scholarly journals The Effects of Storage Temperature on the Aroma of Whole Bean Arabica Coffee Evaluated by Coffee Consumers and HS-SPME-GC-MS

Beverages ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 68 ◽  
Author(s):  
Andrew Cotter ◽  
Helene Hopfer
Keyword(s):  
Room Temperature ◽  
Storage Temperature ◽  
Solid Phase ◽  
Storage Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Green Beans ◽  
Projective Mapping ◽  
Shelf Stable ◽  
Product Maps ◽  
The Impact

Although from a food safety point, coffee is considered a shelf-stable product, changes in volatiles over time due to out-gassing and chemical reactions lead to perceivable differences in coffee aroma and “freshness”. Previous studies have looked at the impact of storage conditions on ground or brewed coffee. This study seeks to answer the question of how coffee consumers perceive the smell of coffee grounds of whole beans that have been stored under different conditions: freezer vs. room temperature for 9 weeks compared to a newly roasted control (stored for 1 day). Green beans from the same production lot were roasted to two different levels to also evaluate the impact of roast level on aroma changes. Using projective mapping (PM) followed by ultra-flash profiling (UFP), 48 coffee consumers evaluated, using only smell, 6 different freshly ground coffee samples presented in blind duplicates. In parallel, the profiles of 48 previously reported important coffee volatiles were measured by headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) to relate chemical changes to perceivable sensory aroma changes. Overall, consumer product maps mimicked the instrumental measurements in that the lighter roast coffees showed smaller changes due to storage conditions compared to the dark roast samples. Consumers also perceived the frozen dark roast samples to be more similar to the newly roasted control than the samples stored at room temperature.

scholarly journals Volatile Changes during Storage of Shelf Stable Apple Juice: Integrating GC-MS Fingerprinting and Chemometrics

Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 165 ◽  
Author(s):  
Biniam Kebede ◽  
Vivien Ting ◽  
Graham Eyres ◽  
Indrawati Oey
Keyword(s):  
Shelf Life ◽  
Solid Phase Microextraction ◽  
Apple Juice ◽  
Solid Phase ◽  
Storage Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Dimethyl Sulphide ◽  
Processing And Storage ◽  
Shelf Stable ◽  
And Storage

This is the first study to reveal potential markers for volatile changes during ambient and accelerated shelf life of pasteurized apple juice. The volatile changes were monitored at 20, 30 and 40 °C using a headspace solid-phase microextraction-gas chromatography-mass spectrometry fingerprinting method. Using modern chemometrics and feature selection, hexanal, trans-2-hexenal, dimethyl sulphide, furfural, ethyl acetate and 1-pentanol were chosen as potential shelf life markers. Volatiles associated with the green, grassy and fresh apple aroma, such as hexanal and trans-2-hexenal, decreased during storage, whereas thermal load and browning associated compounds, like dimethyl sulphide and furfural, increased during storage. Hexanal and trans-2-hexenal can be markers to monitor the change in green-apple like character. Furfural and dimethyl sulphide can be markers of temperature abuse during juice processing and storage. Furfural can also be an indicator for juice browning. The present work effectively identified potential markers to monitor and predict volatile aroma changes of shelf stable apple juice in different storage conditions. Sensory analysis can be conducted in the future to confirm the aroma relevance of selected markers.

scholarly journals Impact of Storage Conditions on the Methanogenic Activity of Anaerobic Digestion Inocula

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1321 ◽  
Author(s):  
Sergi Astals ◽  
Konrad Koch ◽  
Sören Weinrich ◽  
Sasha D. Hafner ◽  
Stephan Tait ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Room Temperature ◽  
Storage Time ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Methanogenic Activity ◽  
Specific Methanogenic Activity ◽  
The Impact ◽  
And Storage ◽  
Over Time

The impact of storage temperature (4, 22 and 37 °C) and storage time (7, 14 and 21 days) on anaerobic digestion inocula was investigated through specific methanogenic activity assays. Experimental results showed that methanogenic activity decreased over time with storage, regardless of storage temperature. However, the rate at which the methanogenic activity decreased was two and five times slower at 4 °C than at 22 and 37 °C, respectively. The inoculum stored at 4 °C and room temperature (22 °C) maintained methanogenic activity close to that of fresh inoculum for 14 days (<10% difference). However, a storage temperature of 4 °C is preferred because of the slower decrease in activity with lengthier storage time. From this research, it was concluded that inoculum storage time should generally be kept to a minimum, but that storage at 4 °C could help maintain methanogenic activity for longer.

scholarly journals Health Risk Assessment of Toxic and Harmful Air Pollutants Discharged by a Petrochemical Company in the Beijing-Tianjin-Hebei Region of China

