Effect of the matrix system in the delivery and in vitro bioactivity of microencapsulated Oregano essential oil

The effect of encapsulating matrix on retention, protection and delivery of Oregano essential oil (EO) was studied. EO was encapsulated in rice starch porous spheres, inulin and gelatine/sucrose capsules by spray drying. Gelatine/sucrose matrix was also dried by freeze drying. Experimental designs were applied to test the effect of bonding agents and solids content for rice starch and drying temperature and solids content for inulin and gelatine/sucrose systems. The ratio of gelatine/sucrose was also tested. EO was identified (confocal laser scanning microscopy and FT-IR) in all tested matrices and the release profiles, antioxidant activity and antimicrobial activity of encapsulates evaluated. Results showed that the three tested materials are able to encapsulate Oregano EO. Higher diffusion coefficients were obtained for starch microcapsules (about 10⁻¹³ m²/s) followed by spray-dried gelatine/sucrose systems (about 10⁻¹⁵ m²/s) and inulin microcapsules (about 10⁻¹⁶ m²/s). Gelatine/sucrose microparticles exhibit high antioxidant and antimicrobial activity while inulin and rice starch microencapsulates ensure higher stability.     

Effect of spray drying and freeze drying on the immunomodulatory activity,bitter taste and hygroscopicity of hydrolysate derived from whey protein concentrate

The main aim of the present work was to obtain microencapsulated whey protein concentrate hydrolysate (WPCH) in order to reduce its bitter taste and resistance to hygroscopicity without impairing its immunoregulatory activity by spray drying or freeze drying with whey protein concentrate (WPC) and sodium alginate (SA) as carriers. To attenuate its bitter taste, the WPCH were encapsulated with WPC or the mixture of WPC and sodium alginate (WPC/SA). The splenocyte proliferation activity, hygroscopicity, bitter taste and morphology of non-encapsulated WPCH and encapsulated WPCH were evaluated. Results revealed that WPCH could significantly enhance splenocyte proliferation activity compared with WPC itself. Both spray drying and freeze drying with or without carrier material addition did not exert negative effect on the immunomodulatory activity of WPCH. The bitterness, determined by taste dilution analysis method, of both WPC-encapsulated WPCH and WPC/SA-encapsulated WPCH was significantly lower than that of the original non-encapsulated WPCH. Morphological analysis showed that freeze drying process could not encapsule WPCH as spray drying did. All of these indicated that spray drying with WPC or the mixture of WPC and SA (WPC/SA) as carriers was beneficial for reducing the bitter taste and hygroscopicity without impairing the immunoregulatory activity of whey protein hydrolysate.     

Effectiveness of Jet-Cooked Pearl Cornstarch as a Controlled Release Matrix

The effectiveness of non-chemically modified pearl cornstarch as an encapsulating matrix for active agents such as herbicides is reported. Aqueous gelatinization of pearl cornstarch at high temperatures followed by active agent addition, drying and grinding yielded encapsulated products showing slow release of active agent. Efficiency of encapsulation and rate of release of the herbicide butylate varied with temperature and concentration of starch during steam-jet cooking, amount of butylate incorporated and method of drying. Retrogradation is the major factor influencing efficiency of encapsulation and rate of active agent release.     

Encapsulation of EPTC in Starch by Twin-screw Extrusion

A twin-screw extruder was used for encapsulation of the herbicide EPTC (S-ethyl dipropylcarbamothioate) in starch. Three starch/water ratios, 35/65, 50/50, and 65/35, were evaluated for efficiency to encapsulate 13.9% EPTC on a dry starch basis. Analysis of extrudates, after drying and grinding to the desired particle size, showed recovery of active ingredient (a.i.) and effectiveness of encapsulation to be best at 35% starch solids (35/65 starch/water ratio). Scanning electron micrographs showed smaller and a more even distribution of a.i. at 35% starch. Suspending particles in water caused a release of EPTC which increased with agitation and smaller mesh size. Air-dried particles released EPTC more slowly than oven-dried particles of the same mesh range. Particles from extrusion at 35% solids released a.i. more slowly than those from extrusion at 65% solids. The slowest releasing particles showed the least swellibility. EPTC was also encapsulated at 10.2% a.i. using 20% and 35% starch solids with steam-injection cooking followed by Sigma blade mixing for comparison with an extrusion. Herbicide retention and encapsulation were superior, release of a.i. into water was slower, and swelling of particles was less in twin-screw extrusion prepared products.     

