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Nowadays, the application of nano/microencapsulated natural bioactives in food products has been an ever-growing platform in the realm of encapsulation strategy. Indeed, the forerunners in the food industry are grappling with the development of label-friendly food products, which are formulated by nature-inspired food components and can endow health-benefiting effects. Controlled release nano/microsystems reckon as effective tools for the delivery of natural food bioactive agents as they could engineer efficacious structures to shield the bioactives from the deleterious conditions of food processing and storage time, and assure their safe delivery to the target sites. This chapter essentially offers facile and efficient nano/microencapsulation strategies to boost water-solubility, (bio)stability, and even functionality of natural bioactives/nutraceuticals with an emphasis on their food applicabilities. Firstly, the formulation strategies for nano/microencapsulation purposes are comprehensively reviewed. Then, an overview of encapsulation for food applications, including the selection of the target bioactive(s), proper carrier agent(s), and encapsulation approach, together with the controlled-release concepts of bioactive, characterization of encapsulated biomolecules, and the evaluation of their bioavailability is critically summarized. The strategies for the incorporation of encapsulated bioactives into different food products are highlighted. Lastly, the market perspective and current status concerning the commercialization of encapsulated food compounds are systematically introduced.

Foods contain both natural nanomaterials, like casein micelles in milk or certain organelles found in plant or animal cells (DNA, ribosomes, enzymes, antibodies), and engineered nanomaterials, which are deliberately added in order to increase food quality and safety, such as nanoparticle-based delivery systems. Other nanoparticles do not directly enter foods, but may come into contact with foods as a result of their inclusion in packaging or nanosensors. Food-grade nanomaterials are used in food processing as food additives, in the manufacture of smart and active packaging, reinforced bionanocomposites, and antimicrobial packaging through incorporation of metal nanoparticles; for nutraceutical protection, nanocarriers, and nanodelivery systems for the increase of their bioavailability; for producing nanobiosensors for detection of toxins, pathogens, and pesticides; in applications in food processing such as nanofluids, nanoadsorbents, and nanofiltration; and as nanostructures as food ingredients such as nanoemulsions. This chapter presents a brief overview of nanotechnology applications in various fields of the food industry along with characterization techniques for analysis of nanomaterials, safety and regulatory issues, and consumer expectations toward “nanofoods.”

Different nanocarriers have been efficiently designed to provide a matrix for the delivery of food bioactive compounds such as polyphenols, carotenoids, essential oils, vitamins, minerals, and essential fatty acids to the right site at the right time. Nanoemulsions, nanoliposomes, nanohydrogels, solid lipid nanoparticles, and biopolymeric nanoparticles are such nanodelivery systems that can be triggered by the environmental conditions and release the entrapped bioactives. The controlled and targeted release is the topic of research worldwide, and designing systems to have sufficient resistance to pass the gastric and reach the right place in the small intestine and colon is very important. Indeed, bioaccessibility and bioavailability are the terms that are denoted for delivery systems in which the entrapped bioactive cores should be liberated and then absorbed. In addition, modeling the release of bioactives from nanocarriers by different techniques is another important topic which is useful in predicting the release profiles and affecting factors on release. In this chapter, after a brief overview of controlled release vs. targeted release, different approaches for studying the release profile including in vitro/in vivo assays will be explained along with various release modeling techniques. Finally, the importance of bioavailability for nanoencapsulated food ingredients and their fate within gastrointestinal tract will be covered.

Some of the major contributions of nanoencapsulation to the food industry are the enrichment/fortification of food products by incorporating health-promoting nutraceuticals, nutrients, and bioactive agents, resulting in the enhancement of properties such as stability, longer shelf life for storage, better tracking of contaminants, improvement of taste, flavor, color, and texture, and finally, nutraceutical delivery into our bodies. Nanoemulsions, nanogels, nanoliposomes, nanofibers, nanosponges, nanotubes, and biopolymeric nanocarriers are some nanovehicles fabricated from edible biopolymers/lipids and designed for encapsulation of food bioactives. Analysis of bioactive-loaded nanocarriers and encapsulated food ingredients provides information for the evaluation of successful performance of the encapsulation process Encapsulation efficiency and stability of released bioactives from nanocarriers should be well emphasized to improve safe application opportunities of those nanomaterials. Physical and chemical properties including surface charge and area, polarity, size, shape, morphology, solubility, molecular weight, composition, structure, color, thermal stability, and aggregation behavior are significant factors defining characteristic of produced nanostructures. Different analytical tools have been developed to determine the efficiency of nanoencapsulation processes, along with the mentioned parameters. These techniques are reviewed briefly in this chapter and more comprehensive details will be provided in the following chapters of the book.

