Currently, there are no books that cover all the dimensions of Polyphenol Oxidases (PPOs), which is why publication of the book is needed. The book focuses on its types, structure, distinctive aspects, applications, genetic engineering, and commercial status. PPOs have been used for wastewater remediation and in environmental biosensors. The role of PPOs in global sustainability along with challenges and future prospects is also discussed.

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 °C. 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.

Man-made textile fibers are frequently encountered as trace evidence in criminal investigations. This study examined the effects of burial in soil on the biodeterioration of synthetic textile fibers such as cellulose acetate, nylon, polyesters and acrylics. Cellulose acetate fibers began to show signs of decomposition within two months after burial in common garden topsoil and were completely degraded within four to nine months. It was found that severely decomposed cellulose acetate fibers could be identified by pyrolysis-gas liquid chromatography even when other methods such as polarized light microscopy and dispersion staining failed. The solubility behavior of the cellulose acetate fibers also was altered. The other types of fibers showed no detectable alteration at the end of the twelve-month study. REFERENCES American Association of Textile Chemists and Colorists (1971). AATCC Technical Manual, AATCC, Triangle Park, NC. Cook, R., and Paterson, M.D. (1978). New techniques for the identifi- tion of microscopic samples of textile fibers by infrared spectroscopy. Forensic Sci. Int., 12, 237-243. DeForest, P.R., Geansslen, R.E., and Lee, H.C. (1983). Forensic Science: An Introduction to Criminalistics, McGraw-Hill Book Company, NY. Federal Bureau of Investigation (1978). Solubility schemes by generic class. Federal Bureau of Investigation, Washington, DC. Fong, W. (1982). Rapid microscopic identification of synthetic fibers in a single liquid mount. ~ Forensic Sci., 27, 257-263.

The Springer Handbook of Enzymes provides concise data on some 5,000 enzymes sufficiently well characterized – and here is the second, updated edition. Their application in analytical, synthetic and biotechnology processes as well as in food industry, and for medicinal treatments is added. Data sheets are arranged in their EC-Number sequence. The new edition reflects considerable progress in enzymology: the total material has more than doubled, and the complete 2nd edition consists of 39 volumes plus Synonym Index. Starting in 2009, all newly classified enzymes are treated in Supplement Volumes.

Food Enzymes: Structure and Mechanism is the first volume to bring together current information on the structures and mechanisms of important food enzymes. It provides an in-depth discussion of the dynamic aspects of enzyme structures and their relationship to the chemistry of catalysis. The book emphasizes aspects of the chemistry of enzyme structure and mechanism seldom covered in the food science literature. It includes a thorough discussion of the genetic modification of enzyme structures and functions with reference to specific food enzymes. More than 100 illustrations enhance the clarity of important concepts. Comprehensive references reflect the current state of knowledge on enzyme actions.