The intelligent delivery systems for bioactive compounds in foods: Physicochemical and physiological conditions,absorption mechanisms,obstacles and responsive strategies

BackgroundBioactive natural compounds have received considerable attention due to their health benefits, including anti-oxidant, anti-cancer, anti-diabetes and cardiovascular disease-preventing functions. However, the stability of these sensitive compounds can be influenced by unfavourable environmental conditions during processing and storage. In addition, delivery of bioactive compounds via the oral route is restricted by various physiological barriers, including a harsh pH, gastrointestinal enzymes, the mucus layer, and the epithelium. Intelligent delivery systems are a promising method to protect bioactive molecules from degradation and improve their bioavailability.Scope and approachWe have demonstrated the physicochemical and physiological GI conditions. The structural composition of the epithelium and transport mechanisms of bioactives and nanoparticles across the intestinal epithelium were discussed. The effects of enhanced aqueous solubility, stability, bioaccessibility and bioavailability after encapsulation were illustrated. Furthermore, novel intelligent carriers that are responsive to the oral route, pH, enzymes and cell receptors were also discussed.Key findings and conclusionsThis comprehensive multidisciplinary review provides useful guidelines for the application of bioactive compounds in the food industry. Intelligent carrier systems are designed to improve the low solubility, poor stability and low permeability of the gastrointestinal tract, and they have the potential to improve oral bioavailability.     

静电纺丝技术包埋抗菌物质研究进展

近年来,人们已成功地开发出多种不同来源的天然抗菌物质。由于食品加工和储存条件对其抗菌效果产生很大的影响,极大地限制了其在食品工业中的应用。目前常用的包埋技术在包埋抗菌物质时仍存在许多不足之处。因此,开发出高效包埋天然抗菌物质的包埋技术成为研究的热点问题。静电纺丝技术是一种新颖的、简单的生物活性物质包埋技术,能够显著提高生物活性物质的包埋效率、稳定性和利用度,在一定程度上克服了传统包埋技术在包埋生物活性物质时的弊端。本文主要综述了静电纺丝技术的原理,纺丝参数对静电纺丝纳米纤维的影响以及以多糖和蛋白质为基质利用静电纺丝技术包埋抗菌物质及其应用的研究进展,为其在食品工业中的良好应用奠定基础。     

Coaxial electrospraying of biopolymers as a strategy to improve protection of bioactive food ingredients

Coaxial electrospraying is a promising technique for the production of multilayer encapsulation structures whose potential has already been demonstrated for pharmaceutical and biomedical applications. The aim of this work was to extend its application to the food sector by developing novel coaxially electrosprayed microcapsules using all food-grade materials. For this purpose, zein and gelatin were used as shell biopolymers to microencapsulate two model bioactive ingredients, i.e. epigallocatechin gallate (EGCG) as a model hydrophilic compound and α-linolenic acid (ALA) as a model hydrophobic molecule. The performance of the coaxially-obtained particles in terms of protection was evaluated in comparison with that of uniaxially electrosprayed materials. Particle sizes varied with composition and encapsulation efficiency (EE) was dependent on the chemical affinity between the shell matrix and the bioactive compound, but in general, greater EE was obtained in the coaxial systems. Moreover, enhanced bioactive protection ability was demonstrated by the coaxial structures, as observed in thermal degradation assays (for ALA) and antioxidant activity after in-vitro digestion (for EGCG).Industrial relevanceThis work emphasizes the usefulness of the electrospraying technique for the production of encapsulation structures for bioactive protection using all food-grade materials, without the need of applying high temperatures and generating small capsule sizes (in the submicron range). It also demonstrates that the coaxial configuration may be used to design encapsulation systems with enhanced protection ability for both hydrophilic and hydrophobic bioactive compounds.     

