Effects Of Prolonged Cold Storage Research Articles

Effect of Prolonged Cold Storage on the Dynamics of the Enzymatic and Non-Enzymatic Antioxidant System in the Mesocarp of Avocado (Persea americana) cv. Hass: Relationship with Oxidative Processes

This work evaluated the enzymatic and non-enzymatic antioxidant defense systems of avocados cv. Hass stored at 7 ± 0.5 °C for 10, 20, and 30 d, and at the stage of edible ripeness. The enzymatic antioxidant enzyme system included superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and the non-enzymatic antioxidant system was composed of total phenolic compounds (TPC), total carotenoids (TC), α-, β-, and γ-tocopherols, as well as hydrophilic (H-AOX) and lipophilic (L-AOX) antioxidant activities. In addition, polyphenol oxidase (PPO) and lipoxygenase (LOX) activities, TBARS values and pulp browning area were determined. At edible ripeness, low SOD and POD but higher CAT activities were evidenced in response to their joint participation in the oxidative stress developed. In addition, low content of γ-tocopherol and higher contents of TPC and TC were evidenced and suggest their individual or joint participation in defense against oxidation. The other compounds and activities evaluated tended to remain constant. Oxidative damage was evidenced by the increase in PPO activity and TBARS values, while LOX did not play a significant role. Pulp browning area did not surpass 6% in affected fruit. The results indicate that under these conditions oxidative stress was largely restrained by the endogenous fruit antioxidant defense system.

Human Milk Adrenomedullin Is Unstable During Cold Storage at 4°C

Under some circumstances human milk (HM) extraction and refrigerated storage may be necessary. Depending on the length and on the type of cold storage, milk may lose some important properties, but current advices on safe HM storage are discordant. Moreover until now no data in literature were present on the effect of prolonged cold storage on biologically active components of the HM such as adrenomedullin (AM). This important peptide is involved in response to hypoxia and inflammation, associated with neovascularization, in several tissues. The aim is to evaluate: (a) the presence of AM in preterm and term HM and (b) the concentration of AM in refrigerated milk at 4°C at 24-hour intervals, up to 96 hours of storage. The experiment was repeated four times. Immediately after collection, each HM sample deriving from each mother was divided into two parts as follows: "Pool" line and "Single Mother" line. One part (Pool line) was pooled and then divided into five aliquots. The other part (Single Mother line) was divided into five aliquots. From each line, one aliquot was analyzed within 3 hours, while the others were stored in the refrigerator for 24, 48, 72, and 96 hours, respectively, and then analyzed. AM levels were determined using a specific ELISA test. AM was detectable in all samples. Its concentration was significantly higher in preterm milk with respect to term milk (p < 0.05). Significant differences were observed during the cold storage: the AM levels decreased steadily during the storage and the remaining concentration at 96 hours is ∼2%. This study provides evidences regarding the presence of AM in HM, regardless of the gestational age. In particular, the refrigeration of fresh HM in controlled conditions significantly affected its bioactivity and nutritional quality related with AM, already at 24 hours.

Effect of prolonged cold storage on the sensory quality of peach and nectarine

To maintain peach and nectarine quality after harvest, low temperature storage is used. Low temperatures induce physiological disorders in peach, but the effect of cold storage on the sensory quality of the fruit before it is damaged by chilling injury syndrome remains unclear. To evaluate the cold storage effect on the sensory quality two peach cultivars (’Royal Glory’ and ‘Elegant Lady’) and two nectarines (’Ruby Diamond’ and ‘Venus’) were harvested at a standardized firmness level and subjected to quality evaluations and sensory analysis at harvest and after storage at 0°C for 35d. For both time points, a supplementary ripening followed such that homogeneous flesh firmness and suitability for consumption was achieved.The fruit segregation through the Durofel firmness (DF), evaluated using a non-destructively method (Durofel device), allowed the formation of a uniform group of fruit in terms of flesh firmness (FF), showing scores between 45.1 and 55.9N. The average FF in fruit ripened immediately after harvest was 22.9N and 25.6N in fruit ripened after cold storage for 35d.The “acceptability” of fruit is highly correlated with “aroma”, “sweetness”, “juiciness”, “texture” and “flavor”. Only the “acid taste” parameter had no significant correlation with “acceptability” or with the other parameters evaluated.It is possible to conclude that the sensory quality and acceptability of peach and nectarine are characteristic of each cultivar and change, depending on the time elapsed after harvest. In general, it was confirmed that nectarine cultivars have a more consistent quality than peach cultivars.

