Long-term Storage Temperature Research Articles

Using Fungal and Bacterial Bioagent Formula Antagonists to Combat Fusarium Oxysporum f. sp. Lycopersici Under Greenhouse Conditions

Objective: This study aimed to test fungal and bacterial bioagents as formula antagonists of Fusarium oxysporum f. sp. lycopersici under greenhouse conditions. Methods: The fungal and bacterial formulations' shelf life under different temperatures as well as under growth chamber and greenhouse conditions, as well as their effects on biochemical alterations involved in the induction of plant defense against the causative pathogen were investigated. Results: In-vitro antagonist screening of bacterial and fungal isolates on radial growth, reduction and inhibition percentages revealed that T. harzianum exhibited 45.6% of inhibition followed by B. pumilus with 36.7%. Among the fungal and bacterial bio-agents, the highest effect on disease incidence and efficiency against pathogenic fungus under greenhouse conditions was B. pumilus 27 and 69%, respectively followed by T. harzianum 33 and 62% when applied before pathogen inoculation. Under greenhouse conditions, the effects of bio-fungicides also affected defense enzymes like peroxidase and polyphenol oxidase. The shelf life of the wettable powder formulation of bio-agents under different temperature was very important factor and established that the most suitable temperature for long term storage is 25 ºC for both B. pumilus and T. harzianum. Conclusion: Target application of disease control techniques in tomato plants demonstrated the efficacy of B. pumilus and T. harzianum in reducing Fusarium wilt. These results pave the way for the development of bio-agents that can replace fungicides in agriculture, offering a practical substitute.

OPTIMIZATION OF DRIED BLOOD SPOT ASSAYS FOR HEPATITIS B VIRUS SURFACE ANTIBODY QUANTIFICATION.

Dried blood spot (DBS) cards can be used as an alternative sample collection method to plasma, however, there is no optimized elution protocol for DBS cards specifically for hepatitis B surface antibody (anti-HBs) testing. The study aimed to develop a DBS elution protocol for anti-HBs quantification. Our study sought to determine the ideal phosphate-buffered saline (PBS) buffer volume to use by comparing three PBS volumes (300uL, 450uL, and 500uL), and the optimal time to agitate DBS discs on a plate shaker (1hr, 2hrs, 3hrs, and 4hrs) to yield DBS anti-HBs concentrations that are comparable to corresponding plasma anti-HBs concentrations. The optimal DBS storage temperature (25°C, -20°C, and -80°C) was investigated to determine the ideal long-term storage temperature of the cards. Residual samples were used for optimization (2019-2021). A total of 50 DBS-plasma pairs was used throughout the study, with plasma anti-HBs concentrations being used as the golden standard to compare. The analysis of results was carried out by determining the p-values of the Wilcoxon sign rank. A two-way analysis of variance (ANOVA) was also performed to determine the impact of PBS elution volumes, elution time, and storage temperature on the anti-HBs concentration of DBS samples on STATA Version 15.0. No statistically significant difference between the DBS-plasma anti-HBs pairs was observed when using 450 or 500uL of PBS buffer and when samples were agitated for 3 hours (p=0.594, p=0.499 respectively). The optimal storage temperature for DBS cards was 25°C because the results showed no statistically significant difference between DBS-plasma anti-HBs titers (p=0.594). The two-way ANOVA analysis showed that elution volumes and time had no statistically significant impact on the DBS anti-HBs concentrations, p=0.948 and p=0.381 respectively. Storage temperature had a statistically significant impact on the DBS anti-HBs concentrations, p=0.002. The optimized DBS elution protocol for anti-HBs quantification will help monitor vaccine efficacy in infants due to the low sample volumes required compared to plasma and also can be used for anti-HBs testing in resource-limited areas around the country.

