Strict Temperature Control Research Articles

Risk of infection with Salmonella and Listeria monocytogenes due to consumption of ready-to-eat leafy vegetables in Brazil

The current study was carried out to estimate the risks of infection due to consumption of RTE vegetables contaminated with Salmonella and Listeria monocytogenes in Brazil. The risk assessment model was composed of five different modules comprising the retail-consumption steps. Scenarios were simulated using prevalence and concentration levels reported in RTE vegetables in Brazil as well as considering values 10 times lower. In addition, scenarios in which temperature during transportation and storage are maintained below 5 °C were also evaluated. Models built in Excel spreadsheets were run (100,000 iterations) using @Risk software. The two outputs were risk of infection per month (probability of infection per month due to consumption of RTE vegetables) and number of infections per month (number of people that consumed RTE vegetables and get infected per month). The QMRA models predicted that the mean risk of Salmonella infection per month is 5.7E-03, while the mean risk of infection for L. monocytogenes was 8.1E-06 per month. The reduction of prevalence of Salmonella from 1.7% to 0.17% resulted in a decrease of risk of infection per month by about 6 times. In the case of L. monocytogenes, the reduction of prevalence from 2.2% to 0.22% resulted in decrease of risk of infection from 8.1E-06 to 1.0E-06. The risks and number of cases predicted in scenarios in which temperature was kept below 5 °C were reduced for both pathogens studied when compared to scenarios where this was not the case. The scenario where prevalence and concentration of pathogens was reduced and where temperature was <5 °C led to the lowest number of infections due by Salmonella and L. monocytogenes (187 and 3.3E-05 cases, respectively). The results suggest that effective mitigation strategies need to be adopted. The strict control of temperature during transportation, storage and consumption was more effective to reduce risk and number of cases due to L. monocytogenes than to Salmonella. More data is needed to improve the accuracy of risk assessment models developed.

Measurement of electric field enhanced optical absorption in hydrogenated amorphous silicon

AbstractOptical properties of amorphous semiconductors are influenced by applied or built‐in electric fields. Measurements of the optical absorption change of device grade intrinsic hydrogenated amorphous silicon were performed indirectly by measuring the optical transmission of the samples with and without an applied DC electric field. Effects of ambient temperature changes were limited by strict control of the ambient temperature. Temperature effects caused by self‐heating of the samples were compensated in two different ways to ensure the validity of the results. The influence of temperature change on optical absorption was identified and compensated by the analysis of measurements of multiple samples with different levels of power dissipation brought about by sample conductivity variations. The second method of temperature compensation consisted of determining the temperature change of each sample during the measurements, modelling absorption coefficient change caused by the temperature change and by subtracting the calculated absorption change caused by the temperature change from the measured absorption change. Results of both methods of temperature compensation are in good agreement. The obtained results are also in agreement with the results of other researchers up to photon energies slightly above the mobility edge, where our measurements exhibit a slightly different dependency on photon energy than previously published measurements. (© 2014 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Nonlinear Geometric Temperature Control of a Vinyl Acetate Emulsion Polymerization Reactor

In this paper, an industrial emulsion polymerization process, which is characterized by exothermic reactions with complex nonlinear dynamics, is addressed. In this process vinyl acetate is used as monomer, potassium persulfate as initiator and polyvinyl alcohol as protective colloid. A model of the system to calculate average molecular weight and dispersity is implemented. A fine and strict temperature control is required in order to guarantee the product quality and safe operation. Nonlinear geometric control based on input/output linearization is used for reactor temperature control. An extended Kalman filter is implemented to estimate unmeasured states. Performance tests of the controller and state estimator are carried out by introducing modeling and estimator errors. It is also verified that the nonlinear controller can work with different initiator feed policies helping to improve the process productivity. Finally, compared to a traditional PID controller, the nonlinear geometric controller is superior in rejecting disturbances and performing set point tracking.

A facile synthetic pathway of monodisperse Fe3O4 nanocrystals

A facile approach was used for synthesize size-controlled monodisperse magnetite (Fe3O4) nanoparticles. In this method, precursors were obtained only using iron (III) chloride though a simple non-alkoxide sol–gel method. Meanwhile, this operation is without the need for inert gas atmosphere and refluxing conditions and without the strict control of high temperature and pressure. The phase structures, morphologies, particle sizes and magnetic properties of Fe3O4 nanoparticles were characterized by X-ray diffraction, transmission electron diffraction, fourier-transform infrared spectroscopy, near-edge X-ray absorption fine structure and vibrating sample magnetometer. Although this approach is a small modification to other methods, the synthetic pathway includes the advantages of several other methods. In addition, this method may offer a feasible strategy for those reaction which need more moderate reaction conditions.

