Typical Storage Conditions Research Articles

Carbon Dioxide Solubility in Beer

The amount of CO2 within a beer is a function of CO2 solubility, which in turn is affected by temperature, containing pressure, and beer composition. Historically, this variable was assessed through empirically derived pressure/temperature charts with the first appearing about 1939. Modern methods often involve empirical or semi-empirical formulas that yield close approximations to the aforementioned charts (at typical storage conditions). Other methods to determine CO2 solubility incorporate additional variables such as extract and alcohol content. Unfortunately, the origin of various pressure-temperature solubility charts contained in ASBC's Methods of Analysis or MBAA's Beer Packaging: A Manual for the Brewing and Beverage Industries, are largely unknown, as are the composition of the beers used to create these charts! This discrepancy results in potentially inaccurate CO2 values for differing beer compositions and is especially problematic when assessing modern methods that incorporate additional parameters. This paper attempts to contrast and compare modern and historical methods while considering the limited CO2 solubility reports in beer and sugar and ethanol solutions. In this paper, the accuracy of CO2 solubility charts and formulas are discussed while considering assumptions reported by the original authors. Finally, modern formulae are used with non-linear optimization techniques to generate the likely composition of the “standard beer” used to construct the original ASBC solubility chart. It appears that a “standard beer” of yesteryear is stronger than an average modern beer with an alcohol content of 4.22% (w/w) and a Real Extract of 5.78°P.

Evaluation on the harm effects of accidental releases from cryo-compressed hydrogen tank for fuel cell cars

Cryogenic compressed hydrogen tank may open new possibilities for onboard storage due to its high energy density and acceptable thermal endurance. As promising hydrogen storage for commercial use, its hazards need comprehensive investigation. This paper studies the consequences of accidental hydrogen releases from cryo-compressed storage and evaluates the cold effects, thermal effects, and overpressure and missile effects. Two typical storage conditions for a fuel cell car are considered, including driving condition and quasi-venting condition after a long-term of parking. Results show that flash fire and vapor cloud explosion can be considered as the leading consequences. Without ignition, catastrophic rupture may be more dangerous than leakages but with ignition the results may vary for different release diameters. For leakages, quasi-venting condition may be more dangerous than driving condition. However, for catastrophic rupture, the results may be not uniformed but depend on whether and when the hydrogen is ignited. Moreover, the influences of wind velocity and atmospheric pressure are also investigated.

Changes in Pore Structure and Connectivity Induced by CO2 Injection in Carbonates: A Combined Pore-Scale Approach

We investigate at the pore scale fluid-rock interactions that occur in the context of carbon dioxide (CO2) storage in saline carbonate aquifers. Brine saturated with super critical CO2 is injected into two carbonate samples (Estaillades limestone and an aquifer sample) at typical storage conditions (9MPa and 50oC). Dry high resolution micro-computed tomography scans are obtained prior to and after the experiments and thepore structure, connectivity and computed flow fields are compared using image analysis and pore-scale modeling techniques. We perform direct simulations of transport properties and velocity fields on the 3Dscans and we extract representative pore-throat networks to compute average coordination number and assess changes in pore and throat size distributions. In this study, we experimentally mimic near wellbore region conditions by injecting fluids at relatively high flow rates. For high Péclet and Damkö hler numbers, experimental observations confirm the formation of highly conductive channels i.e wormholes.A significant increase in porosity and permeability is found with fewer pore and throats after dissolutionwhile the average coordination number does not change significantly. Flow becomes concentrated in the wormhole regions after reactions although a very wide range of velocities is still observed.