Integrative Phytohormone and Transcriptome Analyses Reveal the Inhibitory Mechanism of Ethylene on Potato Tuber Sprouting at Room Temperature

As a commercial potato sprout suppressant, ethylene (Eth) is usually used under a low temperature for long-term storage of potato tubers. However, in many cases, potato tubers are usually transferred from a refrigeration house and sold at room temperature. In the present research, Eth’s inhibitory effects on tuber sprouting at room temperature were investigated. The potential molecular mechanisms of Eth-induced sprout suppression were revealed by phytohormone and transcriptome analyses. Results showed that exogenous Eth significantly suppressed sprout growth in potato tubers during two weeks of storage. The endogenous plant hormone levels of abscisic acid (ABA) and auxin (Aux) were markedly reduced by Eth treatment. Transcriptomic analysis revealed that more transcriptional changes occurred in the early stage of sprouting. The differentially expressed genes (DEGs) assigned to the pathways of plant hormone signal transduction, photosynthesis, starch and sucrose metabolism and phenylpropanoid biosynthesis, which were closely associated with sprouting, were extensively down-regulated by Eth treatment. In addition, the heat map of six hormone signal transduction pathways showed that the expression of most DEGs annotated into the Aux signal transduction pathway was suppressed by Eth treatment, while the expression of many DEGs annotated as ETR (Eth receptor) and ERF1/2 (Eth-responsive transcription factor 1 and 2) in the Eth signal transduction pathway was enhanced by Eth treatment. Taken together, our results indicated that Eth-induced sprout inhibition might be closely related to the suppression of internal Aux production and signal transduction and the activation of Eth signal transduction.

Cryogenic vacuum valve with actuation times down to 50 ms.

We have conceived, built, and operated a cryogenic vacuum valve with opening and closing times as short as 50ms that can be used in strong magnetic fields and across a broad range of duty cycles. It is used to seal a cryogenic Penning trap at liquid-helium temperature for long-term storage of highly charged ions in a vacuum better than 10-15 hPa from a room-temperature ion beamline at vacuum conditions around 10-9 hPa. It will significantly improve any experiment where a volume at the most extreme vacuum conditions must be temporarily connected to a less demanding vacuum during repeated experimental cycles. We describe the design of this valve and show measurements that characterize its main features.

A K-17 serotype specific Klebsiella phage JKP2 with biofilm reduction potential

Klebsiella pneumoniae is an opportunistic pathogen responsible for nearly one-third of all Gram-negative infections. Increasing antibiotic resistance has pushed scientists to look for alternative therapeutics. Bacteriophages have emerged as one of the promising alternatives. In the current study, the Klebsiella phage JKP2 was isolated from a sewage sample and characterized against the K-17 serotype of K. pneumoniae. It produced bulls-eye-shaped clear plaques and has a latent period of 45 min with a burst size of 70 pfu/cell. It remained stable at tested pH (5 to 10) and temperatures (37 to 60 °C). Its optimum temperature for long-term storage is 4 °C and -80 °C. The JKP2 showed its infectivity against the K. pneumoniae K-17 serotype only. It controlled planktonic cells of K. pneumoniae 12 h post-incubation. At MOI-1, it efficiently eliminated 98% of 24 and 96% of 48-hour-old biofilm and 86% and 82% of mature biofilm of day 3 and 4, respectively. The JKP2 has an icosahedral capsid of 54 ± 0.5 nm with a short, non-contractile tail, measuring 12 ± 0.2 nm. It possesses a double-stranded DNA genome of 43.2 kbp with 54.1% GC content and encodes 54 proteins, including 29 with known functions and 25 with unknown functions. JKP2 was classified as Drulisvirus within the Autographiviridae family. It uses a T7-like direct terminal repeat strategy for genome packaging. JKP2 can be applied safely for therapeutic purposes as it does not encode an integrase or repressor genes, antibiotic resistance genes, bacterial virulence factors, and mycotoxins.

Short- and Long-Term Stability of Aromatic Amines in Human Urine.

