New Trends in the Microencapsulation of Functional Fatty Acid‐Rich Oils Using Transglutaminase Catalyzed Crosslinking

Preparing stable protein‐based microcapsules containing functional fatty acids and oils for food applications has been a big challenge. However, recent advances with transglutaminase (TGase) enzyme as an effective protein cross‐linker could provide workable solutions for the encapsulation of omega‐3 and omega‐6 fatty acids without compromising their targeted release and their biological and physicochemical characteristics. The recent and available literature related to the microencapsulation techniques, physical and oxidative properties, and core retention and release mechanisms of TGase‐crosslinked microcapsules entrapping edible oils were reviewed. The effects of factors involved in microencapsulation processes, on the efficiency and quality of the produced innovative microcapsules were also discussed and highlighted. A brief focus has been finally addressed to new insights and additional knowledge on micro‐ and nanoencapsulation of lipophilic food‐grade ingredients by TGase‐induced gelation. Two dominant microencapsulation methods for fish, vegetable, and essential oils by TGase‐crosslinking are complex coacervation and emulsion‐based spray drying. The developed spherical particles (<100 μm) with some wrinkles and smooth surfaces showed an excellent encapsulation efficiency and yield. A negligible release rate and a substantial retention level can result for different lipid‐based cores covered by TGase‐crosslinked proteins during the oral digestion and storage. A significant structural, thermal and oxidative stability for edible oils‐loaded microcapsules in the presence of TGase can be also obtained.     

Industrially scalable complex coacervation process to microencapsulate food ingredients

Microencapsulation by conventional complex coacervation, though highly effective and achievable at the bench-scale, is challenging to scale-up because of the complexity of the process. A novel, industrially-scalable microencapsulation process by in situ complex coacervation during spray drying (the ‘CoCo process’) is introduced, where the multiple steps are collapsed into one, to form dry complex coacervated (CoCo) microcapsules by spray drying. The CoCo process was used to encapsulate d-limonene in CoCo microcapsules using alginate and gelatin as wall materials. Insoluble CoCo particles were produced without chemical cross-linking, with extents of complex coacervation of 75 ± 6% and 64 ± 6% for CoCo particles with and without d-limonene, respectively. Up to 82.7% of d-limonene was retained during spray drying; moreover, the CoCo matrix exhibited excellent barrier properties, retaining up to 80.0% of total d-limonene over 72-day storage in sealed vials at room temperature.Industrial relevanceCommercialization of microencapsulation of bioactives by complex coacervation in agricultural and food applications is hindered by the high-cost and time-intensive multistep process consisting of emulsification, coacervation, shell hardening and drying. In this work, we overcome these limitations by developing an industrially scalable in situ complex coacervation process during spray drying (‘CoCo process’). One-step complex coacervation during spray-drying opens the door to cost-effective, high-throughput, high-volume production of bioactive-containing microcapsules. The protective matrix microcapsules formed by this novel process stabilize and protect the bioactive, while allowing controlled release of the cargo for various applications in the food and many other industries.     

Encapsulation of food ingredients

Microencapsulation is a relatively new technology that is used for protection, stabilization, and slow release of food ingredients. The encapsulating or wall materials used generally consist of starch, starch derivatives, proteins, gums, lipids, or any combination of them. Methods of encapsulation of food ingredients include spraydrying, freeze‐drying, fluidized bed‐coating, extrusion, cocrystallization, molecular inclusion, and coacervation. This paper reviews techniques for preparation of microencapsulated food ingredients and choices of coating material. Characterization of microcapsules, mechanisms of controlled release, and efficiency of protection/ stabilization of encapsulated food ingredients are also presented.     

花椒油微胶囊工艺的研究

研究通过对影响喷雾干燥法花椒油微胶囊实验的因素:心材比例、均质温度和次数、壁材组合、进风温度、有效成分滞留率等进行考察,以期为花椒油微胶囊化的工业化大生产提供科学依据。     

复合凝聚法包埋功能性食品组分的研究进展

复合凝聚法是一种新兴的包埋技术,食品领域研究者对该技术日益关注。本文深入讨论了影响复合凝聚的 环境因素;以功能性油脂、精油、脂溶性维生素、脂溶性抗氧化物为代表组分,归纳总结了复合凝聚法包埋脂溶性 活性组分的研究进展;以益生菌、酶、水溶性维生素、甜味剂、苦味肽等为例,详细介绍了复合凝聚法包埋亲水性 活性组分的研究进展。     