Study on Crack Prevention Measures of Mass RCC Dams

Actually, both simple construction and fast construction are advantages of RCC dams. In view of taking strict temperature control measures, those are turned to be disadvantages instead. The way of fast pouring and the measure of controlling the placing temperature are introduced to RCC dams and 6 cases are analyzed separately to explain the effect of their crack prevention. It is concluded that controlling only the last layer placing temperature of concrete lifts can remarkably decrease the stress of working plane concrete during off period. Furthermore, the pouring way of thick lifts and short off period do not deteriorate the temperature and stress but rather has an impressive effect on crack prevention and construction period contraction.

Enabling a transferable calibration model for metal-oxide type electronic noses

While electronic noses have been around for over 30 years, little effort has been devoted to the development of transferable calibration models, which are models that can be applied to multiple equivalent devices without adjustment. The majority of published results limit itself to data sets gathered with a single device. This lack of insight in transferable models hampers large scale implementations of eNose-based applications as individual calibration of a multitude of devices for a specific application area is generally unrealistic due to the requirement of actual samples to be measured. For simple gases this may be do-able, but in the case of more complex samples such as biological patient material it is logistically impossible.In this paper we show the influence of the deviation of the sensor temperature on the measurement reproducibility and by inference on the transferability of calibration models. We introduce the total inertia (φ2) as a measure for the heterogeneity within the measured data. The total inertia is an objective measure known from linear algebra, where it is used to calculate the correspondence between matrices.We use 5 micro-hotplate metal-oxide sensors from the same wafer, with an inter-sensor heater temperature difference of approximately 15°C in combination with 2 substances, n-butyl-acetate and hexane. This research demonstrates the increase in heterogeneity of the measured response values in relation to a temperature shift. A shift of 15°C at the sensor surface causes an increase of heterogeneity that is 10–15 times higher than the increase in heterogeneity caused by inter-sensor responses to the substances when operated at exactly the same temperature. Some mixtures of substances will be separable by pattern recognition under virtually any condition, and strict temperature control will neither improve nor deteriorate results. However the significant contribution of temperature deviation toward data heterogeneity renders it plausible that optimized temperature control, and by inference lower data heterogeneity, is a prerequisite for transferability of a calibration model. This holds true when applied to metal-oxide sensors and for mixtures containing substances showing a fair degree of similarity.

Establishing and maintaining biobanks: experience of Rajiv Gandhi Centre for Biotechnology, (RGCB) Trivandrum

A biobank is a depository for biomaterials from a representative portion of a human population and acts as a vault with intricate detailed information pertaining to the individuals from whom biological materials have been collected. Biobanks can be classified into population biobanks, biobanks for molecular epidemiology and biobanks for disease biology. RGCB has been involved in biobanking with respect to three large studies in India namely i)Molecular Epidemiology of HPV in India, ii) A Randomized 2 versus 3 dose HPV Vaccination Clinical trial and iii) HPV AHEAD- : Role of Human Papilloma Virus Infection and other co-factors in the aetiology of Head & Neck Cancer. A cervical cytology biobank has been established at the centre which is an almost inexhaustible resource for fundamental and applied biological research. It helps to understand the natural history of HPV infection and HPV induced lesions and cancers, screening effectiveness, exploration of new biomarkers, surveillance of the short- and long-term effects of the introduction of HPV vaccination. However legal and ethical principles concerning personal integrity and data safety must be respected strictly and biobank based studies require approval of ethical review boards. The HPV vaccination study involves 10 different sites & different collaborating institutes across the country and all samples are shipped to RGCB, Trivandrum, which acts as a Central storage facility/ biobank. Sample shipment was an important procedure involving communication between base laboratory and biobank, import of registration database, strict temperature control, tracking of shipment and ready storage freezers on arrival. The sample verification process involves a temperature logger, freeze control tubes and bar code verification. The amount of clinical data linked to the samples determinate the availability and biological value of the sample. Thus acquiring the background information of each sample and cataloguing the available information systematically and meticulously is a must. The major problems faced in the management of cervical cytology biobanks have been reclassification of smears before entry into database, failure of temperature logger, bar codes slipping off and maintaining uninterrupted power supply. Publicly funded biobanks aim to promote the development of new knowledge by giving the research community access to data and samples. The most efficient way to acquire these benefits is to first maximize the use of biobanks in research and, second, to maximize the dissemination of knowledge developed by the research projects that used the biobanks. However there are issues with regard to the use of such stored materials especially when the demand occurs from the private sector. The decision is finally made by a scientific management committee consisting of members of World Health Organization (WHO) and the international agency for research on cancer (IARC).