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1604
Author(s):  
Tao Zhu ◽  
Furong Li ◽  
Wenfeng Niu ◽  
Zijun Gao ◽  
Yiwei Han ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Solid Phase ◽  
Carcinogenic Risk ◽  
Pollutant Emissions ◽  
Oil Refining ◽  
Pollutant Emission ◽  
Gas Chromatography Mass Spectrometry ◽  
Hazardous Air Pollutants ◽  
Petrochemical Company ◽  
The Impact

Monitoring of toxic and hazardous air pollutants (HAPs) in a petrochemical company in the Beijing-Tianjin-Hebei region of China to assess the impact of HAPs on the health risks of workers in the petrochemical company. The samples were tested by solid-phase adsorption thermal desorption/gas chromatography-mass spectrometry (HJ734-2014), and the pollutant emission list was obtained. According to the pollutant emission inventory, it can be seen that benzene, toluene and xylene are the main components of toxic and harmful air pollutants emitted by the petrochemical enterprise. The method of combining actual monitoring and CALPUFF model prediction was used to evaluate the impact of the toxic and harmful air pollutants emitted by the enterprise on the health of workers. The risk characterization results show that when benzene is the maximum concentration value predicted by the model, it will pose a carcinogenic risk to the factory workers. Therefore, based on the results of this study, it is recommended not to allow residents to live within the predicted concentration range of the model. The results of this study can enable China’s oil refining industry to better understand the characteristics of pollutant emissions from petrochemical companies in the Beijing-Tianjin-Hebei region. Moreover, the results of this study can be used as a policy basis for improving the health of workers in petrochemical enterprises, and are of great significance to the protection of public health.

scholarly journals Madeira Wine Volatile Profile. A Platform to Establish Madeira Wine Aroma Descriptors

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3028 ◽  
Author(s):  
Rosa Perestrelo ◽  
Catarina Silva ◽  
José S. Câmara
Keyword(s):  
Solid Phase ◽  
Point Of View ◽  
Gas Chromatography Mass Spectrometry ◽  
Wine Aroma ◽  
Grape Variety ◽  
Volatile Phenols ◽  
Starting Point ◽  
Furanic Compounds ◽  
The Impact ◽  
And Diffusion

In the present study we aimed to investigate the volatile organic compounds (VOCs) that may potentially be responsible for specific descriptors of Madeira wine providing details about Madeira wine aroma notes at molecular level. Moreover, the wine aroma profile, based on the obtained data, will be a starting point to evaluate the impact of grape variety (Malvasia, Bual, Sercial, Verdelho and Tinta Negra), type (sweet, medium sweet, dry and medium dry), and age (from 3 to 20 years old) on Madeira wine sensorial properties. Firstly, a comprehensive and in-depth Madeira wine volatile profiling was carried out using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS–SPME/GC–qMS). Secondly, a relation among the varietal, fermentative and aging aroma compounds, and their aroma descriptors with the Madeira wine sensorial properties was assessed. A total of 82 VOCs, belonging to different chemical families were identified, namely 21 esters, 13 higher alcohols, ten terpenic compounds, nine fatty acids, seven furanic compounds, seven norisoprenoids, six lactones, four acetals, four volatile phenols and one sulphur compound. From a sensorial point of view, during the aging process the wine lost its freshness and fruitiness odor related to the presence of some varietal and fermentative compounds, whereas other descriptors such as caramel, dried fruits, spicy, toasty and woody, arose during ageing. The Maillard reaction and diffusion from the oak were the most important pathways related with these descriptors. A relationship-based approach was used to explore the impact of grape variety, wine type, and age on Madeira wine sensorial properties based on shared number of VOCs and their odors.

scholarly journals Influence of storage time and temperature on the activity of urease

2019 ◽  
Vol 51 (2) ◽  
pp. 159-163
Author(s):  
B. Alev ◽  
S. Tunali ◽  
R. Yanardag ◽  
A. Yarat
Keyword(s):  
Room Temperature ◽  
Storage Time ◽  
Urease Activity ◽  
Storage Temperature ◽  
Practical Importance ◽  
Storage Conditions ◽  
Relative Activity ◽  
Significant Loss ◽  
Long Term Storage ◽  
Activity Measurements

