Microencapsulation of Banana Passion Fruit (<i>Passiflora tripartita Var. Mollissima</i>): A New Alternative as a Natural Additive as Antioxidant

Banana passion fruit (P. tripartita var. Mollissima) is one of the most promising tropical fruits giving its antioxidant activity (AOA) to replace synthetic additives. Despite this property, there are no studies about the metabolites responsible for its biological function or proposals for the application of technologies, such as microencapsulation by spray drying, to improve its properties and ease its incorporation in several food matrices. The aim of this study is to microencapsulate the pulp of banana passion fruit with several mixtures of encapsulants and identify which one of these mixtures is better to preserve its AOA. The antioxidant activity values for the banana passion fruit pulp were as follows: DPPH: 6630.2 ± 91 μMtrolox/100g;ABTS: 18764.3 ± 270.4 μMtrolox/100g;FRAP: 1703.6± 938.2 mgAA/100g, ORAC: 8105.4 ± 424.2 μmol TEAC/100g of sample;Total phenols: 8862.2 ± 451.4 gallic ac. mg/100g. The concentrations of the bioactive compounds expressed in mg of gallic acid per 100 g of the pulp on a dry base were 13.9 ± 0.004;5.9 ± 0.001 and 126.3 ± 0.004 for caffeic, p-coumaric and ferulic acids, respectively. The best shelf-life followed by ABTS in eight assays was between 28.8 and 31.5 weeks using maltodextrin and modified starch, MD:MS (1/4:3/4) and MD:MS (0:1), respectively. In conclusion, ABTS is the best method to measure the AOA in banana passion fruit because it correlated with the phenolic compounds better than DPPH and FRAP methods. Additionally, two options were found to protect the AOA and to extent the shelf-life of the passion fruit by spray-drying, with mixtures of encapsulants widely used in the food industry.

Microencapsulation improves inhibitory effects of transplanted olfactory ensheathing cells on pain after sciatic nerve injury

Olfactory bulb tissue transplantation inhibits P2X2/3 receptor-mediated neuropathic pain. However, the olfactory bulb has a complex cellular composition, and the mechanism underlying the action of purified transplanted olfactory ensheathing cells（OECs） remains unclear. In the present study, we microencapsulated OECs in alginic acid, and transplanted free and microencapsulated OECs into the region surrounding the injured sciatic nerve in rat models of chronic constriction injury. We assessed mechanical nociception in the rat models 7 and 14 days after surgery by measuring paw withdrawal threshold, and examined P2X2/3 receptor expression in L4–5 dorsal root ganglia using immunohistochemistry. Rats that received free and microencapsulated OEC transplants showed greater withdrawal thresholds than untreated model rats, and weaker P2X2/3 receptor immunoreactivity in dorsal root ganglia. At 14 days, paw withdrawal threshold was much higher in the microencapsulated OEC-treated animals. Our results confirm that microencapsulated OEC transplantation suppresses P2X2/3 receptor expression in L4–5 dorsal root ganglia in rat models of neuropathic pain and reduces allodynia, and also suggest that transplantation of microencapsulated OECs is more effective than transplantation of free OECs for the treatment of neuropathic pain.

Microencapsulation of stearic acid with polymethylmethacrylate using iron(Ⅲ) chloride as photo-initiator for thermal energy storage

Aiming to identify the validity of fabricating microencapsulated phase change material(PCM) with polymethylmethacrylate(PMMA) by ultraviolet curing emulsion polymerization method using iron(III) chloride as photoinitiator,SA/PMMA microcapsules were prepared and various techniques were employed to determine the ignition mechanism,structural characteristics and thermal properties of the composite.The results shown that the microcapsules containing SA with maximum percentage of 52.20 wt% formed by radical mechanism and only physical interactions existed in the components both in the prepared process and subsequent use.The phase change temperatures and latent heats of the microencapsulated SA were measured as 55.3 °C and 102.1 J·g^(-1) for melting,and 48.8 °C and 102.8 J·g^(-1) for freezing,respectively.Thermal gravimetric analysis revealed that SA/PMMA has good thermal durability in working temperature range.The results of accelerated thermal cycling test are all shown that the SA/PMMA have excellent thermal reliability and chemical stability although they were subjected 1000 melting/freezing cycles.In summary,the comparable thermal storage ability and good thermal reliability facilitated SA/PMMA to be considered as a viable candidate for thermal energy storage.The successful fabrication of SA/PMMA capsules indicates that ferric chloride is a prominent candidate for synthesizing PMMA containing PCM composite.

Microencapsulation of Mixed Fetal Pituitary-Hypothalamic-Nigral Cells

With the microencapsulation technique for immunoisolation of transplanted tissues, a study on pituitary transplantation was performed in our lab. Mixed fetal pituitary hypothalamic nigral cells were microencapsulated and cultured to investigate the secretion of growth hormone (GH), prolactin(PRL) and PRL releasing function stimulated by thyrotropin releasing hormone (TRH) in the medium. Rabbits were immunized with the encapsulated cells for 50 days. The results revealed that: ①GH, PRL could be secreted into medium through the capsules; ②PRL concentration augmented when TRH was added to the medium; ③No antibody against the fetal brain tissue could be detected in rabbit serum. These indicated that the material and the procedure of microencapsulation did not disturb the viability and function of encapsulated cells; the membrane of the microencapsulation was permeable to the pituitary hormones and hypothalamic factors, and had the function of immunoisolation.

