The Influence of Supercritical Carbon Dioxide on Graham Flour Enzyme Polyphenol Oxidase Activity

Graham flour is a form of whole wheat flour made by grinding the endosperm and is thus also the most nutritious. Generally, the enzyme polyphenol oxidase (PPO) catalyzes two different reactions in the presence of molecular oxygen: the hydroxylation of monophenols to ortho-diphenol and the oxidation...

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Main Authors: Gordana Hojnik Podrepšek, Željko Knez, Maja Leitgeb
Format: Article
Language:English
Published: MDPI AG 2020-12-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/25/24/5981
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author Gordana Hojnik Podrepšek
Željko Knez
Maja Leitgeb
author_facet Gordana Hojnik Podrepšek
Željko Knez
Maja Leitgeb
author_sort Gordana Hojnik Podrepšek
collection DOAJ
description Graham flour is a form of whole wheat flour made by grinding the endosperm and is thus also the most nutritious. Generally, the enzyme polyphenol oxidase (PPO) catalyzes two different reactions in the presence of molecular oxygen: the hydroxylation of monophenols to ortho-diphenol and the oxidation of <i>o</i>-diphenol to <i>o</i>-quinone. The purpose of the work was to inactivate PPO activity to extend the shelf life of graham flour and at the same time preserve all the of its high-quality properties. The influence of supercritical CO<sub>2</sub> (scCO<sub>2</sub>) treatment on PPO activity in graham flour was investigated. First, graham flour was exposed to scCO<sub>2</sub> conditions, then the proteins were extracted, and in the last step the concentration of total proteins and the specific activity of the PPO enzyme were determined by spectrophotometric assay. PPO activity decreased with an increase in treatment pressure. Furthermore, the flour quality characteristics that meet all needs for wheat end-use products after scCO<sub>2</sub> treatment have been preserved. No major changes in the structure of the granulate or shape of the flour particles were observed. A slightly reduced value of the moisture content in scCO<sub>2</sub>-treated graham flour also implies an extension of the shelf life.
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spelling doaj.art-4d4b28d79f0346548952f952b21ba0b42023-11-21T01:13:29ZengMDPI AGMolecules1420-30492020-12-012524598110.3390/molecules25245981The Influence of Supercritical Carbon Dioxide on Graham Flour Enzyme Polyphenol Oxidase ActivityGordana Hojnik Podrepšek0Željko Knez1Maja Leitgeb2Laboratory for Separation Processes and Product Design, Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, SloveniaLaboratory for Separation Processes and Product Design, Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, SloveniaLaboratory for Separation Processes and Product Design, Faculty of Chemistry and Chemical Engineering, University of Maribor, Smetanova ulica 17, 2000 Maribor, SloveniaGraham flour is a form of whole wheat flour made by grinding the endosperm and is thus also the most nutritious. Generally, the enzyme polyphenol oxidase (PPO) catalyzes two different reactions in the presence of molecular oxygen: the hydroxylation of monophenols to ortho-diphenol and the oxidation of <i>o</i>-diphenol to <i>o</i>-quinone. The purpose of the work was to inactivate PPO activity to extend the shelf life of graham flour and at the same time preserve all the of its high-quality properties. The influence of supercritical CO<sub>2</sub> (scCO<sub>2</sub>) treatment on PPO activity in graham flour was investigated. First, graham flour was exposed to scCO<sub>2</sub> conditions, then the proteins were extracted, and in the last step the concentration of total proteins and the specific activity of the PPO enzyme were determined by spectrophotometric assay. PPO activity decreased with an increase in treatment pressure. Furthermore, the flour quality characteristics that meet all needs for wheat end-use products after scCO<sub>2</sub> treatment have been preserved. No major changes in the structure of the granulate or shape of the flour particles were observed. A slightly reduced value of the moisture content in scCO<sub>2</sub>-treated graham flour also implies an extension of the shelf life.https://www.mdpi.com/1420-3049/25/24/5981graham floursupercritical CO<sub>2</sub>polyphenol oxidaseenzyme inactivation
spellingShingle Gordana Hojnik Podrepšek
Željko Knez
Maja Leitgeb
The Influence of Supercritical Carbon Dioxide on Graham Flour Enzyme Polyphenol Oxidase Activity
Molecules
graham flour
supercritical CO<sub>2</sub>
polyphenol oxidase
enzyme inactivation
title The Influence of Supercritical Carbon Dioxide on Graham Flour Enzyme Polyphenol Oxidase Activity
title_full The Influence of Supercritical Carbon Dioxide on Graham Flour Enzyme Polyphenol Oxidase Activity
title_fullStr The Influence of Supercritical Carbon Dioxide on Graham Flour Enzyme Polyphenol Oxidase Activity
title_full_unstemmed The Influence of Supercritical Carbon Dioxide on Graham Flour Enzyme Polyphenol Oxidase Activity
title_short The Influence of Supercritical Carbon Dioxide on Graham Flour Enzyme Polyphenol Oxidase Activity
title_sort influence of supercritical carbon dioxide on graham flour enzyme polyphenol oxidase activity
topic graham flour
supercritical CO<sub>2</sub>
polyphenol oxidase
enzyme inactivation
url https://www.mdpi.com/1420-3049/25/24/5981
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