缓释型精油微胶囊壁材的研究进展

微胶囊化技术是实现精油产品缓释功能的重要技术手段之一，壁材的合理选用是调控精油的作用时间、提高精油产品稳态化性能的关键所在。本文从蛋白质和多糖分类概述了缓释型精油微胶囊选用壁材的研究现状，并对该领域的发展趋势和前景进行了展望，以期为精油微胶囊在食品等领域的科学研究和工业化生产提供有益的指导。     

Recent advances in the microencapsulation of omega-3 oil and probiotic bacteria through complex coacervation: A review

BackgroundFunctional foods are a fastest growing sector of the food industry. The development of functional foods comprising omega-3 fatty acids and probiotic bacteria, through complex coacervation process is an emerging area of research and product development.Scope and approachWe reviewed relevant literature concerning the use of complex coacervation in microencapsulation, focusing primarily on the inclusion of probiotic bacteria and omega-3 oils into a single delivery format. This review covers advantages and disadvantages of the complex coacervation process to microencapsulate bioactive ingredients, viability of probiotic bacteria and oxidative stability of omega-3 oil during the complex coacervation process, the bioaccessibility of omega-3 oil and probiotic bacteria during simulated gastrointestinal conditions and in-vivo testings.Key findings and conclusionsThe review describes the advantages of co-encapsulation using complex coacervation followed by spray drying. It also describes the technological hurdles that need to be resolved for further development of industrial applications of co-encapsulation of probiotic bacteria and omega-3 lipids. The co-encapsulation concept has been widely used in pharmaceutical delivery systems, but is a relatively new concept in food ingredient stabilisation and delivery. There is a commercial need of co-encapsulation of multiple bioactive ingredients within a single microcapsules, due to decreased cost and enhanced product quality. Complex coacervation has been shown to be a useful method for the co-encapsulation of multiple unstable bioactive ingredients. Although in-vitro evaluation deliver useful bioavailability information, additional in-vivo and clinical trials are needed to determine the efficacy of bioactive release, particularly for microcapsules containing multiple bioactive ingredients.     

Microencapsulation of flax oil with zein using spray and freeze drying

Microencapsulation of flax oil was investigated using zein as the coating material. Central Composite Design - Face Centered was used to optimize the microencapsulation with respect to zein concentration (x₁) and flax oil concentration (x₂) using spray drying. Also, freeze drying was carried out at two zein:oil ratios. The quality of microcapsules was evaluated by determining encapsulation efficiency, flowing properties (Hausner ratio), and evaluating the morphology with scanning electron microscopy. The response surface model for microencapsulation efficiency showed a high coefficient of determination (R² = 0.992) and a non-significant lack of fit (p = 0.256). The maximum microencapsulation efficiencies were 93.26 ± 0.95 and 59.63 ± 0.36% for spray drying and freeze drying, respectively. However, microcapsules prepared by spray and freeze drying had very poor handling properties based on the Hausner ratio. The bulk density decreased with an increase in zein concentration at the same flax oil concentration. The morphology of the flax oil microcapsules depended on the zein:flax oil ratio and the process used for microencapsulation. Flax oil microcapsules prepared by spray drying appeared to be composed of heterogeneous spheres of various sizes at high zein:flax oil ratios. Microcapsules prepared by freeze drying resulted in agglomerated small spheres. These microcapsules might find a niche as functional food ingredients.     

Effect of Spray Nozzle Design on Fish Oil–Whey Protein Microcapsule Properties

Abstract: Microencapsulation improves oxidative stability and shelf life of fish oil. Spray and freeze drying are widely used to produce microcapsules. Newer spray-nozzles utilize multiple fluid channels allowing for mixing of wall and core materials at the point of atomization. Sonic energy has also been employed as a means of atomization. The objective of this study was to examine the effect of nozzle type and design on fish oil encapsulation efficiency and microcapsule properties. A total of 3 nozzle types, a pressure nozzle with 1 liquid channel, a pressure nozzle with 2 liquid channels, and a sonic atomizer with 2 liquid channels were examined for their suitability to encapsulate fish oil in whey protein isolate. Physical and chemical properties of freeze dried microcapsules were compared to those of microcapsules produced by spray drying. The 2-fluid pressure and ultrasonic nozzles had the highest (91.6%) and the lowest microencapsulation efficiencies (76%), respectively. There was no significant difference in bulk density of microcapsules produced by ultrasonic and 3-fluid pressure nozzles. The ultrasonic nozzle showed a significantly narrower particle size distribution than the other nozzles. This study demonstrated that new nozzle designs that eliminate emulsion preparation prior to spray drying can be beneficial for microencapsulation applications. However, there is still a need for research to improve microencapsulation efficiency of multiple channel spray nozzles. Practical Application: Since this research evaluates new spray nozzle designs for oil microencapsulation, the information presented in this article could be an interest to fish oil producers and food industry.     

