Electrochemical oxidation of volatile organic compounds in all-solid cell at ambient temperature

HighlightsAromatic compounds generated 72.6% of the total odor activity values (OAVs) over time.Cold treatments had significantly lower total OAVs than hot treatments regardless of the age of the bedded pack.Abstract. Beef cattle producers are beginning to raise cattle in confinement facilities such as slatted-floor barns, hoop barns, and mono-slope facilities. Hoop and mono-slope facilities typically use bedding packs as part of their manure management system, with crop residues being the most commonly used bedding material. This study was conducted to determine the effects of bedding material, i.e., corn stover (CS), bean stover (BS), wheat straw (WS), or pine wood chips (PC), and environmental ambient temperature, i.e., cold (15°C) or hot (30°C), on the concentrations of odorous volatile organic compounds (VOCs) in air samples collected in the headspace above lab-scale bedded packs over a 42-day period. Total aromatic compounds, sulfide compounds, straight-chain fatty acids (SCFAs), and branched-chain fatty acids (BCFAs) were measured and used to calculate total odor activity values (OAVs) for each bedding and temperature effect. No significant three-way interactions for bedding material × ambient temperature × age of bedded pack were observed. Significant bedding material × ambient temperature interactions were observed for total aromatic compounds and total sulfide compounds (p = 0.0455 and p = 0.0083, respectively). The concentration of total aromatic compounds was greater for all hot treatments compared to cold treatments, with hot-CS and hot-WS bedding types (389.83 and 365.5 ng L-1, respectively) significantly (p < 0.05) greater than all other bedding types, while total aromatic compounds were lowest (87.09 ng L-1) for BS across cold treatments. Total sulfide compounds from cold-PC (51.69 ng L-1) were significantly (p = 0.0143) greater than all other treatments. Within hot treatments, total sulfide compounds were similar across all bedding materials. Total SCFAs for both cold and hot treatments decreased significantly from weeks 4 to 6. Total SCFA concentrations within weeks were significantly (p < 0.0001) greater for WS and CS compared to BS and PC but similar across bedding materials at week 6. Total BCFA concentrations from bedded packs containing CS and WS were significantly (p < 0.0001) higher at week 4 compared to concentrations from bedded packs containing BS or PC. As bedded packs aged, total BCFA concentrations for all bedding materials were similar at week 6. Total OAVs decreased over time for both hot and cold treatments, although cold treatments had significantly (p < 0.0001) lower total OAVs regardless of the age of the bedded pack. Aromatic compounds generated 72.6% of the total OAV over the 42-day study. Bedding types BS and PC had the lowest total OAVs across all weeks. The results indicate that feedlot operators maintaining bedded pack facilities will achieve the greatest overall odor reduction when using BS or PC bedding material, no matter the ambient temperature. Keywords: Bedding, Beef, Odor, Volatile organic compounds.

Download Full-text

Short-Term Post-Harvest Stress that Affects Profiles of Volatile Organic Compounds and Gene Expression in Rocket Salad during Early Post-Harvest Senescence

Plants ◽

10.3390/plants9010004 ◽

2019 ◽

Vol 9 (1) ◽

pp. 4 ◽

Cited By ~ 1

Author(s):

Natasha D. Spadafora ◽

Giacomo Cocetta ◽

Antonio Ferrante ◽

Robert J. Herbert ◽

Simone Dimitrova ◽

...

Keyword(s):