多孔淀粉对姜黄素的吸附

采用扫描电子显微镜(scanning electron microscope,SEM)、傅里叶变换红外光谱(fourier transform infrared spectroscopy,FTIR)、粒度分布、吸附能力等指标对复合物进行表征;利用差示扫描量热法(differential scanning calorimety,DSC)和水溶性分析其稳定性;通过自由基清除能力及体外模拟胃液(SGF)和肠液(SIF)环境研究其释放特性。比较SEM、FTIR结果,可以看出姜黄素被吸附在多孔中并表现为化学吸附。姜黄素以不同的质量比进行吸附,0.4wt%的负载量实现了最高的吸附能力(3.67 mg/g),吸附后样品呈淡黄色,水溶性大大提高,保留大部分抗氧化能力,体外SGF和SIF中表明具有缓释效果。该研究成功制备马铃薯多孔淀粉-姜黄素复合物,且有望扩大姜黄素在食品工业中的应用。     

咖啡因-淀粉微胶囊的制备、结构表征及形成机理

该文探究以淀粉为壁材包埋水溶性咖啡因的可行性。以膨胀淀粉、多孔淀粉、颗粒态V型结晶淀粉为包埋壁材,对咖啡因进行吸附和包埋,采用扫描电镜、X-射线衍射、紫外光谱对微胶囊进行结构表征。实验结果表明,颗粒态V型结晶淀粉制备的微胶囊对咖啡因的包埋量和包埋效率最高,分别为45.89 mg/g和65.27%;扫描电镜结果显示,膨胀淀粉和多孔淀粉制备的微胶囊与原淀粉形态相似,而V型结晶淀粉制备的微胶囊呈不规则块状;X-射线衍射结果显示,淀粉和咖啡因之间未形成新的V型峰;紫外光谱结果显示,3种微胶囊均在275.5 nm处有最大吸收峰,表明咖啡因的包埋成功。3种淀粉壁材主要通过淀粉大分子对咖啡因分子进行物理截留,而多孔淀粉的多孔结构对咖啡因分子的吸附和包埋贡献不显著。3种淀粉壁材均可用于包埋水溶性咖啡因,拓展了咖啡因在食品中的应用范围。     

高价离子型辛烯基琥珀酸淀粉酯作为微胶囊壁材的研究

以钠型辛烯基琥珀酸淀粉酯为原料,制备高价离子型辛烯基琥珀酸淀粉酯(钡型、钙型、三价铁型),并以柠檬油为芯材,高价离子型辛烯基琥珀酸淀粉酯为壁材,采用喷雾干燥法制备柠檬油微胶囊,测定了高价离子型辛烯基琥珀酸淀粉酯的离子交换率,乳液的乳化稳定性及黏度,并考察了此种淀粉酯作为微胶囊壁材对柠檬油包埋率的影响,最后利用扫描电子显微镜观察微胶囊的形貌特征。结果表明,淀粉酯中离子化合价的改变对乳液黏度、乳化稳定性和柠檬油的包埋率均有显著影响(p<0.05),其中,三价铁型辛烯基琥珀酸淀粉酯作壁材时,乳液黏度为1.04 mPa·s,柠檬油包埋率达到了96.51%;扫描电镜分析表明,三价铁型壁材制备的微胶囊粒径最大,囊壁最厚。说明三价铁型辛烯基琥珀酸淀粉酯可作为一种性能良好的微胶囊壁材。     

Temporal Sodium Release Related to Gel Microstructural Properties—Implications for Sodium Reduction