原花青素的微胶囊化研究

研究了原花青素喷雾干燥微胶囊化工艺。选用阿拉伯胶和麦芽糊精做为原花青素微胶囊壁材(阿拉伯胶占40%),按芯壁材比为30%、混合物中固形物浓度为20%的组成比例来混合各种材料并经均质处理后进行喷雾干燥。喷雾干燥工艺条件为：进风温度180℃,出风温度88℃,此时产品微胶囊化效率可达88．44%。     

微胶囊技术在功能性油脂生产中的应用

在介绍微胶囊技术基本原理的基础上,分析其在功能性油脂生产中的意义,着重探讨了几种常用的微胶囊壁材和生产技术,总结了功能性油脂微胶囊的研究现状及在食品工业中的应用.功能性油脂微胶囊化不仅可保护其中的功能成分,防止氧化,而且产品有较优的稳定性、流动性,以及较高的生物消化率,因而微胶囊技术在功能性油脂生产中具有广阔的开发和应用前景.     

Patent-based review on industrial approaches for the microencapsulation of oils rich in polyunsaturated fatty acids

The principal industrial techniques for microencapsulation of oils rich in polyunsaturated fatty acids are spray-drying, fluidized bed coating and extrusion as well as polymer gelation and coacervation with subsequent cross-linking. In order to minimize non-encapsulated core material and oxygen diffusivity multiple interfacial structures and multiple shell structures are built up combining these techniques. The resulting microcapsule structure can affect the core material release, but this should not necessarily be regarded as a constraint, since it offers the possibility of a target-oriented delivery of the core material in vivo.     

响应面法优化孜然精油微胶囊工艺

以β-环糊精和麦芽糊精为壁材采用真空抽滤法包埋制备孜然精油微胶囊。在复合壁材比、固形物质量浓度、芯壁比和包埋时间4 个单因素筛选的基础上采用四因素三水平响应面试验设计确定了最佳微胶囊制备工艺参数为β-环糊精与麦芽糊精比8∶2（g/g）、固形物质量浓度40 g/100 mL、芯材与壁材比1∶5（mL/g）、包埋时间55 min,该条件下孜然精油的包埋效率可达97.68%。     

微胶囊技术在多不饱和脂肪酸中的应用进展

多不饱和脂肪酸是人体生长和健康不可或缺的营养物质, 但是这些脂肪酸容易被氧化, 并且气味不佳, 因此有必要通过微胶囊技术对其进行包埋来解决这些问题。本文综述了喷雾干燥法、复合凝聚法、锐孔法、冷冻干燥法在制备不饱和度高的油脂粉末中的应用, 并介绍了新型壁材、玻璃态微胶囊、纳米微胶囊在多不饱和脂肪酸微胶囊化的研究进展。这些研究显示, 微胶囊化多不饱和脂肪酸在食品工业上具有良好的发展前景。     

Application of microencapsulated essential oils in cosmetic and personal healthcare products – a review

Nowadays, the consumers around the world are increasingly focused on health and beauty. The renewed consumer interest in natural cosmetic products creates the demand for new products and reformulated others with botanical and functional ingredients. In cosmetic products, essential oils (EOs) play a major role as fragrance ingredients. They can optimize its proprieties and preservation, as well as the marketing image of the final product. Microencapsulation of EOs can protect and prevent the loss of volatile aromatic ingredients and improve the controlled release and stability of this core materials. The importance of EOs for cosmetic industry and its microencapsulation was reviewed in this study. Also a briefly introduction about the preparation of microparticles was presented. Some of the most important and usual microencapsulation techniques of EOs, as well as the conventional encapsulating agents, were discussed. Despite the fact that microencapsulation of EOs is a very promising and extremely attractive application area for cosmetic industry, further basic research needs to be carried out, for a better understanding of the biofunctional activities of microencapsulated EOs and its release modulation, as well as the effects of others cosmetic ingredients and the storage time in the microparticles properties.     