Recently, most functional foods are consumed to prevent or ameliorate important diseases such as various types of cancer, cardiovascular problems, eye diseases, bone diseases, etc. These foods, known as functional foods, have been extensively researched in terms of both bioefficiency and preparation techniques. An important problem in the formulation of functional foods is the bioavailability of the nutrients, i.e., the fraction of an ingested nutrient which reaches an active form in the blood. This chapter first describes the main physico-chemical processes that take place inside the gastrointestinal tract (GIT) and contribute to improving or decreasing the bioavailability of nutrients. The processes that define bioaccessibility (release, solubilization, interaction), the transport mechanisms of nutrients through the intestinal cell monolayer (passive transport, active transport, efflux, etc.), and their metabolism by chemical and biochemical transformations are also presented. Finally, this chapter reviews the main in vitro methods for measuring bioaccessibility and absorption of nutrients. It will also cover the techniques of releasing and digestion of nutrients using static and dynamic gastrointestinal models. The nutrient permeability study is described on the basis of the Caco-2 cells model.

(In recent years, a new concept in nanoscience has been developing called “nanofoods.” Food nanomaterials have special physicochemical and biological properties that contribute to the development of innovative foods and smart packaging. In this chapter, the main properties of food nanomaterials and their characterization will be discussed, such as structure and morphology, surface area, surface charge, surface hydrophobicity, particle size, mechanical strength, thermal stability, sensory attributes, and their impacts on quality and food safety. The main techniques for analyzing the physical characteristics of food nanomaterials are also described: microscopic techniques including light microscopy, polarizing microscopy, fluorescence microscopy, confocal laser scanning microscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy (AFM), environmental scanning electron microscopy; light scattering techniques such as static light scattering, dynamic light scattering, nanoparticle tracking analysis, small-angle X-ray scattering, laser Doppler electrophoresis, X-ray diffraction; thermal techniques, mainly differential scanning calorimetry; and techniques for the characterization of mechanical properties of nanomaterials including oscillatory tests, colloidal probe AFM, and counterrotating shear method.

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.

Recently, lipophilic nutraceuticals have been the focus of attention because of their excellent functional properties and health-promoting effects such as antioxidant, antiinflammatory, wound healing, and even anticancer effects. However, their applications in food industries and oral administration are limited due to their poor water solubility and low bioavailability. The design of appropriate innovative formulations for encapsulating of these valuable compounds allows their protection from unfavorable environmental conditions, easy solubilization, or masking of their undesirable taste or odor. Among the nanodelivery systems, nanostructured lipid carriers (NLCs) are a group of nanoparticulate carrier systems derived from O/W nanoemulsions composed of solid and liquid lipids within their dispersed particles which have some advantages such as high bioactive loading, sustained release of bioactive molecules during storage and physical and chemical stability when compared with other colloidal carriers. In this chapter, we will provide an outline of recent progresses in different aspects of NLC systems including their ingredients, preparation, characterization, and application for improving the performance of nutraceuticals in functional foods and beverages.

One of the most common nanocarriers for the protection and delivery of food bioactive ingredients and nutraceuticals is biopolymeric nanostructures. They can have different morphologies like nanoparticles, nanospheres, nanotubes, nanogels, and so on, and two main approaches for preparation of these nanocarriers are top-down and bottom-up strategies. Fortunately, there are various sources for the selection of biopolymers including milk proteins, other animal proteins, plant proteins, polysaccharides, and biodegradable chemical polymers. In this chapter, after a quick overview of nanoencapsulation advantages and classification of different nanocarriers, a short introduction to different biopolymeric nanocarriers has been provided in order to make the foundation for the remaining chapters of the book which cover more details and relevant studies of each biopolymeric nanostructures for the encapsulation and delivery of food bioactives.

