Weeks Of Storage Research Articles

346 Effects of Gibberellic Acid and Seed Location on Seed Germination of Echinacea pallida

Echinacea pallida, one of the three medicinal Echinacea species native to North America, is generally wildcrafted, and low and uneven seed germination are obstacles to its widespread cultivation. Nonstratified E. pallida seeds were treated with 2500, 3500, and 4500 mg/L GA3 to increase seed germination. Treated seeds were directly germinated at 25 °C and 25/15 °C (14/10h) or stored at 5 and 10 °C for 4, 8, and 12 weeks before germination at the same temperatures. Seed germination across treatments was higher at 25 °C (19%) than at 25/15 °C (14%). Application of 2500, 3500, and 4500 mg/L GA3 significantly increased seed germination rate and total seed germination of nonstratified seeds of E. pallida and resulted in 44%, 50%, and 63% total seed germination, respectively, while untreated control seeds germinated at only 9%. The effect of GA3 as a germination stimulant increased with cold storage, with maximum germination (83%) occurring after seeds were treated with 4500 mg/L GA3 and an 8-week cold storage period at 10 °C. The effect of cold storage periods of 4, 8, and 12 weeks and cold storage temperatures of 5 and 10 °C on seed germination were generally similar. Seeds collected from the upper rows of the seed heads germinated significantly higher (10.6%) than those collected from the lowest seed rows (2.4%).

Stability of topotecan infusion solutions in polyvinylchloride bags and elastomeric portable infusion devices

Purpose. The purpose of this study was to determine the physicochemical stability of topotecan after reconstitution and after further dilution in two commonly used infusion fluids (0.9% sodium chloride, 5% dextrose) in both polyvinylchloride (PVC) bags and elastomeric portable infusion devices. Methods. Each vial of topotecan (Hycamtin®) was reconstituted with sterile water for injection, yielding a nominal concentration of 1 mg/mL. Topotecan infusion solutions were aseptically prepared by further dilution of reconstituted topotecan solutions with either 0.9% sodium chloride or 5% dextrose in both PVC bags and portable elastomeric infusion devices, in amounts yielding topotecan concentrations of 10 µg/mL, 25 µg/mL, or 50 µg/mL. Test solutions were stored light-protected at room temperature (25°C) or under refrigeration (2-8°C) in parallel. One test solution of the nominal concentration of 10 µg/mL topotecan in a 0.9% sodium chloride PVC infusion bag was stored under ambient light conditions (mixed daylight and normal laboratory fluorescent light) at room temperature. Topotecan concentrations were obtained periodically throughout a 4-week storage period via a stability-indicating high performance liquid chromatography assay with ultra-violet detection. In addition, measurements of pH values were performed regularly, and test solutions were visually examined for colour change and precipitation. Results. The stability tests revealed that the currently available topotecan formulation is stable (at a level of ≥90% topotecan) after reconstitution and dilution, independent of temperature (refrigerated, room temperature), the vehicle (0.9% sodium chlo-ride, 5% dextrose), the concentration (10 µg/mL, 25 µg/mL, or 50 µg/mL), or the container material (PVC bags, elastomeric portable infusion devices). The results were obtained over a test period of ≥4 weeks. Topotecan infusion solutions exposed to daylight were stable for only 17 days. Conclusions. Reconstituted and diluted topotecan infusion solutions are shown to be physicochemically stable for 4 weeks. Light protection during administration is not necessary.

Survival of Escherichia coli O157:H7 in dried beef powder as affected by water activity, sodium chloride content and temperature

A study was carried out to determine the rate of inactivation of Escherichia coli O157:H7 in beef powder as affected by aw(0·34±0·06±0·01), sodium chloride content (0·5, 3·0 and 20%) and temperature (5 and 25° C) over an 8-week storage time. Retention of viability of acid-adapted, acid-shocked, and control cells was determined. Overall, there were no significant differences (P≤0·05) in survival among the three types of cells subjected to the same test parameters, suggesting that mechanisms associated with induction of acid adaptation or acid shock do not result in cross protection against dehydration or osmotic stresses. At each awand within cell type, an increase in sodium chloride concentration resulted in significant reductions in the number of viable cells after a given storage time. Regardless of cell type, survival was significantly higher in beef powder containing 0·5 or 3% sodium chloride compared to powder containing 20% salt. The rate of inactivation was enhanced at aw0·34±0·06 compared to aw0·68±0·01 and at 25° C compared to 5° C.