Several aromatic amines (AAs) are established by the International Agency for Research on Cancer as carcinogenic (group 1) or probable/possible carcinogens to humans (group 2A/2B). AAs can be found in mainstream and sidestream smoke from combustible tobacco products, as well as in certain environmental pollution and occupational exposure from several chemical industry sectors. Exposure to AAs can be estimated by measuring their concentrations in urine; however, information about the short-term and long-term stabilities of AAs in urine need to be characterized before conducting large-scale population studies on AA exposure and the potentially harmful effects of AA exposure. In this report, the storage stability of o-toluidine, 2,6-dimethylaniline, o-anisidine, 1-aminonaphthalene, 2-aminonaphthalene, and 4-aminobiphenyl fortified in pooled, filtered, non-smokers' urine is analyzed by isotope dilution gas chromatography-triple quadrupole mass spectrometry (ID GC-MS/MS). The six AAs were measured in urine samples stored at ~20 °C (collection temperature), 4 °C and 10 °C (short-term transit temperatures), and -20 °C and -70 °C (long-term storage temperatures) over a 10-day period. All six analytes were stable for 10 days at transit and long-term storage temperatures but showed reduced recovery at 20 °C. The instability of the target AAs at 20 °C suggests that immediate storage of freshly voided urine at low temperatures is needed to attenuate degradation. A subset of the urine samples was analyzed following a longer storage duration at -70 °C: all AAs were stable for up to 14 months at this temperature. The stability of the six AAs in urine samples can be maintained at the various temperature levels and storage times expected in a typical study set.

Influence of long-term storage temperatures and sodium fluoride preservation on the stability of synthetic cathinones and dihydro-metabolites in human whole blood

PurposeSynthetic cathinones, one of the largest groups of new psychoactive substances, represent a large analytical and interpretative challenge in forensic laboratories. Of these is the synthetic cathinones’ instability in different biological samples, which may lead to drug concentration discrepancies when interpreting toxicological findings. In this study, the stability of a panel of synthetic cathinones and their dihydro-metabolites (n = 26) together with internal standard was monitored in human whole blood stored at various temperatures over 6 months. The influence of sodium fluoride as a preservative in blood collection tubes was also investigated.MethodsSamples were extracted using a two-step liquid-liquid extraction technique, and analyzed using a validated liquid chromatography–tandem mass spectrometry method following recommendations of published guidelines.ResultsThe influence of temperature over analytes’ stability was an important element in whole blood samples, with − 40 °C being the best storage temperature for all tested analytes. Sodium fluoride did not significantly affect the stability of cathinones except at room temperature. Dihydro-metabolites displayed better stability in whole blood samples and remained detectable for a longer period of time under all tested conditions.ConclusionsThe data suggest that samples containing synthetic cathinones should be analyzed immediately, if possible. Alternatively, whole blood samples should be stored frozen (at − 40 °C or lower); however, (quantitative) results should be interpreted with caution after long-term storage. The data also promote the use of dihydro-metabolites as biomarkers for synthetic cathinones intake, as these reduced metabolites may be detected for longer period of time when compared with parent drugs in whole blood samples.

Deep-Freezing Temperatures During Irradiation Preserves the Compressive Strength of Human Cortical Bone Allografts: A Cadaver Study.

