Decreased storage stability of creatine kinase in a cardiac reperfusion solution

1990 ◽  
Vol 36 (5) ◽  
pp. 778-780 ◽  
Author(s):  
G Dunphy ◽  
D Ely

Abstract Creatine kinase (CK; EC 2.7.3.2) has been used as an indicator of myocardial cellular damage. In this study we used a Krebs-Henseleit (KH) solution to reperfuse isolated rat hearts after 24 h of cold preservation and collected the KH reperfusate for assay of CK to assess cellular damage. We wanted to determine the stability of CK in the KH solution at different cold-storage temperatures and albumin concentrations. CK activity (mean +/- SEM) after one week of refrigeration (5 degrees C) was 93% +/- 1% of control values, whereas CK activity in nitrogen-frozen (-200 degrees C) samples was only 1.6% +/- 1% of control values, and that in samples frozen at moderately low temperatures (-10 degrees C) was 63% +/- 1% of control values. To enhance stability, we added albumin at several concentrations (49, 25, 12, and 6 g/L) to reperfusion collections in which CK had been previously determined. Specimens were frozen (-10 degrees C), then re-analyzed for CK weekly for three weeks. CK activity was maintained (100% +/- 5%) only in samples containing 25 g/L or more albumin. These data suggest that refrigeration (5 degrees C) for one week maintains normal CK activity in KH solution; however, if prolonged storage is necessary, a stabilizer such as albumin (greater than or equal to 25 g/L) will maintain analyte stability in frozen storage (-10 degrees C) for at least three weeks.

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1945
Author(s):  
Soraya Mousavi ◽  
Roberto Mariotti ◽  
Vitale Stanzione ◽  
Saverio Pandolfi ◽  
Valerio Mastio ◽  
...  

The extent and conditions of storage may affect the stability and quality of extra virgin olive oil (EVOO). This study aimed at evaluating the effects of different storage conditions (ambient, 4 °C and −18 °C temperatures, and argon headspace) on three EVOOs (low, medium, and high phenols) over 18 and 36 months, analyzing the main metabolites at six time points. The results showed that low temperatures are able to maintain all three EVOOs within the legal limits established by the current EU regulations for most compounds up to 36 months. Oleocanthal, squalene, and total phenols were affected by storage temperatures more than other compounds and degradation of squalene and α-tocopherol was inhibited only by low temperatures. The best temperature for 3-year conservation was 4 °C, but −18 °C represented the optimum temperature to preserve the organoleptic properties. The present study provided new insights that should guide EVOO manufacturers and traders to apply the most efficient storage methods to maintain the characteristics of the freshly extracted oils for a long conservation time.


1986 ◽  
Vol 32 (10) ◽  
pp. 1901-1905 ◽  
Author(s):  
J C Koedam ◽  
G M Steentjes ◽  
S Buitenhuis ◽  
E Schmidt ◽  
R Klauke

Abstract We produced three batches of a human-serum-based enzyme reference material (ERM) enriched with human aspartate aminotransferase (EC 2.6.1.1), alanine aminotransferase (EC 2.6.1.2), creatine kinase (EC 2.7.3.2), and lactate dehydrogenase (EC 1.1.1.27). The added enzymes were not exhaustively purified; thus the final ERMs contained some enzymes as contaminants, of which only glutamate dehydrogenase activity might interfere. The stability during storage and after reconstitution was good. The commutability of the four enzymes in the three ERM batches was also good, except when German or Scandinavian methods for aminotransferases were involved. The temperature-conversion factors for the ERMs were equivalent to those for patients' sera. Reactivation after reconstitution was complete within 5 min and was independent of the temperature of the reconstitution fluid. We believe that these secondary ERMs will aid in the transfer of accuracy between well-defined reference methods and daily working methods so that clinical enzymology results will become more comparable from laboratory to laboratory.