The microstructure of food can be engineered to enhance sodium release during mastication, which may be used as a strategy to reduce sodium content in foods. This study aimed to relate sodium release to microstructural properties of solid lipoproteic colloid (SLC) foods. The SLC gels with 1.5% (w/w) NaCl were prepared by homogenization of whey protein isolate and anhydrous milk fat, followed by heat‐induced gelation. The gels varied in protein content (8% or 16%), fat content (0%, 11%, 22%, or 33%), and homogenization pressures (14 or 55 MPa). The maximum rate of sodium release during the initial gel compression increased with increasing gel porosity and pore size. This was due to more releasable serum in the gels with larger pore volume and larger pores. The maximum concentration of sodium at the end of sodium release increased with reduced size of the fat particles in the gels. The smaller fat particles were dispersed more uniformly and interrupted the protein network more, and facilitated the gel breakdown. The above findings suggested that, during the breakdown of the SLC gels, the major mechanisms of sodium release are via serum release followed by sodium diffusion, which are governed by the gel porosity and the particle size of fat, respectively. This study demonstrated the dependence of temporal sodium release properties on the microstructural properties of an SLC food system. The findings from this study could lay the foundation for further investigation of the dependence of saltiness perception on SLC microstructure, which can provide insight for sodium reduction in SLC products.     

Exploring the protective effects of calcium-containing carrier against drying-induced cellular injuries of probiotics using single droplet drying technique

Protective carriers that encapsulate probiotics in spray drying could improve the survival ratio of dried cells through different mechanisms. Unveiling the protective mechanism of each carrier will contribute to a rational design of high performance carrier formulation. This study utilized single droplet drying (SDD) technique to investigate the effects of calcium cation in varied carrier formulation. Inactivation histories of Lactobacillus rhamnosus GG (LGG) in different carriers were compared, and cellular injury history of probiotics during droplet drying was studied for the first time. Adding 1 mM CaCl₂ to lactose carrier protected cell viability, mitigated cellular injuries, and enhanced regrowth capability as drying progressed, demonstrating the positive effect of Ca^2 + with possible mechanism of stabilizing sub-cellular structures. At later drying stages, cell survival in Lac/Ca carrier was increased by 0.5–1.5 log on selective media compared to lactose carrier. Supplementing calcium-binding agents lowered the protective effect, shortening the initiation of rapid cell inactivation down to 120 s of drying. Adding CaCl₂ to trehalose carrier barely improved cell survival, indicating that the protective effect could be influenced by carrier formulation. Pure trehalose carrier exerted excellent protection on LGG, supporting cells to regrow in liquid rich medium even after 180 s of drying. The protection of trehalose may stem from stabilization of sub-cellular structures, which possibly overlap the effect of Ca^2 +. The findings suggested that high performance carrier formulation might be developed by combining carrier materials with different protective mechanisms, for maximizing the survival of active dry probiotics in industrial spray drying operation.     

Effect of annealing on the semicrystalline structure of normal and waxy corn starches

The influence of amylose and amylopectin on structural reorganization occurred during annealing was studied for normal and waxy corn starches. Annealing caused an increase in crystallinity in the waxy corn starch, whereas the number of pores on the granule surface, observed by SEM, increased especially for normal corn starch. Amylose and amylopectin chains of the annealed normal corn starch were degraded to greater extension during enzymatic hydrolysis than those of the native starch. On contrary, the annealing caused a protective effect on waxy corn starch amylopectin toward the enzymatic reaction suggesting that this treatment promoted a better interaction between amylopectin chains of waxy corn starch. The amylose molecules of normal corn starch may have impaired the mobility of amylopectin molecules and restricted the reorganization of the crystalline structure during the annealing. The major increase in pores number on the granule surface of annealed normal corn starch, resulted of the endogenous amylase action during annealing, could facilitate the exogenous enzymes’ role in the degradation of the starch granules’ amorphous area.     

Conductive drying methods for producing high-quality restructured pineapple-starch snacks

Restructured fruit pulps can be dried to obtain new added-value products. In the present study, restructured pineapple pulp was dehydrated by two innovative methods, cast-tape drying (CTD) and conductive multiflash drying (KMFD). The snack produced was evaluated by physical, chemical, and sensory aspects. CTD required a half time length (30 min) than KMFD (60 min) for drying. The drying processes did not affect the ascorbic acid content present in the fresh fruit but decreased its antioxidant activity in 50–70%. The natural volatile compounds were also changed. The product from KMFD was preferred by consumers, which may be a consequence of a more expanded structure with larger pores created by the vacuum pulse and flash water evaporation. KMFD resulted in more jagged acoustic-mechanical curves, which is a characteristic of crispy foods. Therefore, KMFD can be considered the most promising process to produce restructured pineapple snacks in approximately one hour with excellent quality.Industrial relevanceIn recent years, a growing number of consumers have been looking for healthy, convenient, and ready-to-eat foods. Dried restructured fruits can be healthy snacks with very attractive sensory characteristics depending on the drying method. Cast-tape drying (CTD) and conductive multiflash drying (KMFD) are novel technologies with great potential to produce high-quality dried products at an industrial scale in a relatively short time. This study provides important results regarding the most suitable drying processes setup for producing high-quality dried restructured pineapple.     