Enzymes are made of protein, that is why they are sensitive molecules and are affected by storage conditions. A small change in enzyme activity during storage may cause a big error in analysis results. The aim of the study was to evaluate the effects of storage time and temperature on urease activity. Urease solutions were prepared at different activities (from 100 to 2000 U/mL) and stored at room temperature, in the refrigerator (4°C), and in the deep freezer (-18°C and -80°C). Activity measurements were made at regular intervals until 28 days by the modified Weatherburn method. The relative activities of 100-1000 U/mL urease solutions stored at room temperature, 4, -18 or -80°C were 75% and below after 4 days. Twenty-eight days later, for 2000 U/mL urease solutions, only at room temperature, the relative activity was reduced to 37%, while at 4, -18 or -80°C, the relative activities were above 80%. Since urease can be maintained at 4°C for 28 days without significant loss of activity, it has practical importance. Low-activity urease solutions (such as 100-1000 U/mL) should not be stored at -18 or -80°C for short or long term storage, they should be stored at 4°C only for one day. Keywords: Urease activity, storage time, storage temperature

scholarly journals Comparison of Chemical Compounds and Their Influence on The Taste of Coffee Depending on Green Beans Storage Conditions

2021 ◽  
Author(s):  
Magdalena Zarebska ◽  
Natalia Stanek ◽  
Krzysztof Barabosz ◽  
Anna Jaszkiewicz ◽  
Renata Kulesza ◽  
...  
Keyword(s):  
Storage Temperature ◽  
Chemical Compounds ◽  
Treatment Method ◽  
Storage Conditions ◽  
Sensory Profile ◽  
Roasted Coffee ◽  
Green Beans ◽  
Grain Processing ◽  
Better Than ◽  
Natural Way

Abstract Currently, there is no technology for storing green coffee (GC), which results in obtaining high-quality roasted coffee (RC). The aim of this study was evaluating the effects of storage temperature (-10, 5, 10, 18, 20ºC, uncontrolled), post-harvest treatment method (natural (N), washed (W)) and type of packaging material (GrainPro (G), jute (J) bags) on content of chlorogenic acids, caffeine and trigonelline as also on sensory profile of GC from “specialty’ sector after 12 months of measured storage. HPLC results showed that GrainPro bags preserve considered compounds better than jute. Exception was 10oC chamber, where in the samples from jute have been reported higher contents of all analyzed compounds. Also natural way of grain processing retains more assayed compounds. The best results were obtained in 10oC for jute both, natural and washed, where the highest level of all considered compounds were noted. The tendency was supported by the sensory analysis.

scholarly journals Chemical Variability in the Composition of Zhumeria majdae (Rech. F. & Wendelbo) Essential Oil According to Storage Time and Temperature

Horticulturae ◽  
2021 ◽  
Vol 7 (11) ◽  
pp. 463
Author(s):  
Akbar Karami ◽  
Fatemeh Tashani ◽  
Aminallah Tahmasebi ◽  
Filippo Maggi
Keyword(s):  
Essential Oil ◽  
Room Temperature ◽  
Storage Time ◽  
Storage Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Average Value ◽  
Oil Storage ◽  
Chemical Variability ◽  
Refrigerator Temperature ◽  
Storage Temperatures

Zhumeria majdae (Rech. F. & Wendelbo) is an aromatic herb belonging to the Lamiaceae family, traditionally employed in the Persian medicine for the treatment of a wide number of diseases. In the present study, the chemical composition of Z. majdae essential oil obtained from the plant’s aerial features, and stored at various temperatures (refrigerator temperature 4 °C, freezer temperature −20 °C, and room temperature 20 ± 3 °C) and times (0, 3, 6, and 9 months) was studied. The essential oil was isolated through hydrodistillation, and its composition was evaluated by gas chromatography/mass spectrometry (GC/MS). The results showed that the composition of essential oils changed as a function of the various storage temperatures and times. Linalool (34.85–48.45%), camphor (27.09–39.17%), limonene (1.97–4.88%), and camphene (1.6–4.84%) made up the main volatile compounds which showed differences in their concentrations according to the various storage conditions. Notably, when compared to a non-stored treatment sample (analyzed immediately after essential oil collection), the amount of linalool and camphor increased in all samples stored in all conditions of temperature and time, with the exception of the samples stored for nine months at room temperature. On the other hand, limonene and camphene contents decreased during the storage treatments, showing that the highest content of these compounds occurred in the non-stored treatment. Essential oil storage at the freezer temperature and for three months storage time resulted in the highest average value of the major constituents, highlighting these as the best conditions for obtaining the highest content of the major compounds.

scholarly journals Contribution of Grape Skins and Yeast Choice on the Aroma Profiles of Wines Produced from Pinot Noir and Synthetic Grape Musts

