Effect of storage temperature on Streptococcus mutans viability

Abstract Introduction Proper storage conditions and maintenance of viable biological material plays an important role in microbiological research, allowing for the opportunity to conduct future studies. Objective To evaluate the viability of Streptococcus mutans strains that were previously grown and stored under different temperatures for approximately eight years. Material and method In this study, we evaluated 393 bacterial isolates that were stored in a freezer at -80°C (G1) and 200 isolates stored in a freezer at -20°C (G2). Aliquots of each sample were plated on blood agar and mitis-salivarius bacitracin sucrose agar-solidified medium. After incubating under microaerophilic conditions in an incubator at 37°C for 72 hours, the presence, morphology and purity of bacterial growth was observed. The data were analyzed by means of descriptive statistics. Result Microbial viability was observed in almost all samples (99.7%) in G1, whereas all isolates stored at -20°C were considered inviable. Conclusion The viability of S. mutans is influenced by the storage temperature of the samples, and the strains remain viable when stored under ideal temperature conditions (-80°C), even when stored for a long period of time.

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Changes of Physicochemical Properties of Starch Syrups Recommended for Winter Feeding of Honeybees during Storage

Agriculture ◽

10.3390/agriculture11040374 ◽

2021 ◽

Vol 11 (4) ◽

pp. 374

Author(s):

Teresa Szczęsna ◽

Ewa Waś ◽

Piotr Semkiw ◽

Piotr Skubida ◽

Katarzyna Jaśkiewicz ◽

...

Keyword(s):

Chemical Composition ◽

Physicochemical Properties ◽

Physicochemical Parameters ◽

Storage Temperature ◽

Storage Conditions ◽

Different Temperatures ◽

And Storage ◽

Bee Colonies ◽

Temperature Time ◽

Winter Feeding

The aim of this study was to determine the influence of storage temperature and time on physicochemical parameters of starch syrups recommended for the winter feeding of bee colonies. The studies included commercially available three starch syrups and an inverted saccharose syrup that were stored at different temperatures: ca. 20 °C, 10–14 °C, and ca. 4 °C. Physicochemical parameters of fresh syrups (immediately after purchase) and syrups after 3, 6, 9, 12, 15, 18, 21, and 24 months of storage at the abovementioned temperatures were measured. It was observed that the rate of unfavorable changes in chemical composition of starch syrups and the inverted saccharose syrup, mainly the changes in the 5-hydroxymethylfurfural (HMF) content, depended on the type of a syrup and storage conditions (temperature, time). Properties of tested starch syrups intended for winter feeding of bees stored at ca. 20 °C maintained unchanged for up to 6 months, whereas the same syrups stored at lower temperatures (10–14 °C) maintained unchanged physicochemical parameters for about 12 months. In higher temperatures, the HMF content increased. To date, the influence of this compound on bees has not been thoroughly investigated.

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Aroma of mature-green and tree-ripe mangoes after refrigerated air or controlled atmosphere storage

Ciência Rural ◽

10.1590/0103-8478cr20210062 ◽

2022 ◽

Vol 52 (6) ◽

Author(s):

Renar João Bender ◽

Jeffrey Karl Brecht ◽

Elizabeth Amory Baldwin

Keyword(s):