An evaluation of the effect of microwave irradiation on bone decalcification aimed to DNA extraction

An effect of intermittent microwave irradiation on decalcification of compact bone followed by DNA extraction was verified. In order to perform quantitative analysis regarding the degree of decalcification, Cubic bone specimens were prepared from bovine metacarpal bone and micro-focus X-ray CT imaging was applied to measure precise volume of decalcified area in the cubes. Microwave irradiation was performed under strict control of temperature using commercially available experimental device which is designed for advancing tissue fixation, decalcification, and antigen-antibody reaction by intermittent microwave. The integrity of the DNA obtained from irradiated specimen was also examined by PCR analysis. The results of morphological analysis with CT imaging showed that microwave irradiation has a positive effect on decalcification though that effect is not so drastic. The results obtained from PCR analysis showed that microwave irradiation decrease amplifiable DNA, suggesting that we should be careful to use microwave for the purpose of bone DNA extraction.

Microwave-assisted organic synthesis versus conventional heating. A comparative study for Fisher glycosidation of monosaccharides

Abstract The Fisher glycosidation of monosaccharides ( d -glucose and d -mannose) with fatty alcohols was studied under microwave irradiation and conventional heating with strict internal temperature control using a fiber optic sensor. Surfactants were obtained in only 3 minutes under microwave at maximum power of 5 W to avoid overshoot and products decomposition. In contrast with the typical reported glycosidation methods, the reaction under conventional heating can be carried out at the same time and temperature with high conversion.

Temperature-insensitive detection of low-concentration nanoparticles using a functionalized high-Q microcavity

The ability to detect nanoparticles in extremely dilute solutions in the presence of environmental noise is crucial for biosensing applications. In this paper we propose a scheme for detecting target nanoparticles through their scattering effects in a high-Q whispering gallery microcavity. The detection signal, defined as the total linewidth broadening of the two new split modes that appear upon nanoparticle adsorption, is highly sensitive and proportional to the nanoparticle concentration. Furthermore, this new method of detection eliminates the requirement for strict temperature control and is capable of distinguishing the signal from the biorecognitions (e.g., antibodies) initially attached to the resonator and that from the target nanoparticles (e.g., antigens).

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Introduction: Therapeutic hypothermia improves neurological outcome for comatose survivors of out-of-hospital cardiac arrest. Generally, it is known that faster cooling and stable maintenance of hypothermia result in better outcomes, although there is insufficient clinical evidence. Therefore, the reliable cooling devices are necessary for the effective and safe therapeutic hypothermia. We want to compare the effectiveness and safety of Arctic Sun (AS) and water blanket (WB) during therapeutic hypothermia. Hypothesis: There is no difference between AS and WB regarding the effectiveness and safety during therapeutic hypothermia. Methods: Retrospective analysis was performed in single hospital. Patients who received therapeutic hypothermia after cardiac arrest from January 2010 to May 2012 were identified. Patients who did not complete 24-hour of therapeutic hypothermia were excluded. Demographics and resuscitation factors were abstracted. The time to target temperature (<34?) from the application of cooling was measured to evaluate the effectiveness of cooling method. After the achievement of target temperature, the temperature most remote from 33? was selected every hour. If the selected temperature was not between 32? and 34?, then that hour was considered as violation of maintenance. The rate of violation during maintenance of hypothermia was compared to evaluate the safety of cooling method. In addition, generalized estimation equations (GEE) analysis, which can adjust the correlation among serial temperature of one patient, was used to compare the absolute temperature differences from 33? during maintenance period. All patients were treated by either AS or WB and were continuously monitored using rectal thermometer. Hospital survival and 28-day cerebral performance category score were obtained. Cerebral performance category score 1 and 2 were considered as good neurologic outcome.Statistics: Continuous variables were compared using t-test or GEE. The proportions were compared using Chi square test. P value < 0.05 was considered statistically significant. Stata version 10.1 was used for statistical analysis. Results: AS was used in 23 patients among 53 patients enrolled. Demographics and factors associated with resuscitation did not differ between two groups. Patients discharged alive were more frequent in AS group (73.9% [AS] vs. 43.3% [WB], p=.026). Patients with good neurologic outcome were not different between two groups (26.1% [AS] vs. 16.7% [WB], p=.402). There was no difference between two groups regarding temperature at start of cooling (35.6? [AS] vs. 35.6? [WB], p=.992). Time to target temperature (134.2 min [AS] vs. 233.4 min [WB], p=.056) was lesser in AS group, but it was not statistically significant. Patients with target temperature before 4-hour of cooling (87.0% [AS] vs. 63.3% [WB], p=.053) were not different between two groups. Total maintenance duration (22.7 hr [AS] vs. 21.6 hr [WB], p=.091) was not different between two groups. However, violation of maintenance (2.0% [AS] vs. 23.7% [WB], p<.001) was more frequently observed in WB group. Most violations (103/156 [76.3%]) were hypothermic event (<32?) in WB group. However, all violations were hyperthermic event (>34?) in AS group. The mean absolute temperature differences from 33? during maintenance period were 0.19? (95% CI, 0.17?-0.21?) in AS and 0.76? (95% CI, 0.71?-0.80?) in WB. GEE has revealed that AS decreased this difference by 0.59? (95% CI, 0.44?-0.75?; p<.001) compared to WB. Conclusions: Arctic Sun is superior to water blanket in the maintenance of therapeutic hypothermia. Strict temperature control achieved by Arctic Sun may be useful to minimize unwanted adverse effects of therapeutic hypothermia in cardiac arrest victims.