One of the main challenges in the food and nutraceutical fields is the potential risks arising from nanomaterial fabrication and consumption. On the other hand, many recent research activities have shown that nanocarriers loaded with food bioactive ingredients can be a promising strategy to safely and successfully deliver these nutraceuticals into the body. Therefore, developing green and facile approaches to produce healthy nanostructures, suitable for bioactive nanoencapsulation, is very essential. High-energy techniques or so-called top-down methods are effective technologies to generate different biobased structures in submicron or nanometer scale. These include electrospinning/spraying, nanospray drying, nano-/microfluidics, high-pressure homogenization, microfluidization, high-intensity ultrasonication, and some other less common techniques. This chapter gives a brief overview of these technologies and more details and coverage of recent studies for each specialized equipment that have been provided in the following chapters of this book.

In this chapter, after a comparison between nanoencapsulation and microencapsulation highlighting their main differences, a systematic and brief overview of nanoencapsulation techniques applicable to food ingredients is provided. These include lipid-based nanoencapsulation systems (nanoemulsions, nanoliposomes, solid lipid nanoparticles, and nanostructured lipid carriers), nature-inspired nanocarriers (caseins, cyclodextrins, and amylose nanohelices), specially equipment based nanoencapsulation systems (electrospinning, electrospraying, nano spray dryer, and micro/nanofluidics), biopolymer nanoparticles (single biopolymer nanocarriers, and complexed biopolymer nanoparticles), and other miscellaneous nanoencapsulation technologies (nanocrystals, dendrimers, and niosomes). For each type of nanocarrier, some studies and recent developments on nanoencapsulation of different food bioactive ingredients are summarized, including phenolic compounds and antioxidants, antimicrobial agents and essential oils, fish oil and essential fatty acids, flavors, natural food colorants, vitamins, and minerals.

Nanoencapsulation of food bioactive ingredients has attracted the attention of food scholars and public due to their versatile benefits. Using this technology, it is possible to increase the bioavailability, obtain a targeted and sustainable release, providing healthier and functional foods, large-scale production, yielding higher stability plus longer shelf life and fabricating transparent solutions and desirable food products with modified textures as well as flavor and other attributes. For producing targeted nanoencapsulation systems, it is necessary to acquire information concerning their release properties and biological fate. On the other hand, the characterization of generated nanoencapsulated products is of utmost importance for the fortification of a variety of formulations, such as foods and other biological systems. Currently, organic nanomaterials are being utilized in food products instead of the nonbiodegradable metal oxides and metal particles, which were used previously. Exposure to nanomaterials via several routes (oral, skin permeation, inhalation, etc.) may cause the generation of bio-corona, reactive oxygen species, etc. that induce deleterious effects on living cells. In this chapter, first, the release of bioactives in the gastrointestinal tract is explored plus their biological fate as they may be accumulated or how they are digested since their uptake properties are different from the conventional materials and requires further study. Next, the characterization methods of nanocapsules are underlined in order to determine their size, shape, surface charge, bulk chemistry, surface chemistry as well as other physicochemical features. Although all of these tests may be time-consuming and not cheap, the practical and valuable tests should be chosen regarding the proposed study so as to be worthy of funding. At last, the safety and toxicity aspects of nanoparticles (NPs) applied to food are highlighted by the in vitro and in vivo assays. Despite the solid information being provided in recent years, more investigations should be carried out to fill the gaps in the safety of consumption of NPs in food products and lots of relevant issues should be addressed by conducting more sponsored studies; then the safety strategies can be legislated to lower the possible deleterious effects of NPs.

Nanoemulsions are considered as ideal vehicles for nanoencapsulation of food bioactive ingredients and nutraceuticals. They serve as nanocarriers in many different materials as they are capable of improving water solubility and preventing the degradation of bioactive food components. Oil in water emulsions (O/W) can be used for the encapsulation of lipophilic active agents; on the other hand, water in oil emulsions (W/O) can be also used to encapsulate hydrophilic compounds including most polyphenols. In the current chapter, both simple emulsions (nano- and microemulsions) and double emulsions, as a potential encapsulation matrix, will be discussed; for readability we will use the term nanoemulsions for all emulsions with a droplet size of less than one micron.