Does bruising influence the volatile profile of pears?

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Martina Bodner ◽  
Matteo Scampicchio
Keyword(s):  
Proton Transfer Reaction ◽  
Linear Increase ◽  
Main Role ◽  
Content Type ◽  
Color Changes ◽  
Volatile Flavor ◽  
Green Component ◽  
Volatile Organic ◽  
Bruise Susceptibility ◽  
Cielab Color

Purpose Volatile flavor plays a main role in defining the fruit quality by consumers. Bruising leads often to dark spots on fruits and its amount could highly affect product quality. This paper aims to study the effect of bruising on the volatilome released by pears by using proton transfer reaction – mass spectrometry (PTR-MS). Design/methodology/approach Fingerprints of non-bruised and bruised pear samples were collected through PTR-MS for 28 days, and discriminant analysis was used to discriminate the fruit products. The CIELAB color changes were also measured during the entire ripening period. Findings Bruised pears released a higher intensity of volatile organic compounds (VOCs) compared to non-bruised pears (p16days = 0.049, p22days = 0.012, p28days = 0.006). In particular, the release of m/z 45 and m/z 47 were significantly (pm/z 45 = 0.076, pm/z 47 = 0.095.) higher in bruised samples, suggesting that the bruising event accelerated the natural ripening process. CIELAB color coordinates were also recorded. The coordinate a* showed a linear increase during the whole 28 days because of the loss of the green component. The CIELAB ΔE* was higher in the bruised pears than the non-bruised pears (p = 0.022). Originality/value Bruising can affect food quality and taste. Bruise susceptibility has been largely studied on apples, tomatoes and peaches, but rarely on pears. Very little is known about the effect of bruising on the volatilome of pears. Moreover, bruising research usually involved the study of physical properties; on the contrary, PTR-MS, applied to bruising research, has never been used before. Besides the analysis of volatilome, the changes in color were also recorded for the whole 28 days of analysis. The proposed method could be applied for the monitoring of pears quality in the food industry.

Benzene food exposure and their prevent methods: a review

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Parisa Sadighara ◽  
Mohadeseh Pirhadi ◽  
Melina Sadighara ◽  
Parisa Shavaly-Gilani ◽  
Mohammad Reza Zirak ◽  
...  
Keyword(s):  
High Risk ◽  
Organic Compound ◽  
Design Methodology ◽  
Food Packaging ◽  
Preventive Measures ◽  
Food Groups ◽  
Mechanism Of Formation ◽  
Content Type ◽  
Volatile Organic ◽  
Practical Implications

Purpose Benzene contamination has been reported in some food groups. This study aims to identify high-risk foods groups to assess exposure to benzene. Design/methodology/approach Benzene is a hazardous volatile organic compound commonly used in the production of chemicals, detergents, paints and plastics. In addition, benzene is present in food and beverages. Findings Citrus juice-based beverages are usually more contaminated with benzene than other beverages. Benzene was also detected in carbonated beverages, fruit juices, pickles, lime juices, mayonnaise and salad dressing. Smoked and canned products have higher content of benzene. Aromas that are used in food contained benzene. Food packaging is one of the sources of benzene contamination of food. One of the reasons for its formation in food staff is due to the reaction of vitamin C (or similar acid) with benzoate, which is mainly used as a preservative in various foods. Practical implications Foods contaminated with benzene were determined. Moreover, mechanisms of its formation and some preventive measures were discussed. Originality/value This review determined the amount of benzene in foods, mechanism of formation and suggestion for prevention of benzene contamination in food.

scholarly journals Conflict-induced forced CEO turnover and firm performance

2018 ◽  
Vol 44 (9) ◽  
pp. 1134-1154
Author(s):  
Kuntara Pukthuanthong ◽  
Saif Ullah ◽  
Thomas J. Walker ◽  
Jing Zhang
Keyword(s):  
Firm Performance ◽  
Univariate Analysis ◽  
Ceo Turnover ◽  
Main Role ◽  
Corporate Boards ◽  
Firm Characteristics ◽  
Stock Performance ◽  
Content Type ◽  
Strategic Direction ◽  
The Board Of Directors