Temperature-Tolerant COLD-PCR Reduces Temperature Stringency and Enables Robust Mutation Enrichment

Low-level mutations in clinical tumor samples often reside below mutation detection limits, thus leading to false negatives that may impact clinical diagnosis and patient management. COLD-PCR (coamplification at lower denaturation temperature PCR) is a technology that magnifies unknown mutations during PCR, thus enabling downstream mutation detection. However, a practical difficulty in applying COLD-PCR has been the requirement for strict control of the denaturation temperature for a given sequence, to within ±0.3 °C. This requirement precludes simultaneous mutation enrichment in sequences of substantially different melting temperature (T(m)) and limits the technique to a single sequence at a time. We present a temperature-tolerant (TT) approach (TT-COLD-PCR) that reduces this obstacle. We describe thermocycling programs featuring a gradual increase of the denaturation temperature during COLD-PCR. This approach enabled enrichment of mutations when the cycling achieves the appropriate critical denaturation temperature of each DNA amplicon that is being amplified. Validation was provided for KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) and TP53 (tumor protein p53) exons 6-9 by use of dilutions of mutated DNA, clinical cancer samples, and plasma-circulating DNA. A single thermocycling program with a denaturation-temperature window of 2.5-3.0 °C enriches mutations in all DNA amplicons simultaneously, despite their different T(m)s. Mutation enrichments of 6-9-fold were obtained with TT-full-COLD-PCR. Higher mutation enrichments were obtained for the other 2 forms of COLD-PCR, fast-COLD-PCR, and ice-COLD-PCR. Low-level mutations in diverse amplicons with different T(m)s can be mutation enriched via TT-COLD-PCR provided that their T(m)s fall within the denaturation-temperature window applied during amplification. This approach enables simultaneous enrichment of mutations in several amplicons and increases significantly the versatility of COLD-PCR.

ChemInform Abstract: Parallel Microwave Chemistry in Silicon Carbide Microtiter Platforms: A Review

AbstractReview: 45 refs.

Modeling and Simulation of Hydrocracking of Fischer–Tropsch Hydrocarbons in a Catalytic Microchannel Reactor

Product quality of Fischer–Tropsch synthesis is improved by catalytic hydrocracking which converts heavy hydrocarbon fractions (wax) to commercially valuable fuels. The process is highly exothermic and requires strict temperature control; high temperatures cause overcracking to lower, commercially undesired hydrocarbons, whereas low temperatures reduce the conversions. Running hydrocracking in microchannel reactors is promising, since submillimeter dimensions lead to significant compaction that favors robust temperature control. This work investigates modeling and simulation of hydrocracking in a heat-exchange-integrated microchannel reactor involving parallel groups of square-shaped cooling and catalyst-coated reaction channels. Effects of material type and thickness of the wall separating the channels, and operating parameters (reactant and coolant feed temperatures and space velocity of the reactant stream) on reaction temperature and product distribution are investigated. Mole fractions of the product...