Effects of cold storage and heat–acid shocks on growth and verotoxin 2 production ofEscherichia coliO157:H7

Escherichia coliO157:H7 was cold-stored (4°C) either in nutritious menstruum [buffered Brain Heart Infusion (BHI) broth] or with starvation (buffered saline) at pH 7.0 or 5.5. Cultures grown in BHI broth at 37°C for 24h served as non-cold-stored controls. After 4-weeks cold storage, bacterial cells were shocked by heat (45°C for 5min) and acid (pH 2.5 for 30min at 37°C) and subsequently moved to optimal conditions (BHI broth of pH 7.4 incubated at 37°C). The results showed: (a) both lag-phase duration and growth rate of this pathogen at 37°C significantly increased after cold-storage with starvation, but not after cold storage in the nutritious menstruum; (b) combined heat–acid shocks increased growth rates at 37°C of both previously cold-stored and non-cold-stored bacterial cells; (c) final concentrations of verotoxin produced by bacterial cells at 37°C were not affected by previous cold storage in the nutritious menstruum; (d) verotoxin production by bacterial cells at 37°C increased after cold storage with starvation, and heat–acid shocks further enhanced that production. Further research is needed to evaluate the food safety implications of these results, i.e. whether cells ofE. coliO157:H7 originating from nutrient-poor/lower-pH environments may be more harmful to humans than those from nutrient-rich/higher-pH foods.

In vitro characterization of a controlled-release chlorpheniramine maleate delivery system prepared by the air-suspension technique

Non-pareil cores were spray-coated with a chlorpheniramine maleate (an alkylamine antihistamine) layer and a EudragitR N overcoat in a Wurster air-suspension apparatus. In vitro dissolution studies demonstrated that drug release was a function of polymer membrane thickness. Polyethylene glycol 6000, as a hydrophillic additive, increased the in vitro release of chlorphenir amine maleate from the pellets. Pellets coated with 8 0% EudragitR N, 0 0% talc and 0% polyethylene glycol 6000 were found to display desirable controlled release characteristics for chlorpheniramine maleate over the 8-h testing period, which were also comparable with that of DykatussR capsules. The controlled release pellets exhibited first-order release characteristics for chlorpheniramine maleate. Reproducibility of the manufacturing conditions employed in the study were confirmed thus ensuring reproducibility of drug release characteristics between batches of chlorpheniramine maleate pellets. Drug release from the pellets was shown to be independent of the dissolution method and medium used. Pellets displayed no significant change in drug release characteristics relative to the initial drug release data when stored for 12 weeks at room temperature (20+2) and for 8 weeks at a low temperature (5 + 1 °C). However, pellets stored at 37 °C with 80% relative humidity and at 40 + 2 showed a slower in vitro drug release after 8-week storage and therefore failed to maintain their initial drug release profile.

Ethylene-forming capacity during cold storage and chilling injury development in ‘Keitt’ mango fruit

Abstract The capacity to convert ACC into ethylene in ‘Keitt’ mango fruit peel was influenced by storage temperature. At harvest, ACC-treated peel discs produced about 10-fold more ethylene than untreated peel discs. Ethylene production rates of untreated peel discs prepared from fruits stored at 0, 2, 5, 14 and 20 °C were around 10 nl g −1 h −1 or lower, during the whole 4-week storage period. At all storage temperatures ACC-induced ethylene production declined with time, and after 2 weeks it fell almost to the level of ethylene production of the untreated discs. When fruits were transferred to storage at 20 °C after 2 weeks at the various temperatures, it appeared that the transient capacity to convert ACC to ethylene after rewarming was maintained at low storage temperatures and lost at the higher temperatures. After 4 weeks of storage, at all the different temperatures, no significant capacity to convert added ACC to ethylene was observed upon removal of the fruit to shelf-life conditions. It appears that this capacity in mango fruit peel was maintained at storage temperatures which cause delay in ripening as well as chilling injury to the peel. Changes in the ability to convert ACC to ethylene in the peel were not related to changes in ripening parameters in the fruit pulp.

Analysis of free amino acids in green coffee beans. II. Changes of the amino acid content in arabica coffees in connection with post-harvest model treatment.

