Woodhead Publishing in Food Science, Technology and Nutrition Lipid glossary 2 Frank D. Gunstone Honorary Professor, Scottish Crop Research Institute, Dundee, UK Bengt G. Herslöf Managing Director, Scotia LipidTeknik AB, Stockholm, Sweden Oxford Cambridge Philadelphia New Delhi Published by Woodhead Publishing Limited, 80 High Street, Sawston, Cambridge CB22 3HJ, UK www.woodheadpublishing.com; www.woodheadpublishingonline.com Woodhead Publishing, 1518 Walnut Street, Suite 1100, Philadelphia, PA 19102-3406, USA Woodhead Publishing India Private Limited, G-2, Vardaan House, 7/28 Ansari Road, Daryaganj, New Delhi – 110002, India www.woodheadpublishingindia.com First published by The Oily Press, 2000. Reprinted by Woodhead Publishing Limited, 2013 © PJ Barnes & Associates, 2000; © Woodhead Publishing Limited, 2012 The authors have asserted their moral rights This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. Reasonable efforts have been made to publish reliable data and information, but the authors and the publisher cannot assume responsibility for the validity of all materials. Neither the authors nor the publisher, nor anyone else associated with this publication, shall be liable for any loss, damage or liability directly or indirectly caused or alleged to be caused by this book. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming and recording, or by any information storage or retrieval system, without permission in writing from Woodhead Publishing Limited. The consent of Woodhead Publishing Limited does not extend to copying for general distribution, for promotion, for creating new works, or for resale. Specific permission must be obtained in writing from Woodhead Publishing Limited for such copying. Trademark notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation, without intent to infringe. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 978-0-9531949-2-6 (print) ISBN 978-0-85709-797-2 (online) This book is Volume 12 in The Oily Press Lipid Library Typeset by Ann Buchan (Typesetters), Middlesex, UK Printed by Lightning Source Produced in cooperation with Karlshamns Oils and Fats Academy iii Preface to Lipid Glossary 2 Our Preface to A Lipid Glossary published in 1992 (see page v) ended with “if this book is well-received we hope to correct it, update it, and extend it in a few years time...”. The book was well received and this was reflected in its high sales. How does Lipid Glossary 2 published in 2000 differ from the slimmer volume of 1992? (cid:127) We have extended the text by adding new entries, by extending existing entries, and by adding key references to many of them. We have also used more graphics to depict molecular structures. The number of entries has been raised from 900 to over 1200, and graphics from about 60 to over 180. As a consequence, the main text has increased from 100 to 237 pages. (cid:127) The book is still replete with cross references but these are now indicated in italic rather than in bold type. This gives a better appearance to the pages of text. However it does mean that some botanical references which are italicized do not have a cross reference. (cid:127) We have also revised the Appendices. Appendices 1–3 are deleted but all the information is now contained in the main text. Appendices 4 and 5 have been retained (though renumbered) and updated. No information has been lost through these changes except that we have removed some of the earlier book titles from the list. We hope this new glossary will be as popular and as useful as the first. We offer it as a handy reference for a wide range of lipid scientists and technologists as well as those involved in the business and commerce of these materials. Many companies bought several copies of A Lipid Glossary for wide distribution to their staff. They recognized the importance of having a copy readily available for quick consultation. iv As with A Lipid Glossary, we thank Bill Christie who has acted as friend, mentor, adviser, and consultant for his generous help and advice. We also thank Peter Barnes for his efforts in connection with this volume. For help with typing and formulas we thank Birgitta Taube, Marie Sedig, Jan Holmbäck and Anders Viberg. Kersti Sundbro gave assistance from the Scotia LipidTeknik library for which we are grateful. Frank Gunstone (Dundee) Bengt Herslöf (Stockholm) March 2000 v Preface to A Lipid Glossary (published 1992) Having produced this Lipid Glossary it is incumbent upon us to indicate our understanding of the word lipid. There is no exact, succinct and agreed definition of lipids and whilst there is no disagreement over a wide range of compounds, there is a gray zone of compounds not uniformly accepted as lipids. There are several problems. Are lipids only natural products and do we exclude the wide range of synthetic compounds? We think not. Are lipids adequately defined in terms of their solubility in a range of `fat solvents’? Solubility is linked with structure but it seems a rather vague criterion designed to distinguish typical lipids from typical carbohydrates and proteins and leaves many doubtful cases. We prefer a definition of lipids based mainly, if not entirely, on structure and related, in turn, to the underlying biosynthetic pathways by which fatty acids are produced. The acetate–malonate pathway of biosynthesis leads, through simple variants, to three major categories of natural products: fatty acids by a reductive pathway, isoprenoids via mevalonate, and phenols by cyclisation of polyketides. We consider that lipids are compounds based on fatty acids or closely related compounds such as the corresponding alcohols or the sphingosine bases. We accept, of course, that in some complex compounds the acyl chain is less significant and less important than the polar head group. This is true of some complex glycolipids. We believe further that increasing understanding of biological membranes will justify the importance of the acyl part of even complex lipid molecules. Our definition includes all the major groups of materials generally recognized as lipids. It includes the sterol esters but not the free sterols and we accept this omission. To be interested in lipids, however, does not exclude an interest in compounds vi which though not strictly lipids are nevertheless closely associated with them such as some sterols and the tocopherols. This