Protein glycosylation: a promising way to modify the functional properties and extend the application in food system

Abstract

Modification of functional properties by glycosylating with polysaccharides is an effective solution to improve the internal disadvantages of native proteins. Generally, protein glycosylation belongs to the first stage of the Maillard reaction in essence. Dry-heating, wet-heating, and their combination are the major methods for the preparation of protein-polysaccharide conjugates (PPC). Spectrophotometry, spectroscopy, electrophoresis, calorimetry, chromatography, and mass spectrometry are confirmed to be the most effective methods for the identification of PPC. After glycosylation, functionalities of the native protein, including solubility, rheological properties, emulsifying properties, foaming properties, gel property, film-forming properties, thermal stability, antioxidant activity, allergenicity, and antibacterial properties, are improved. The PPC is extensively used as an encapsulation or a delivering material in order to improve the bioaccessibility of bioactive compounds in food system. Some new applications in food processing could be explored using PPC as an ingredient based on the improved functional properties, such as 3-dimensional printing food, gelled food, and colloid food. Furthermore, the model of protein glycosylation and the application of PPC in food processing could be extended to other protein modification to broaden the exploitation of native protein resource for the processing of novel foods.     

Improving the bioavailability of phenolic compounds by loading them within lipid-based nanocarriers

BackgroundPhenolic compounds¹ are one of the main interested nutraceuticals in the food and pharmaceutical industries. The application of phenolics is limited due to their low bioavailability, low solubility, low stability, and un-targeted release. These limitations could be overcome by novel ‘‘lipid-based nano-encapsulation technologies’’ capable of appropriated and targeted delivery functions into foods.Scope and approachIn this review, preparation, application, and characterization of lipid-based nanocarriers for phenolics have been considered and discussed including nano-emulsions, nano-scale phospholipids, and nanostructured lipid carriers. The bioavailability of nano-encapsulated phenolic products and capability of them to produce functional foods have been considered as well.Key findings and conclusionsIn the food and nutraceutical industries, the main aims of loading phenolics into nanocarriers are masking their undesirable flavor for oral administration, providing high stability and high absorption, and better release in gastrointestinal (GIT) conditions. Compared with micro-sized carriers, nanocapsules based on lipid formulations provide more surface area and have the potential to enhance solubility, improve bioavailability, and ameliorate controlled release of the nano-encapsulated phenolic compounds.     

Emulsion electrospinning: Fundamentals,food applications and prospects

BackgroundIn the past decades, many natural bioactive compounds with antioxidant, immunoregulatory, antimicrobial, and anticancer activities have been successfully identified in plant and animal materials. However, due to their poor solubility, unfavorable flavor, low bioavailability and instability during food processing and storage, the development of bioactive compounds used in the food industry presents many technological challenges.Scope and approachEmulsion electrospinning is a novel and simple technique to fabricate core-shell nanofibers, and either water-in-oil (W/O) or oil-in-water (O/W) emulsions can be electrospun to directly encapsulate hydrophilic or hydrophobic compounds into core-shell fibers, respectively. This review introduces fundamentals and advantages of emulsion electrospinning as well as its food applications. The effects of different types of emulsifiers on the formation of emulsion systems and emulsion-based electrospun fibers are highlighted. Further, the existing limitations and scope for future research are discussed.Key findings and conclusionsRecent studies have found that the emulsion-based electrospun nanofibers can enhance the encapsulation efficiency, stability, and bioavailability of bioactive compounds, as well as achieve targeted delivery and controlled release, thus providing new strategies to improve their barrier performance compared to conventional electrospinning and therefore facilitating the development of emulsion-based electrospun mats in the food industry.     

Nanoencapsulation Techniques for Food Bioactive Components: A Review

The protection and controlled release of bioactive compounds at the right time and the right place can be implemented by encapsulation. Nanoencapsulation remains to be the one of the most promising technologies having the feasibility to entrap bioactive compounds. Nanoencapsulation of bioactive compounds has versatile advantages for targeted site-specific delivery and efficient absorption through cells. However, researches in the application of nanotechnology in the food industry have been very limited and there are only a few review articles that explored the nanoencapsulation technology. This review focuses on the various nanoencapsulation techniques such as emulsification, coacervation, inclusion, complexation nanoprecipitation, emulsification–solvent evaporation, and supercritical fluid for food ingredients. Drying techniques such as spray drying and freeze drying for stabilization of nanoparticles are also discussed. Current state of knowledge, limitations of these techniques, and recent trends are also discussed. Finally, safety and regulatory issues in the nanoencapsulation of bioactive compounds are also highlighted.     

