Nucleotide Degradation and Quality in Ordinary and Red Muscle of Iced and Frozen Swordfish (Xiphias gladius)

1966 ◽  
Vol 23 (12) ◽  
pp. 1821-1833 ◽  
Author(s):  
W. J. Dyer ◽  
Doris I. Fraser ◽  
Dianne P. Lohnes

In iced dressed swordfish, inosine monophosphate, initially the predominant nucleotide (5.2 μmole/g), was dephosphorylated to inosine during 19 days storage. Hypoxanthine increased very slowly to about 1 μmole/g while quality (taste panel) showed no significant decrease to 15 days but was near borderline at 19 days. These changes occurred more slowly than in cod and related species. The sequence of nucleotide changes occurred much earlier in the red muscle. Rapid freezing and storage at −26 C for 4–5 months inhibited nucleotide enzymic activity, and quality remained unchanged. Slow freezing and storage for 1 week at −4 C significantly reduced quality to borderline or unacceptable levels, but only slightly affected the nucleotide degradation, indicating that other factors were responsible for the loss in quality. Dephosphorylation and hypoxanthine accumulation continued during further storage at −4 C. The levels of hypoxanthine reached during 19 days iced storage or 4–5 months frozen storage were not sufficiently high to impart bitter flavors, except possibly in the red muscle. A simple measure of inosine (+ hypoxanthine) may be useful as a quality test; a supplementary hypoxanthine test could be used to confirm spoilage.

1969 ◽  
Vol 26 (6) ◽  
pp. 1597-1603 ◽  
Author(s):  
W. J. Dyer ◽  
Doris I. Hiltz

In frozen swordfish steaks, inosine monophosphate (IMP) dephosphorylation was active at − 8 C and less so at − 18 C. A loss of IMP at − 26 C became apparent during a 2-year storage period. Rates of loss were about 0.24 and 0.029 μmoles per g per week at − 8 and − 18 C, the Arrhenius plot being linear over the temperature range 0 to − 26 C. Inosine ribohydrolase was less active; nevertheless, about 2.5 μmoles per g of hypoxanthine accumulated in 2 years at − 8 C. Taste panel tests indicated a storage life of 3 months at − 8 C, 9 months at − 18 C, and several years at − 26 C. The loss of IMP was slightly slower than the associated taste panel score decrease and thus may have potential as an indicator of frozen storage quality in some fish species, though it did not prove useful for swordfish. Hypoxanthine formation at low storage temperatures is sufficiently slow to allow use of hypoxanthine as an index of prefreezing quality; however, red muscle must not be included in the sample because of its high initial hypoxanthine content, about 1.9 μmoles per g.


1993 ◽  
Vol 23 (12) ◽  
pp. 2459-2466 ◽  
Author(s):  
George J. Harper ◽  
Edith L. Camm

Nursery grown seedlings of Piceaglauca (Moench) Voss were stored frozen in the dark from approximately 10–31 weeks, thawed and grown for 28 days in a growth chamber at three soil temperatures (3, 7, and 11 °C). During the growing period gas exchange measurements were made every three days. Seedling net photosynthesis (pn) and stomatal conductance (gs) showed significant interactions between soil temperature and storage duration treatments. Soil temperature did not affect seedling gs or pn, though the degree and extent of storage duration effects were dependent on soil temperature. Recovery of gs occurred over a 4–7 day period from low levels after planting. Seedlings stored longer than 22 weeks showed lower rates of pn, than those stored for shorter durations. The lower pn in long-stored seedlings did not result from stomatal limitations to carbon fixation, as gs increased in seedlings stored >22 weeks.


2017 ◽  
Vol 61 (No. 8) ◽  
pp. 443-448 ◽  
Author(s):  
DA Bala ◽  
E. Eraslan ◽  
I. Akyazi ◽  
EE Ekiz ◽  
M. Ozcan ◽  
...  