2002 ◽  
Vol 365 (1) ◽  
pp. 249-258 ◽  
Author(s):  
Bernard KORZENIEWSKI ◽  
Jerzy A. ZOLADZ

Cytosolic pH in skeletal muscle may vary significantly because of proton production/consumption by creatine kinase and/or proton production by anaerobic glycolysis. A computer model of oxidative phosphorylation in intact skeletal muscle developed previously was used to study the kinetic effect of these variations on the oxidative phosphorylation system. Two kinds of influence were analysed: (i) via the change in pH across the inner mitochondrial membrane and (ii) via the shift in the equilibrium of the creatine kinase-catalysed reaction. Our simulations suggest that cytosolic pH has essentially no impact on the steady-state fluxes and most metabolite concentrations. On the other hand, rapid acidification/alkalization of cytosol causes a transient decrease/increase in the respiration rate. Furthermore, changes in pH seem to affect significantly the kinetic properties of transition between resting state and active state. An increase in pH brought about by proton consumption by creatine kinase at the onset of exercise lengthens the transition time. At intensive exercise levels this pH increase could lead to loss of the stability of the system, if not compensated by glycolytic H+ production. Thus our theoretical results stress the importance of processes/mechanisms that buffer/compensate for changes in cytosolic proton concentration. In particular, we suggest that the second main role of anaerobic glycolysis, apart from additional ATP supply, may be maintaining the stability of the system at intensive exercise.


1970 ◽  
Vol 44 (2) ◽  
pp. 147-156
Author(s):  
Tamanna Sultana ◽  
GP Savage ◽  
NG Porter ◽  
DL McNeil ◽  
JR Sedcole

Isothiocyanates (ITCs) contained in purees extracted from wasabi (Wasabia japonica (Miq) Matsum) can be used to manufacture a range of interesting spicy foods. In New Zealand, local manufacturers are showing interest in producing various forms of processed wasabi based sauces. However, isothiocyanates have been shown to degrade quickly in some situations. Therefore, in this study, the stability of allyl ITC was investigated in three wasabi flavoured products stored at four different temperatures (4, 10, 20 and 30°C) for 22 weeks. Two creamy (mayonnaise and tartare) sauces and a non-creamy sauce were prepared from an original recipe and flavoured with a known volume of "wasabi oil". Two types of pouches (clear and metallic plastic) were used to store each product and allyl ITC content was measured in the stored sauces at two week intervals. The initial level of allyl ITC found in mayonnaise, tartare and smoky tomato sauces were 415.3, 411.4 and 144.7 mg/ kg respectively, prior to storage. Temperature showed a strong influence in reducing allyl ITC (P=0.005 to <0.001) but no significant effect was identified for the two types of packets used. The non-creamy smoky tomato sauce was very unstable at 10°C or higher temperatures and the allyl ITC contents reduced rapidly with increasing storage temperatures. For instance, at 30°C, a 66% loss occurred by week 2 and a 90% loss occurred by week 6 in the smoky tomato sauce. However, mayonnaise and tartare sauces had a shelf life of 8 to 9 weeks with only a marginal reduction in allyl ITC (2% overall) at all the stored temperatures (4-30°C). These creamy sauces were characterized by a sudden fall in 10 weeks ending in a 69-70% loss of allyl ITC at 22 weeks. No microbial growth occurred in any of the sauces stored at any of the temperatures during the course of this storage experiment though very small change of colour was noticed for the sauces when stored at 30°C. Keywords: Bangladesh J. Sci. Ind. Res. 44(2), 147-156, 2009DOI: 10.3329/bjsir.v44i2.3665Bangladesh J. Sci. Ind. Res. 44(2), 147-156, 2009


Author(s):  
Adriana Paula David

. The main objective of this work was to determine the influence of formulation on the stability of bread dough during frozen storage. Bread doughs containing gluten and trehalose were submitted to mechanical freezing at -30° C and stored frozen for 45 days. Two types of instant yeast were tested: (A) for sweet doughs and (B) for savoury doughs. Specific volume was significantly affected by the yeast type, type A showing better effect than type B. Frozen storage of the doughs negatively affected the specific volume, crumb hardness and technological score of the bread. The addition of 5% trehalose had a beneficial effect on the cell survival rate for both the yeasts.


Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 7000
Author(s):  
Xueying Fu ◽  
Qiang Wu ◽  
Jian Wang ◽  
Yanli Chen ◽  
Guopeng Zhu ◽  
...  

