Ethyl carbamate formation in sub-optimal wine storage conditions and influence of the yeast starter

Aim: To evaluate the potential risk of ethyl carbamate (EC) formation in wine by studying its production kinetics at suboptimal storage temperatures.Methods and results: The kinetics of EC formation was investigated in 60 white wines obtained from 6 varietal juices fermented with 10 yeast strains. The wines were analysed for their urea content at bottling, then EC formation was monitored during in-bottle storage at < 12 °C for 150 days followed by 152 days at 40 °C. Storage at < 12 °C had no effect on EC formation, regardless of initial urea content ; however, at 40 °C we found a positive correlation between initial urea content and final EC content.Conclusion: Urea content higher than 20 mg/L in wine kept at 40 °C can produce from 15 up to 30 μg/L EC in less than 5 days. Two yeast strains, La Claire SP665 and Maurivin Platinum, minimised the urea in wine, reducing the risk of EC formation.Significance and impact of the study: The temperatures used in this study can be accidentally - but easily - reached during suboptimal wine storage and shipping, and in the presence of substantial amounts of urea, the EC level can exceed the warning levels established by some countries in just a few days. The paper confirms the importance of minimising urea production in wine and controlling temperature during storage and shipping.

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Regulation of Ethyl Carbamate of Saccharomyces cerevisiae in Chinese Luzhou-Flavor Liquor Fermentation

Journal of Biobased Materials and Bioenergy ◽

10.1166/jbmb.2020.2004 ◽

2020 ◽

Vol 14 (5) ◽

pp. 670-675

Author(s):

Chuan Wang ◽

Meng-Ping Zhang ◽

Mou Wang

Keyword(s):

Saccharomyces Cerevisiae ◽

Ethanol Concentration ◽

Ethyl Carbamate ◽

Alcoholic Beverages ◽

Transcription Level ◽

Chinese Liquor ◽

Urea Content ◽

Urea Production ◽

Initial Salt ◽

Spontaneous Reaction

The carcinogen ethyl carbamate (EC) in alcoholic beverages mainly comes from the spontaneous reaction of ethanol and urea, and urea is produced by the breakdown of arginine by arginase in Saccharomyces cerevisiae. Regulating activity of arginase and decreasing urea content are beneficial to reduce EC in liquor. In this study, Saccharomyces cerevisiae isolated from Daqu was fermented under a series of stress conditions to evaluate the content changes of EC and its precursors. Temperature and pH below 25 °C and pH 4.0, ethanol concentration of 4–6% and a certain initial salt concentration could reduce arginine consumption and urea production by decreasing transcription level of arginase and increasing transcription level of urea carboxylase, and eventually lead to the reduction of EC. These methods will help to improve the strategy of EC control in Chinese liquor.

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Evaluation of the Storage Conditions and Type of Cork Stopper on the Quality of Bottled White Wines

Molecules ◽

10.3390/molecules26010232 ◽

2021 ◽

Vol 26 (1) ◽

pp. 232

Author(s):

María Consuelo Díaz-Maroto ◽

Manuel López Viñas ◽

Lourdes Marchante ◽

María Elena Alañón ◽

Ignacio Javier Díaz-Maroto ◽

...

Keyword(s):

Volatile Compounds ◽

Light Exposure ◽

Total Content ◽

Storage Conditions ◽

Sensory Profile ◽

Cork Stopper ◽

White Wines ◽

White Leds ◽

Retail Outlets

The effects of different storage conditions, light exposure, temperature and different commercially available cork stoppers on the phenolic, volatile and sensorial profile of Verdejo wines were studied. Two natural corks of different visual quality and a microgranulated cork stopper were investigated over one year at two different storage conditions. One simulating light exposure and temperature in retail outlets and the other simulating optimal cellar conditions (darkness and 12 °C). The wines stored under commercial conditions showed greater losses of total and free SO2 and higher levels of brown-yellowish tones, related to the oxidation of flavan-3-ols. Although these wines underwent a decrease in the total content of stilbenes, a significant increase in trans-piceid was observed. In addition, these wines suffered important changes in their volatile and sensory profile. Volatile compounds with fruity and floral aromas decreased significantly, while volatile compounds related to aged-type characters, as linalool oxides, vitispirane, TDN or furan derivatives increased. Wines stored in darkness at 12 °C underwent minor changes and their sensory profiles were similar to wine before bottling. The high-quality natural corks and microgranulated corks better preserved the quality of the white wines from a sensory point of view. These results showed that temperature and light exposure conditions (diffuse white LEDs and 24 ± 2 °C) in retail outlets considerably decrease the quality of bottled white wines and, consequently, their shelf life, due to the premature development of aged-type characters.