Fermentation ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 168
Author(s):  
Yifeng Qiao ◽  
Diana Hawkins ◽  
Katie Parish-Virtue ◽  
Bruno Fedrizzi ◽  
Sarah J. Knight ◽  
...  
Keyword(s):  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Fermentation Medium ◽  
Pinot Noir ◽  
Gas Chromatography Mass Spectrometry ◽  
Wine Quality ◽  
Aroma Profile ◽  
Aroma Production ◽  
Grape Skins ◽  
The Impact

The aroma profile is a key component of Pinot noir wine quality, and this is influenced by the diversity, quantity, and typicity of volatile compounds present. Volatile concentrations are largely determined by the grape itself and by microbial communities that produce volatiles during fermentation, either from grape-derived precursors or as byproducts of secondary metabolism. The relative degree of aroma production from grape skins compared to the juice itself, and the impact on different yeasts on this production, has not been investigated for Pinot noir. The influence of fermentation media (Pinot noir juice or synthetic grape must (SGM), with and without inclusion of grape skins) and yeast choice (commercial Saccharomyces cerevisiae EC1118, a single vineyard mixed community (MSPC), or uninoculated) on aroma chemistry was determined by measuring 39 volatiles in finished wines using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC-MS). Fermentation medium clearly differentiated the volatile profile of wines with and without yeast, while differences between EC1118 and MSPC wines were only distinct for Pinot noir juice without skins. SGM with skins produced a similar aroma profile to Pinot noir with skins, suggesting that grape skins, and not the pulp, largely determine the aroma of Pinot noir wines.

scholarly journals Preanalytical Variables Affecting the Quantification of Fatty Acid Ethyl Esters in Plasma and Serum Samples

1999 ◽  
Vol 45 (12) ◽  
pp. 2183-2190 ◽  
Author(s):  
Britt L Soderberg ◽  
Ewa T Sicinska ◽  
Emily Blodget ◽  
Joanne E Cluette-Brown ◽  
Paolo M Suter ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Solid Phase ◽  
Alcoholic Beverage ◽  
Ethanol Consumption ◽  
Ethanol Intake ◽  
Fatty Acid Ethyl Esters ◽  
Ethyl Esters ◽  
Gas Chromatography Mass Spectrometry ◽  
Clinical Test ◽  
The Impact

Abstract Background: Fatty acid ethyl esters (FAEEs) are cytotoxic nonoxidative ethanol metabolites produced by esterification of fatty acids and ethanol. FAEEs are detectable in blood up to 24 h after ethanol consumption. The objective of this study was to assess the impact of gender, serum or plasma triglyceride concentration, time and temperature of specimen storage, type of alcoholic beverage ingested, and the rate of ethanol consumption on FAEE concentrations in plasma or serum. Methods: For some studies, subject were recruited volunteers; in others, residual blood samples after ethanol quantification were used. FAEEs were isolated by solid-phase extraction and quantified by gas chromatography–mass spectrometry. Results: For weight-adjusted amounts of ethanol intake, FAEE concentrations were twofold greater for men than women (P ≤0.05). Accounting for triglycerides improved the correlation between blood ethanol concentrations and FAEE concentrations for both men (from r = 0.640 to r = 0.874) and women (from r = 0.619 to r = 0.673). FAEE concentrations did not change when samples were stored at or below 4 °C, but doubled when stored at room temperature for ≥24 h. The type of alcoholic beverage and rate of consumption did not affect FAEE concentrations. Conclusion: These studies advance plasma and serum FAEE measurements closer to implementation as a clinical test for ethanol intake.

Effect of storage, light and homogenization on the colour of ultra heat treated and sterilized milk

1986 ◽  
Vol 53 (4) ◽  
pp. 615-624 ◽  
Author(s):  
Geoffrey R. Andrews
Keyword(s):  
Room Temperature ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Rate Of Change ◽  
Uht Milk ◽  
Rates Of Change ◽  
Heat Treated ◽  
Whole Milk ◽  
Light Reflectance ◽  
Sterilized Milk

SummaryThe rates of change in light reflectance and in CIELAB tri-stimulus colour values were compared for direct and indirect ultra heat treated (UHT) and sterilized milk in glass and polyethene bottles stored under different conditions. The rate of change of milk reflectance was higher at shorter wavelengths and the milk colour changed more rapidly at 30 and 37 °C than at room temperature. Sterilized milk in polyethene bottles was bleached when stored in an illuminated cabinet. The colour of skimmed milk changed more rapidly than that of whole milk. The rate of change in reflectance of direct UHT milk above 590 nm was found to be higher than in other milks. A statistical interaction was found between the fat content and the storage temperature for the CIELAB values. The homogenization pressure used in processing UHT milk samples did not affect the rate of change of the milk colour. The main implication of these findings may be that milk colour cannot be used to assess the heat treatment of a milk when the age or storage conditions of the milk are unknown.

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