Studies on the frozen storage of human blood products have benefited veterinary transfusion medicine in recent years, but the long-term cryopreservation of canine red blood cells (RBCs) has not yet been thoroughly investigated. Further, no studies are available with respect to the frozen storage of leukocyte-depleted canine red blood cells (LD-RBCs). The objective of the current study was to investigate time-dependent effects of long-term frozen storage on leukocyte-depleted canine RBCs. Twelve healthy adult dogs meeting the criteria for blood transfusion were used in the study. Whole blood samples (450 ± 45 ml) collected from each dog were centrifuged for 5 min at 22 °C and 4200 × g in a cryogenic microcentrifuge and concentrated RBC (pRBC) suspensions were obtained. Leukocyte depletion was achieved by filtration (2.6 log<sub>10</sub>). Then, the filtrated samples were prewashed three times in 0.9% NaCl solution and were allocated into three subgroups to be evaluated at three different time points (Day 0, Month 4 and Month 6). The samples for cryopreservation were subjected to glycerolisation and then stored at –80 °C for 4- and 6-month periods. At the end of this period pRBC units were thawed by manual agitation in a water bath maintained at 36–38 °C, centrifuged and then washed in a consecutive series of 12%, 1.6% and 0.9% of NaCl + 0.2 dextrose solutions. 2,3-Diphosphoglycerate (2,3-DPG), adenosine triphosphate (ATP), supernatant haemoglobin (SupHb), sodium (Na<sup>+</sup>) and potassium (K<sup>+</sup>) levels, residual glycerol concentrations and haemograms of thawed and deglycerolised pRBC samples were evaluated together with those of Day 0. Sterility tests were performed on all samples for bacterial contamination. No statistically significant differences were noted except for Hct and SupHb levels. No bacterial contamination was noted in any of the samples on the basis of sterility tests. It was found that the described glycerolisation procedure could be a method of choice in the cryopreservation of leukocyte-depleted pRBCs (LD-pRBCs) since no negative effect was observed on the quality of the products and long-term frozen storage did not cause RBC destruction.


2000 ◽  
Vol 67 (1) ◽  
pp. 83-90 ◽  
Author(s):  
FERNANDA FONSECA ◽  
CATHERINE BÉAL ◽  
GEORGES CORRIEU

We have developed a method to quantify the resistance to freezing and frozen storage of lactic acid starters, based on measuring the time necessary to reach the maximum acidification rate in milk (tm) using the Cinac system. Depending on the operating conditions, tm increased during the freezing step and storage. The loss of acidification activity during freezing was quantified by the difference (Δtm) between the tm values of the concentrated cell suspension before and after freezing. During storage at −20 °C, linear relationships between tm and the storage time were established. Their slope, k, allowed the quantitation of the decrease in acidification activity during 9–14 weeks of frozen storage. The method was applied to determine the resistance to freezing and frozen storage of four strains of lactic acid bacteria and to quantify the cryoprotective effect of glycerol.


Zygote ◽  
2011 ◽  
Vol 20 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Alessandra Corallo Nicacio ◽  
Renata Simões ◽  
Fabiola Freitas de Paula-Lopes ◽  
Flavia Regina Oliveira de Barros ◽  
Maria Angelica Peres ◽  
...  