Gamma irradiation, which minimizes the risk of infectious disease transmission when human bone allograft is used, has been found to negatively affect its biomechanical properties. However, in those studies, the deep-freezing temperature during irradiation was not necessarily maintained during transportation and sterilization, which may have affected the findings. Prior reports have also suggested that controlled deep freezing may mitigate the detrimental effects of irradiation on the mechanical properties of bone allograft. Does a controlled deep-freezing temperature during irradiation help preserve the compressive mechanical properties of human femoral cortical bone allografts? Cortical bone cube samples, each measuring 64 mm3, were cut from the mid-diaphyseal midshaft of five fresh-frozen cadaver femurs (four male donors, mean [range] age at procurement 42 years [42 to 43]) and were allocated via block randomization into one of three experimental groups (with equal numbers of samples from each donor allocated into each group). Each experimental group consisted of 20 bone cube samples. Samples irradiated in dry ice were subjected to irradiation doses ranging from 26.7 kGy to 27.1 kGy (mean 26.9 kGy) at a deep-freezing temperature below -40°C (the recommended long-term storage temperature for allografts). Samples irradiated in gel ice underwent irradiation doses ranging from 26.2 kGy and 26.4 kGy (mean 26.3 kGy) in a freezing temperature range between -40°C and 0°C. Acting as controls, samples in a third group were not subjected to gamma irradiation. The mechanical properties (0.2% offset yield stress, ultimate compression stress, toughness, and the Young modulus) of samples from each group were subsequently evaluated via axial compression loading to failure along the long axis of the bone. The investigators were blinded to sample group during compression testing. The mean ultimate compression stress (84 ± 27 MPa versus 119 ± 31 MPa, mean difference 35 [95% CI 9 to 60]; p = 0.005) and toughness (3622 ± 1720 kJ/m3 versus 5854 ± 2900 kJ/m3, mean difference 2232 [95% CI 70 to 4394]; p = 0.009) of samples irradiated at a higher temperature range (-40°C to 0°C) were lower than in those irradiated at deep-freezing temperatures (below -40°C). The mean 0.2% offset yield stress (73 ± 28 MPa versus 109 ± 38 MPa, mean difference 36 [95% CI 11 to 60]; p = 0.002) and ultimate compression stress (84 ± 27 MPa versus 128 ± 40 MPa, mean difference 44 [95% CI 17 to 69]; p < 0.001) of samples irradiated at a higher temperature range (-40°C to 0°C) were lower than the nonirradiated control group samples. The mean 0.2% offset yield stress (73 ± 28 MPa versus 101 ± 28 MPa, mean difference 28 [95% CI 3 to 52]; p = 0.02; effect size = 1.0 [95% CI 0.8 to 1.2]) of samples irradiated at higher temperature range (-40°C to 0°C) were no different with the numbers available to those irradiated at deep-freezing temperature. The mean toughness (3622 ± 1720 kJ/m3 versus 6231 ± 3410 kJ/m3, mean difference 2609 [95% CI 447 to 4771]; p = 0.02; effect size = 1.0 [95% CI 0.8 to 1.2]) of samples irradiated at higher temperature range (-40°C to 0°C) were no different with the numbers available to the non-irradiated control group samples. The mean 0.2% offset yield stress, ultimate compression stress, and toughness of samples irradiated in deep-freezing temperatures (below -40°C) were not different with the numbers available to the non-irradiated control group samples. The Young modulus was not different with the numbers available among the three groups. In this study, maintenance of a deep-freezing temperature below -40°C, using dry ice as a cooling agent, consistently mitigated the adverse effects of irradiation on the monotonic-compression mechanical properties of human cortical bone tissue. Preserving the mechanical properties of a cortical allograft, when irradiated in a deep-freezing temperature, may have resulted from attenuation of the deleterious, indirect effects of gamma radiation on its collagen architecture in a frozen state. Immobilization of water molecules in this state prevents radiolysis and the subsequent generation of free radicals. This hypothesis was supported by an apparent loss of the protective effect when a range of higher freezing temperatures was used during irradiation. Deep-freezing temperatures below -40°C during gamma irradiation may be a promising approach to better retain the native mechanical properties of cortical bone allografts. A further study of the effect of deep-freezing during gamma radiation sterilization on sterility and other important biomechanical properties of cortical bone (such as, tensile strength, fracture toughness, and fatigue) is needed to confirm these findings.

The Effect of Different Freezing Rates and Long-Term Storage Temperatures on the Stability of Sliced Peaches.

The purpose of this research was to determine if freezing rates and holding temperatures influence peach quality during short- and long-term frozen storage. Fresh peaches (Prunus persica) were purchased locally, sliced, dipped in 2% ascorbic acid then drained, and packaged. The study was divided into two experiments, one to determine the effect of the freezing rate on peach quality and the second to determine the effect of frozen holding temperatures on peach quality. For the freezing rate experiment, freshly packaged peaches were placed in freezers at different temperatures (-7°C, -12°C, -18°C, -29°C, and -77°C) then removed for testing when the core temperature of the peaches reached the temperature of all freezer temperatures. The second experiment determined the long-term holding effect on quality using both fresh and prefrozen peaches held at -7°C, -12°C, -18°C, -29°C, and -77°C through 360 days. Quality measurements included freeze thaw and weight loss, lightness, firmness, moisture content, ascorbic acid equivalent antioxidant capacity (AAEAC), hexanal detection using gas chromatography (GC), scanning electron microscopy (SEM), and sensory evaluation. During the freezing phase (experiment 1), peach weight loss and surface ice crystal pore size significantly decreased with increased freezing rates. Peaches held at -77°C and -29°C maintained overall quality to a greater degree than the higher holding temperatures. However, all samples enzymatically browned when thawed; therefore, frozen peaches may best if used in the frozen state or in applications where appearance is a critical factor. In general, fresh and prefrozen peaches were not acceptable by the sensory panelists after 270 days of frozen storage.

