Lipid-Based Nanostructures for Food Encapsulation Purposes

Volume 2 in the Nanoencapsulation in the Food Industry series

,

• Publisher: Academic Press
• Year: 2019
• Print ISBN: 9780128156735
• eBook ISBN: 9780128156742
• Topic: Technik & Maschinenbau
• Subtopic: Lebensmittelwissenschaft

Lipid-Based Nanostructures for Food Encapsulation Purposes, Volume Two in the Nanoencapsulation in the Food Industry series, reviews recent studies on the formulation and evaluation of different categories of lipid-based nano-carriers and discusses how lipid nanoencapsulation is a feasible technology for the food industry. This book covers nano-emulsions, nano-liposomes, nanostructured lipid carriers and surfactant nanoparticles. Authored by a team of global experts in the fields of nano and microencapsulation of food, nutraceutical and pharmaceutical ingredients, this title is of great value to those engaged in the various fields of nanoencapsulation.- Provides recent studies on the formulation and evaluation of different categories of lipid-based nanocarriers- Discusses how technology of lipid nanoencapsulation can be used in industries- Summarizes the practical application of nanostructures from lipid formulations, such as nanoemulsions, nanoliposomes and nanostructured lipid carriers

Chapter One

An overview of lipid-based nanostructures for encapsulation of food ingredients

Elham Assadpour ¹ , and Seid Mahdi Jafari ^{2 1} Department of Food Science and Technology, Baharan Institute of Higher Education, Gorgan, Iran ² Department of Food Materials and Process Design Engineering, Gorgan University of Agricultural Science and Natural Resources, Gorgan, Iran

Abstract

There has been an expanding interest on food bioactive ingredients over the recent years, and the food and pharmaceutical industry is looking at incorporating these health-promoting compounds into different products and formulations. A major issue with most of these ingredients is their low solubility in aqueous solutions and their poor bioavailability within the body. One successful strategy to solve these problems is nanoencapsulation of bioactive components with lipid-based nanostructures. This chapter gives an overview of different lipid-based nanodelivery systems in four groups of nanoemulsions, solid lipid nanocarriers, phospholipid nanostructures, and surfactant-based nanocarriers which will be discussed in more details in the remaining chapters of this book.

Keywords

Delivery; Encapsulation; Food bioactives; Lipid-based nanocarriers; Release

1. Introduction

Most of the bioactive substances suffer from low stability and decomposition when exposed to unfavorable conditions during food processing and storage (e.g., light, oxygen, and moisture) as well as within the gastrointestinal tract (GIT) which reduces their efficiency and bioactivity (Mokhtari et al., 2017; Abaee et al., 2017). Moreover, they exhibit low water solubility, poor bioavailability, and insufficient dispersibility in food systems; interact with food ingredients; and negatively influence sensory properties of food systems (da Silva et al., 2016; Donsì et al., 2011; Fang and Bhandari, 2010; Gleeson et al., 2016). On the other hand, health concerns have recently increased the tendency for development of functional foods and novel food products fortified with bioactive compounds and nutraceuticals especially phytochemicals (Ting et al., 2014). However, there are some limitations for direct utilization of bioactive compounds in food matrices. Food-grade delivery systems for nanoencapsulation of bioactive compounds represent an efficient way to solve these drawbacks. Among different nanodelivery techniques, lipid-based nanocarriers are a promising strategy for successful delivery of food bioactives.

Lipid-based nanostructures have great potentials to accommodate and release various bioactive compounds (hydrophilic, lipophilic, and amphiphilic compounds) in a sustained and controlled manner, improve solubility and encapsulation efficiency of hydrophobic bioactive compounds, decrease their volatility, and enhance their target specificity. Lipid-based nanocarriers also promote effectiveness and bioavailability by enhancing stability of entrapped compounds in food mediums and during digestion (de Souza Simões et al., 2017; Jafari, 2017; Shin et al., 2015). Furthermore, these systems are biocompatible and can be fabricated by inexpensive and safe components for large-scale industrial practices via simple and available production technologies without the use of organic solvents (Jafari, 2017; Katouzian and Jafari, 2016).

It should be mentioned that the terminology for nanocarriers is very versatile and various words and expressions are being used in the relevant literature such as nanocarrier, nanocargo, nanovehicle, nanocapsule, nanosphere, nanoparticle, nanodelivery system, nanocomplex, nanodroplet, nanoencapsulant, nanocoating, etc. Although their technical meaning and intention could be different, generally speaking, researchers are using them with a common sense of nanocarriers particularly in the food science field which is not as advances as pharmaceutical field in terms of nanoencapsulation and nanodelivery systems.