Growth and survival of Salmonella in ground black pepper (Piper nigrum)

A four serovar cocktail of Salmonella was inoculated into ground black pepper (Piper nigrum) at different water activity (aw) levels at a starting level of 4–5 log cfu/g and incubated at 25 and at 35 °C. At 35 °C and aw of 0.9886 ± 0.0006, the generation time in ground black pepper was 31 ± 3 min with a lag time of 4 ± 1 h. Growth at 25 °C had a longer lag, but generation time was not statistically different from growth at 35 °C. The aw threshold for growth was determined to be 0.9793 ± 0.0027 at 35 °C. To determine survival during storage conditions, ground black pepper was inoculated at approximately 8 log cfu/g and stored at 25 and 35 °C at high (97% RH) and ambient (≤40% RH) humidity. At high relative humidity, aw increased to approximately 0.8–0.9 after approximately 20 days at both temperatures and no Salmonella was detected after 100 and 45 days at 25 and 35 °C, respectively. Under ambient humidity, populations showed an initial decrease of 3–4 log cfu/g, then remained stable for over 8 months at 25 and 35 °C. Results of this study indicate Salmonella can readily grow at permissive aw in ground black pepper and may persist for an extended period of time under typical storage conditions.

Addition of Omega-3 α-Linolenic Acid to Platelet Apheresis Units Preserves Platelet Activatability Over Time and Reduces Baseline Activation Under Routine Storage Conditions: A Pilot Study

Abstract 3433 Background:Omega-3 fatty acids (W3-FA) have been shown to be cardioprotective by reducing plasmatic triglycerides, atherosclerosis, arrhythmias, inflammation, and thrombosis. We have previously demonstrated that the plant-derived W3-FA a-linolenic acid (ALA) can achieve similar effects as the marine-derived EPA and DHA; it reduced platelet activation and aggregation, atherosclerosis and thrombosis in mouse models. In particular, ALA increased platelet survival by reducing their clearance, thus resulting in an increased platelet count. Hypothesis:To translate this finding to transfusion medicine, we hypothesized that the addition of ALA to platelet apheresis units a) could reduce platelet baseline activation during storage and b) result in a better function/activatability over 5–10 days of storage. Methods:In this pilot study, 4 platelet apheresis units from 2 healthy volunteers were collected according to routine blood bank standards and stored under typical conditions at 22°C on a rocker for 10 days. The units were supplemented with 30 uM ALA (a concentration which can be achieved by dietary intake) or vehicle (ethanol). Samples were analyzed daily over 10 days for impedance aggregometry, thrombin generation, thrombus formation on collagen and adhesion to VWF under high shear conditions (2500 s−1). Receptor expression/activation/cleavage was determined by flow cytometry (GPIb, P-selectin, activated a2bb3 integrin, Annexin V binding) and loss of mitochondrial membrane potential by JC-1 staining. Results:After 10 days of storage, platelets from ALA-treated bags showed a better activatability compared to vehicle-treated bags. Thrombus formation on collagen in the flow chamber at d10 was higher for ALA-treated platelets (covered area: 102.779 um2 vs 68.729 um2) as well as the adhesion to VWF (platelet-covered area: 2072,2 um2 vs 427,3 um2). Thrombin generation (as measured by CAT assay) was also higher for ALA-treated samples on d10 (ETP: 15.5 nm thrombin/min vs <2 nm thrombin/min). Thrombin-induced aggregation was higher for the ALA-treated samples (AUC: 17.1±10.4 vs 3.65±0.21 with 0.25 U/ml thrombin; 59±51 vs 15.35±10.5 with 0.5 U/ml thrombin). ALA reduced GPIb cleavage from the platelet membrane (decrease of surface exposed GPIb: d1=100%, d10= 69±10% vs 63±7%). On the other hand, ALA reduced the spontaneous expression of the active conformation of a2bb3 integrin (1.18 vs 1.94 fold) and the P-selectin expression (0.9 vs 1.20 fold), while the thrombin-induced activatability of these receptors was preserved. ALA also reduced the platelet aggregation in response to collagen and thrombin on d1. Conclusions:The addition of ALA to single donor platelet apheresis units at a concentration which is nutritionally achievable results in preserved platelet activatability and function over time, while it reduces baseline activation under typical storage conditions. Both endpoints appear favorable in transfusion medicine and encourage further evaluation. [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Volumetrics of CO2 Storage in Deep Saline Formations