Legume proteins are smart carriers to encapsulate hydrophilic and hydrophobic bioactive compounds and probiotic bacteria: A review

Encapsulation is a promising technological process enabling the protection of bioactive compounds against harsh storage, processing, and gastrointestinal tract (GIT) conditions. Legume proteins (LPs) are unique carriers that can efficiently encapsulate these unstable and highly reactive ingredients. Stable LPs-based microcapsules loaded with active ingredients can thus develop to be embedded into processed functional foods. The recent advances in micro- and nanoencapsulation process of an extensive span of bioactive health-promoting probiotics and chemical compounds such as marine and plant fatty acid-rich oils, carotenoid pigments, vitamins, flavors, essential oils, phenolic and anthocyanin-rich extracts, iron, and phytase by LPs as single wall materials were highlighted. A technical summary of the use of single LP-based carriers in designing innovative delivery systems for natural bioactive molecules and probiotics was made. The encapsulation mechanisms, encapsulation efficiency, physicochemical and thermal stability, as well as the release and absorption behavior of bioactives were comprehensively discussed. Protein isolates and concentrates of soy and pea were the most common LPs to encapsulate nutraceuticals and probiotics. The microencapsulation of probiotics using LPs improved bacteria survivability, storage stability, and tolerance in the in vitro GIT conditions. Moreover, homogenization and high-pressure pretreatments as well as enzymatic cross-linking of LPs significantly modify their structure and functionality to better encapsulate the bioactive core materials. LPs can be attractive delivery devices for the controlled release and increased bioaccessibility of the main food-grade bioactives.     

多孔淀粉对葡萄籽原花青素的吸附及微胶囊化研究

研究了多孔淀粉对葡萄籽原花青素的吸附能力，并以3种壁材（明胶、明胶-蔗糖、明胶-阿拉伯胶）包埋多孔淀粉-原花青素复合物。结果表明，多孔淀粉对原花青素的吸附速度较快，每克干多孔淀粉能吸附约40mg原花青素。3种壁材均有较好的包埋效果，包埋效率在87.1％-98.4‰但总体的包埋率较低。     

沙棘果油微胶囊化制备工艺的优化及其表征

为研究混合壁材及乳化剂对沙棘果油微胶囊包埋效果及稳定性的影响,本文以沙棘果油为芯材,以酪蛋白酸钠和变性淀粉(辛烯基琥珀酸淀粉钠)为混合壁材,单双硬脂酸甘油酯为乳化剂,麦芽糊精为填充剂,柠檬酸钾为缓冲盐,通过喷雾干燥法制备50%载油率的沙棘果油微胶囊。在单因素实验的基础上,以酪蛋白酸钠添加量、变性淀粉添加量、乳化剂添加量为实验因素,采用Box-Behnken法设计三因素三水平试验进行优化,确定微囊粉的最佳包埋效果。结果表明,所得的回归模型具有高度的显著性(P<0.0001),方程对试验拟合较好,在酪蛋白酸钠添加量8%、变性淀粉添加量16%、乳化剂添加量2%条件下,制备得到的沙棘果油微囊粉包埋率最大,可以达到91.6%;扫描电镜观察微胶囊粉表面圆润无裂痕,马尔文激光粒度分析仪测定复原乳粒径<800 nm,通过油脂氧化自动分析仪进行油脂氧化诱导期分析,对照组沙棘果油氧化诱导期为7 h,试验组沙棘果油微囊粉氧化诱导期为40 h,表明沙棘果油微囊粉稳定性强,不易氧化变质,货架期较长。     

丁香油微胶囊的制备及表征

以明胶和海藻酸钠为壁材,采用复凝聚法对丁香油进行包覆,通过喷雾干燥法得到干燥的微胶囊产物,研究pH、明胶和海藻酸钠质量比、芯壁质量比、壁材用量、搅拌转速对微胶囊形成的影响,并对微胶囊的缓释性进行研究,采用红外、TG、SEM对优选实验条件下制备得到的微胶囊进行表征.结果表明:经过微胶囊化的丁香油挥发性明显降低,热稳定性大...     