Effects of prolonged cold storage on double peaked vasoconstrictor responses to periarterial nerve stimulation in isolated canine splenic arteries.

1. P2X-Purinoceptors and alpha1-adrenoceptors have previously been shown to involve in the double peaked vasoconstrictor responses to periarterial electrical nerve stimulation in the isolated and perfused canine splenic artery. The present study made an attempt to investigate effects of prolonged cold storage (7 days at 4 degrees C) on vasoconstrictor responses to periarterial electrical nerve stimulation, tyramine, noradrenaline and adenosine 5'-triphosphate (ATP) in the isolated canine splenic artery. 2. The periarterial nerve stimulation (1-10 Hz) readily causes a double peaked vasoconstriction in the non-stored preparations. After cold stored for 7 days, the double peaked vasoconstriction was still recognized, although the response became significantly smaller. The first phase was decreased relatively greater than the second phase by the cold storage. 3. In the cold stored preparations, the dose-response curve for tyramine was shifted to the right in a parallel manner. Prazosin almost completely inhibited tyramine-induced vasoconstriction but alpha,beta-methylene ATP failed to influence the response to tyramine. 4. The vasoconstrictor responses to noradrenaline and ATP were not significantly modified by the prolonged cold storage. 5. From these results, it is concluded that the functions of sympathetic co-transmission of purinergic components might be influenced more than that of adrenergic components in the cold storage canine splenic artery.

Coronary endothelial dysfunction of isolated hearts subjected to prolonged cold storage: patterns and contributing factors

Background A key role of endothelial dysfunction in the pathogenesis of early low coronary flow of heart transplants and late cardiac allograft vasculopathy indicates the importance of optimal coronary endothelial preservation during cold heart storage. We designed this study to investigate the effect of prolonged cold storage on endothelial and smooth muscle function of proximal (epicardial) and distal (intramyocardial) coronary arteries. Methods Four groups of isolated rat hearts were subjected to cold cardioplegic perfusion and immersed in storage medium at 4°C. In groups 1, 2, and 3, hearts were perfused with and stored in Celsior solution for 10, 15, and 30 hours, respectively. In group 4, hearts were perfused with Plegisol and stored in saline for 15 hours. At the end of cold heart storage, arterial segments were taken from the proximal and distal parts of the left coronary artery and mounted on an isometric wire myograph for functional studies. In fifth group, proximal and distal segments of coronary artery isolated from fresh hearts were used as controls. At the end of control measurements, these vessels were used for storage in vitro at 4°C for 15 hours in saline (group 5A) or Celsior (group 5B). Results The endothelium-dependent relaxation to acetylcholine was reduced in distal coronary arteries in group 1, and in both proximal and distal coronary artery segments in groups 2, 3, 4, and 5A. Endothelial function was significantly more impaired in both proximal and distal coronary arteries in group 4, as compared with group 2. The impairment of relaxation to acetylcholine was more pronounced following cold storage of the heart than after a similarly long storage of the isolated vessels. The endothelium-independent relaxations to isoprenaline did not differ among all groups. The basal myogenic tone was increased in distal coronary arteries in group 1, and in both proximal and distal coronary arteries in groups 2, 3, 4, and 5A. The sensitivity to the vasoconstricting action of 5-hydroxytryptamine was increased in distal coronary arteries in group 2, and in both proximal and distal coronary arteries in groups 3, 4, and 5A. Conclusions: Prolonged ischemic cold heart storage induces coronary endothelial dysfunction that is more pronounced in distal than in proximal arteries and is related to the duration of heart storage and the composition of storage medium.