A Pyroxenic View on Magma Hybridization and Crystallization at Popocatépetl Volcano, Mexico

The Popocatepetl Volcanic Complex (PVC) is an active arc volcano located in Central Mexico, 70 km southeast of Mexico City. Current models of the PVC’s plumbing system and magma petrogenesis are largely based on the study of isolated Plinian eruptions in the past 23.5 ka and present-day Vulcanian activity, while voluminous effusive summit and flank eruptions remain underrepresented. Here, we present a detailed petrological characterisation focussed on ortho- and clinopyroxene in six effusive flank eruptions and two Plinian eruptions of the PVC during the last ~14.1 ka. Texturally and compositionally defined pyroxene populations facilitate novel approaches to constraining magmatic temperatures and deconvolving crystallisation histories. At least two inter-connected magma reservoirs are present in the mid-to upper crust beneath the PVC: (1) a magnesian andesitic reservoir crystallising high-Mg orthopyroxene (Mg# 79–90) + clinopyroxene (Mg# 82–91) + Cr-spinel ± sulfide at temperatures of 1000–1115°C, and (2) a more evolved, shallower magma reservoir crystallising plagioclase (An50–28) + low-Mg orthopyroxene (Mg# 56–71) + clinopyroxene (Mg# 64–79) + magnetite + ilmenite + apatite ± sulfide at a long-term storage temperature of ~970°C. These mid- to upper crustal magma reservoirs are periodically recharged with a hydrous, high-Mg basaltic mantle melt that crystallised fosteritic olivine (Fo82–89) + Cr-spinel + low-Ca clinopyroxene with elevated Al2O3 (≤6 wt. %) in the lower- to mid-crust at 1080–1220°C. Short- and long-term melt and crystal hybridisation is the primary driver producing the diverse crystal cargo and restricted whole-rock compositions that characterise effusive and explosive eruptions of the PVC in the last ~14.1 ka. Injections of the magnesian andesite into the evolved reservoir produce transient melts crystallising hybrid rims around pre-existing pyroxene and plagioclase crystals. Crystals are subsequently stored in a heterogeneous mush comprising multiple generations of crystals dominated by injected pyroxene of mafic origin. The majority of mafic pyroxene crystals (≤78 %) were stored in the evolved reservoir for centuries to millennia, resulting in near-complete diffusive overprinting of the mafic compositions. Magma injections from depth frequently remobilise the crystal mush and may lead to effusive and explosive eruptions of hybridised PVC andesites and dacites.

Exploration of temperature and shelf-life dependency of the therapeutically available Insulin Detemir

PurposeInsulin, in typical use, undergoes multiple changes in temperature; from refrigerator, to room temperature, to body temperature. Although long-term storage temperature has been well-studied, the short term changes to insulin are yet to be determined.Insulin detemir (IDet) is a clinically available, slow-acting, synthetic analogue characterised by the conjugation of a C14 fatty acid. The function of this modification is to cause the insulin to form multi-hexameric species, thus retarding the pharmacokinetic rate of action. In this investigation, the temperature dependence properties of this synthetic analogue is probed, as well as expiration. MethodsDynamic light scattering (DLS) and viscometry were employed to assess the effect of temperature upon IDet. Mass spectrometry was also used to probe the impact of shelf-life and the presence of certain excipients. ResultsIDet was compared with eight other insulins, including human recombinant, three fast-acting analogues and two other slow-acting analogues. Of all nine insulins, IDet was the only analogue to show temperature dependent behaviour, between 20 °C and 37 °C, when probed with non-invasive backscatter dynamic light scattering. Upon further investigation, IDet observed significant changes in size related to temperature, direction of temperature (heated/cooled) and expiration with cross-correlation observed amongst all 4 parameters. ConclusionsThese findings are critical to our understanding of the behaviour of this particular clinically relevant drug, as it will allow the development of future generations of peptide-based therapies with greater clinical efficacy.