Many studies have indicated superiority of nanocarriers; as shown in Fig. 1.1, compared with microencapsulation systems, nanosized carriers offer more stability, solubility in different media, functionality, bioavailability, absorption, homogeneity, targeting properties, and the ability of controlled release in food and pharmaceutical practices which are associated with their greater surface area and larger reactivity (Ezhilarasi et al., 2013; Faridi Esfanjani and Jafari, 2016). Briefly:

Figure 1.1 Potential advantages of nanocarriers for encapsulation of food bioactive ingredients.

1. • An increase in surface area may lead to an increase in nutraceutical bioavailability due to faster digestion of the particles within the GIT.
2. • A decrease in particle size may lead to faster penetration through the mucus layer coating the epithelium cells.
3. • A decrease in particle size may lead to direct absorption of undigested nutraceutical-loaded nanoparticles by epithelium cells.
4. • A decrease in particle size may improve the water dispersibility of nonpolar nutraceuticals.
5. • A decrease in particle size may lead to the development of optically transparent products, which is important for some food and beverage applications, such as fortified waters and soft drinks.
6. • Encapsulation of bioactives within nanoparticles may lead to improved protection against chemical or biochemical degradation.
7. • Encapsulation of bioactives within nanoparticles may be used to prevent their adverse interactions with other food ingredients.
8. • Encapsulation of bioactives within nanoparticles may help to mask undesirable flavor profiles.

An important result of applying bioactive-loaded nanocarriers is the improvement of bioavailability. Typically, a number of different steps determine the biological fate of bioactive components before and after ingestion (Katouzian and Jafari, 2016), which is summarized in Fig. 1.2.

As mentioned before, lipid-based nanostructures (Fig. 1.3) are an important group of nanocarriers for the encapsulation and delivery of food bioactive components. These carriers can be classified into four groups: (1) nanoemulsions, (2) solid lipid nanocarriers, (3) phospholipid nanocarriers, and (4) surfactant-based nanocarriers. This chapter will present an overview of lipid-based nanostructures for encapsulation of food bioactive ingredients, and more details for each group of these nanocarriers along with their preparation methods, properties, applications, characterization, etc. will be provided in the following chapters of the book.

2. Nanoemulsions for encapsulation of food ingredients

An emulsion is defined as a system composed of two immiscible liquids (mostly water and oil) where one is dispersed as the droplet form (the dispersed or internal phase) in the other one (the continuous or external phase). Emulsions can be classified into three main types in terms of droplet size: microemulsions (10–100 nm), macroemulsions (0.5–100 μm), and nanoemulsions (known as miniemulsions, 100–500 nm) (Jafari et al., 2008; McClements, 2005). Different forms of nanoemulsions can be applied for encapsulation of food bioactives including single oil-in-water (O/W) and water-in-oil (W/O) nanoemulsions (Chapter 2), double nanoemulsions (W/O/W or O/W/O) (Chapter 3), microemulsions (Chapter 4), and Pickering nanoemulsions (Chapter 5) which are described briefly in the following sections.

Figure 1.2 Different parameters affecting the bioavailability of bioactive ingredients loaded within nanocarriers.

Figure 1.3 Different lipid-based nanostructures for encapsulating food bioactives.

2.1. Single O/W and W/O nanoemulsions

Nanoemulsions, differently from microemulsions, are thermodynamically unstable systems, which naturally tend to phase separation (McClements and Jafari, 2018b). However, gravitational separation is hampered by the onset of Brownian motions, which dominate over inertial motion in the typical size range of nanoemulsions. Depending on their formulations, nanoemulsions might undergo other instability phenomena, such as coalescence, Ostwald ripening, or flocculation, which cause the size of their drops to increase with time, ultimately leading to phase separation (Porras et al., 2008). Therefore, an appropriate nanoemulsion formulation is required to impart the long-term kinetic stability (Solans and Solé, 2012), while abiding by the severe constraints, posed by the current food regulations, as well as by possible impact on the organoleptic properties, or by economic considerations.

Different methods are currently available for preparing nanoemulsions, which can be classified into high-energy methods, such as high-pressure homogenization, ultrasonication, and colloid milling, and low-energy methods, such as phase inversi...

Table of contents

• Cover image
• Title page
• Table of Contents
• Acknowledgment
• Copyright
• List of Contributors
• Preface to the Series
• Preface to Volume 2
• Chapter One. An overview of lipid-based nanostructures for encapsulation of food ingredients
• Section One. Nanoemulsions for encapsulation of food ingredients
• Section Two. Lipid nano carriers for encapsulation of food ingredients
• Section Three. Nanostructured phospholipid carriers for encapsulation of food ingredients
• Section Four. Nanostructured surfactants for encapsulation of food ingredients
• Index