Concern about the role of greenhouse gases in global climate change has generated interest in sequestering CO(2) from fossil-fuel combustion in deep saline formations. Pore space in these formations is initially filled with brine, and space to accommodate injected CO(2) must be generated by displacing brine, and to a lesser extent by compression of brine and rock. The formation volume required to store a given mass of CO(2) depends on the storage mechanism. We compare the equilibrium volumetric requirements of three end-member processes: CO(2) stored as a supercritical fluid (structural or stratigraphic trapping); CO(2) dissolved in pre-existing brine (solubility trapping); and CO(2) solubility enhanced by dissolution of calcite. For typical storage conditions, storing CO(2) by solubility trapping reduces the volume required to store the same amount of CO(2) by structural or stratigraphic trapping by about 50%. Accessibility of CO(2) to brine determines which storage mechanism (structural/stratigraphic versus solubility) dominates at a given time, which is a critical factor in evaluating CO(2) volumetric requirements and long-term storage security.

Concordance Study: Methods of Quantifying Corn and Soybean Genomic DNA Intended for Real-Time Polymerase Chain Reaction Applications

Quantitative real-time polymerase chain reaction (qPCR) is a technology commonly used for the detection and quantification of genetically engineered (GE) traits in grains and oilseeds. The method involves measuring copy numbers of taxon-specific, endogenous control genes exposed to the same manipulations as trait-specific target genes. Accurate DNA quantification is essential for successful and predictable results with qPCR. A systematic study of seven different DNA quantification methods, incorporating different chemistries and different instrumentation, were evaluated on corn and soy DNA that was extracted using two distinct extraction methods. A time course study showed that corn and soy DNA was stable under typical laboratory storage conditions. CornCTAB and cornQiagen DNA extracts produced statistically similar quantification values when measured by picogreen PG(TD700), PG(Lum20/20), Hoescht(TD700), and Hoescht(Lum20/20) methods, suggesting that these methods can be used interchangeably to quantify DNA in corn samples prior to initiation of qPCR. Soy(Qiagen) provided greater stochastic measurement variability when quantification methods were compared, whereas soyCTAB had statistically significant differences when a PG method was compared to a Hoescht method of DNA quantification. Finally, agarose gel electrophoresis data revealed more pronounced degradation for Qiagen-extracted DNA compared with CTAB extracts in both corn and soy. Consequently, Ct values generated by qPCR suggested that absolute copy numbers of PCR amplifiable targets were not concordant between Qiagen and CTAB DNA extracts. Understanding measurement uncertainty from component steps used in qPCR can contribute toward harmonizing methods for the detection of GE traits in grains and oilseeds.

“Wetting Enhancer” Pullulan Coating for Antifog Packaging Applications

A new antifog coating made of pullulan is described in this work. The antifog properties are discussed in terms of wettability, surface chemistry/morphology, and by quantitative assessment of the optical properties (haze and transparency) before and after fog formation. The work also presents the results of antifog tests simulating the typical storage conditions of fresh foods. In these tests, the antifog efficiency of the pullulan coating was compared with that of two commercial antifog films, whereas an untreated low-density polyethylene (LDPE) film was used as a reference. The obtained results revealed that the pullulan coating behaved as a "wetting enhancer", mainly due to the low water contact angle (∼24°), which in turn can be ascribed to the inherent hydrophilic nature of this polysaccharide, as also suggested by the X-ray photoelectron spectroscopy experiments. Unlike the case of untreated LDPE and commercial antifog samples, no discrete water formations (i.e., droplets or stains) were observed on the antifog pullulan coating on refrigeration during testing. Rather, an invisible, continuous and thin layer of water occurred on the biopolymer surface, which was the reason for the unaltered haze and increased transparency, with the layer of water possibly behaving as an antireflection layer. As confirmed by atomic force microscopy analysis, the even deposition of the coating on the plastic substrate compared to the patchy surfacing of the antifog additives in the commercial films is another important factor dictating the best performance of the antifog pullulan coating.