DETERMINATION OF PROPOSED MAXIMUM RESIDUE LIMIT OF DELTAMETHRIN IN BLACK PEPPER (PIPER NIGRUM L.)

Residue trials of deltamethrin in black pepper (Piper nigrum) were conducted to estimate the maximum residue limit (MRL). Five residue trials were conducted at three commercial growers’ plots in Johor, Perak and Sarawak (Malaysia). The study plots contained 120 mature pepper vines which were selected and treated with deltamethrin using the manufacturer’s recommended rate (0.01 kg a.i./ha). The insecticide was applied with a motorized sprayer on monthly intervals. Green pepper berries samples (500g) were randomly collected from the plots at 1, 3, 5 and/or 7 days after the last spray. Analytical procedure of deltamethrin extraction was validated prior to actual analysis. Satisfactory recoveries ranging from 86.2% to 110.2% were obtained for the fortified pepper berries samples. The limits of detection and limits of quantification for deltamethrin were 0.521 μg kg−1 and 1.63 μg kg−1, respectively. Results showed that deltamethrin residues were at the low level with the residue value ranging between <0.08 mg/kg to 0.032 mg/kg. Dissipation of deltamethrin in black pepper berries followed first-order kinetics, and the mean half-lives was 3.2 days after the last treatment. The results also indicated that pepper berries could be safely consumed after 5 days of application. The determined value of proposed MRL for deltamethrin was 0.5 mg/kg. The Dietary Intake Assessment based on Malaysian Food Consumption Pattern confirmed that the proposed MRL concentration will not cause health risks to consumers. Results obtained also showed that all the pesticide residue were stable at -20oC and did not show any significant decrease or increase in the pesticide levels with the degradation percentage of 2.6% indicated that this was the recommended temperature for long term storage.

Reduction Interpolation Function for Determining The Rheological Properties of Bile In Farm Animals To Increase The Entrepreneurial Activity of The Agricultural Sector

Aim of the study: In this work, the density and viscosity of bile extract of cattle are determined experimentally, depending on the evaporation time, its humidity and temperature. These parameters are used to determine the optimal evaporation temperature for long-term storage of bile extract. Methodology: During the experiment, an isothermal process occurs. Methods for interpolating experimental data with splines are considered. A computer program was developed for interpolating the bicubic spline function experimentally obtained values of density and viscosity depending on the time and humidity of the bile extract. Conclusion: The interpolated results of the experiments are presented as graphs of spatial functions using the SURFER graphical editor.

Determination of optimum temperature for long-term storage and analysis of ripening-related genes in ‘Rainbow Red’ kiwifruit

Kiwifruit is considered a climacteric fruit since exogenous ethylene induces ripening-associated changes. However, we previously reported that low temperature modulated ripening in kiwifruit since ripening occurred faster during storage at 5°C compared to 20°C, in the absence of any detectable ethylene. It is therefore not clear which temperature is suitable for long-term storage of kiwifruit. The purpose of this study was to determine the optimum temperature for long-term storage, and analysis of ripening-related genes in 'Rainbow Red' kiwifruit. Kiwifruit were harvested at commercial maturity, and stored at either 0, 2, 5 or 22°C in ethylene-free chambers. During storage, incidence of fruit deterioration and changes in fruit firmness, soluble solids concentration (SSC) and titratable acidity (TA) were monitored at 4-week intervals. Real-time PCR was also conducted to analyze the changes in expression of selected ripening-related genes. Incidence of fruit fast senescence and deterioration was high at 22°C, so kiwifruit could only be stored for a maximum of 8 weeks. Nevertheless, healthy fruit at 22°C remained firm and maintained high TA for 8 weeks. The incidence of ethylene-producing fruit, and consequent fast senescence, was greatly reduced at 5°C, while it was completely suppressed at 0 and 2°C. Fruit at 5°C decreased in firmness and TA faster, attaining eating-ripe quality within 8 weeks. At 2°C, fruit decreased in firmness and TA gradually, achieving eating-ripe quality after 12 weeks. Conversely, fruit at 0°C maintained higher firmness and TA, and did not attain eating-ripe quality even after 12 weeks. SSC increased at all storage temperatures, although the lowest levels were observed in fruit at 0°C. Real-Time PCR analysis revealed that cell-wall-modifying genes (AcPG, AcPL2, AcEXP1 and AcXET2) and carbohydrate-metabolism-associated genes (Acβ-AMY1 and Acβ-AMY2) were markedly induced in fruit at 5°C. Overall, these results indicate that 0°C is the suitable temperature for long-term storage of kiwifruit, while 2°C is suitable for medium-term storage. For short-term storage, 5°C can be recommended.