Recent Advances on Application of Ultrasound and Pulsed Electric Field Technologies in the Extraction of Bioactives from Agro-Industrial By-products

Agro-industrial by-products are rich sources of natural bioactive compounds and their valorisation is a must for global food sustainability. Along with conventional techniques, numerous novel methods have been developed and optimised to facilitate extraction of the bioactives in sustainable and efficient manner. This review summarises the recent advances in the application of novel extraction technologies for various classes of bioactive molecules from agro-industrial by-products with special emphasis on two emerging techniques, i.e. ultrasound- and pulsed electric field-assisted extraction. These two technologies have shown promising extraction efficacy with reduced usage of extraction solvents, thus saving time and cost. The mechanism through which these techniques aid extraction, the various parameters affecting their efficacy, integration with other novel techniques, and promising applications for by-product valorisation are discussed.     

Biodegradable polymers as wall materials to the synthesis of bioactive compound nanocapsules

BackgroundNanoparticles have been synthetized using polymers as wall materials to protect bioactive compounds against external factors (light, heat and oxygen), increasing the stability and improving the bioavailability of nanoencapsulated compounds.Scope and approachThe encapsulation processes and type of polymers (natural or synthetic) exert a direct impact on the synthesis of bioactive compound nanocapsules, which reflect in parameters, such as size, zeta potential, encapsulation efficiency, aqueous solubility, aqueous stability, surface permeability, desired bioactive compounds release profile and wall resistance; and these characteristics might limit its use by food, pharmaceutical and cosmetic industries. This review summarizes researches on nanocapsules synthesis (advantages and limitations of different techniques) and focuses on the importance of different biodegradable polymers as wall materials for obtaining stable and safe nanocapsules.Key findings and conclusionsDifferent wall materials can be used to synthesize bioactive compound nanocapsules; however, biodegradable polymeric nanocapsules have proven to be one of the most stable structures during storage and showed high efficiency to control the release of encapsulated compounds and due to these characteristics, they have been focus of various studies for future applications in health and food-related areas.     

Encapsulation systems for lutein: A review

BackgroundThe increased demand by consumers for clean labels has encouraged industry to search for replacements of synthetic ingredients in food products, and in particular, colorants. Lutein, a xanthophyll found in marigolds and corn, can be used in food products as a natural colorant replacing yellow food dyes. Moreover, lutein is considered a nutraceutical due to its potentially beneficial health effects, such as prevention of macular degeneration, role in the development of the visual and nervous systems of fetuses, and its antioxidant properties. However, incorporation of lutein into foods is often limited because of its low-water solubility, chemical instability, and poor oral bioavailability. For this reason, colloidal encapsulation systems have been developed to facilitate the incorporation of lutein into aqueous food and beverage products.Scope and approachThis review focuses on exploring encapsulation options for lutein using various emulsion-based, nanoparticle- and microparticle-based and molecular inclusion encapsulation systems, as well as additives that can be used to increase its chemical stability in these systems. This review covers all aspects of lutein encapsulation, including both food-grade and pharmaceutical-grade encapsulation systems.Key findings and conclusionsThough lutein-loaded encapsulation systems are extensively explored in this review, emulsions are of the most interest in industry as they are cost efficient and can be designed to increase the stability of lutein by selecting the proper emulsifiers and emulsification techniques. Despite the extensive amount of research carried out on the encapsulation of hydrophobic bioactive molecules such as lutein, there are still opportunities to develop encapsulation systems that further protect these molecules during storage and also increase their bioavailability after ingestion.     