Effects of prolonged cold storage on purinergic and adrenergic components of sympathetic co-transmission in isolated canine splenic arteries.

The present study demonstrated the progressive inhibition by prolonged cold storage (4, 7 and 14 days at 4 degrees C) on prejunctional and postjunctional functions of purinergic and adrenergic components of double-peaked vasoconstrictor responses to periarterial electrical nerve stimulation in the isolated canine splenic artery. After the cold storage for 4 days, the first phase constriction was markedly decreased, whereas the second response was not significantly modified. Furthermore, after the 7 days of cold storage, the first phase was substantially depressed at low frequencies, but at high frequencies, a low level of contractile responses was still observed. On the other hand, the second phase in the cold stored artery for 7 days largely remained at any used frequencies. Moreover, the 14 days of cold storage almost completely inhibited the vasoconstrictor responses to nerve stimulation. Tyramine-induced constrictions were progressively decreased in the stored-days dependent manner, although the ATP and the noradrenaline-induced one was not modified for 4 and 7 days of the cold storage. In conclusion, 1) the 4 degrees C cold stored artery for 4 days may show preferential injury of its tyramine-dependent noradrenaline releasing mechanisms, whereas nerve excited ones might well remain; and 2) the prejunctional contractile response of purinergic transmission might be damaged more preferentially than that of adrenergic transmission within 7 days storage.

Effects of Prolonged Cold Storage on Purinergic and Adrenergic Components of Sympathetic Co-transmission in Isolated Canine Splenic Arteries

Effects of Prolonged Cold Storage on Purinergic and Adrenergic Components of Sympathetic Co-transmission in Isolated Canine Splenic Arteries

Development to blastocysts of domestic cat oocytes matured and fertilized in vitro after prolonged cold storage.

Four experiments determined the kinetics of in vitro maturation and fertilization of cat oocytes and the effects of prolonged cold storage of ovaries before oocyte recovery on in vitro maturation/in vitro fertilization (IVM/IVF) success. Domestic cat ovaries were collected at ovariohysterectomy and stored at 4 degrees C in PBS until oocyte recovery and culture in Eagle's minimal essential medium (EMEM) containing FSH, LH, oestradiol and BSA for maturation. In Expt 1, meiotic maturation was assessed at 0, 12, 24, 38 and 48 h of culture. After 24 h, > 61% of oocytes were in telophase I or metaphase II. In Expt 2, oocytes were recovered from ovaries stored for 24, 48 or 72 h and cultured in EMEM for 24 h. There was no difference among groups (P > 0.05) in the ability to achieve nuclear maturation (mean +/- SEM, 57.1 +/- 5.3%, 60.4 +/- 5.4%, 55.4 +/- 15.1% for 24, 48 and 72 h, respectively). Fertilization and embryo development after insemination at 16, 24, 32, 40 and 48 h of culture were examined in Expt 3. Of 98 oocytes inseminated at 32 h, 69% cleaved, 59% developed into morulae and 13% into blastocysts, more (P < 0.05) than those oocytes inseminated at earlier and later times. Development to blastocysts occurred after insemination at 16 (1.2%), 24 (9.1%) and 32 (13.3%) h of culture, but not after insemination at 40 or 48 h. Expt 4 involved cold storage of ovaries for 24, 48 or 72 h before oocyte recovery and insemination at 32 h of culture (the optimal time measured in Expt 3). Compared with storage for 24 h, fertilization success was lower (P < 0.05) in the 48 and 72 h groups, and, although 9.1% of inseminated oocytes from the 24 h storage group developed to blastocysts, none (P < 0.05) achieved this stage after 48 or 72 h of storage. These results indicate that domestic cat oocytes reach nuclear maturity by 24 h in culture and can be fertilized and develop to blastocysts optimally after insemination at 32 h. Oocytes recovered from ovaries stored at 4 degrees C for up to 72 h are capable of reaching telophase I or metaphase II in vitro. However, only oocytes stored within the ovary for 24 h produce blastocysts, indicating that the ability to achieve nuclear maturation is an inadequate indicator of fertilization and developmental competence.