definition is not very far away from that of Christie: ‘Lipids are fatty acids and their derivatives, and substances related biosynthetically or functionally to these compounds’. Included in the glossary are the names of fatty acids and lipids, the major oils and fats, terms associated with their analysis, refining, and modification, and the major journals and societies concerned with lipid chemistry. Lipids have become the concern of a range of disciplines — from medicine to organic chemistry, from food applications to pharmaceutical formulations, from oleochemicals to analytical reference compounds, to mention only a few examples. However, to some extent separate terminologies have developed and terms are sometimes used without an understanding of the original meaning. Many synonyms and trivial names are used and we have felt the need to collect all terms that we think are related to lipids, to explain them and hopefully to clarify the important concepts. We have written this glossary for all those who are working with lipids and who sometimes need a reminder, like ourselves, but especially for those who are entering into the lipid field and find themselves overwhelmed by the many new terms and trivial names they meet. We see our book as a source of information for those who work with lipids and for those who find themselves needing to understand the terminology of oil/fat/lipid scientists and technologists. The major part of the book is the glossary which contains brief and simple definitions of 900 terms. Many cross references are included to make it easier to find information from different starting points. These are often but not always indicated by words in bold type. But we have also included a number of appendices. Some of these represent a collation of information given in the glossary in more detail. Others represent listings of what we believe to be additional useful information. These appendices are detailed in the Contents and are a valuable addition to the glossary itself. vii If this book is well-received we hope to correct it, update it, and extend it in a few years time and we invite readers to contact either of us with comments and suggestions. We wish to thank our publisher (and friend), Bill Christie, for his help and advice in producing this book. Frank D. Gunstone (St Andrews) Bengt G. Herslöf (Stockholm) January 1992 viii Books on fats, oils and other lipids PJ Barnes & Associates, PO Box 200, Bridgwater, TA7 0YZ, UK Tel: +44-1823-698973 E-mail: [email protected] Fax: +44-1823-698971 Web site: www.pjbarnes.co.uk The titles of Oily Press books currently in print are shown below. Please see our web site at www.oilypress.com or www.pjbarnes.co.uk for full details of each book and to download a catalogue. Trans Fatty Acids in Human Nutrition - Second Edition (2009) Phospholipid Technology and Applications (2008) Long-Chain Omega-3 Specialty Oils (2007) Antioxidants in Food and Biology: Facts and Fiction (2007) Lipids: Structure, Physical Properties and Functionality (2006) Lipid Oxidation - Second Edition (2005) Bioactive Lipids (2004) Advances in Lipid Methodology — Five (2003) Lipid Analysis — Third Edition (2003) Lipids for Functional Foods and Nutraceuticals (2003) Lipid Glossary 2 (2000) Confectionery Fats Handbook (2003) Lipids in Nutrition and Health: A Reappraisal (1999) Advances in Lipid Methodology — Four (1997) Advances in Lipid Methodology — Three (1996) LIPID GLOSSARY 2 A abietic acid a major resin acid present in tall oil fatty acids. Tall oil is a by-product of the wood pulp industry and consists of almost equal parts of fatty acids (mainly oleic and linoleic) and a series of cyclic isoprenoid acids like abietic acid along with some triterpenes. The fatty acids and resin acids can be separated by distillation. A. Hase et al., Tall oil as a fatty acid source, Lipid Technology, 1994, 6, pp.110-114. H H COOH Abietic acid C H O 20 30 2 Mol. Wt.: 302.5 accelerated oxidation tests methods of estimating the induction period (and hence the shelf life under normal storage conditions) of a fat or fatty food. Peroxide values are measured at time intervals whilst the material is held at an elevated temperature (e.g. 100°C). Results obtained at these temperatures must be interpreted with care when using them to predict shelf life since the mechanisms of oxidation change with temperature. See active oxygen method. E.N. Frankel, Lipid Oxidation, The Oily Press, 1998. acceptable daily intake defined as the average amount of a food additive that can be safely consumed every day for life. It is expressed as mg of additive per kg of body weight per day. aceituno oil oil from the seeds of Simarouba glauca. The oil contains palmitic (12%), stearic (28%), and oleic acid (58%), with a low level of linoleic acid (2%). 2 LIPID GLOSSARY 2 acetate salt or ester of acetic acid. Acetems TM produced commercially by reaction of mono or diacylglycerols with acetic anhydride to give products with 50, 70 or 90% of the free hydroxyl groups acetylated. They have lower melting points than the monoacylglycerols from which they are prepared. Partially acetylated products (50 or 70%) are used in toppings, whipping emulsions and cake mixes. Fully acetylated acetems form flexible films with low penetration of oxygen or water vapour and are used as coating agents for frozen meats or fruit. These compounds are designated E472(a) in Europe and 172,828 in the USA. N. Krog, Lipid Technologies and Applications (ed. F.D. Gunstone and F.B. Padley) Marcel Dekker, New York (1997), pp.521-534. O O O H C O 3 O CH 3 O 1-palmitoyl-2,3-diacetyl-sn-glycerol C H O 23 42 6 Mol. Wt.: 414.6 acetic acid ethanoic acid (2:0), the fatty acid of lowest molecular weight to occur naturally in lipids. It occurs only rarely but it is the only fatty acid present in platelet-activating factor. It is also present as a minor component of milk fat, occurs unusually in some seed oil triacylglycerols (e.g. Euonymus verrucosus), and in synthetic monoacylglycerol derivatives (AcetemsTM). It is an important biosynthetic unit — usually as a coenzyme ester such as acetyl-CoA — in the production of many natural products including the fatty acids. J.L. Harwood, Lipid Synthesis and Manufacture (ed. F.D. Gunstone) Sheffield Academic Press, Sheffield (1999) pp.422-466 CH COOH 3 Acetic acid (ethanoic acid, 2:0) CHO 2 4 2 Mol. Wt.: 60.1