in the lysosomes, in the sarcoplasm, and in the extracellular matrix of the connective tissue surrounding each cell. The lysosomal proteases, cathepsins, have optimum activity in the acidic range, although many of them retain high activity also 1 or 2 pH units away from the optimum value. Among the cathepsins there are endopeptidases and exopeptidases. Most cathepsins hydrolyse several proteins of the myofibrils. The major protease of the lysosomes in fish and squid muscles is cathepsin D, an aspartyl endoproteinase. Although it is present in the muscle fibre itself, its generally rather low activity at low temperature limits its significance in tenderization of refrigerated fish of most species. Cathepsin L, a cysteinyl protease, is involved in autolysis and softening in matured chum salmon. Cathepsin B, a cysteinyl carboxypeptidase, is capable to attack also some myofibrillar proteins. Cathepsin A or carboxypeptidase A, and cathepsin C, a dipeptidyl hydrolase and dipeptidyl transferase, contribute to the hydrolysis of muscle proteins in a concerted action with the other cathepsins.
13
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

The properties and utilization of proteases of marine fish and invertebrates

63%
Kolodziejska I., Sikorski Z. E.
Polish Journal of Food and Nutrition Sciences
|
1995
|
tom 04
|
nr 1
The muscles and internal organs of marine animals contain many proteases. These enzymes fulfill different metabolic functions in the living organisms and affect the sensory quality and functional properties of the catch. Their activity depends on the species, life cycle, and the feeding status of the organism. Many proteases of marine origin differ from their counterparts in terrestrial animals in being more active at lower temperature and less resistant to thermal denaturation. Of practical importance in the industry is their role in ripening of salted fish, fish sauces and marinades, modyfying fish protein concentrates, ensilaging of seafood offal, and deskinning of fishery products. The negative effects comprise mainly the early post morten quality degradation of the catch and deterioration of the rheological properties of fish gels. Proteolytic preparations form different marine sources may be used successfully in food processing and as industrial enzymes, e. g. tanning agents.
14

Enzymatyczna modyfikacja chityny

51%
Kolodziejska I., Wojtasz-Pajak A., Sikorski Z. E.
Biotechnologia
|
1995
|
nr 3
133-139
15
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Twardosc miesa kalmarow Illex argentinus po obrobce cieplnej

51%
Kolodziejska I., Sadowska M., Sikorski Z. E.
Żywność Technologia Jakość
|
1997
|
tom 04
|
nr 2
41-50
16
Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik
Content available

Effect of high pressure on selected bacteria at subzero temperature

51%
Malinowska-Panczyk E., Kolodziejska I., Dunajski E.
Polish Journal of Food and Nutrition Sciences
|
2008
|
tom 58
|
nr 4
The objective of these investigations was to determine the viability of selected Gram-negative and Gram-positive bacteria exposed to high pressure and subzero temperature, in the range of 60÷193 MPa and –5 ÷ –20°C, without freezing of water. The results showed that similarly to the process conducted at the temperature above 0°C, Gram-negative bacteria and cells in the exponential growth phase are more sensitive to pressure treatment than the Gram-positive bacteria and cells being in the stationary phase of growth. Variations in resistance of microorganisms to high pressure were observed not only among the different species of bacteria but also among the strains belonging to the same species. Both pressure-sensitive and pressure-resistant strains appeared within mesophilic, psychrotrophic and thermophilic bacteria. However, the tendency to greater pressure sensitivity of Gram-negative psychrotrophic and psychrophilic strains than of the Gram-negative mesophiles was emphasized. The temperature of growth influenced the microorganisms’ sensitivity to pressure.
17

Mechanical and antioxidant properties of gelatin films modified with fruit’s waste extracts

51%
Gottfried K., Staroszczyk H., Kusznierewicz B., Kolodziejska I.
Polish Journal of Food and Nutrition Sciences
|
2011
|
tom 61
|
nr Suppl.1
18

Aktywnosc deacetylazy chityny i glikozydaz w ekstraktach z grzybni Mucor rouxii

51%
Kolodziejska I., Wojtasz-Pajak A., Malesa-Ciecwierz M., Niecikowska C.
Biotechnologia
|
1997
|
nr 2
158-169
19

The influence of powdered rosemary on the quality of fish oil during storage

51%
Glowacz A., Wielesik B., Kolodziejska I.
Polish Journal of Food and Nutrition Sciences
|
2011
|
tom 61
|
nr Suppl.1
20

Biodegradowalne i jadalne opakowania do żywności z polimerów naturalnych

51%
Gottfried K., Sztuka K., Statroszczyk H., Kolodziejska I.
Opakowanie
|
2010
|
tom 55
|
nr 08
Artykuł jest przeglądem literatury, dotyczącym wykorzystania polimerów naturalnych do wytwarzania jadalnych powłok powierzchniowych lub opakowań do żywności. Omówione zostały właściwości folii z różnych białek i polisacharydów oraz sposoby poprawy ich właściwości użytkowych poprzez modyfikacje fizyczne, chemiczne i enzymatyczne. Przedstawiono również możliwości włączania w matrycę polimerową nanonapełniaczy i scharakteryzowano właściwości otrzymanych nanokompozytów polimerowych. Ponadto wskazano możliwości poszerzenia właściwości użytkowych folii z naturalnych polimerów poprzez wprowadzenie dodatkowych substancji, przede wszystkim o aktywności przeciwdrobnoustrojowej.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.