Effect of prolonged cold storage on the production capacity of strawberry plants

After cold storage for various periods (42, 99, 155, 189, 227 and 259 days) strawberry waiting-bed plants cultivar ‘Elsanta’ were planted on six dates between January and August. Plant performance was evaluated simultaneously in a growth chamber under controlled environmental conditions and in a greenhouse. Starch content in the crown tissue was clearly reduced during the cold storage period. In the greenhouse trials a variable decline in fruit number and yield per plant was found in relation to the length of cold storage and the temperature conditions during the growth and harvest period. Also in the growth chamber, under a constant temperature regime, a significant decline in the number of flowers per plant developing up to anthesis was observed after increasing periods of storage. This indicates that it is not only stressing climatical conditions after planting which are influencing the performance of cold stored plants. Also, the length of cold storage strongly affects plant vigour and productivity. This is related to the carbohydrate status of the plants after cold storage.

Effects of prolonged cold storage on carbohydrate and protein content and field performance of white spruce bareroot seedlings

Three-year-old bareroot white spruce (Piceaglauca (Moench) Voss) seedlings from three seedlots were either lifted in the fall of 1990 and stored over winter at −2 °C, or lifted in the spring of 1991. The soluble sugar, starch, and protein contents of needles, stems, and roots were measured in fall-lifted seedlings before, during, and at the end of cold storage and compared with those in spring-lifted seedlings 10 days before outplanting. The soluble sugar content of the seedlings decreased significantly in all tissues during cold storage. At the time of spring planting, sugar and protein levels were similar in fall- and spring-lifted seedlings, but starch content was about two times higher in spring-lifted seedlings. After outplanting, spring-lifted seedlings flushed and resumed root growth sooner than the fall-lifted, cold-stored seedlings. Spring-lifted seedlings also had initially higher photosynthetic rates and water potentials compared with the fall-lifted seedlings. However, both types of seedlings had similar survival rates and 1st year shoot growth in the field. The responses of seedlings to cold storage were similar among seed lots.

ATPase and Lactate Dehydrogenase Activities in Frozen Stored Fish Muscle as Indices of Cold Storage Deterioration

ABSTRACTThe effect of prolonged cold storage on muscle adenosine triphosphatase (ATPase) and lactate dehydrogenase (LDH) activities was studied in a variety of fresh water and brackish water fish. Decrease in enzyme activity was observed in all samples stored frozen (‐ 20°C) over a period of 180 days. Highly significant negative correlation was observed between enzyme activity and frozen storage period with mullet, pearlspot, milk fish and tilapia. Significant linear correlations were observed between decrease in enzyme activities and other biochemical indices and sensory scores. The results indicated that loss of activities of ATPase and LDH in fish muscle was significantly related to early changes in quality of frozen stored fish.

Effects of prolonged cold storage on phenology and performance of Douglas-fir and noble fir 2 + 0 seedlings from high-elevation sources

