Crystallization of Lipids

Fundamentals and Applications in Food, Cosmetics, and Pharmaceuticals

Kiyotaka Sato

• Publisher: Wiley-Blackwell
• Year: 2018
• Print ISBN:
  9781118593929
• eBook ISBN:
  9781118593899
• Edition: 1
• Topic: Technologie et ingénierie
• Subtopic: Sciences de l'alimentation

An authoritative reference that contains the most up-to-date information knowledge, approaches, and applications of lipid crystals

Crystallization of Lipids is a comprehensive resource that offers the most current and emerging knowledge, techniques and applications of lipid crystals. With contributions from noted experts in the field, the text covers the basic research of polymorphic structures, molecular interactions, nucleation and crystal growth and crystal network formation of lipid crystals which comprise main functional materials employed in food, cosmetic and pharmaceutical industry. The authors highlight trans-fat alternative and saturated-fat reduction technology to lipid crystallization. These two issues are the most significant challenges in the edible-application technology of lipids, and a key solution is lipid crystallization.

The text focuses on the crystallization processes of lipids under various external influences of thermal fluctuation, ultrasound irradiation, shear, emulsification and additives. Designed to be practical, the book's information can be applied to realistic applications of lipids to foods, cosmetic and pharmaceuticals. This authoritative and up-to-date guide:

• Highlights cutting-edge research tools designed to help analyse lipid crystallization with the most current and the conventional techniques
• Offers a thorough review of the information, techniques and applications of lipid crystals
• Includes contributions from noted experts in the field of lipid crystals
• Presents cutting-edge information on the topics of trans-fat alterative and saturated-fat reduction technology

Written for research and development technologists as well as academics, this important resource contains research on lipid crystals which comprise the main functional materials employed in food, cosmetic and pharmaceutical industry.

1
Introduction: Relationships of Structures, Properties, and Functionality

Kiyotaka Sato

1.1 Introduction

This chapter presents a comprehensive sketch of the lipid species and functionality of lipid crystals present in various end products by outlining different stages of crystallization. In doing so, topics will be highlighted that will be elaborated further in chapters of this book. At the end of this chapter, a particular effort is made to relate trans‐fat alternative and saturated‐fat reduction technology to lipid crystallization because these two issues are the most significant problems in the edible‐application technology of lipids and one of the key solutions is lipid crystallization.

1.2 Lipid Species

Lipids are a class of compounds that contain long‐chain aliphatic hydrocarbons and their derivatives (O’Keefe 2008). There is a wide variety of lipid materials such as hydrocarbons, fatty acids, acylglycerols, sterols and sterol esters, waxes, phospholipids, plasmalogens, sphingolipids, and so on. Typical lipids whose crystallization properties have critical implications in food and other industries include hydrocarbons, fatty acids, alcohols, waxes, and acylglycerols. Because the lipid species of natural lipids of vegetable or animal resources vary from one to another, the understanding of the crystallization, melting, and physical properties must be based on the effects of major and minor lipid components included in every lipid material.

In this section, we take a brief look at the chemical structures of these typical lipid molecules.

1.2.1 Hydrocarbons

Hydrocarbons comprise a group of the simplest lipid molecules and are composed of hydrogen and carbon atoms. A typical molecular shape of hydrocarbons containing all saturated carbon–carbon bonds is expressed as CH₃‐(CH₂)_n‐2‐CH₃, in which n is the number of carbon atoms. Hereafter, we use n_c as the number of carbon atoms in the all‐hydrocarbon chains. In nature, even‐numbered and odd‐numbered hydrocarbons occur, depending on whether n_c is even or odd.

Molecular interactions operating among the hydrocarbon molecules are van der Waals forces, and these comprise the major molecular interactions among lipid molecules when they contain hydrocarbon chains as hydrophobic moieties. When the number of carbon atoms exceeds four, structural isomers occur (e.g., straight chains or branched chains). The straight‐chain hydrocarbons are called n‐alkanes as illustrated for n‐octadecane with n_c=18 (Fig. 1.1a).

Fig. 1.1 Typical lipid molecules. (a) n‐Octadecane, (b) stearic acid, (c) oleic acid, (d) elaidic acid, and (e) triacylglycerol. In (a)–(d), carbon atoms are shown except for COOH groups for fatty acids. In (e), R is fatty acid moiety.

1.2.2 Fatty Acids

Fatty acids are formed by replacing one end of –CH₃ in n‐hydrocarbons with a carboxyl group (–COOH). In contrast, dicarboxilic acids are formed when both end groups of –CH₃ in n‐hydrocarbons are replaced with –COOH. There are saturated and unsaturated fatty acids, depending on whether double bonds are included and stereoisomers of cis or trans unsaturated fatty acids occur.

In nature, a wide variety of fatty acids is present, differing in n_c, the number of double bonds having cis or trans conformations or the positions of the double bonds at the hydrocarbon chains. Similarly to hydrocarbons, even‐ and odd‐numbered fatty acids occur. The principal fatty acids abundantly occurring in nature are summarized in Table 1.1. Although standard (IUPAC) systematic names are given to fatty acids, the common names and abbreviations presented in the table will be used throughout this book.

Table 1.1 Systematic, common, and shorthand names of principal fatty acids.

...

Systematic	Common	Shorthand	Abbreviation
Saturated
Octanoic	Caprylic	8:0	Ca
Decanoic	Capric	10:0	C
Dodecanoic	Lauric	12:0	L
Tetradecanoic	Myristic	14:0	M
Hexadecanoic	Palmitic	16:0	P or PA
Heptadecanoic	Margaric	17:0	Ma
Octadecanoic	Stearic	18:0	S or SA
Nonadecanoic	Nonadecanoic	19:00	No
Eicosanoic	Arachidic	20:0	A
Docosanoic	Behenic	22:0	B
Unsaturated
c‐9‐Hexadecenoic	Palmitoleic	16:1, Δ9‐ω7	POA
c‐9‐Octadecenoic	Oleic	18:1, Δ9‐ω9	O or OA
c‐12‐Octadecenoic	Petroselinic	18:1, Δ6‐ω12	PSA
t‐9‐Octadecenoic	Elaidic	18:1, Δ9‐ω9	E
c‐11‐Octadecenoic	Asclepic	18:1, Δ11‐ω7	APA

Table of contents

• Cover
• Title Page
• Table of Contents
• Preface
• List of Contributors
• 1 Introduction
• 2 Polymorphism of Lipid Crystals
• 3 Molecular Interactions and Mixing Phase Behavior of Lipid Crystals
• 4 Fundamental Aspects of Crystallization of Lipids
• 5 Supramolecular Assembly of Fat Crystal Networks from the Nanoscale to the Mesoscale
• 6 Effects of Dynamic Temperature Variations on Microstructure and Polymorphic Behavior of Lipid Systems
• 7 Lipid Crystal Networks Structured under Shear Flow
• 8 Tailoring Lipid Crystal Networks with High-Intensity Ultrasound
• 9 Effects of Foreign and Indigenous Minor Components
• 10 Crystallization Properties of Milk Fats
• 11 Crystallization Behavior of Sunflower Oil–Based Fats for Edible Applications
• 12 Physical Properties of Organogels Developed with Selected Low-Molecular-Weight Gelators
• 13 Formation and Properties of Biopolymer-Based Oleogels
• 14 Lipid Crystallization in Water-in-Oil Emulsions
• 15 Crystallization of Lipids in Oil-in-Water Emulsion States
• 16 Lipid Crystals and Microstructures in Animal Meat Tissues
• 17 Conventional and New Techniques to Monitor Lipid Crystallization
• Index
• End User License Agreement