Active food packaging evolution: transformation from micro- to nanotechnology

Predicting which attributes consumers are willing to pay extra for has become straightforward in recent years. The demands for the prime necessity of food of natural quality, elevated safety, minimally processed, ready-to-eat, and longer shelf-life have turned out to be matters of paramount importance. The increased awareness of environmental conservation and the escalating rate of foodborne illnesses have driven the food industry to implement a more innovative solution, i.e. bioactive packaging. Owing to nanotechnology application in eco-favorable coatings and encapsulation systems, the probabilities of enhancing food quality, safety, stability, and efficiency have been augmented. In this review article, the collective results highlight the food nanotechnology potentials with special focus on its application in active packaging, novel nano- and microencapsulation techniques, regulatory issues, and socio-ethical scepticism between nano-technophiles and nano-technophobes. No one has yet indicated the comparison of data concerning food nano- versus micro-technology; therefore noteworthy results of recent investigations are interpreted in the context of bioactive packaging. The next technological revolution in the domain of food science and nutrition would be the 3-BIOS concept enabling a controlled release of active agents through bioactive, biodegradable, and bionanocomposite combined strategy.     

Natural phytochemicals and probiotics as bioactive ingredients for functional foods: Extraction,biochemistry and protected-delivery technologies

BackgroundThe well-known correlation between diet and physiology demonstrates the great possibilities of food to maintain or improve our health, increasing the interest in finding new products with positive physiological effects. Nowadays, one of the top research areas in Food Science and Technology is the extraction and characterization of new natural ingredients with biological activity that can be further incorporated into a functional food, contributing to consumer's well-being. Furthermore, there is a high demand for effective encapsulation methodologies to preserve all the characteristics of bioactive compounds until the physiological action site is reached.Scope and approachIn this review, the relevance of developing standard approaches for the extraction of the highly diverse bioactive compounds was described, as it defines the suitability of the following steps of separation, identification and characterization. Special attention was also dedicated to the encapsulation techniques used on hydrophilic and/or lipophilic compounds (e.g., emulsification, coacervation, supercritical fluid, inclusion complexation, emulsification-solvent evaporation and nanoprecipitation).Key findings and conclusionsSome useful conclusions regarding the selection of the best extraction methodology (Soxhlet extraction, ultrasound-assisted extraction, supercritical fluid extraction, accelerated solvent extraction, or shake extraction) were achieved, considering important aspects such as cost, required technical skills, extract integrity, green chemistry principles, solvent type, sample size, pH, temperature and pressure. In addition, this comprehensive review allowed defining the best protective approach to solve the limitations related to the extremely low absorption and bioavailability of bioactive phytochemicals, overcoming problems related to their low solubility, poor stability, low permeability and metabolic processes in the GI tract.     

Selected commercial plants: A review of extraction and isolation of bioactive compounds and their pharmacological market value

BackgroundEntrepreneurs involved in the commercialization of natural products are currently displaying significant interests in herbal drugs, medicines, and natural product-based herbal products. A broad range of bioactive chemical compounds have been derived from medicinal plants, either in their pure form or as homogenous extracts. As these compounds have broad structural and functional diversities, they offer pharmaceutical companies numerous opportunities for the development of new drug leads. They also represent an excellent source of molecules for the production of food additives, functional foods, nutritional products, and nutraceuticals for the growing number of natural food companies.Scope and approachA number of bioactive compounds, including polyphenols, are present in high concentrations in plant species whereas a number of other important compounds such as saponin are present at very low levels. Several identification, extraction, and isolation techniques are currently used to extract bioactive compounds from plants. However, as these techniques are generally laborious and very expensive, there is an urgent need for new advanced techniques for identification, extraction, and isolation of plant bioactive compounds in quantities sufficient for their potential applications in various sectors.Key findings and conclusionsThe aim of this review is to collate and present information on the identification, extraction, and isolation of the most widely used bioactive compounds from selected commercial medicinal plants, thereby providing a useful resource for medicinal scientists and pharmaceutical and food-related industries seeking to generate high yields at low cost to meet market requirements.     