Storage Temperature ◽

Storage Conditions ◽

Controlled Atmosphere Storage ◽

Controlled Atmospheres ◽

Postharvest Handling ◽

Terpene Synthesis ◽

Almost All ◽

Atmosphere Storage ◽

Aroma Components ◽

Green Stage

ABSTRACT: Mango flavor is dependent on cultivar characteristics and postharvest handling procedures. Mangoes harvested with the ripening metabolism initiated develop better flavor than mangoes harvested at the mature-green stage. Different cultivars were harvested at both ripeness stages and evaluated to determine the effect of fruit ripeness, storage temperature and atmosphere on the volatiles present in aroma profiles. Mangoes of the cultivars Haden, Keitt and Tommy Atkins at distinct ripeness stages were stored in controlled atmospheres (CA) with 2, 5 or 21 kPa O2 plus 0, 10 or 25 kPa CO2 at 5, 8, 12 or 15 °C. Terpene concentrations of mangoes stored in air were higher than the concentrations in mangoes stored in CA. The sesquiterpene α-copaene did not present recognizable peaks in almost all elusion sequences. The same result was observed with the monoterpene β-pinene in cv. Haden and cv. Keitt mangoes while in ‘Tommy Atkins’ fruit β-pinene concentrations were below 1.06 µL.L-1. Ethanol and acetaldehyde concentrations were significantly higher in mangoes from 2 kPa O2 storage than those from air storage or the other CA treatments. Terpene synthesis in air or CA storage in all cultivars varied significantly, preventing generalizations as to what storage conditions favor or limit aroma components elution.

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Color change of bottled white wines as a quality indicator

OENO One ◽

10.20870/oeno-one.2020.54.3.3367 ◽

2020 ◽

Vol 54 (3) ◽

pp. 543-551

Author(s):

Antonios Kanavouras ◽

Frank Coutelieris ◽

Eleni Karanika ◽

Yorgos Kotseridis ◽

Stamatina Kallithraka

Keyword(s):

Storage Temperature ◽

Color Change ◽

Colour Change ◽

Storage Conditions ◽

White Wine ◽

Grape Variety ◽

White Wines ◽

Root Cause ◽

Different Temperatures ◽

One Year

Aim: The present work aimed to estimate the probability of bottled white wine exhibiting acceptable colour change during a certain predefined time using a predictive model based on a descriptive mathematically expressed theory.Materials and methods: Nine mono-varietal Greek white wines (produced by three varieties) were bottled and stored at two different temperatures (20 and 30 °C). Their absorbance at 420 nm (A420) was recorded every three months for 12 months. Results were processed by applying the root cause analysis versus storage conditions. Furthermore, a predictive mathematical model was adapted to the experimental data based on the probability of the product showing browning-index values higher than a specific threshold during its shelf life.Results: As expected, the absorbance at 420 nm increased with time, while the elevated storage temperature had a significant effect on colour alteration. The browning rate was dependent on grape variety. When storage temperature was 20 °C, a lower A420 increase was observed for Sauvignon blanc wine, while at 30 °C, browning was higher. Assyrtiko wines were more resistant to colour change at both temperatures. The probability of a bottled product maintaining an acceptable colour change by the end of one year, was used as a measure of its quality. A very successful fit was achieved between mathematical and experimentally obtained data for shelf life predictions.Significance and impact of the study: The modelling of the experimental results, as well as the exploitation of this fitting to make predictions independently of the specific results, indicate that storage temperature will potentially impact the colour of wines over time, depending on the evolution of the absorbance values at 420 nm. For the wine sector, the selection of the appropriate storage conditions for a given grape variety is an important factor to take into consideration.

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Impact of delays to incubation and storage temperature on blood culture results: a multi-centre study

BMC Infectious Diseases ◽

10.1186/s12879-021-05872-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Clare L. Ling ◽

Tamalee Roberts ◽

Sona Soeng ◽

Tomas-Paul Cusack ◽

David A. B. Dance ◽

...

Keyword(s):