To investigate amino acid changes in green coffee beans in the post-harvest period, amino acid concentrations were determined in green beans and after modelled drying, fermentation and storage. After the drying at alternating temperatures up to maximally 40 degrees C, considerable changes in the concentrations of individual amino acids were identified. At the beginning of the storage period, significant changes in concentration were found to a minor extent. Under the condition of drying, it was mainly the concentration of glutamic acid that changed considerably. There was an increase in all the samples by 500 mg/kg dry matter on average, which corresponds to an increase of about 50% of the original value. In contrast, the concentration of aspartic acid in most of the samples decreased clearly due to drying. For the predominant part of the coffee samples, there was a significant increase in the hydrophobic amino acids Val, Phe, Ile and Leu. Changes of the quantities of other amino acids were non-uniform and only insignificant. Constant drying at 80 degrees C for most of the amino acids brought about only minor concentration changes compared to those values obtained at 40 degrees C. Modelled fermentation had no significant effect on the concentrations of the individual amino acids. After a 4-week storage of dried beans, amino acid concentrations did not change further. It is very possible that different post-harvest treatment parameters may influence the amount of aroma precursor compounds in the coffee beans.

Combined treatment of heat shock and low temperature conditioning reduces chilling injury in zucchini squash

The severity of chilling injury in zucchini squash stored at 5°C and then transferred to 20°C was reduced by a prestorage treatment with hot water of 42°C for 30 min. The chilling injury was further reduced when zucchini squash were preconditioned at 15°C for 2 days after hot water treatment but before the 5°C storage. Zucchini squash stored at 15°C did not develop any symptoms of chilling injury. However, weight loss was most severe in zucchini squash stored at 15°C. Squash kept at 5°C had the least weight loss during the 2-week storage. Weight losses were comparable in squash treated and not treated with hot water. Analysis of polyamines in zucchini squash showed that putrescine increased with time during storage at 5°C. The putrescine level in hot water treated samples was low initially but increased rapidly during storage at 50C. Temperature conditioned squash showed a similar rate of increase in putrescine as those treated with hot water. Spermidine and spermine levels decreased in all samples during storage at 5°C. However, temperature conditioning as well as hot water treatments maintained higher levels of spermidine and spermine in the skin of zucchini squash.

Determination of the Serum Protein Binding of Oxycodone and Morphine Using Ultrafiltration

Protein binding of oxycodone and morphine in human serum was determined in vitro using ultrafiltration. Binding studies were also performed using both purified human serum albumin and human alpha 1-acid glycoprotein (AAG). Albumin was found to be the major binding protein for both oxycodone and morphine. The serum protein binding of both oxycodone and morphine was independent of drug concentration in the therapeutic range (5-100 ng/ml), but was dependent on protein concentration. In addition, bound fractions of oxycodone and morphine increased with increasing concentrations of both albumin and AAG. At physiological pH and temperature, the mean (+/- SD) serum protein binding of oxycodone was 45.1% (+/- 0.4%) and that of morphine was 35.3% (+/- 0.2%) A decrease in temperature from 37 to 23 degrees C significantly increased the serum protein binding of oxycodone and morphine by 8-9% (p < 0.0001) and 7-10% (p < 0.0001), respectively, indicating the importance of maintaining the temperature at 37 degrees C during protein binding experiments. A reduction in pH from 7.75-8.85 to 7.4 significantly reduced serum protein binding of both oxycodone and morphine by 4-5% (p < 0.0001) and 4-7% (p < 0.0001), respectively. Serum samples, to which known concentrations of oxycodone had been added and which were stored at -20 degrees C, showing a gradual but significant decline (p < 0.0001) in serum protein binding of oxycodone from approximately 45 to 39% during the 4-week storage period.(ABSTRACT TRUNCATED AT 250 WORDS)

REDUCTION OF CHILLING INJURY WITH HIGH- AND LOW-TEMPERATURE CONDITIONING

The severity of chilling injury in zucchini squash stored at 5C than transferred to 20C was reduced with the prestorage treatment of 42C hot water for 30 min. The chilling injury was further reduced when squash were preconditioned at 15C for 2 days after hot water treatment but before the 5C storage. Squash stored at 15C did not develop any symptoms of chilling injury. However, weight loss was most severe in squash stored at 15C. Squash kept at 5C had the least weight loss during the 2-week storage. Weight losses were comparable in squash treated or not treated with hot water. Analysis of polyamines in squash preconditioned with high and low temperatures is in progress. The effect of hot water treatment on the changes of putrescine, spermidine, and spermine and its implication in reducing chilling injury will be discussed.