Advancements in liposome technology: Preparation techniques and applications in food,functional foods,and bioactive delivery: A review

Liposomes play a significant role in encapsulation of various bioactive compounds (BACs), including functional food ingredients to improve the stability of core. This technology can be used for promoting an effective application in functional food and nutraceuticals. Incorporation of traditional and emerging methods for the developments of liposome for loading BACs resulted in viable and stable liposome formulations for industrial applications. Thus, the advance technologies such as supercritical fluidic methods, microfluidization, ultrasonication with traditional methods are revisited. Liposomes loaded with plant and animal BACs have been introduced for functional food and nutraceutical applications. In general, application of liposome systems improves stability, delivery, and bioavailability of BACs in functional food systems and nutraceuticals. This review covers the current techniques and methodologies developed and practiced in liposomal preparation and application in functional foods.     

Zein and zein -based nano-materials for food and nutrition applications: A review

BackgroundZein, a byproduct of corn with renewable resources, unique hydrophobic/hydrophilic character, film/fiber forming and antioxidant properties, is a promising biopolymer for food and nutrition applications. The advantages in properties and efficiencies of nano materials over bulk counterparts are the basis of their unique nature in novel technologies. These advantages also expand their possible applications.Scope and approachAn effort has been made to review on applications of zein/zein-based nano-materials in various branches of food (except food packaging) and nutrition sectors. The effects of various parameters affecting preparations and properties of the nano-materials are also discussed. Nano-encapsulation of foods and nutrients is the major section of this study.Key findings and conclusions(i) the average size of zein nanoparticles reported to be 50–200 nm; (ii) the functions of zein nanomaterials were multiples: a carrier of delivery (food, beverage, and nutrient) systems; a shell or a core of encapsulated systems; or a food ingredient; (iii) zein-based nano-materials have been used for encapsulation of food and nutrient components including lipids; essential oils; fat soluble vitamins; food colorants; flavors; and natural anti-oxidants; (iv) the bioavailability of food and nutrient components such as folic acid, vitamin D₃, curcumin, beta-carotene, and resveratrol was improved by employing the zein-nanoparticles in comparison with the bulk counterparts; and (v) bioactive substances with potential applications for food and nutrition sectors were stabilized by zein/zein-based nano-materials.     

Understanding the potential benefits of thyme and its derived products for food industry and consumer health: From extraction of value-added compounds to the evaluation of bioaccessibility,bioavailability, anti-inflammatory,and antimicrobial activities

ABSTRACT

Natural bioactive compounds isolated from several aromatic plants have been studied for centuries due to their unique characteristics that carry great importance in food, and pharmaceutical, and cosmetic industries. For instance, several beneficial activities have been attributed to some specific compounds found in Thymus such as anti-inflammatory, antioxidant, antimicrobial, and antiseptic properties. Moreover, these compounds are classified as Generally Recognized as Safe (GRAS) which means they can be used as an ingrident of may food producs. Conventional extraction processes of these compounds and their derived forms from thyme leaves are well established. Hoewever, they present some important drawbacks such as long extraction time, low yield, high solvent consumption and degradation thermolabile compounds. Therefore, innovative extraction techniques such as ultrasound, microwave, enzyme, ohmic and heat-assisted methods can be useful strategies to enhance the exytraction yield and to reduce processing temperature, extraction time, and energy and solvent consumption. Furthermore, bioaccessibility and bioavailability aspects of these bioactive compounds as well as their metabolic fates are crucial for developing novel functional foods. Additionally, immobilization methods to improve stability, solubility, and the overall bioavailability of these valuable compounds are necessary for their commercial applications. This review aims to give an overall perspective of innovative extraction techniques to extract the targeted compounds with anti-inflammatory and antimicrobial activities. Moreover, the bioaccessi-bility and bioavailability of these compounds before and after processing discussed. In addition, some of the most important characteristics of thyme and their derived products discussed in this paper.     