Stability of dexmedetomidine 4 μg/mL in polypropylene syringes

The results of a study to determine the long-term (up to 14 days) stability of diluted dexmedetomidine kept in polypropylene syringes under typical pharmacy storage conditions are presented. Four samples of dexmedetomidine injection diluted to 4 μg/mL in 0.9% sodium chloride were prepared and divided into 25-mL portions for storage in syringes at ambient room temperature (20-25 °C) with light exposure or under refrigeration (5 °C) in darkness. At 24 and 48 hours, the percentage of the initial dexmedetomidine concentration remaining in all samples was assessed via high-performance liquid chromatography with diode-array detection; further stability testing of the refrigerated samples was performed on days 7 and 14. At each time point, the test samples were visually inspected for color, clarity, and signs of formation of particulate matter. As determined by chromatographic analyses, the samples of diluted dexmedetomidine stored in syringes at room temperature exhibited a loss of drug concentration of <10% over 48 hours; the refrigerated samples exhibited a loss of drug concentration of <5% over 14 days. All of the syringe-stored samples remained clear and colorless on visual inspection for the duration of the study. Dexmedetomidine diluted to 4 μg/mL in 0.9% sodium chloride injection was stable for at least 48 hours at 20-25 °C and 14 days at 5 °C when stored in polypropylene syringes.

Stability of Cholesterol; Cholesterol-5β,6β-Epoxide; Cholesta-3,5-Dien-7- One, and 5α-Cholestane in Solution During Short-Term Storage

Because cholesterol and its oxide products (COPs) are used as standards during analysis, their stability and autoxidation were assessed under typical storage conditions. Individual toluene solutions of cholesterol; cholesterol- 5β, 6β-epoxide; cholesta-3,5-dien-7-one; and 5α-cholestane were prepared and aliquots were stored at 23 ± 2°C, 4°C, and -20°C for 7 days. Samples were removed from storage, dried under nitrogen, derivatized and analyzed using gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. β-sistosterol and 5-colest-ene-7-one were found to be a suitable recovery internal standard and an instrument internal standard, respectively. All compounds in solution had no detectable artifact generation during 7 days of storage; thus, they were stable. Storage temperatures of 23 ± 2°C, 4°C, and -20°C did not affect stability. Chromatograms revealed contaminants and other peaks likely associated with incomplete derivatization of some compounds; potential causes for the unusual lack of derivitization are discussed.

Long-term stability of teicoplanin in dialysis fluid: Implications for the home-treatment of CAPD peritonitis

Abstract The long-term stability of teicoplanin in dialysis solution was determined at various storage temperatures. The investigation was undertaken using dialysis solution (1.36 per cent glucose) containing 25mg/L teicoplanin. Stability under refrigerated conditions (4°C), room temperature (representing typical home storage conditions of 20°C) and body temperature (37°C) was determined in triplicate over a 42 day period. Samples (5ml) from each dialysis bag were taken at 0, 1, 2, 5, 7, 10, 14, 21, 28 and 42 days. Measurement of teicoplanin was by stability-indicating bioassay involving a standard plate technique using spore suspensions of Bacillus subtilis. All bioanalyses were performed in triplicate. Loss of teicoplanin activity of more than 10 per cent was indicative of instability. At 4°C, the mean concentration (±SD) of teicoplanin over the 42-day period was 24.05±1.53mg/L with a coefficient of variation of 6.36 per cent. However, loss in antibiotic activity was observed at the higher temperature storage conditions. At 20°C, a 10 per cent reduction in activity occurred after 25 days' storage; at 37°C it occurred after seven days. Therefore, teicoplanin is stable in dialysis fluid but the storage conditions have a marked effect on shelf-life.

The stability of free‐β human chorionic gonadotrophin and pregnancy‐associated plasma protein‐A in first trimester dried blood spots

To determine the stability of first trimester free-β human chorionic gonadotrophin (free-β hCG) and pregnancy-associated plasma protein-A (PAPP-A) in dried blood spots (DBSs) under typical storage conditions. First trimester maternal blood was spotted onto filter paper and left to dry. DBSs were analysed for PAPP-A and free-β hCG using an AutoDELFIA dual assay at t = 0. Cards were stored at one of - 20 °C, refrigerator temperature, room temperature or 30 °C and reanalysed at set future time points. Free-β hCG was stable (<10% change in concentration) under all temperatures tested for at least 35 days. PAPP-A was stable at - 20 °C and refrigerator temperature for at least 35 days. However, PAPP-A levels decreased by 10% at 4.1 days at room temperature and at 3.9 days at 30 °C. Longer-term storage at - 20 °C and refrigerator temperature showed that both PAPP-A and free-β hCG levels were significantly decreased by 107 and 244 days. Free-β hCG stability is greatly improved in DBS compared to serum storage; however PAPP-A stability is decreased in the DBS medium. Despite this DBS, screening may not necessitate such strict storage and transportation rules compared to serum screening programmes.