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Dissolution kinetics of CO2 and CO2-SO2 mixtures in water and brine at geological storage conditions of 16 MPa and 333 K

International Journal of Greenhouse Gas Control ◽

10.1016/j.ijggc.2018.10.010 ◽

2018 ◽

Vol 79 ◽

pp. 173-180 ◽

Cited By ~ 2

Author(s):

Philipp Amshoff ◽

Thomas Weger ◽

Christian Ostertag-Henning

Keyword(s):

Dissolution Kinetics ◽

Storage Conditions ◽

Geological Storage ◽

Kinetics Of

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Substantiation of the sell-by date of food products

One Health and Nutrition Problems of Ukraine ◽

10.33273/2663-9726-2020-52-1-59-63 ◽

2020 ◽

Vol 52 (1) ◽

pp. 59-63

Author(s):

S.M. Kuzminskiy ◽

T.V. Adamchuk ◽

О.М. Holinko ◽

N.P. Levytska

Keyword(s):

Food Products ◽

Storage Conditions ◽

Lag Phase ◽

Contamination Level ◽

Second Phase ◽

Phase Duration ◽

Normative Documents ◽

Culture Development ◽

Storage Distribution ◽

Kinetics Of

Objective of the Work. The overview of current methodical approaches for experimental substantiation of the sell-by date of food products. Methods and Materials. Data analysis of scientific literature and normative documents on methods of substantiation of the sell-by date of food products. Results and Discussion. Sell-by date is a period since product’s manufacture, during which it maintains its safety and quality (including nutritional value) within reasonably foreseeable conditions of storage, distribution and consumption. In the case of new products (recipes) introduction it is necessary to review the sell-by date, and its extending as the need arises. The main aspects of microbiological substantiation of the sell-by date of food products are considered. The identification of microbial hazard for particular product is the first phase of the work. The second phase of the work is to determine the kinetic parameters of precise microorganism’s accumulation to maximum permitted level within regulated and aggravated conditions of product’s storage. Conclusions. In the process of microbiological substantiation of the sell-by date of food products it should be taken into consideration the presence of leading pathogen and causative microorganisms of microbial spoilage, the initial contamination level, the lag phase duration of germ culture development, variations between strains, the kinetics of microorganisms’ accumulation within the product in real and aggravated storage conditions, the indetermination connected with biological nature of microorganisms and their inhomogeneous allocation within the product, the limitation for shortcut research methods (if applicable). The decision rule should be based on the consumer’s risk concept. Key Words: food products, sell-by date, substantiation, microbiological indicators.

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Growth kinetics of Salmonella Typhimurium and Listeria monocytogenes in buffalo milk under different processing and storage conditions

Ciência Rural ◽

10.1590/0103-8478cr20200967 ◽

2021 ◽

Vol 51 (11) ◽

Author(s):

Joelson Sousa Lima ◽

Ana Paula Presley Oliveira Sampaio ◽

Mylla Christy da Silva Dufossé ◽

Paula Fernanda Morais de Sousa ◽

Josyane Brasil da Silva ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Salmonella Typhimurium ◽

Growth Kinetics ◽

Storage Conditions ◽

Buffalo Milk ◽

Production Chain ◽

Pasteurized Milk ◽

Processing And Storage ◽

And Storage ◽

Kinetics Of

ABSTRACT: Buffalo milk is rich in nutrients and can serve as a substrate for the proliferation of microorganisms. Thus, the objective of the present study was to evaluate the growth kinetics of Salmonella Typhimurium and Listeria monocytogenes in buffalo milk under different processing and storage conditions. Samples of raw and pasteurized milk were inoculated with 1 CFU of each bacterium, separately and together, per 25 mL. After contamination, samples were stored at 8 °C or 37 °C, and bacterial counts were performed at 24, 48, and 168 h. In addition, the accompanying microbiota growth, pH, and the effect of these variables on the growth kinetics of microorganisms were monitored. The pathogens tested were able to proliferate under most conditions tested, reaching high titers throughout the experimental period. At 37 °C, there was a decrease in pH and an increase in the accompanying microbiota that interfered with the microbial growth curve. It was also observed that pasteurized milk subjected to 8 °C provided better conditions for the multiplication of bacteria. Therefore, it was concluded that care throughout the production chain, storage, and commercialization of milk must be adopted to guarantee the microbiological safety of this food.

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Influencing the growth kinetics of yeast strains with vitamin supplementation

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/74/1674 ◽

2018 ◽

pp. 113-115

Author(s):

Judit Molnár ◽

Erika Lakatos ◽

Balázs Ásványi

Keyword(s):

Corn Steep Liquor ◽

Cell Mass ◽

Single Cell Protein ◽

Vitamin Supplementation ◽

Cell Protein ◽

Specific Rate ◽

Yeast Strains ◽

Matter Production ◽

Steep Liquor ◽

Kinetics Of

The aim of the current experiment was to optimize the creation process of single cell protein on plant-based substrate solution with the intention to improve end-product turn out by means of adding vitamin solution. Based on the results of the fermentation processes of yeast strains, it was concluded that the vitamin-supplementation produced its greatest effect on the dry matter production, primarily on the K. marxianus DSM 4908 strain, while it was less beneficent when it comes to the figures of wet cell mass. In addition, it can be assumed that vitamin supplementation increased the maximum specific rate of growth (μmax) and decreased the generation time (tg) significantly. In the case of the K. marxianus yeast strain on corn steep liquor treated with vitamin-supplementation, the highest (μmax) and the lowest (tg) data were observed [(0.226 h-1) and (4.4 h), respectively]. Based on the results it was found that K. marxianus DSM 4908 is expedient to be applied on corn steep liquor medium in order to determine its suitability to produce additive for feeding.