Gene Expression ◽

Volatile Organic Compounds ◽

Ambient Temperature ◽

Organic Compounds ◽

Mechanical Damage ◽

Storage Period ◽

Nutrient Content ◽

Short Term ◽

Post Harvest ◽

Volatile Organic

Once harvested, leaves undergo a process of senescence which shares some features with developmental senescence. These include changes in gene expression, metabolites, and loss of photosynthetic capacity. Of particular interest in fresh produce are changes in nutrient content and the aroma, which is dependent on the profile of volatile organic compounds (VOCs). Leafy salads are subjected to multiple stresses during and shortly after harvest, including mechanical damage, storage or transport under different temperature regimes, and low light. These are thought to impact on later shelf life performance by altering the progress of post-harvest senescence. Short term stresses in the first 24 h after harvest were simulated in wild rocket (Diplotaxis tenuifolia). These included dark (ambient temperature), dark and wounding (ambient temperature), and storage at 4 °C in darkness. The effects of stresses were monitored immediately afterwards and after one week of storage at 10 °C. Expression changes in two NAC transcription factors (orthologues of ANAC059 and ANAC019), and a gene involved in isothiocyanate production (thiocyanate methyltransferase, TMT) were evident immediately after stress treatments with some expression changes persisting following storage. Vitamin C loss and microbial growth on leaves were also affected by stress treatments. VOC profiles were differentially affected by stress treatments and the storage period. Overall, short term post-harvest stresses affected multiple aspects of rocket leaf senescence during chilled storage even after a week. However, different stress combinations elicited different responses.

Download Full-text

Volatile Organic Compound Profiles Associated with Microbial Development in Feedlot Pellets Inoculated with Bacillus amyloliquefaciens H57 Probiotic

Animals ◽

10.3390/ani11113227 ◽

2021 ◽

Vol 11 (11) ◽

pp. 3227

Author(s):

Thi Thuy Ngo ◽

Peter Dart ◽

Matthew Callaghan ◽

Athol Klieve ◽

David McNeill

Keyword(s):

Volatile Organic Compounds ◽

Ambient Temperature ◽

Organic Compounds ◽

Bacillus Amyloliquefaciens ◽

Principal Component ◽

Gas Chromatography Mass Spectrometry ◽

Score Plot ◽

Volatile Organic ◽

Microbial Volatile Organic Compounds ◽

Odour Profile

Mould and bacterial contamination releases microbial volatile organic compounds (mVOCs), causing changes in the odour profile of a feed. Bacillus amyloliquefaciens strain H57 (H57) has the potential ability to inhibit microbial growth in animal feeds. This study tested the hypothesis that H57 influences the odour profile of stored feedlot pellets by impeding the production of mVOCs. The emission of volatile organic compounds (VOCs) of un-inoculated pellets and those inoculated with H57, stored either at ambient temperature (mean 22 °C) or at 5 °C, was monitored at 0, 1, 2, and 3 months by gas chromatography–mass spectrometry. Forty VOCs were identified in all the pellet samples analysed, 24 of which were potentially of microbial and 16 of non-microbial origin. A score plot of the principal component analysis (PCA) showed that the VOC profiles of the pellets stored at ambient temperature changed more rapidly over the 3 months than those stored at 5 °C, and that change was greater in the un-inoculated pellets when compared to the inoculated ones. The bi-plot and correlation loading plots of the PCA indicated that the separation of the un-inoculated pellets from the other treatments over the 3 months was primarily due to nine mVOCs. These mVOCs have been previously identified in grains spoiled by fungi, and could be considered potential markers of the types of fungi that H57 can protect pellets against. These data indicate the ability of H57 to maintain the odour profile and freshness of concentrated feed pellets. This protective influence can be detected as early as 3 months into ambient temperature storage.

Download Full-text

Some Insights into Analytical Bias Involved in the Application of Grab Sampling for Volatile Organic Compounds: A Case Study against Used Tedlar Bags

The Scientific World JOURNAL ◽

10.1100/2011/529532 ◽

2011 ◽

Vol 11 ◽

pp. 2160-2177 ◽

Cited By ~ 12

Author(s):

Samik Ghosh ◽

Ki-Hyun Kim ◽

Jong Ryeul Sohn

Keyword(s):

Volatile Organic Compounds ◽

Ambient Temperature ◽

Organic Compounds ◽

Grab Sampling ◽

Essential Information ◽

Mechanical Abrasion ◽

Potential Source ◽

Volatile Organic ◽

Strong Source

In this study, we have examined the patterns of VOCs released from used Tedlar bags that were once used for the collection under strong source activities. In this way, we attempted to account for the possible bias associated with the repetitive use of Tedlar bags. To this end, we selected the bags that were never heated. All of these target bags were used in ambient temperature (typically at or below 30°C). These bags were also dealt carefully to avoid any mechanical abrasion. This study will provide the essential information regarding the interaction between VOCs and Tedlar bag materials as a potential source of bias in bag sampling approaches.

Download Full-text