Production and Storage of Edible Film Using Gellan Gum

The properties of gellan gum edible membranes under different prepared conditions were studied in this research. Firstly, the results indicated that 0.08% gellan gum treatment can be obtained good tensile strength, moisture resistance and excellent gas-barrier edible films during the drying temperature of 60–70°C. Four typical storage conditions also were tested: refrigerated conditions (0°C), supermarket storage environment (6°C), room temperature (25°C) and high temperature (35°C). The change of gellan gum edible film properties were detected in this study for the further development of high strength gellan gum edible films.

Perspectives on Method Validation: Validation is a Multistep Process with USP Regulatory Guidelines at each Step

<b>Perspectives on Method Validation</b>: Validation is a Multistep Process with USP Regulatory Guidelines at each Step

MULTISCALE MODELLING OF GAS TRANSPORT IN FRUIT IN RELATION TO CA STORAGE DISORDERS

A multiscale gas exchange model was developed to perform in silico experiments to evaluate the effect of external storage conditions, fruit size and maturity on the intra-cellular respiration and risks of occurrence of physiological disorders. Pear fruit was chosen as a model system. The approach consists of interconnected models that describe the transport phenomena at the macro- and the microscale. First, macroscale model simulations of the respiratory gas concentrations in the critical fruit region (region of the lowest and highest O 2 and CO 2 concentration of intact fruits) were performed. This region was considered to be more susceptible to physiological disorders caused by anoxia and high CO 2 partial pressure. Next, the microscale model was applied to compute the corresponding intra-cellular metabolic gas concentration. The in silico study revealed that O 2 concentration of optimally picked pear stored at typical controlled atmosphere condition (2.5 kPa O 2 , 0.7 kPa CO 2 at -1°C) were higher than the Michaelis-Menten constant for cytochrome c oxidase K m,c , the rate limiting enzyme of the respiration pathway. In contrast to small pears, large pears and extreme low O 2 storage conditions lead to O 2 concentrations well below the K m,c . This most probably leads to fermentation and physiological disorders that have been observed under such conditions. Ripening of the fruit increased the risk of physiological disorders since increased respiration resulted in anoxia in the fruit center even at the typical storage conditions.

Dopant-vacancy binding effects in Li-doped magnesium hydride

We use a combination of ab initio calculations and statistical mechanics to investigate the substitution of Li+ for Mg2+ in magnesium hydride (MgH2) accompanied by the formation of hydrogen vacancies with positive charge (with respect to the original ion at the site). We show here that the binding energy between dopants and vacancy defects leads to a significant fraction of trapped vacancies and therefore a dramatic reduction of the number of free vacancies available for diffusion. The concentration of free vacancies initially increases with dopant concentration, but reaches a maximum at around 1 mol% Li doping and slowly decreases with further doping. At the optimal level of doping, the corresponding concentration of free vacancies is much higher than the equilibrium concentrations of charged and neutral vacancies in pure MgH2 at typical hydrogen storage conditions. We also show that Li-doped MgH2 is thermodynamically metastable with respect to phase separation into pure magnesium and lithium hydrides at any significant Li concentration, even after considering the stabilization provided by dopant-vacancy interactions and configurational entropic effects. Our results suggest that lithium doping may enhance hydrogen diffusion hydride, but only to a limited extent determined by an optimal dopant concentration and conditioned to the stability of the doped phase.

A model for gas transport in pear fruit at multiple scales

A two-dimensional multiscale gas exchange model was developed to evaluate the effect of ambient conditions, fruit size, and maturity on intracellular O(2) and CO(2) concentrations in pear fruit via computational analysis. The model consists of interconnected submodels that describe the gas exchange at the macroscopic scale of the fruit and the microscopic scale of the cells. The multiscale model resulted in a comprehensive description of gas exchange at different scales. The macroscale model was used to describe the gas exchange of the fruit under controlled atmosphere conditions while corresponding intracellular concentrations of microstructure tissue were computed from the microscale. Ripening of the fruit increased the risk of physiological disorders, since increased respiration resulted in anoxia in the fruit centre even under typical storage conditions.