Exploiting blackcurrant juice press residue in extruded snacks

Extrusion process was developed to exploit blackcurrant juice press residues from industrial side-streams. Press residues obtained from conventional enzymatic pressing, with high content of fiber and seed oil, and novel non-enzymatic juice processing, with high content of sugars, fruit acids and anthocyanins, were extruded with barley flour, oat flour or oat bran. The recipes consisted of blackcurrant press residues (30%), cereal materials (40%) and potato starch (30%) and small amount of sugar and salt. When compared to enzymatic press residue and oat bran, the novel non-enzymatic press residue extruded with barley or oat flour had higher expansion, lower hardness and density, higher redness (a*), lower pH, and higher contents of fructose, glucose and fruit acids, all contributing positively to liking of texture, appearance, and flavor as well as berry-like experience. These characteristics were obtained with more gentle processing parameters, consisting of a lower total mass flow, screw speed and barrel temperature. Female consumers gave lower ratings in flavor, appearance and overall pleasantness for blackcurrant snacks than males. The study presented a sustainable way of utilizing industrial press residues from different processes of berry juice pressing for production of healthy snacks and breakfast cereals.     

酶解-交联法制备多孔淀粉及其负载红景天苷研究

以玉米淀粉为原料,采用α-淀粉酶和糖化酶复合酶解与三偏磷酸钠交联改性相结合的方法制备了一系列具有不同交联度的交联多孔淀粉。通过各种表征手段考察了原玉米淀粉、多孔淀粉和交联多孔淀粉的形态结构和理化性质,并应用于负载红景天苷研究。该方法制备的交联多孔淀粉具有良好的蜂窝状中空结构,有利于淀粉颗粒对目的物质的吸附。相比原淀粉和未交联多孔淀粉,交联多孔淀粉的吸油率有较大提高,对红景天苷的包封率为58.89%。经过交联反应后的交联多孔淀粉不但晶型没有发生改变,还具有更高的总孔面积、平均孔直径和孔隙率值,其分子结构也更加紧凑,更具刚性和更高的糊化温度,说明交联改性提高了多孔淀粉的结构性能。体外释放结果表明载药交联多孔淀粉具有一定的缓释性能,能够提高红景天苷的生物半衰期和生物利用度。      

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.     

Investigations into the stabilization of a volatile aroma compound using a combined emulsification and spray drying process

The aromatic compound 3-methylbutyraldehyde (3-mba) was stabilized using a combined emulsification (W₁/O/W₂) and spray drying process. The process suitability and the encapsulation properties of eight materials were evaluated. Whey protein concentrate (WPC), sodium octenyl succinate modified starch (modified starch 1), maltodextrin, and gum Arabic (GA) were found to be the best process-adapted microencapsulation materials. These materials were chosen for further experiments in which the influence of the solids content on flavor intensity and flavor retention during storage were determined. The amount of encapsulated 3-mba increased with increasing solids content from 40–50% using WPC, modified starch 1, and maltodextrin. Microcapsules with GA reached the maximum value of encapsulated 3-mba at 45% solids. After 11 days of storage, flavor retention decreased in the following order: GA > modified starch 1 > WPC ∼ maltodextrin. Finally, the spray drying process was optimized by design of experiments (DoE). The optimized parameters were a feed temperature of 40 °C, a dry mass in W₂ of 60%, and an amount of W₁/O of 40% using modified starch 1.     

Preparation and Properties of Oxidatively and Zinc Coupled Starch Xanthates

Conditions for the precipitation of sodium starch xanthate as the zinc salt were determined to be: xanthate degree of substitution greater than 0.02 and zinc ion concentration of 0.005–0.015-M. As xanthate ion concentration is increased, less zinc is required for complete precipitation of the starch xanthate. Oxidatively crosslinked starch xanthates (starch xanthides) were more stable when washed with dilute acid before drying. Shelf-life was greatly improved when the moisture content of the samples was less than 5%. Starch xanthides rapidly decompose in water. Pyrolysis of starch xanthides at temperatures of 145 to 215°C liberates carbon disulfide and carbonyl sulfide.