Purpose The purpose of this paper is to examine operational and stock performance changes around forced CEO turnovers caused by conflicts between corporate boards and CEOs over the strategic direction of the firm. In addition, the authors investigate whether changes in performance can be explained by board, CEO, or firm characteristics. Design/methodology/approach The authors apply propensity score matching to choose matching firms that do not forced CEO turnover but have similar characteristics with the sample firms. The authors compare their operating and stock performances. The authors apply both univariate analysis and multivariate regression analyses. Findings The authors find that the CEO turnovers caused by conflicts between corporate boards and CEOs over the strategic direction of the firms tend to be preceded by significant declines in a firm’s operating and stock performance and that corporate performance improves after turnovers. In addition, the authors find that an increase in long-term incentives and firm size and a decrease in turnover improve firm performance. Originality/value While the existing corporate governance literature emphasizes oversight as the main role of the board of directors and identifies the CEO as the leader who sets the strategic direction of the firm, in cases of conflict-induced forced CEO turnover, it is the board that sets the strategic direction. This paper is the first to provide evidence regarding the implications of conflict-induced forced CEO turnovers.

scholarly journals Segmented flow coil equilibrator coupled to a proton-transfer-reaction mass spectrometer for measurements of a broad range of volatile organic compounds in seawater

Ocean Science ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 925-940 ◽  
Author(s):  
Charel Wohl ◽  
David Capelle ◽  
Anna Jones ◽  
William T. Sturges ◽  
Philip D. Nightingale ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Exchange ◽  
Proton Transfer ◽  
Organic Compounds ◽  
Mass Spectrometer ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Reaction Mass ◽  
Segmented Flow ◽  
Volatile Organic

Abstract. We present a technique that utilises a segmented flow coil equilibrator coupled to a proton-transfer-reaction mass spectrometer to measure a broad range of dissolved volatile organic compounds. Thanks to its relatively large surface area for gas exchange, small internal volume, and smooth headspace–water separation, the equilibrator is highly efficient for gas exchange and has a fast response time (under 1 min). The system allows for both continuous and discrete measurements of volatile organic compounds in seawater due to its low sample water flow (100 cm3 min−1) and the ease of changing sample intake. The equilibrator setup is both relatively inexpensive and compact. Hence, it can be easily reproduced and installed on a variety of oceanic platforms, particularly where space is limited. The internal area of the equilibrator is smooth and unreactive. Thus, the segmented flow coil equilibrator is expected to be less sensitive to biofouling and easier to clean than membrane-based equilibration systems. The equilibrator described here fully equilibrates for gases that are similarly soluble or more soluble than toluene and can easily be modified to fully equilibrate for even less soluble gases. The method has been successfully deployed in the Canadian Arctic. Some example data from underway surface water and Niskin bottle measurements in the sea ice zone are presented to illustrate the efficacy of this measurement system.

scholarly journals Measurements of volatile organic compounds over West Africa

2010 ◽  
Vol 10 (2) ◽  
pp. 3861-3892 ◽  
Author(s):  
J. G. Murphy ◽  
D. E. Oram ◽  
C. E. Reeves
Keyword(s):  
Boundary Layer ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Marine Boundary Layer ◽  
Deep Convection ◽  
Proton Transfer Reaction ◽  
Oxidation Products ◽  
High Time Resolution ◽  
Airborne Measurements ◽  
Volatile Organic

Abstract. In this paper we describe measurements of volatile organic compounds (VOCs) made using a Proton Transfer Reaction Mass Spectrometer (PTR-MS) aboard the UK Facility for Atmospheric Airborne Measurements during the African Monsoon Multidisciplinary Analyses (AMMA) campaign. Observations were made during approximately 85 h of flying time between 17 July and 17 August 2006, above an area between 4° N and 18° N and 3° W and 4° E, encompassing ocean, mosaic forest, and the Sahel desert. High time resolution observations of counts at mass to charge (m/z) ratios of 42, 59, 69, 71, and 79 were used to calculate mixing ratios of acetonitrile, acetone, isoprene, the sum of methyl vinyl ketone and methacrolein, and benzene, respectively using laboratory-derived humidity-dependent calibration factors. Strong spatial associations between vegetation and isoprene and its oxidation products were observed in the boundary layer, consistent with biogenic emissions followed by rapid atmospheric oxidation. Acetonitrile, benzene, and acetone were all enhanced in airmasses which had been heavily influenced by biomass burning. Benzene and acetone were also elevated in airmasses with urban influence from cities such as Lagos, Cotonou, and Niamey. The observations provide evidence that both deep convection and mixing associated with fair-weather cumulus were responsible for vertical redistribution of VOCs emitted from the surface. Profiles over the ocean showed a depletion of acetone in the marine boundary layer, but no significant decrease for acetonitrile.

scholarly journals Eddy covariance emission and deposition flux measurements using proton transfer reaction-time of flight-mass spectrometry (PTR-TOF-MS): comparison with PTR-MS measured vertical gradients and fluxes

