Polyphenol oxidases (PPOs) in plants
Author(s)
Bibliographic Information
Polyphenol oxidases (PPOs) in plants
Springer, c2017
Available at 1 libraries
  Aomori
  Iwate
  Miyagi
  Akita
  Yamagata
  Fukushima
  Ibaraki
  Tochigi
  Gunma
  Saitama
  Chiba
  Tokyo
  Kanagawa
  Niigata
  Toyama
  Ishikawa
  Fukui
  Yamanashi
  Nagano
  Gifu
  Shizuoka
  Aichi
  Mie
  Shiga
  Kyoto
  Osaka
  Hyogo
  Nara
  Wakayama
  Tottori
  Shimane
  Okayama
  Hiroshima
  Yamaguchi
  Tokushima
  Kagawa
  Ehime
  Kochi
  Fukuoka
  Saga
  Nagasaki
  Kumamoto
  Oita
  Miyazaki
  Kagoshima
  Okinawa
  Korea
  China
  Thailand
  United Kingdom
  Germany
  Switzerland
  France
  Belgium
  Netherlands
  Sweden
  Norway
  United States of America
Note
Includes bibliographical references
Description and Table of Contents
Description
This book is first of its kind exclusively dedicated to plant polyphenol oxidases (PPOs), highlighting their importance in the food processing industry. By reviewing the scientific developments of the past several decades, it offers a comprehensive overview of various aspects of plant PPOs, including chemistry, structure, functions, regulation, genetics/genomics and molecular aspects. PPOs are copper-containing proteins found in several plant species that catalyze the hydroxylation of o-monophenols to o-diphenols and oxidation of the o-dihydroxyphenols to o-quinones. Further, the quonines undergo self-polymerization or react with amines/thiol groups to produce brown/dark coloration of products. All the PPOs contain two Cu-binding sites (CuA and CuB) as their central domain, these interact with phenolic substrates and molecular oxygen. Several of the plant PPOs contain an N-terminal transit peptide (~80-100 amino acids
) necessary for plastid import. The PPOs occur in latent form that are activated by various treatments including acid and base shock, exposure to detergents or proteolytic degradation. The pH optimum of PPOs varies widely depending upon different plant species but is usually ~4.0 - 8.0. Similarly, the optimum temperature also varies as per the source and substrate involved ranging from 30 to 45 DegreesC.
Multiple PPO isoforms have been reported in several plant species, and the chromosomal location of PPOs has also been studied in some species. The physiological role (s) of PPOs is not entirely understood, but they could be involved in defense-related functions in plants. From an applied perspective, PPOs are implicated in enzymatic browning/darkening of cereal products, vegetables and fruits. Interestingly, browning is preferred in some instances like the processing of black tea, cocoa, and coffee as it enhances their quality by forming flavorful products. There have b
een initiatives to specifically breed and develop cultivars with reasonably low PPO levels in the mature grain or fruit. Further, several types of inhibitors that reduce the PPO activity have also been identified.
Despite their commercial/economic importance and the availability of literature on different aspects of PPOs in different plant species, this is the first book to provide basic information regarding PPOs. It is a valuable resource for researchers involved in quality-related research specifically in crops, vegetables and fruits. Further, as PPOs are also implicated in defense- or stress-related functions, the book is also useful to breeders, pathologists, molecular biologists, physiologists and entomologists.
Table of Contents
Chapter 1. Introduction.- Chapter 2. Distribution, Localization and Structure of Plant Polyphenol Oxidases (PPOs).- Chapter 3. Physicochemical Properties of Polyphenol Oxidases.- Chapter 4. Reaction Features of Polyphenol Oxidases.- Chapter 5. Function(s)/Role(s) of Polyphenol Oxidases.- Chapter 6. Polyphenol Oxidases(s): Importance in Food Industry.- Chapter 7. Advances in Polyphenol Oxidase (PPO) Research.
by "Nielsen BookData"