Reduction of chilling injury in grapefruit and oranges stored at 1°C by prestorage hot dip treatments, curing, and wax application

Chilling injury in Marsh grapefruit during storage at 1�C was reduced 61% by dipping in hot water(50�C) for 2 min before storage. The fungicide thiabendazole (TBZ) at 1000 mg/L applied as a cold dip(14�C) reduced the susceptibility of these fruit to chilling injury by 28% over an 8-week storage period. Susceptibility of Washington navel oranges to chilling injury was reduced 65% after dipping in hot TBZ (50�C) for 2 min. Wax application and prestorage curing for 1 week at 20�C also reduced chilling injury damage. Where there is a risk of chilling injury in fruit to be disinfected against fruit fly, the risk can be reduced by dipping in a hot TBZ suspension at 50�C. A thorough application of wax has also been shown to reduce the I susceptibility of citrus fruit to chilling injury.

Evaluation of biochemical markers (sugar, proline, malonedialdehyde and ethylene) for cold sensitivity in microcuttingsof two coffee species

Microcuttings of coffee ( Coffea arabica L. and Coffea canephora Pierre) were conserved in vitro for 0–20 weeks at various temperatures (12, 17, 22 and 27°C). Survival was generally high, except for C. canephorastored at 12°C. After a transitory increase in fructose and glucose concentration at the beginning of the storage period, the sugar level remained stable. During the first weeks of storage, the quantity of proline increased to twice the initial level for both species at 12°C. A drop in the proline concentration was observed with C. canephora at the end of the storage period at 12°C. Whereas in the case of C.arabica, no modification was noted in the malonedialdehyde (MDA) concentration, its level increased in microcuttings of C. canephora stored at 12°C. This increase was reversible after 10 days at 27°C at the beginning of the storage period, but became irreversible after a 20-week storage duration. Ethylene production started after transfer to 27°C after a 2-week storage period with C. canephora, but after 12 weeks only in the case of C. arabica. This synthesis decreased at the end of the storage period for C. canephora microcutting stored at 12°C. These results indicate that among the four compounds studied, MDA appears as the most reliable indicator of cold sensitivity for the two coffee species studied.

Microbiological and Other Characteristics of Chicken Breast Meat Following Electron-Beam and Sous-Vide Treatments

The combined effects of radiation and sous-vide treatment of chicken breast meat were investigated with respect to survival and growth of Listeria monocytogenes, shelf life, thiamine content, and sensory qualities. Chicken breasts were inoculated with L. monocytogenes 81–861 (105 CFU/g), vacuum-packed, irradiated with electron beam (EB) up to 2.9 kGy, and cooked to an internal temperature of 65.6°C. Sous-vide treatment alone had marginal lethal effect on the L. monocytogenes; the residual inoculum reached 107 CFU/g after 8 weeks at 2°C. However, after the combined treatments of sous-vide and EB at 2.9 kGy, the organism remained undetectable during the 8-week storage period. Parallel studies on uninoculated breast meat revealed that sous-vide samples had a shelf life of less than 6 weeks without EB treatment, whereas samples that were irradiated and then received sous-vide treatment had a shelf life of at least 8 weeks. There was a slight reduction in thiamine levels as a result of the EB treatment, but there was essentially no additional loss of thiamine due to the subsequent sous-vide treatment and storage at 2°C. Electron-beam treatment had very little effect on the odor and flavor of the reheated samples. It was concluded that EB treatment combined with sous-vide treatment can greatly enhance the microbial safety and shelf life of chicken breast meat.

Optisol Corneal Storage Medium

Optisol is an investigational, intermediate-term corneal storage medium containing chondroitin sulfate and dextran to enhance corneal dehydration during storage. We used scanning electron microscopy to grade endothelial cell morphologic characteristics in terms of cell shape, cell borders, cell swelling, and apical holes in pairs of corneas stored in Optisol and Dexsol. Optisolstored corneas showed significantly fewer morphologic changes after 14 days at 4 degrees C than did Dexsol-stored corneas. No significant differences were seen after 1 to 4 days at 26 degrees C. Temperature-reversal analysis showed no significant change in corneal thickness with warming after 2-week storage at 4 degrees C in either medium, although Optisol-stored corneas were significantly thinner than those stored in Dexsol at all times. The results of scanning electron microscopy suggest that preservation at refrigerator temperature for 2 weeks in Optisol is superior to preservation in Dexsol. Both media may be useful in preserving endothelial structure for limited periods at room temperature, which could provide a measure of safety in shipping or storage where refrigeration is unreliable.