Prenatal Effects of Plastic Migrants in Commercial Peritoneal Dialysis Solution

Commercial peritoneal dialysis solution (PDS) is widely used in the treatment of uremic patients. This type of PDS is expected to be contaminated with leachable agents originating from the plastic material of the packaging bags. Injection of the solution (280 ml/kg, i.p) into pregnant MF1 mice was applied to investigate the prenatally-induced adverse effects in their progeny due to such plastic leachables. Daily injection started; from Day 0 of gestation and continued up to delivery. The dose was divided into two equal volumes given at 10 a.m. and 10 p.m. A group of pregnant mice, of 10 animals, was given the PDS of bags stored at room temperature (25oC). A similar group was given the PDS of bags preheated in a waterbath (50oC) for overnight. A third group was given a prepared control PDS from the same chemicals, stored in glass bottles from the manufacturing companies, according to the concentrations specified on the PDS bag. After weaning (one-month age), the offspring of each group were subjected to a battery of biochemical tests. The results showed that commercial PDS has induced the following significant effects in the offspring: elevation in the activity of blood alkaline phosphatase (ALP), increase in the blood concentration of the nonprotein nitrogenous (NPN) compounds (urea, creatinine and uric acid), and total blood cholesterol. There were also a higher percentage of stillbirths in the progeny of treated mothers. Most of the previous effects were clearly pronounced in the offspring of mothers treated with preheated-bag PDS.It was concluded that the plastic bags of the investigated PDS were leachable, and the chemical agents originating from the plastic material of these bags were toxic to the mice under study. The PDS concentration of these leachables may increase with time and storage of the bags under hot weathers. Based on the results of this study, strict control of storage temperature is recommended to minimize the leachability of these PDS bags and thus lessening the health problems that may arise in patients undergoing long-term peritoneal dialysis.

Growth potential of Escherichia coli O157:H7 on fresh-cut fruits (melon and pineapple) and vegetables (carrot and escarole) stored under different conditions

Minimally processed fruits and vegetables are ready-to-eat and do not require further treatment at home. These foods are usually stored in a modified atmosphere and should be maintained at refrigerated conditions until consumption. These fruits and vegetables can become contaminated by foodborne pathogens such as Escherichia coli O157:H7, Salmonella and Listeria monocytogenes, and it has been demonstrated that current industrial sanitising washing treatments do not guarantee the total elimination of the pathogen when present. Thus, it is very important to elucidate whether pathogens are able to grow or survive during storage at different conditions. This study was conducted to determine the effect of the type of produce (escarole, carrot, pineapple or melon), package gas composition (air or modified atmosphere) and temperature (5 or 25 °C) on the population dynamics of a strain of E. coli O157:H7. For vegetables, the growth in two films, which created different O2 and CO2 concentrations, and air were compared. At 25 °C, growth of E. coli O157:H7 was higher in fresh-cut carrots than in endive, reaching populations between 7.0–8.4 log cfu g−1 and 5.2–6.3 log cfu g−1 after 3 days of storage, respectively. In fruits, E. coli O157:H7 grew well in fresh-cut melon regardless of the atmospheric conditions in the package, reaching populations of 8.5 and 8.9 log cfu g−1 after 1 day of storage in modified atmosphere packaging (MAP) or under air conditions, respectively. No growth was observed in the fresh-cut pineapple. At 5 °C, E. coli O157:H7 did not grow but survived throughout the studied period in all tested commodities. This work emphasises the importance of strict temperature control from processing to consumption, including transportation, distribution, storage and handling in supermarkets and by consumers.

Parallel microwave chemistry in silicon carbide microtiter platforms: a review

In this review, applications of silicon carbide-based microtiter platforms designed for use in combination with dedicated multimode microwave reactors are described. These platforms are employed not only for the efficient parallel synthesis of compound libraries, but also in the context of high-throughput reaction screening/optimization and a number of other (bio)analytical and biomedical applications. Since the semiconducting plate material (silicon carbide) is strongly microwave absorbing and possesses high thermal conductivity, no temperature gradients across the microtiter plate exist. Therefore, many of the disadvantages experienced in attempting to perform microtiter plate chemistry under conventional microwave conditions can be eliminated. In general, the silicon carbide-based microtiter platforms allow sealed vessel processing (either directly in the well or in glass vials placed into the wells) of volumes ranging from 0.02-3.0 mL at a maximum temperature/pressure limit of 200°C/20 bar. Depending on the specific plate and rotor configuration, a maximum of 80-192 transformations can be carried out in parallel in a single microwave irradiation experiment under strict temperature control. A platform type utilizing HPLC/GC vials as reaction vessels allows analysis directly from the reaction vessel eliminating the need for a transfer step from the reaction to the analysis vial. The latter system is particularly useful for analytical applications as well as reaction optimization/screening.

