Review of Citrus Oils - American Chemical Society

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Book Review pubs.acs.org/jnp

Review of Citrus Oils: Composition, Advanced Analytical Techniques, Contaminants, and Biological Activity germacrenes, homoterpenes, sulfur- and nitrogen-containing compounds) in conjunction with the major volatile components have a major role in the organoleptic properties of citrus. The final three chapters deviate from the chemical composition of citrus to address instrumentation (Chapter 11), analysis of contaminants (Chapter 12), and the pharmacology of citrus oils (Chapter 13). The description for analytical instrumentation and techniques goes well beyond routine GC and GC-MS techniques. This chapter provides unique insight into the laboratory techniques needed for highthroughput analysis in an industrial lab setting serving the citrus industry. Contaminants in citrus oils discussed include trace metals, pesticides, plasticizers, polychlorinated aromatics, and compounds associated with biological contamination. The final chapter on the pharmacology looks at the many reported health benefits of citrus oils. These include a theory on reported antimicrobial activity, discussions on the neuroprotective properties, anxiolytic and sedative uses, antinociceptive properties, and antioxidant properties. The final topics includes a brief discussion on the use of citrus in cancer treatment and its applications in various skin treatments. I have not seen the original volume (26) but assume that this book has some substantial updates (post 1999 to 2009). It also has three new topics not included in Volume 26. If anyone needs to know the compounds in citrus, this book would be the gold standard. As with all review-oriented books, this one is well referenced. The first six chapters were mostly tables, giving this volume a reference book appearance. The last seven chapters read more like a textbook. I found these chapters both informative and interesting. I am sure that this book will find use in both my teaching and research.

Citrus Oils: Composition, Advanced Analytical Techniques, Contaminants, and Biological Activity (Medicinal and Aromatic Plants−Industrial Profiles). Edited by Giovanni Dugo and Liugi Mondello. CRC Press, Boca Raton, FL, USA. 2011. xvii + 561 pp. 7 × 10.25 in. $179.95. ISBN 978-1-43980028-7.

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his book is volume 49 of the Medicinal and Aromatic Plants−Industrial Profiles. It is an update to Citrus, volume 26 of the series. On the basis of the preface it is made clear to the reader that this book contains material from the previous volume. Each chapter also contains an update section (2000−2009), which specifies work not included in the previous volume. Two new subjects (chapters) are introduced in this volume: minor components of citrus fruits and carotenoids of citrus. The final chapter on the biological activities of citrus oils appears to be new to this volume and gives an up to date (2010) overview of the pharmacology of various citrus products. Throughout this book the majority of the discussion deals with the main citrus varieties that make up the citrus oil industry. These include lime, bitter orange, lemon, mandarin, sweet orange, and bergamot oils. Chapters 1, 3, and 4 pretty much cover the chemical composition of the above oils as they relate to extraction/distillation techniques, geographical location of the fruit, and laboratory techniques used for the analysis. The many tables provided in this book give the reader a clear idea of the chemical components found in the major citrus oils, as well as their variance from the source. I doubt there is a more comprehensive study of the components of citrus oils in print. In Chapter 2 the above compositions are discussed for the less common citrus oils (Japanese citrus, Australian citrus, and others). Chapter 5 covers the volatile components that are isolated from petitgrain portions (leaves, buds, and small branches) of the main citrus plants. Chapter 6 gives a discussion of the extracts from bitter orange flowers, which is the source of the commercially valuable neroli oil used in perfumary. This chapter also identifies compounds associated with the adulteration of neroli oils. I found the first six chapters to read more like a reference book and found the remaining chapters to be of more interest as an academic chemist. I found Chapter 7 quite interesting in that it provides many references for the optical purity of various volatile compounds of the major citrus fruits. I was quite surprised to find such a variability in optical purity of the chiral compounds. Chapters 8, 9, and 10 discuss the less abundant compounds isolated from citrus oils. These include oxygen heterocycles (Chapter 8), carotenoids (Chapter 9, carotenes and xanthophylls), and minor components (Chapter 10). Chapter 8 provides an interesting section on the health benefits of limoncello and provides some chemical differences between commercial and home-produced. Chapter 10 discusses the minor compounds of citrus that provide the unique organoleptic properties of citrus oils. These minor components (e.g., © 2017 American Chemical Society and American Society of Pharmacognosy

Kirk P. Manfredi

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University of Northern Iowa, Cedar Falls, Iowa, United States

AUTHOR INFORMATION

ORCID

Kirk P. Manfredi: 0000-0001-5777-6043 Notes

The author declares no competing financial interest.

Published: February 16, 2017 1229

DOI: 10.1021/acs.jnatprod.7b00094 J. Nat. Prod. 2017, 80, 1229−1229