Microencapsulation of antioxidant compounds through innovative technologies and its specific application in meat processing

BackgroundMeat has a complex physical structure and chemical composition that is very prone to oxidation. Plants are sources of biologically active compounds (antioxidants) of interest as potential raw materials for meat processing, primary as replacements for synthetic additives. Some examples are essential oils from aromatic plants that are usually unstable under common processing and storage conditions and exhibit strong smell and off flavour. Hence, stable delivery systems like encapsulation are required.Scope and approachEncapsulation, and particularly spray-drying, offers protection of active compounds, their controlled and targeted release in food products and ability to mask unacceptable odours in products.Key findings and conclusionsAlbeit current results are promising for microparticles and nanomaterials, more research is needed to evaluate the application of various natural ingredients in meat processing. Direction of future research should address functionality of systems, consumers’ health concerns and benefits, better sensory acceptance, reduced operating costs, scalability for industrial needs, and size of environmental footprints.     

Agro-industrial potential of exotic fruit byproducts as a source of food additives

Exotic fruit consumption and processing is increasing worldwide due to the improvement in preservation techniques, transportation, marketing systems and consumer awareness of health benefits. The entire body of tropical exotic fruits is rich in bioactive compounds, such as phenolic constituents, carotenoids, vitamins and dietary fiber. However, the fruit processing industry deals with the large percentage of byproducts, such as peels, seeds and unused flesh, generated in the different steps of the processing chains. In most cases, the wasted byproducts can present similar or even higher contents of bioactive compounds than the final produce does. The aim of this review is to promote the production and processing of exotic fruits highlighting the possibility of the integral exploitation of byproducts rich in bioactive compounds. Amongst the possible uses for these compounds that can be found in the food industry are as antioxidants (avoiding browning and lipid oxidation and as functional food ingredients), antimicrobials, flavoring, colorants and texturizer additives. Finally, the importance of extraction techniques of bioactive compounds designated as food additives is also included.     

Food protein-based materials as nutraceutical delivery systems

Incorporation of bioactive compounds–such as vitamins, probiotics, bioactive peptides, and antioxidants etc.–into food systems provide a simple way to develop novel functional foods that may have physiological benefits or reduce the risks of diseases. As a vital macronutrient in food, proteins possess unique functional properties including their ability to form gels and emulsions, which allow them to be an ideal material for the encapsulation of bioactive compounds. Based on the knowledge of protein physical–chemistry properties, this review describes the potential role of food proteins as substrate for the development of nutraceutical delivery systems in the form of hydrogel, micro-, or nano- particles. Applications of these food protein matrices to protect and delivery-sensitive nutraceutical compounds are illustrated, and the impacts of particle size on release properties are emphasized.     

Nanoliposomes,from food industry to nutraceuticals: Interests and uses

Nanoliposomes are a form of vector used both in the pharmaceutical and food industries. In food industry, these lipid nanostructures are incorporated during the manufacturing process of food products, primarily to improve texture, flavors and for food preservation. Because of their natural lipid composition, and their ability to encapsulate both hydrophobic and hydrophilic compounds, nanoliposomes represent an interesting form of carrier for bioactive molecules. Encapsulation in these lipid-based vectors of molecules known for their beneficial effects on certain organs or tissues can be envisaged in nutraceutical applications to create functional foods designed for disease prevention. To achieve this objective, however, it is necessary to control certain parameters during preparation and storage of nanoliposomes to ensure optimal digestibility and bioavailability. Indeed, challenges still exist to ensure the stability of nanoliposomes during storage, as well as following ingestion. Many preparation techniques are available, but the oxidative nature of lipids and their phase transition temperature all affect the stability of nanoliposomes. These issues and the feasibility for use of nanoliposomes in industrial applications for nutraceuticals, as well as the importance of establishing product specifications and the claims for using nanoliposomes in nutraceuticals are discussed in this review. Finally, although industrial scale-up raises questions of quality control and reproducibility, investigations nevertheless suggest a promising future for the use of these lipid nanostructures in nutraceutical applications.