Survival, phenology, and growth performance of 2 + 0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and noble fir (Abiesprocera Rehd.) seedlings planted at 1500 m in the Oregon Cascade Range were determined following a lifting on November 7 with 7 months of cold storage or lifting on March 1 with 3 months of cold storage. Storage temperature remained between 1 and 2 °C. There was no difference in Douglas-fir survival attributable to the lifting – cold-storage treatments during the first two growing seasons. The first-season survival of noble fir stored for 7 months was superior to that of those stored for 3 months, but no difference was evident after the second growing season. Timing of bud burst did not differ significantly among treatments for either species. However, the rate of bud burst was significantly greater for noble fir seedlings lifted in November and stored 7 months than for those lifted in March and stored 3 months. No difference in the rate of bud burst was observed between treatments for Douglas-fir. Shoot/root ratio for both species and treatments decreased significantly in the first growing season, but did not change significantly in the second growing season. Regardless of species, no differences were found in height growth or diameter increment between the two lifting – cold-storage treatments for the two consecutive growing seasons. The results suggest that Douglas-fir and noble fir seedlings originating from high-elevation seed sources can be lifted in fall and cold stored for 7 months without adverse effects on seedling performance.

Effect of prolonged cold storage on the mechanical activity of rabbit atria

1. 1. Even after 21 days of cold storage at 2°C, rabbit atria still showed a detectable response only to isoproterenol while other cardiostimulants (norepinephrine, ouabain, anthopleurin-A and nicotine) failed to activate tissues stored up to 14 days. 2. 2. The specific fluorescence of catecholamines disappeared from the tissue after 5 days of cold storage. 3. 3. The maximum decrease in oxygen consumption and tissue catecholamine content was observed after 14 days and a concomitant decrease in tissue ATP content, Na +-K +, Ca 2+ and Mg 2+-ATPases was nearly maximal after 7 days of cold storage. 4. 4. The cold storage had no apparent effect on the ultrastructures of myocardial cells except a disappearance in glycogen granules.

The effect of cold storage on the inhibitory action of isoprenaline, phenylephrine and nicotine on the mechanical and membranal activities of guinea-pig taenia caecum.

1. The effects of prolonged cold storage on the mechanical and membranal responses to stimulation of alpha- and beta-adrenoceptors by phenylephrine and isoprenaline, respectively, were studied on the guinea-pig taenia caecum.2. Cold storage invariably caused a decrease in the resting membrane potential, and this effect was enhanced as the duration of treatment was prolonged.3. After cold storage (18 days) the tissue potassium ion content (89.7 +/- 1.7 mmol/kg wet wt.) was decreased to 30.5 +/- 1.9 mmol/kg wet wt. whereas that for sodium (69.2 +/- 1.4 mmol/kg wet wt.) increased to 134.0 +/- 2.3 mmol/kg wet wt.4. In the fresh preparations, phenylephrine (1 and 2 muM) caused a cessation of spontaneous action potentials, accompanied by hyperpolarization of the membrane and relaxation of the muscle. These effects were markedly diminished after 18 days of cold storage. Isoprenaline (1 and 2 muM) also blocked the action potentials and caused a concomitant muscle relaxation, but in most cases the hyperpolarization was not observed. After 14 days of cold storage these mechanical and membranal changes associated with isoprenaline treatment were not demonstrable in most preparations.5. Nicotine (5 muM and 50 muM) produced a biphasic effect, cessation of the action potential, hyperpolarization and subsequent relaxation followed by a long lasting depolarization, an accelerated discharge of action potentials and an increase in muscle tension. After a few days of cold storage the hyperpolarization effect disappeared but the intensity of the long-lasting depolarization as well as the contractile effects were increased. After cold storage for more than 7 days, nicotine did not affect mechanical or electrical activity.6. Dibutyryl 3'5' cyclic AMP (1 muM to 500 muM) failed to affect the mechanical and electrical activities of taenia caecum.7. Phenylephrine and isoprenaline had no effect on the high potassiumdepolarized taenia.8. These observations suggest that the electro-mechanical effect of an alpha-adrenoceptor stimulant on the guinea-pig taenia caecum is more resistant to cold treatment than that of a beta-adrenoceptor stimulant. This inhibitory system of stimulation of both a- and 8-receptors of guinea-pig taenia caecum may react by different mechanisms. The results also demonstrate that cold storage itself changes the membrane permeability to ions and the tissue ion content (Na+ and K+) of smooth muscle of guinea-pig taenia caecum.