Effects of Deep Freezing Temperature for Long-term Storage on Quality Characteristics and Freshness of Lamb Meat.

This study investigated the effects of deep freezing and storage temperature (–50°C, –60°C, and –80°C) on the quality and freshness of lamb. To compare the qualities of deep frozen and stored lamb, fresh control and normal freezing conditions (–18°C) were adopted. As quality and freshness parameters, drip loss (thawing loss and cooking loss), water-holding capacity (WHC), texture profile analysis (TPA), thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVBN) were evaluated during 5 months of storage. Temperature influenced the drip loss and WHC, and deep freezing minimized the moisture loss during frozen storage compared to the normal freezing condition. Lamb frozen and stored at deep freezing temperature showed better tenderness than that stored in normal freezing conditions. In particular, lamb frozen at lower than –60°C exhibited fresh lamb-like tenderness. Regardless of temperature, evidence of lipid oxidation was not found in any frozen lamb after 5 months, while TVBN was dependent on the applied temperature. Therefore, this study demonstrated that deep freezing could potentially be used to maintain freshness of lamb for 5 months. From the quality and economic aspects, the freezing and storage condition of –60°C is estimated as the optimum condition for frozen lamb.

Effect of storage on quality attributes of lactic-acid-fermented mulberry juice subjected to combined pulsed light and ultrasonic pasteurization treatment

Quality attributes of long-term stored fruit juice are susceptible to change. Therefore, it is of paramount importance to assess the rate of change in the quality parameters of processed fruit juices during storage. The objective of this study was to assess the effect of storage on brix, pH, chromatic parameters, phenolic, antioxidant activities as well as microbial shelflife of lactic-acid-fermented mulberry juice subjected to combine pulsed light and ultrasonic treatment. The non-thermal treated fermented mulberry juice was kept in a plastic bottle and store at 5 and 25 °C. The changes in the quality parameters were assessed for a period of 210 days. The results revealed that, obrix, phenolic concentrations, antioxidant activities and chromatic parameters decreased during the storage period. The variations in these parameters were relatively less pronounced at 5 °C but were considerable at 25 °C. The juices were considered microbiologically unacceptable after 120 and 180 days storage at 25 and 5 °C respectively based of the European Union legislation (EC) No 2073/2005. Therefore, the best temperature for long-term storage of pulsed light-ultrasonic treated lactic-acid-fermented juice was 5 °C with microbial shelflife of 180 days.

Long-Term Stability of Volatile Nitrosamines in Human Urine

Volatile nitrosamines (VNAs) are established teratogens and carcinogens in animals and classified as probable (group 2A) and possible (group 2B) carcinogens in humans by the IARC. High levels of VNAs have been detected in tobacco products and in both mainstream and sidestream smoke. VNA exposure may lead to lipid peroxidation and oxidative stress (e.g., inflammation), chronic diseases (e.g., diabetes) and neurodegenerative diseases (e.g., Alzheimer's disease). To conduct epidemiological studies on the effects of VNA exposure, short-term and long-term stabilities of VNAs in the urine matrix are needed. In this report, the stability of six VNAs (N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosopiperidine, N-nitrosopyrrolidine and N-nitrosomorpholine) in human urine is analyzed for the first time using in vitro blank urine pools fortified with a standard mixture of all six VNAs. Over a 24-day period, analytes were monitored in samples stored at ∼20°C (collection temperature), 4-10°C (transit temperature) and -20 and -70°C (long-term storage temperatures). All six analytes were stable for 24 days at all temperatures (n = 15). The analytes were then analyzed over a longer time period at -70°C; all analytes were stable for up to 1 year (n = 62). A subset of 44 samples was prepared as a single batch and stored at -20°C, the temperature at which prepared samples are stored. These prepared samples were run in duplicate weekly over 10 weeks, and all six analytes were stable over the entire period (n = 22).