Inactivation of Neosartorya fischeri and Paecilomyces variotii on paperboard packaging material by hydrogen peroxide and heat

This study reports on the influence of heat and hydrogen peroxide combination on the inactivation kinetics of two heat resistant molds: Neosartorya fischeri and Paecilomyces variotii. Spores of different ages (1 and 4 months) of these molds were prepared and D-values (the time required at certain temperature/hydrogen peroxide combination to inactivate 90% of the mold ascospores) were determined using thermal death tubes. D-values found for P. variotii ranged from 1.2 to 25.1 s after exposure to different combinations of heat (40 or 60 °C) and hydrogen peroxide (35 or 40% w/w) while for N. fischeri they varied from 2.7 to 14.3 s after exposure to the same hydrogen peroxide concentrations and higher temperatures (60 or 70 °C). The influence of temperature and hydrogen peroxide concentration on the d-values varied with the genus of mold and their ages. A synergistic effect of heat and hydrogen peroxide in reducing D-values of Paecilomyces variotti and N. fischeri has been observed. In addition to strict control of temperature, time and hydrogen concentration, hygienic storage and handling of laminated paperboard material must be considered to reduce the probability of package’s contamination. All these measures together will ensure package’s sterility that is imperative for the effectiveness of aseptic processing and consequently to ensure the microbiological stability of processed foods during shelf-life.

Control Strategies for an Inline Cooling Device in Hot Strip Processing of Innovative Steel Materials

Abstract Heat treatment of steel is used to adjust different microstructures and mechanical properties. The Quenching and Partitioning (Q&amp;P) process or cyclic annealing for grain refinement lead to increased strength and ductility. Both approaches demand a strict temperature control and a close strip temperature tracking. A control strategy for optimal properties is developed. Herefore a one-stand laboratory scale hot rolling process line was equipped with a water cooling section. A detailed temperature control during the cooling process was established accounting for strip thickness and velocity, set point temperatures, and amount of water cooling. While industrial set points and parameters of closed-loop controllers are often empirical, the presented control system and strategies are investigated by MatLab-Simulink. The improved material properties were evaluated in annealing tests. The control system for the cooling track reduces the temperature gradient within the strip to 12 K. The simulation of the cooling track gives an optimal set point. As a prerequisite for a controlled design of time-temperature-cycles, it can be calculated for various process parameters. Grain sizes &amp;lt;5 μm are achieved by cyclic annealing and accompanied by increased strength and ductility. The Q&amp;P treatment produces tempered martensite and retained austenite with improved mechanical properties.

Effects of Storage Temperature on the Postharvest Quality of Three Asparagus Cultivars Harvested in Spring

The effects of storage temperature (5°C, 10°C, and 15°C) on the appearance, weight, and ascorbic acid content of 3 asparagus cultivars—‘UC157’, ‘Gijnlim’, and ‘Purple Passion’—cultivated as green asparagus in open fields were investigated over a 4-day storage period. In addition, we investigated the respiration rate (CO2 production rate), which is closely related to the qualitative deterioration of fresh produce. Among the 3 cultivars, ‘Gijnlim’ had the loosest spear-head and the highest ascorbic acid content immediately after harvest. The extent of opening of the spear-head during the 4-day storage period varied among the cultivars, and was most marked in ‘Gijnlim’ and was least in ‘Purple Passion’. Discoloration of the cut end of the spear was found to be dependent upon the storage temperature to a greater extent than the individual cultivars. ‘Gijnlim’ had marked discoloration at 10°C. Moreover, ‘Gijnlim’ had the largest decline in weight among the 3 cultivars at each of the 3 temperatures examined. A similar tendency was observed in the decline in ascorbic acid content. The respiration rate of ‘Purple Passion’ within 2–8 h after harvest tended to be smaller than that of ‘UC157’ and ‘Gijnlim’. These findings suggested that there are differences among the cultivars with respect to the rates of changes in postharvest quality. ‘Gijnlim’ tended to deteriorate faster than ‘UC157’ and ‘Purple Passion’, suggesting that strict temperature control and/or packaging might be required to maintain the quality of ‘Gijnlim’ harvested in the spring.