Anthocyanins from flowers of the butterfly pea (Clitoria ternatea L.) are promising edible blue food colorants. Food processing often faces extreme pHs and temperatures, which greatly affects the color and nutritional values of anthocyanins. This study explored the color, spectra, storage stability, and antioxidant properties of C. ternatea anthocyanin extract (CTAE) at different pHs. The color and absorption spectra of CTAEs at a pH of 0.5–13 were shown, with their underlying structures analyzed. Then, the storage stability of CTAEs were explored under a combination of pHs and temperatures. The stability of CTAE declines with the increase in temperature, and it can be stored stably for months at 4 °C. CTAEs also bear much resistance to acidic and alkaline conditions but exhibit higher thermal stability at pH 7 (blue) than at pH 0.5 (magenta) or pH 10 (blue-green), which is a great advantage in food making. Antioxidant abilities for flower extracts from the butterfly pea were high at pH 4–7, as assessed by DPPH free radical scavenging assays, and decreased sharply when the pH value exceeded 7. The above results provide a theoretical basis for the application of butterfly pea flowers and imply their great prospect in the food industry.


2011 ◽  
Vol 28 (2) ◽  
pp. 119-128 ◽  
Author(s):  
Jacinth Devanesan ◽  
Alagusundaram Karuppiah ◽  
C. Abirami

Effect of storage temperatures, O2 concentrations and variety on respiration of mangoesThe respiration rate of fruits and vegetables is an important indicator of senescence and ethylene production in fruits. Storage temperatures play a major role in the respiration rates of fruits and vegetables. Experiments were conducted to establish the influence of storage temperatures, O2 concentrations and variety on the respiration of mangoes. The study was conducted on two varieties of mangoes namely, cvs ‘Banganapalli’ and ‘Thothapuri’. Experiments were conducted on a single fruit, weighing approximately 500 g and kept in separate glass bottles stored at 12, 20, 28, and 40 °C. Respiration rates were calculated and presented as the rate of release of CO2 or the rate of consumption of O2. Respiration rates decreased with a decrease in temperature from 40 °C to 12 °C, and with a decrease in O2 concentration from 21% to 1% in the micro-environment. The respiration rate was faster in ‘Banganapalli’ than in ‘Thothapuri’ as indicated by the CO2 release rate. The rate of CO2 release was very slow in mangoes stored at 12 °C in both the varieties and the rate decreased from 8.60 to 8.00 ml kg-1 h-1 in ‘Banganapalli’ variety and from 11.00 to 7.80 ml kg-1 h-1 in ‘Thothapuri’ variety. The respiration rates were faster at higher temperatures and remained low and stable at low temperatures. Using the respiration data, predictive models were developed for calculating the CO2 release and O2 consumption patterns.


1987 ◽  
Vol 87 (1) ◽  
pp. 183-188 ◽  
Author(s):  
C.J. Duncan ◽  
M.J. Jackson

Cellular damage, induced by either A23187 (2 X 10(−5)M) or 2,4-dinitrophenol (DNP) (10(−3)M), has been studied in incubated mouse soleus muscle and has been monitored by electron microscopy and measurement of creatine kinase (CK) efflux. CK efflux induced by DNP was dependent on extracellular Ca, whereas the characteristic myofilament breakdown was not. Chlorpromazine (2 X 10(−4)M; an inhibitor of phospholipase A (PLA2] or 5 X 10(−6)M-nordihydroguaiaretic acid (NDGA) (a lipoxygenase inhibitor) almost completely inhibited CK efflux, following treatment with either A23187 or DNP, but did not affect myofilament damage. It is concluded that there are at least two separate pathways in cellular damage: (1) PLA2 activation and lipoxygenase activity culminating in sarcolemma damage and (2) a system that produces characteristic destruction of the myofilament apparatus.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Fangfang Zhao ◽  
Jingkun Liu ◽  
Bingjun Han ◽  
Jinhui Luo

To investigate the stability of the pesticide residue in storage samples is a part of detection, which is also an improvement to the accuracy of analytical results. In this work, the UPLC-MS/MS method with perfect accuracy and stability was established for determining residues of difenoconazole in mango. The stability of the residue under different temperatures (4°C and −20°C) and media (fruit samples and pretreated sample solution) was investigated. At 0.1 mg/kg, the residue degraded in 6 months by 12% when at −20°C, while in a week by only 12.2% at 4°C. However, when pretreated and preserved in the solution, the residue remained more than 90% for 6–8 weeks. The results indicated that the main causes of degradation are biochemical factors, and the factors are affected by temperature. The findings also provided appropriate conditions for sample storage. This investigation promotes the accuracy in detection and hence guarantees food safety and quality.


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