Blood Culture ◽

Storage Temperature ◽

Storage Conditions ◽

Significant Loss ◽

Blood Cultures ◽

Multi Centre Study ◽

Middle Income ◽

Ambient Temperatures ◽

Different Temperatures ◽

Pathogen Recovery

Abstract Background Blood cultures are one of the most important tests performed by microbiology laboratories. Many hospitals, particularly in low and middle-income countries, lack either microbiology services or staff to provide 24 h services resulting in delays to blood culture incubation. There is insufficient guidance on how to transport/store blood cultures if delays before incubation are unavoidable, particularly if ambient temperatures are high. This study set out to address this knowledge gap. Methods In three South East Asian countries, four different blood culture systems (two manual and two automated) were used to test blood cultures spiked with five common bacterial pathogens. Prior to incubation the spiked blood culture bottles were stored at different temperatures (25 °C, in a cool-box at ambient temperature, or at 40 °C) for different lengths of time (0 h, 6 h, 12 h or 24 h). The impacts of these different storage conditions on positive blood culture yield and on time to positivity were examined. Results There was no significant loss in yield when blood cultures were stored < 24 h at 25 °C, however, storage for 24 h at 40 °C decreased yields and longer storage times increased times to detection. Conclusion Blood cultures should be incubated with minimal delay to maximize pathogen recovery and timely result reporting, however, this study provides some reassurance that unavoidable delays can be managed to minimize negative impacts. If delays to incubation ≥ 12 h are unavoidable, transportation at a temperature not exceeding 25 °C, and blind sub-cultures prior to incubation should be considered.

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Effects of Storage Duration on Biodiesel Properties Derived from Waste Cooking Oil

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.554.494 ◽

2014 ◽

Vol 554 ◽

pp. 494-499 ◽

Cited By ~ 19

Author(s):

Amir Khalid ◽

Norazwan Azman ◽

Hanis Zakaria ◽

Bukhari Manshoor ◽

Izzuddin Zaman ◽

...

Keyword(s):

Water Content ◽

Fossil Fuels ◽

Storage Temperature ◽

Acid Value ◽

Waste Cooking Oil ◽

Storage Conditions ◽

Storage Duration ◽

Oil Reserves ◽

Cooking Oil ◽

Different Temperatures

The reduction of world oil reserves fossil fuels and increasing environmental concerns significantly influences the popularity of biodiesel as an alternative diesel. This research investigates the effects of storage duration of variant blending waste cooking oil ratio under different storage temperature on fuel properties. The biodiesel samples were stored at different temperatures and were monitored at regular interval over a period of 70 days. Blending of biodiesel was varied from 5vol % (WCO5) ~15vol% (WCO15) and storage temperature from 24°C~35°C. These samples were monitored on a weekly and the effects of storage conditions on properties of biodiesel such as density, kinematics viscosity, acid value, water content and flash point of biodiesel were discussed in detail. The observation of biodiesel shows that the increasing of storage duration of biodiesel derived from waste cocking oil influences to the increasing of density, kinematics viscosity, acid value and water content.

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Quality Changes during Storage of Burkina (a Millet and Milk-based) Drink

Asian Food Science Journal ◽

10.9734/afsj/2020/v15i230146 ◽

2020 ◽

pp. 1-5

Author(s):

Ampofo-Asiama Jerry ◽

Mamudu Hafusatu ◽

Helen Oluchi Emeruwa ◽

Owusu Fokuo Kant ◽

Quaye Bright

Keyword(s):

Phenolic Content ◽

Storage Temperature ◽

Energy Content ◽

Titratable Acidity ◽

Storage Conditions ◽

High Energy ◽

Small Scale ◽

Content Quality ◽

Different Temperatures

Burkina, a drink prepared from millet and milk, is gaining economic attention in Ghana due to its perceived nutritious nature and high energy content. The drink which is produced on a small-scale is usually vended without proper control of storage conditions leading to rapid loss of quality. The objective of this study was to investigate the effect of storing burkina at different temperatures (4 and 30°C) on the microbial and physicochemical (pH, titratable acidity, brix and phenolic content) quality of the drink. The pH, titratable acidity, brix and phenolic content of freshly prepared burkina were 3.65, 0.49%, 2.05 and 0.26 mg GAE/100 g, respectively. Although, changes were observed, storage temperature did not have a significant effect on the physicochemical quality of burkina. The initial load of aerobic mesophiles, lactic acid bacteria, Enterobacteriaceae, and yeast and moulds in the freshly prepared Burkina were 6.45, 5.49, 2.58 and 4.45 log cfu/mL, respectively. Storage at the higher temperature resulted in an increased microbial load within 48 h, leading to faster spoilage, with only marginal increases observed at the lower storage temperature.

