Optical method for detecting oxygen via the chromogenic reaction catalyzed by polyphenol oxidase

• Published in: Enzyme and microbial technology Vol. 114; pp. 1 - 6
• Main Authors: Bouchaib, Abdelaziz, abdellah, Abdellatif Ben, Bakkali, Mohamed, Laglaoui, Amine, Arakrak, Abdelhay, Carboni, Carlo, Benjouad, Abdelaziz, Maurady, Amal
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2018
• Subjects: Enzymatic test; Hydrogel; Mediterranean dwarf palm; Optical detector; Oxygen ingress; Polyphenol oxidase; Visual test; Optical detector; Mediterranean dwarf palm; Oxygen ingress; Enzymatic test; Visual test; Hydrogel; Polyphenol oxidase
• ISSN: 0141-0229; 1879-0909
• DOI: 10.1016/j.enzmictec.2018.02.009

[Display omitted] •We describe a method for detecting the ingress of gas phase oxygen into packed food based on Polyphenol Oxidase incorporated in hydrogel with nontoxic substrate.•The test spot undergoes an irreversible and visible color change from pale to deep brown.•Detector characteristics and response have been studied by spectrophotometry.•The detector is highly selective for oxygen and is stable over time.•The originality of this work is a detector based on natural and non-toxic product and presents no health hazards to human. The present work describes a method for detecting the ingress of gas phase oxygen into packed food. It uses the enzyme polyphenol oxidase (PPO)from Mushroom and Mediterranean dwarf palm. The PPO is incorporated into an indubiose film along with a non-toxic polyphenol such as gallic acid or chlorogenic acid. If exposed to oxygen, the test spot undergoes an irreversible and visible color change from pale to deep brown due to the PPO catalyzed oxidation of the respective polyphenol by oxygen. The color change can be detected visually or by spectrophotometry at 470 nm. The effect of the amount of oxygen or substrate, type of enzyme substrate, enzyme source, temperature and duration of storage on the response were studied. Air oxygen can be detected within 30 min under optimized condition. The smallest amount of oxygen that can be detected with acceptable response time (120 min) is 5%. The test is highly selective for oxygen and the detector is stable over time. The detector may be used in any application as long as the presence or absence of oxygen in a sealed space is determined prior to the application using the detector.