2012 ◽  
Vol 12 (8) ◽  
pp. 20435-20482 ◽  
Author(s):  
J.-H. Park ◽  
A. H. Goldstein ◽  
J. Timkovsky ◽  
S. Fares ◽  
R. Weber ◽  
...  
Keyword(s):  
Reaction Time ◽  
Proton Transfer ◽  
Organic Compounds ◽  
Transfer Reaction ◽  
Vertical Gradient ◽  
Proton Transfer Reaction ◽  
Volatile Organic ◽  
Flux Measurements ◽  
Ion Species ◽  
Tof Ms

Abstract. During summer 2010, a proton transfer reaction-time of flight-mass spectrometer (PTR-TOF-MS) and a standard proton transfer reaction mass spectrometer (PTR-MS) were deployed simultaneously for one month in an orange orchard in the Central Valley of California to collect continuous data suitable for eddy covariance (EC) flux calculations. The high time resolution (5 Hz) and high mass resolution (up to 5000 m Δ m−1) data from the PTR-TOF-MS provided the basis for calculating the concentration and flux for a wide range of volatile organic compounds (VOC). Throughout the campaign, 664 mass peaks were detected in mass-to-charge ratios between 10 and 1278. Here we present PTR-TOF-MS EC fluxes of the 27 ion species for which the vertical gradient was simultaneously measured by PTR-MS. These EC flux data were validated through spectral analysis (i.e. co-spectrum, normalized co-spectrum, and ogive). Based on inter-comparison of the two PTR instruments, no significant instrumental biases were found in either mixing ratios or fluxes, and the data showed agreement within 5% on average for methanol and acetone. For the measured biogenic volatile organic compounds (BVOC), the EC fluxes from PTR-TOF-MS were in agreement with the qualitatively inferred flux directions from vertical gradient measurements by PTR-MS. For the 27 selected ion species reported here, the PTR-TOF-MS measured total (24 h) mean net flux of 299 μg C m−2 h−1. The dominant BVOC emissions from this site were monoterpenes (m/z 81.070 + m/z 137.131 + m/z 95.086, 34%, 102 μg C m−2 h−1) and methanol (m/z 33.032, 18%, 72 μg C m−2 h−1). The next largest fluxes were detected at the following masses (attribution in parenthesis): m/z 59.048 (mostly acetone, 12.2%, 36.5 μg C m−2 h−1), m/z 61.027 (mostly acetic acid, 11.9%, 35.7 μg C m−2 h−1), m/z 93.069 (para-cymene + toluene, 4.1%, 12.2 μg C m−2 h−1), m/z 45.033 (acetaldehyde, 3.8%, 11.5 μg C m−2 h−1), m/z 71.048 (methylvinylketone + methacrolein, 2.4%, 7.1 μg C m−2 h−1), and m/z 69.071 (isoprene + 2-methyl-3-butene-2-ol, 1.8%, 5.3 μg C m−2 h−1). Low levels of emission and/or deposition (<1.6% for each, 5.8% in total flux) were observed for the additional reported masses. Overall, our results show that EC flux measurements using PTR-TOF-MS is a powerful new tool for characterizing the biosphere-atmosphere exchange including both emission and deposition for a large range of BVOC and their oxidation products.

The use of hydroxyethyl cellulose as a transparent filling material in finishing polish

2018 ◽  
Vol 47 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Jülide Erkmen
Keyword(s):  
Design Methodology ◽  
Cost Effective ◽  
Hydroxyethyl Cellulose ◽  
Filling Material ◽  
Limited Information ◽  
Content Type ◽  
Alkyd Resins ◽  
Volatile Organic ◽  
Water Saturated ◽  
Practical Implications

Purpose This study aims to propose a solution to decrease the environmental pollution caused by alkyd resins that harm the environment during their production and use. Design/methodology/approach A commercially produced polish formulation was used in the study. To reduce the use of this formulation in finishing polish, a water-saturated transparent solution of hydroxyethyl cellulose was used as a transparent filling material. Findings The use of hydroxyethyl cellulose at its optimum concentration in finishing polish only reduced the gloss by 0.027 per cent. The amount of alkyd was reduced by 24 per cent in weight. Research limitations/implications The literature contained highly limited information on this subject. No transparent filling material was found. Thus, no comparison can be made with other studies. Practical implications The results obtained from this study can help manufacturers in the polish industry to produce varnish in a more cost-effective and eco-friendly way. Originality/value Considerable amount of volatile organic compounds released into the atmosphere as a result of the use of solvent-based dye/varnishes in the woodworking industry alone proves the importance of water-based systems. The results of this study indicate both economic and environmental gain.

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