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EFFECTS OF STORAGE CONDITIONS AND PRESENCE OF FRUITING BRACTS ON THE GERMINATION OF ATRIPLEX HALIMUS AND SALSOLA VERMICULATA

Experimental Agriculture ◽

10.1017/s0014479797000021 ◽

1997 ◽

Vol 33 (2) ◽

pp. 149-155 ◽

Cited By ~ 16

Author(s):

A. E. OSMAN ◽

F. GHASSALI

Keyword(s):

Seed Germination ◽

Cold Storage ◽

North Africa ◽

Room Temperature ◽

Storage Temperature ◽

Seed Storage ◽

Storage Conditions ◽

Shrub Species ◽

Atriplex Halimus ◽

Different Temperatures

Two shrub species, Atriplex halimus L. and Salsola vermiculata L., are considered useful for rehabilitation of degraded rangelands in west Asia and north Africa. They can be established from direct seeding and are capable of self-sowing. In this study, seed storage at different temperatures and the influence of fruiting bracts on seed germination were examined for the two species during two seasons. Fruits (utricles) were stored at 20–22°C (room temperature), 0°C or −22°C. Germination tests were carried out after 33, 56, 90, 152, 272 and 397 d in storage in the first season and after 44, 76, 104, 170, 288 and 412 d in the second season. Seeds were germinated in their fruiting bracts or after bract removal. Bract removal significantly improved seed germination of both shrubs regardless of storage temperature. For S. vermiculata the increase in germination was in the range of 1.3- to 14.7-fold compared with values for the intact fruit in Season 1 and 0.5 to 3.8 in Season 2. Similarly the ranges for A. halimus were 0.5- to 4.2-fold and 0.7- to 5.3-fold in the two seasons respectively. The effect of cold storage was greater on Salsola than on Atriplex. The reduction of the storage temperature from 21°C to 0°C and −22°C increased the longevity of S. vermiculata seeds by 2.8–46.6 times in Season 1 and by 2.9–2.6 times in Season 2. There was little or no effect on the longevity of A. halimus. A leachate prepared by soaking fruiting bracts from S. vermiculata significantly depressed germination (p < 0.01), the effect being greater on Salsola seeds (20% reduction) than on Atriplex seeds (8% reduction). A leachate from A. halimus produced a slight but non-significant reduction in germination.

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Influence of Alcohol Content and Storage Conditions on the Physicochemical Stability of Spirit Drinks

Foods ◽

10.3390/foods9091264 ◽

2020 ◽

Vol 9 (9) ◽

pp. 1264

Author(s):

Mateusz Różański ◽

Katarzyna Pielech-Przybylska ◽

Maria Balcerek

Keyword(s):

Volatile Compounds ◽

Storage Temperature ◽

Storage Conditions ◽

Deionized Water ◽

Higher Alcohols ◽

Alcohol Content ◽

C Storage ◽

Physicochemical Stability ◽

Different Temperatures ◽

And Storage

The purpose of this study was to investigate the effects of alcohol by volume (ABV) and storage temperature on changes in the clarity of rye and plum distillates, and their content of volatile compounds. Distillates with initial ABVs of 93.26% v/v (rye distillate) and 82.03% v/v (plum distillate) were diluted with deionized water to 40, 50, and 70% v/v. The samples were stored in darkness at different temperatures (−18 °C, 0 °C, 8 °C, 20 °C) for 8 weeks. The results showed that reducing the alcohol content and storage temperature caused turbidity to increase. The samples prepared from rye distillate were characterized by significantly lower turbidity than those produced from plum distillate. The highest increase in turbidity in comparison to the controls was observed in the samples with 40% v/v alcohol content stored at a temperature of −18 °C. Storage of the rye and plum distillates samples at different temperatures resulted in changes to the concentrations of volatile compounds, i.e., lower levels of acetaldehyde and higher alcohols, and increased content of esters. However, the alcohol content and storage temperature had no statistically significant effect on methanol concentration.