The Effects of Cold on Mallard Embryos

Environmental chambers were used to simulate ambient temperatures and lengths of exposure of mallard (Anss platyrhynchos) eggs in nests of wild birds in the vicinity of Delta, Manitoba. The effects of cold exposure on eggs prior to incubation as well as on eggs containing developing embryos were researched. Unincubated eggs withstood much longer exposure than those partially incubated, whereas the oldest embryos were most susceptible to cold. Increased hatchability resulted from cold treatments to both unincubated and partially incubated eggs. When incubated eggs were exposed to O C, males suffered greater mortality than females, and an unbalanced sex ratio resulted. Abnormal embryonic development resulting from exposure tol cold was observed. The degree of tolerance of the mallard embryo to cold appears sufficiently great to minimize lower hatches in the wild caused by cold alone. The effects of cold on waterfowl embryos are of particular importance in view of the low temperatures in the early spring environments, where most temperate zone dabbling ducks initiate nesting. Gottlieb ( 1963 ) devised a technique for determining the developmental age of Pekin ducks (A. p. domesticus ) by the elimination of older embroys through exposure to cold. Romanoff ( 1943) reported that lower than normal temperatures throughout the incubation period will lower the hatch in runner ducks ( A. p. domesticus ), and Prince et al. ( 1969 ) reported similar findings for mallards. The need for study of this aspect of the reproductive cycle was indicated by Sowls (1955:88-89) and by Hunt and Jahn ( 1966) . Our first experiment was designed to examine the effects of prolonged cold storage on the hatchaibility of fresh eggs, whereas the second experiment examined the effects of exposure to cold temperatures at 3-day intervals throughout the incubation period. The work was done at the 1 This project was financed by the University of Florida, the North American Wildlife Foundation, and the Wildlife Management Institute. Experiments were conducted at the Delta Waterfowl Research Station, Delta, Manitoba. 2 Present address: Delta Waterfowl Research Station, Delta, Manitoba. Delta Waterfowl Research Station in southcentral Manitoba, Canada. We thank H. A. Hochbaum and P. NVard of the Delta Waterfowl Research Station for providing facilities and equipment during this study. We are also indebted to H. H. Prince, Michigan State University, for guidance and suggestions at the onset of the study, and to A. E. Snart, University of Florida, who was a laboratory assistant during the 1968 field season. N. F. Godfrey assisted in caring for incubators and in rearing ducklings. J. Cornell, U11iversity of Florida, helped with the statistical analy-

Effect of prolonged cold storage on the contractile response of strips of rabbit aorta to various agents.

After 2 days in cold storage (2.0 ± 0.5°C), the contractile response of spiral strips of rabbit aorta to low concentrations (10 -9 to 10 -10 ) of epinephrine and of norepinephrine was potentiated; after storage for 4 to 7 days, an increased contractile response to high concentrations (10 -8 to 10 -6 M) of these catecholamines was also observed. Reserpine-pretreated strips showed potentiation of epinephrine- and norepinephrine-induced contractions, but only after 2 to 7 days in cold storage. Another result of several days of cold storage was a decrease or loss of contractile response to nicotine (10 -5 to 10 -6 M), tyramine (10 -4 to 10 -6 M), and potassium (10 to 40 mM). Potentiation of the contractile response to epinephrine and to norepinephrine was also observed in potassium depolarized strips at low temperature (19°C). After incubation of the depolarized or cold-stored strips in the Ca-free medium, no potentiation of epinephrine- or norepinephrine-induced contractions was observed. These results indicate that cold storage, up to 7 days, does not interfere with the activation system related to epinephrine- or norepinephrine-induced contractions. However, such treatment does affect the membrane system involved in potassium-induced contraction. The decreased response to nicotine and tyramine after several days of cold storage may be due to the unavailability of tissue catecholamine. No significant histopathologic changes were observed in any layer of the aorta after cold storage up to 7 days.