Dynamics of Acetaldehyde Production during Anoxia and Post-Anoxia in Red Bell Pepper Studied by Photoacoustic Techniques

• Published in: Plant physiology (Bethesda) 1997-03, Vol.113 (3), p.925-932
• Main Authors: Hanna Zuckermann, Frans J. M. Harren, Joerg Reuss, Parker, David H.
• Format: Article
• Language: English
• Subjects: acetaldehyde; acoustic properties; Agronomy. Soil science and plant productions; Anaerobiosis; Anoxia; Biological and medical sciences; biosynthesis; Capsicum annuum; carbon dioxide; Carbon dioxide emissions; catalase; dose response; Economic plant physiology; enzyme activity; Ethanol; Fermentation; Fructification, ripening. Postharvest physiology; Fruits; Fundamental and applied biological sciences. Psychology; Growth and development; hypoxia; Lasers; measurement; Metabolism; Oxygen; Peppers; Photosynthesis, respiration. Anabolism, catabolism; Plant cuticle; Plant physiology and development; stress response; tricarboxylic acid cycle; volatile compounds; Whole Plant, Environmental, and Stress Physiology
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.113.3.925

Acetaldehyde (AA), ethanol, and CO2 production in red bell pepper (Capsicum annum L.) fruit has been measured in a continuous flow system as the fruit was switched between 20% O2 and anaerobic conditions. Minimum gas phase concentrations of 0.5 nL L-1, 10 nL L-1, and 1 mL L-1, respectively, can be detected employing a laser-based photoacoustic technique. This technique allows monitoring of low production rates and transient features in real time. At the start of anaerobic treatment respiration decreases by 60% within 0.5 h, whereas AA and ethanol production is delayed by 1 to 3 h. This suggests a direct slow-down of the tricarboxylic acid cycle and a delayed onset of alcoholic fermentation. Re-exposure of the fruit to oxygen results in a 2- to 10-fold upsurge in AA production. A short anoxic period leads to a sharp transient peak lasting about 40 min, whereas after numerous and longer anoxic periods, post-anoxic AA production stays high for several hours. High sensitivity of the fruit tissue to oxygen is further evidenced by a sharp decrease in post-anoxic AA production upon an early return to anaerobic conditions. Ethanol oxidation by the "peroxidatic" action of catalase is proposed to account for the immediate post-anoxic AA upsurge.