Spray drying microencapsulation of natural canthaxantin using soluble soybean polysaccharide as a carrier

Microencapsulation of canthaxanthin produced by Dietzia natronolimnaea HS-1 using soluble soybean polysaccharide (SSPS) as a wall material by spray drying method was studied. The SSPS showed very good ability for microencapsulation of canthaxanthin due to its emulsifying properties. The effects of the ratios of core to wall on characteristics of microcapsules were investigated at ratios of 0.25, 0.50, 0.75, and 1.00. The best ratio of core to wall was 0.25 because the microcapsules prepared with this ratio had the smallest size in droplets (0.78 μm) and microcapsules (7.94 μm), also they had the highest microencapsulation efficiency (90.1%) and the lowest losing during process (10.3%). The stability of microcapsules was examined at 25°C in light and dark during 16 weeks of storage. The degradation of canthaxanthin was more retarded by microencapsulation and greater canthaxanthin stability was observed in dark than light condition. The results showed the oxidation was more suppressed for the microcapsules prepared from the emulsion having smaller droplets.     

香精包埋技术研究进展

香精包埋是指采用一种保护性壁材以不同过程包覆香精,从而赋予香精在食品中具一定程度抗蒸发,抗反应和抗逸散性质;喷雾干燥、喷雾冷冻或喷雾冷却、挤压、冷冻干燥、凝聚和分子包合都是常用包埋香精方法,选择何种方法进行包埋则取决于产品终端用途和在生产中加工条件。     

Native and modified porcine plasma protein as wall materials for microencapsulation of natural essential oils

Porcine plasma protein (PPP) is of interest as a wall material to encapsulate lemongrass oil, turmeric oil and eucalyptus oil using emulsion technique and freeze drying. The properties of microcapsules were used to evaluate two types of wall material (native porcine plasma protein; NPPP and modified porcine plasma protein; MPPP) at two different ratios of wall material (W) and core material (C) (W:C; 4:1 and 3:1). All NPPP and MPPP emulsions showed Bingham plastic fluid flow behaviours. Moreover, MPPP microcapsules showed lower free oil content on their surface (0.10–0.50%) with higher encapsulation efficiency (91–98%). Fourier-transform infrared spectroscopy showed the outstanding chemical structure of microcapsules. Furthermore, scanning electron microscopy indicated holes on the surface of microcapsules encapsulated with essential oils. Both PPPs can be used as encapsulation material for natural extract and food additives to improve the food texture and as a biopolymer film to maintain the quality of food products.     

A review of the preparation and application of flavour and essential oils microcapsules based on complex coacervation technology

This paper briefly introduces the preparation and application of flavour and essential oils microcapsules based on complex coacervation technology. The conventional encapsulating agents of oppositely charged proteins and polysaccharides that are used for microencapsulation of flavours and essential oils are reviewed along with the recent advances in complex coacervation methods. Proteins extracted from animal‐derived products (gelatin, whey proteins, silk fibroin) and from vegetables (soy proteins, pea proteins), and polysaccharides such as gum Arabic, pectin, chitosan, agar, alginate, carrageenan and sodium carboxymethyl cellulose are described in depth. In recent decades, flavour and essential oils microcapsules have found numerous potential practical applications in food, textiles, agriculturals and pharmaceuticals. In this paper, the different coating materials and their application are discussed in detail. Consequently, the information obtained allows criteria to be established for selecting a method for the preparation of microcapsules according to their advantages, limitations and behaviours as carriers of flavours and essential oils. © 2013 Society of Chemical Industry     

Effect of Microencapsulation of Dietary Oil on Postprandial Lipemia

ABSTRACT: Microencapsulation is increasingly applied to dietary oils, but only limited information is available about the effect on bioavailability. The aim of the present study was to evaluate the bioavailability of microencapsulated vegetable oil from a liquid food product in a clinical trial. Another aim was to compare the suitability of sodium octenyl succinate starch (SOSS) and oat starch aggregate (OSA) in sustained release of a vegetable oil. Twenty-four healthy young men were recruited and randomly allocated into 1 of 3 groups (A, B, C). All subjects consumed 2 liquid test meals, which differed only with respect to microencapsulation. Groups A and B consumed berry juice or fermented oat drink, respectively, containing either non-encapsulated or SOSS-encapsulated blackcurrant seed oil (BCO). Group C received sea buckthorn oil (SBO) encapsulated with SOSS or OSA. Blood samples were collected at 0,30,60,90,180,270, and 360 min after the meal, and chylomicron-rich (CM-rich) fraction was separated for subsequent triacylglycerol (TAG) analysis. Microencapsulation increased the glycemic response. SOSS-encapsulated BCO resulted in a similar CM-rich TAG response as non-encapsulated BCO, indicating that the SOSS-encapsulated oil was fully bioavailable. OSA-encapsulation had a similar bioavailability. The lipemic response of subjects who consumed the oil mixed in the fermented oat drink was higher than that of other subjects. This most likely resulted from the slightly higher fat and energy content of the fermented oat drink compared with berry juice. Contrary to expectations, the use of OSA in microencapsulation did not result in sustained release.