Mass spectrometric investigations on lactate adduction to equine myoglobin

Research focused on determining the fundamental mechanisms by which lactate influences color stability has not considered a direct effect of lactate on myoglobin. Thus, the objective of this study was to use Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry to examine lactate adduction to myoglobin. Equine oxymyoglobin and equine carboxymyoglobin (0.15mM) were incubated with sodium lactate (200mM) at 4 degrees C, pH 5.6 in 50mM sodium citrate buffer or at 37 degrees C, pH 7.4 in 50mM sodium phosphate buffer, simulating typical meat storage and physiological conditions, respectively. Controls consisted of myoglobin plus a volume of deionized water equivalent to that used to deliver the lactate treatments. No peaks corresponding to lactate-Mb adducts could be detected in the mass spectra of samples incubated up to 360min at pH 7.4, 37 degrees C or 8days at pH 5.6 and 4 degrees C. Our results suggest that lactate did not form covalent adducts with equine oxy- and carboxy-myoglobin.

Assessment of variation in seed longevity within rye, wheat and the intergeneric hybrid triticale

AbstractSeed shelf-life or longevity is difficult to predict or to measure on a practical time scale. Predictive models suggest that water has the same effect on ageing rate for all seed lots within a species and that initial seed quality is the dominating factor explaining within-species variation. These assumptions are used in ‘accelerated ageing’ or ‘controlled deterioration’ (AA/CD) tests, which are commonly used to predict seed longevity in commercial and research applications. In this study, we describe within-species variation of longevity for seeds of Secale cereale and S. strictum (cultivated rye and its wild progenitor) under typical dry storage conditions of a genebank, and show that initial seed quality is an important, but not sole, factor explaining measured longevity. We also test the correlation of seed longevity, measured under humid and dry conditions, using 50 cultivars of rye, wheat (Triticum aestivum) and the intergeneric cross triticale, to assess how well AA/CD tests predict seed shelf-life during dry storage. Known differences in longevity between wheat and rye were confirmed at all water contents, and triticale seeds demonstrated intermediate behaviour. Longevity measured for humid and dry conditions were weakly correlated when comparisons included all grain types and were not correlated in within-grain-type comparisons. Response to moisture varied among cultivars. These findings do not support assumptions made in seed ageing models that use AA/CD tests. Our results suggest that more traits are involved in the expression of seed longevity than those typically measured in studies of initial seed vigour.

Study on the microbial status of unseasoned ground turkey meat from an EU producer–a new product with risk potential?

1. The aim of this study was to point out potential risks associated with a product new to the market in the European Union: unseasoned minced turkey meat. 2. On 6 d of sampling, minced turkey meat from a large-scale EU producer was analysed at 4 processing stages. 3. The packaged minced meat was examined during 10 d of storage, once using the legally recommended conditions (<+2°C), and then under simulated consumer handling; one batch was stored for 3 d at +2°C then kept for 45 min at 25°C and then stored at +7°C. Microbiological and physical variables were tested on 5 d. 4. Results showed that the mean total aerobic plate count (APC) of the unprocessed material was 3.8 log CfU/g and did not rise significantly, although the temperature rose briefly after the material left the meat chopper. Listeria monocytogenes was the pathogen detected most often, in 7 (14.6%) of 48 samples, followed by Salmonella in one (2.1%). No Campylobacter were found. 5. Initial contamination (APC) of about 4.5 log CfU/g was common in stored minced meat, conforming to European Union Regulations EC 2073/2005 and 1441/2007. Brochothrix thermosphacta and Pseudomonas spp. were the bacteria found most frequently. Under strict maintenance at a storage temperature of +2°C, the maximum microbiological stability of the material was 7 d. Under simulated consumer handling, the microbial counts increased significantly, immediately after transport. 6. Our findings indicate that unseasoned minced turkey meat is a risky, perishable product, especially if the raw material does not have a low APC, is not pathogen-free and is kept under typical consumer handling and storage conditions.