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Growth Modeling of Listeria monocytogenes in Pasteurized Liquid Egg

Journal of Food Protection ◽

10.4315/0362-028x.jfp-12-524 ◽

2013 ◽

Vol 76 (9) ◽

pp. 1549-1556 ◽

Cited By ~ 3

Author(s):

MIHO OHKOCHI ◽

SHIGENOBU KOSEKI ◽

MASAAKI KUNOU ◽

KATSUAKI SUGIURA ◽

HIROKAZU TSUBONE

Keyword(s):

Listeria Monocytogenes ◽

Specific Growth ◽

Storage Temperature ◽

Growth Parameters ◽

Root Model ◽

Natural Flora ◽

Mean Square Errors ◽

Kinetics Of ◽

Storage Temperatures ◽

Maximum Population Density

The growth kinetics of Listeria monocytogenes and natural flora in commercially produced pasteurized liquid egg was examined at 4.1 to 19.4°C, and a growth simulation model that can estimate the range of the number of L. monocytogenes bacteria was developed. The experimental kinetic data were fitted to the Baranyi model, and growth parameters, such as maximum specific growth rate (μmax), maximum population density (Nmax), and lag time (λ), were estimated. As a result of estimating these parameters, we found that L. monocytogenes can grow without spoilage below 12.2°C, and we then focused on storage temperatures below 12.2°C in developing our secondary models. The temperature dependency of the μmax was described by Ratkowsky's square root model. The Nmax of L. monocytogenes was modeled as a function of temperature, because the Nmax of L. monocytogenes decreased as storage temperature increased. A tertiary model of L. monocytogenes was developed using the Baranyi model and μmax and Nmax secondary models. The ranges of the numbers of L. monocytogenes bacteria were simulated using Monte Carlo simulations with an assumption that these parameters have variations that follow a normal distribution. Predictive simulations under both constant and fluctuating temperature conditions demonstrated a high accuracy, represented by root mean square errors of 0.44 and 0.34, respectively. The predicted ranges also seemed to show a reasonably good estimation, with 55.8 and 51.5% of observed values falling into the prediction range of the 25th to 75th percentile, respectively. These results suggest that the model developed here can be used to estimate the kinetics and range of L. monocytogenes growth in pasteurized liquid egg under refrigerated temperature.

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Kinetics of Ascorbic Acid Degradation in Un-Pasteurized Iranian Lemon Juice During Regular Storage Conditions

Pakistan Journal of Biological Sciences ◽

10.3923/pjbs.2008.1365.1369 ◽

2008 ◽

Vol 11 (10) ◽

pp. 1365-1369 ◽

Cited By ~ 5

Author(s):

Abbasi . ◽

M. Niakousari

Keyword(s):

Ascorbic Acid ◽

Storage Conditions ◽

Lemon Juice ◽

Acid Degradation ◽

Kinetics Of

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Effect of storage temperature on volatile marker compounds in cured loins fermented with Staphylococcus carnosus by brine injection

European Food Research and Technology ◽

10.1007/s00217-020-03621-w ◽

2020 ◽

Author(s):

Ramona Bosse ◽

Melanie Wirth ◽

Jochen Weiss ◽

Monika Gibis

Keyword(s):

High Temperature ◽

Volatile Compounds ◽

Bacterial Growth ◽

Storage Temperature ◽

Maximum Effect ◽

Staphylococcus Carnosus ◽

C Storage ◽

Marker Compounds ◽

Brine Injection ◽

Storage Temperatures

Abstract In this study, the influence of low (5 °C), intermediate (15 °C) and high (25 °C) storage temperatures on the profile of volatile compounds of North European cured loins fermented with Staphylococcus carnosus strains was investigated. In this context, proteolytic activity, bacterial growth, key volatile compounds and sensory attributes were studied. In conclusion, storage temperature significantly affected the volatile marker compounds. A multiple regression indicated significant effects of seven volatile compounds (acetophenone, benzaldehyde, butanone, 3-methylbutanal, 1-octen-3-ol, nonanal and pentanone) on the overall odor (R2 = 95.9%) and overall flavor (R2 = 81.1%). The sum of the marker volatiles aldehydes, ketones and alcohol increased with rising temperatures and the highest amounts of the odor active 3-methylbutanal up to 155 and 166 ng/g meat were detected in high temperature-stored loins. Moreover, the addition of S. carnosus strain LTH 3838 showed maximum effect at 5 °C-storage temperature in comparison to the control.

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