Effects of storage on some chemical indices of beef quality

The effects on quality of storing beef under conditions that simulate those prevailing in Nigerian traditional markets and, most probably, in traditional markets in most other developing countries, were examined. The fresh beef samples obtained from the thighs of mature cows were stored for 11 h at 25 ± 3°C, and chemical indices of quality monitored. Chemical indices monitored included total volatile nitrogen (TVN), extract release volume (ERV), free fatty acid (FFA), thiobarbituric acid number (TBA), protein, total fat, insoluble protein, moisture, fatty acid profiles and spectral characteristics. Changes in these indices, generally, indicated loss of quality. Variations in the TBA values of the beef during a 2-week storage period of water activities (a w ) of 0·11, 0·33 and 0·75, respectively, suggest that a w may influence beef lipid quality via oxidation by affecting either the induction period or the overall extent of oxidation.

Effect of cold storage and maturity on the physical and chemical characteristics and volatile constituents of peaches (cv. Cresthaven)

In general, size, weight, soluble solids (SS), sucrose content, SS/TA ratio, volatiles, and Minolta a value increased with increased maturity of unripened fruit. Minolta L and b values, glucose, fructose, and sorbitol contents, and total phenolics did not vary significantly by maturity. Titratable acidity and hue angle decreased with increased maturity. After 4-week storage, significant deterioration probably will occur

Effects of storage and processing on the nutritive value of certain Nigerian foods.

The effects of storage and processing on the nutritive value of two Nigerian foods--raw cowpea (Vigna unguiculata) flour and palm oil, have been investigated. Increased retention of both thiamine and riboflavin as a result of increased water activity (Aw) were recorded for cowpea flour stored for 6 months. A storage temperature of 5 degrees C led to minimal losses of both vitamins in the stored flour. Differences in physico-chemical characteristics were observed between palm oil produced by the traditional method and that produced by a modern commercial method. Increasing Aw led to decreasing loss of unsaturation in the traditionally-produced palm oil during 4-week storage at ambient temperature (25 degrees C).

Effect of Oxygen Transmission Rate of Packaging Films on Color Stability of Vacuum Packaged Chicken Bologna

Abstract Chicken bologna slices were vacuum packaged in five packaging films with oxygen transmission rates of 2 to 55 cc O2 /m2 /24 hr. Samples were evaluated for changes in color during an 8-week storage period at 3 ± 1 C and 180 to 200 ft-c of continuous lighting. No significant (P>.05) color loss or fading of bologna redness was apparent from homogenate evaluations after 8 weeks of lighted display. A decrease in nitroso-heme pigment content of the total sample homogenate occurred, but this decrease was not related to color changes (Judd-Hunter L, a, b values). Surface lightness (L) of bologna slices was least affected by light exposure. Surface redness (+a) and the redness index (a/b ratio) significantly (P

The effect of donor-specific transfusions on rat heart allograft survival.

A rat heart allograft model employing donor-specific transfusions (DSTs) was used to investigate several questions relevant to their clinical usage. The effects of varying blood storage duration (stored vs. fresh), number and timing of DSTs as well as use of concomitant azathioprine and cyclosporine (CsA) were assessed in terms of allograft survival and recipient sensitization. A comparison of stored and fresh-blood DSTs revealed that blood stored for up to 5 weeks was as effective as fresh blood and that a 2-week storage was optimal. Increased storage appeared to be associated with decreased sensitization. Multiple DSTs were more effective than a single DST and the peak effect appeared after six. Transfusions given at the time of transplantation were ineffective. The addition of concomitant (preoperative) azathioprine or CsA resulted in a further decrease in sensitization but also resulted in a dose-dependent diminution of the transfusion effect.

Donor-specific blood transfusions with stored and fresh blood in a rat heart allograft model

Donor-specific transfusions (DSTs) using stored and fresh blood were investigated in a rat heart allograft model. Lewis rats were recipients of preoperative DSTs and cardiac allografts from ACI donors. Blood was stored for 0, 1, 2, 3, 4, and 5 weeks prior to transfusion. Allograft survival and recipient sensitization were recorded. In all DST groups, allograft survival was superior to nontransfused controls ( P < 0.05). Stored blood was equal or better than fresh blood, and a 2-week storage was optimal ( P < 0.05). Storage of 2 weeks or greater resulted in decreased sensitization compared to storage for 1 week or less ( P < 0.05). This study supports the use of stored blood to enhance allograft survival and reduce recipient sensitization.