The world's leading PTR-MS company

Ultra-Sensitive Real-Time Trace Gas Analyzers  •  Modular TOF-MS for Research & OEM


You are here

Scientific Articles - PTR-MS Bibliography

Welcome to the new IONICON scientific articles database!


Found 2 results
Title [ Year(Asc)]
Filters: Author is Hamid, N  [Clear All Filters]
[Raseetha2013] Raseetha, S., I. Oey, DJ. Burritt, S. Heenan, and N. Hamid, "Evolution of antioxidant enzymes activity and volatile release during storage of processed broccoli ( Brassica oleracea L. italica)", LWT-Food Science and Technology: Elsevier, 2013.
The objective of this study was to investigate the effects of temperature treatments (i.e. freezing at −18 °C, cool storage at 4 °C and heating at 50, 70 and 100 °C for 10 min) on the activity of peroxidase (POD), lipoxygenase (LOX), ascorbic acid oxidase (AAO), superoxide dismutase (SOD) and catalase (CAT) in broccoli (Brassica oleracea L. italica). Volatiles released during storage at 20 °C for 24 h were monitored using on-line Proton Transfer Reaction Mass Spectrometry (m/z 21–180). Partial Least Square Regression (PLSR) was used to evaluate possible correlations between enzymes and volatiles released during storage. The results showed that temperature treatment had significant effect on all enzymes, except LOX. Temperature treatment at 70 °C resulted in at least 65% decrease in POD and AAO activity. In contrast, SOD and CAT activities generally increased during storage after temperature treatments. PLSR2 results showed that volatiles released after different temperature treatments and 24 h storage had a strong correlation with the residual activity of POD, AAO and SOD but not CAT and LOX. PLSR1 results suggested that POD had the highest correlation to volatile release during storage of processed broccoli followed by AAO, SOD, CAT and LOX (the least).
[Raseetha2011] Raseetha, S., SP. Heenan, I. Oey, DJ. Burritt, and N. Hamid, "A new strategy to assess the quality of broccoli ( Brassica oleracea L. italica) based on enzymatic changes and volatile mass ion profile using Proton Transfer Reaction Mass Spectrometry (PTR-MS)", Innovative Food Science & Emerging Technologies, vol. 12, no. 2: Elsevier, pp. 197–205, 2011.
The shelf life of high quality horticultural products such as broccoli is relatively short, thereby limiting their potential for export and long distance trade. To assess the quality and the shelf life of vegetables, a reliable, accurate and high-throughput technique is required. In this study, an approach that profiled enzyme activities and volatile mass ions was used. The possible relationship between volatile mass ions and changes in the activity of enzymes that influence quality of broccoli (i.e., peroxidase/POD and ascorbate oxidase/AAO) during post-harvest storage (25 °C for 6 days) was investigated. Proton Transfer Reaction Mass Spectometry (PTR-MS) was used to scan and quantify volatile mass ions in broccoli during storage, with m/z ratio of between 20 and 180. In this study, the effect of severe wounding on enzyme activities and the volatile profile was simulated by incubating crushed broccoli florets at different time intervals (2, 4 and 6 h). Based on one-way ANOVA, changes in enzyme activities were more influenced by incubation time after crushing rather than days of storage. POD activity gradually decreased over six days of storage, while AAO activity gradually decreased over 3 to 4 days, followed by an increase in activity until the sixth day of storage. Based on Partial Least Square Regression type 1 (PLSR 1) model, a good correlation between PTR-MS volatile mass ions fingerprints and enzymatic activity in broccoli florets that varied with days of storage and incubation time after crushing was found for POD and not for AAO.

Featured Articles

Download Contributions to the International Conference on Proton Transfer Reaction Mass Spectrometry and Its Applications:


Selected PTR-MS related Reviews

F. Biasioli, C. Yeretzian, F. Gasperi, T. D. Märk: PTR-MS monitoring of VOCs and BVOCs in food science and technology, Trends in Analytical Chemistry 30 (7) (2011).

J. de Gouw, C. Warneke, T. Karl, G. Eerdekens, C. van der Veen, R. Fall: Measurement of Volatile Organic Compounds in the Earth's Atmosphere using Proton-Transfer-Reaction Mass Spectrometry. Mass Spectrometry Reviews, 26 (2007), 223-257.

W. Lindinger, A. Hansel, A. Jordan: Proton-transfer-reaction mass spectrometry (PTR–MS): on-line monitoring of volatile organic compounds at pptv levels, Chem. Soc. Rev. 27 (1998), 347-375.


Lists with PTR-MS relevant publications of the University of Innsbruck can be found here: Atmospheric and indoor air chemistry, IMR, Environmental Physics and Nano-Bio-Physics


Download the latest version of the IONICON publication database as BibTeX.