The effects of pre-analysis sample handling on human plasma amino acid concentrations

BackgroundThe accurate and reliable quantification of amino acid concentrations in human plasma is important for the investigation of a number of diseases. However, few systematic studies investigating the changes in amino acid concentrations related to blood collection and storage conditions have been completed. MethodsBlood samples were collected with EDTA-Na2 from 3 healthy volunteers and subjected to a number of different treatments; hemolysis, temperature after blood collection, time from blood collection to cooling, the influence of platelets, long term storage conditions, and repeated freeze–thaw cycles. Changes in the concentrations of 22 amino acids were determined using an Amino Acid Analyzer. ResultsOf the conditions influencing sample stability between blood collection and amino acid analysis, hemolysis, temperature after blood collection, and long-term storage at −20°C affected the concentrations of 11 amino acids. Time from blood collection to cooling, platelet contamination and repeated freeze–thaw cycles altered the levels of 4 amino acids. ConclusionsWe observed changes in amino acid concentrations relating to blood collection and storage conditions. If attention is paid to 4 key factors (hemolysis, temperature immediately following blood collection, time from collection to cooling, and long-term storage temperature) 19 amino acids can be reliably quantified.

The effect of storage temperature and duration on northern red oak acorn viability and vigour

Three separate collections of Ontario sources of northern red oak (Quercus rubra L.) acorns were made to determine the effects of long-term cold storage at +2°C, −1°C, and −2°C on their viability and vigour. We measured acorn moisture content, percent germination during storage, speed of germination and total germination values, root regrowth of seeds that germinated in storage, incidence of fungal contamination, and condition of ungerminated acorns. Viability and vigour peaked six to 12 months after acorns were placed in storage, but decreased with continued storage. After 18 months in storage, ≥60% of the acorns germinated in four of the five seedlots tested and, after 30 months in storage, ≥53% of the acorns germinated in three of the five seedlots tested. Acorn viability was only minimally affected by storage temperature; however, since temperatures above −2°C allowed acorns to germinate during storage, the preferred long-term storage temperature was −2°C. Our results suggest that, assuming proper storage conditions, most red oak seedlots will maintain relatively high germination levels when stored at −2°C for 18 months. Seedlots with particularly high initial germination and vigour may be successfully stored for up to 30 months.

Further Evaluation of Somah: Long-Term Preservation, Temperature Effect, and Prevention of Ischemia-Reperfusion Injury in Rat Hearts Harvested After Cardiocirculatory Death

ObjectiveTo identify and evaluate the ideal temperature for long-term storage of hearts from donation after cardiocirculatory death, in the novel organ preservation solution Somah. MethodsDCD hearts from Sprague-Dawley rats were harvested after 30 minutes of euthanasia, preserved in Somah at 4°C, 10°C, 21°C, or 37°C for 24 hours and then reperfused with blood:Somah (3:1) perfusate at 37°C for 30 minutes. Myocardial biopsies were taken during storage and before and after reperfusion to assess the structural and functional viability of tissue using multiphoton imaging, biochemistry, and immunofluorescence. ResultsMyocyte viability, determined by Live-Dead and esterase assays, was similar at 4°C, 10°C, and 21°C (193, 198 and 217 normalized fluorescence counts [NFC]) with a significant decrease at 37°C (131 NFC). Upon reperfusion, esterase activity was enhanced in DCD hearts stored in Somah at 21°C but noticeably decreased at all other temperatures. High-energy adenosine triphosphate/creatine phosphate (ATP/CP) syntheses and the expression of structural/contractile proteins was well preserved at 21°C, both after 24-hour storage and upon reperfusion. In contrast, hearts stored at all other temperatures demonstrated variable degenerative changes, loss of protein expression, and/or deranged ATP/CP synthesis after 24 hours of storage and/or upon reperfusion. ConclusionThe robust maintenance of structural/functional integrity of cardiac tissue and the preservation of protein expression and cellular energy metabolism in DCD hearts after long-term preservation at subnormothermic temperature suggests that 21°C is ideal for long-term storage of DCD hearts in Somah solution.