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Effect of Storage Temperature and Time on Stability of Liver Enzymes in Blood Serum

Archives of Iranian Medicine ◽

10.34172/aim.2020.18 ◽

2020 ◽

Vol 23 (5) ◽

pp. 296-301

Author(s):

Shadi Kolahdoozan ◽

Sadaf G. Sepanlou ◽

Maryam Sharafkhah ◽

Elaheh Shaker ◽

Ameneh Shayanrad ◽

...

Keyword(s):

Linear Models ◽

Liver Enzymes ◽

Storage Temperature ◽

Linear Regression Analysis ◽

Storage Conditions ◽

Prolonged Storage ◽

Serum Samples ◽

Long Term Storage ◽

The Stability ◽

Almost All

Background: It is increasingly common to collect and store specimens for future unspecified research. However, the effects of prolonged storage on the stability and quality of analytes in serum have not been well investigated. We aimed to determine whether the stability of liver enzymes extracted from frozen bio-samples stored at the baseline is affected by storage conditions. Methods: A total of four liver enzymes in the sera of 400 patients were examined following storage. After deter-mining the baseline measurements, the serum of each patient was aliquoted and stored at −70°C for three and six months, as well as one, two, and five years after collecting the original sample. The percent change from baseline measurements was calculated both statistically and clinically. Linear models were also used to correct the results of the samples based on the time they were frozen. Results: In almost all samples, liver enzymes were detectable until two years after the baseline, while in a signifi-cant proportion of samples, enzymes were not ultimately detectable five years after the baseline. Linear regression analysis on log-transformed levels of enzymes shows that the performance is acceptable until one year after the baseline. The performance of the prediction model declines substantially two and five years after the baseline, except for GGT. Conclusion: Long-term storage of serum samples significantly decreases the concentration of the liver enzymes from the baseline, except for GGT. It is not recommended to store samples for more than two years, as liver en-zymes are not detectable afterwards.

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Some of Frontiers Education Articles: Around First to Eleven December 2020

10.35542/osf.io/8964e ◽

2020 ◽

Author(s):

thobias sarbunan

Keyword(s):

Knowledge Creation ◽

Publishing House ◽

General Point ◽

Human Race ◽

Future Studies ◽

Long Period ◽

Research And Innovation ◽

New Information ◽

Scientific Ideas ◽

Better Than

The research pathway is also an important point to lead researchers in creating and enriching knowledge from a fresh viewpoint, as wellas development for the human race. The frontier is the publishing house of a publication that has established information along with the'other agent' of knowledge around the globe. As a result, one of the sub-journals of this publication was education, expanded awarenesstime by time, by new information on innovation in science and technology. In the meantime, the pandemic, better than the science society,has alerted to the current developments in science aimed at strengthening and gaining some insight and awareness of how to maintainthe 'mode of knowledge creation'. So, through this discussion of the current edition of Frontier Education Journals, I thought that thisdiscussion theoretically involved encouragement and advancement in the middle of the pandemic, also influenced from a general point ofview, here as roadmap or step-stone for all research and innovation researchers. On the basis of the discussion in general, I saw that theroad map of the topic of frontier education is in significance to all branches of expertise of education. I agree that knowledge developmenttime-by-time needs to be reflected-analysed-synthesized-adopted or adapted-also developed for the purpose of education in addition tolearning from a general viewpoint. Note, knowledge is never-never sleeping tight, but it still evolves and progresses a long period with thenewest scientific ideas-concept-and hypothesis. In the other hand, it is possible that my study would miss a range of weaknesses inliteracy resources as well; but at least, I have sought, through this article, to see the importance of knowledge advancement that can enrichknowledge in the middle of the pandemic and for future studies.

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