SummaryThe aim of this work was to evaluate the effect of cryopreservation protocols on subsequent development of in vitro produced bovine embryos under different culture conditions. Expanded in vitro produced blastocysts (n = 600) harvested on days 7–9 were submitted to controlled freezing [slow freezing group: 10% ethylene glycol (EG) for 10 min and 1.2°C/min cryopreservation]; quick-freezing [rapid freezing group: 10% EG for 10 min, 20% EG + 20% glycerol (Gly) for 30 s]; or vitrification [vitrification group: 10% EG for 10 min, 25% EG + 25% Gly for 30 s] protocols. Control group embryos were not exposed to cryoprotectant or cryopreservation protocols and the hatching rate was evaluated on day 12 post-insemination. In order to evaluate development, frozen–thawed embryos were subjected to granulosa cell co-culture in TCM199 or SOFaa for 4 days. Data were analyzed by PROC MIXED model using SAS Systems for Windows®. Values were significant at p < 0.05. The hatching rate of the control group was 46.09%. In embryos cultured in TCM199, slow freezing and vitrification group hatching rates were 44.65 ± 5.94% and 9.43 ± 6.77%, respectively. In embryos cultured in SOFaa, slow freezing and vitrification groups showed hatching rates of 11.65 ± 3.37 and 8.67 ± 4.47%, respectively. In contrast, the rapid freezing group embryos did not hatch, regardless of culture medium. The slow freezing group showed higher hatching rates than other cryopreservation groups. Under such conditions, controlled freezing (1.2°C/min) can be an alternative to cryopreservation of in vitro produced bovine embryos.


1985 ◽  
Vol 231 (1) ◽  
pp. 75-81 ◽  
Author(s):  
M L Niku-Paavola ◽  
A Lappalainen ◽  
T M Enari ◽  
M Nummi

The properties and enzymic activity of endoglucanases (EC 3.2.1.4) of the fungus Trichoderma reesei were studied by means of immunological methods and by using polyglycosidic substrates. Endoglucanases exist in the culture liquid as a series of immunologically related components. The most active endoglucanase component has an Mr of 43 000 and pI value of 4.0. The most abundant components have a value of pI about 5.0, an Mr of 56 000-67 000 and specific activity only one-fifth of that of the pI-4.0 component. During purification and storage the endoglucanases are spontaneously modified; the relative proportion of components having greater Mr values, more alkaline pI values and lower specific activities is increased. The hexose content of the endoglucanase components is 2-7%. Endoglucanases hydrolyse soluble β-1,4 glycans. The enzymes described here differ from endoglucanase preparations described previously in not showing activity towards insoluble substrates. The role of endoglucanases in wood hydrolysis is consequently limited to the stage where wood constituents are already in soluble form.


2018 ◽  
Vol 69 (1) ◽  
pp. 235 ◽  
Author(s):  
C. Aquilani ◽  
T. Pérez-Palacios ◽  
F. Sirtori ◽  
E. Jiménez-Martín ◽  
T. Antequera ◽  
...  

The most beneficial omega-3 PUFAs to human health, EPA and DHA fatty acids, are typically present in fish products, but extraneous to meat. Therefore, Cinta Senese pork burgers were added with microencapsulated (M) and bulk fish oil (F) and subjected to three storage conditions: no storage (T0), chilled (T5) and frozen storage (T30). The physico-chemical and sensory attributes of raw and cooked burgers were investigated. After storage and cooking, EPA and DHA were better preserved in M burgers than in F samples, which showed the highest TBAR values at T0 and T5, while M samples presented scores similar to the control. Panelists observed differences mainly in greasy appearance, odor intensity and cooked meat odor and flavor. The M group showed the best scores at T5 with respect to the control and F burgers. So, fish oil microencapsulation was an effective method to prevent EPA and DHA oxidation while respecting burger quality characteristics.


2020 ◽  
Vol 7 (3) ◽  
pp. 89
Author(s):  
Eka Saputra

This study aim was to determine the effect of washing and raw materials on frozen storage on the quality of surimi and kamaboko from raw material of tilapia (Oreochromis sp). There were three types of raw materials used, namely minced fish, surimi, and surimi with addition of sorbitol, with three washing treatments and four weeks frozen storage period observed every week. The method used consisted of measurements of pH, water content, bite test, and folding test. Then the results obtained for the best kamaboko tilapia (Oreochromis sp) were obtained from fillet raw materials compared to the raw material of Minced fish and raw materials of Minced Fish + Sorbitol, with a frequency of washing once and frozen storage for 3 weeks.


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