Nano-Microencapsulation and Controlled Release of Linoleic Acid in Biopolymer Matrices: Effects of the Physical State, Water Activity, and Quercetin on Oxidative Stability

In this study, linoleic acid (LA) was encapsulated in the presence or absence of quercetin into a dual polymer system of whey protein and kappa-carrageenan using power ultrasound. Atomic Force Microscopy (AFM) and FlowCam imaging technology were used for imaging and size determination of nano-and micro-capsules. Differential scanning calorimeter (DSC) was used to determine the glass transition temperature (Tg) of the freeze-dried nanocapsules. In order to examine the effect of water activity (aw) on the release profile of the encapsulated LA, the nanocapsules were equilibrated over saturated salt solution conditions corresponding to the range of aw between 0.333 and 0.769 in evacuated desiccators at room temperature. Gravimetric measurements of the steady state linoleic acid (LA) contents were conducted. The anti-oxidant activity of quercetin and the stability of encapsulated LA toward long term and thermally induced rancidity was investigated. The capsules were in the nanosize regime and 83% of the LA was effectively encapsulated. Furthermore, at aw of 0.764, the highest percentage of LA (74%) was released from the expelling nanocapsules. Quercetin was found to exhibit protective antioxidant effect against time-dependent oxidation and thermally induced rancidity of LA. Water activity values of 0.662 and 0.764 provided ideal humidity and pressure conditions for sustained release of nanoencapsulated LA at room temperature.

Palm Oil Microencapsulation by Coacervation, Thin Layer Drying, and Silica Dioxide Absorption Technique

Indonesia is the largest palm oil producer in the world. The content of β-carotene in palm oil, which can act as pro-vitamin A, is relatively high, so it has great potential for overcoming cases of vitamin A deficiency. By microencapsulation process of palm oil, β-carotene content in palm oil will be more stable and have a longer shelf life. There are three methods of microencapsulation used in this study, namely coacervation, thin-layer drying, and SiO2 absorption technique, which theoretically are suitable for encapsulating β-carotene in palm oil. The aim of this research is to compare and find the most suitable method of microencapsulation process of palm oil to obtain the highest β-carotene content and retention. Results show that those three methods are significantly different in affecting water absorption, solubility in water, yield, microencapsulation efficiency, β-carotene content, and retention of microencapsulated palm oil. The microencapsulated palm oil made from thin layer drying method has the highest β-carotene content at 200.16 μg/g and β-carotene retention of 68.89%. It also has low water absorption and high water solubility, so it can be applied as a powder premix in food as vitamin A supplement.

Microencapsulation by Spray Drying of Vitamin A Palmitate from Oil to Powder and Its Application in Topical Delivery System

Vitamin A palmitate (VAP) contains retinol and palmitic acid which is easily absorbed by body and widely used in skin care products. But, it is a hydrophobic and oxidation sensitive molecule which undergoes rapid degradation especially in an aqueous environment. The purpose of this study was to prepare microcapsules of VAP using combination maltodextrin and modified starches. Emulsion of VAP was prepared using cremophore RH 40 with Tween 80 in a homogenizer and formed emulsion was spray-dried. The spray process was optimized using a central composite design for two variables to obtain microcapsules with desirable characteristics. Microcapsules containing 30% of VAP were produced using different concentration of wall materials. The prepared microcapsules were evaluated for their physical, morphological, in-vitro drug release and SEM study. The results showed that obtained microcapsules are nearly spherical in shape with a particle size ranged from 1 to 12 μm. The drug content and encapsulation efficiency (53% - 63%) of different batches were found within acceptable range. These stabilized drug loaded microcapsules were incorporated into silicone cream based formulation for convenient topical application and evaluated for its physicochemical parameters. The drug release study showed 80.18% to 83.43% of drug release from VAP microcapsules while topical formulations prepared by VAP microcapsules showed 67.09% to 71.45% drug release at the end of 24 hrs. The formulations were kept for 3 months stability study as per ICH guidelines and found to be stable.

Coacervation Microencapsulation of CaCO₃Particles with a Fluoropolymer by Pressure-induced Phase Separation of Supercritical Carbon Dioxide Solutions

We report a method for the coacervation micro-encapsulation of several forms of CaCO3 microparticles with the fluoropolymer poly(heptadecafluorodecyl acrylate) (poly (HDFDA)) by pressure-induced phase separation of a supercritical CO2 solution.? A suspension of CaCO3 in CO2 and dissolved poly(HDFDA) were mixed in supercritical CO2.? After the system pressure was slowly decreased to atmospheric pressure, the microcapsules were obtained.? Coacervation was achieved by the precipitation of poly(HDFDA) during the decrease in the pressure of CO2;the solubility of poly(HDFDA) in CO2 decreased with the pressure.? The structure and morphology of the microparticles were investigated by using a scanning electron microscope (SEM) and an electron probe microanalyzer (EPMA) equipped with a wavelength dispersive X-ray spectroscope (WDX).

Acrocomia aculeata(Jacq.)Lodd.Oil Microencapsulation by Complex Coacervation:Preservation of Bioactive Compounds

Acrocomia aculeata (Jacq.) Lodd. shows possibilities for pharmaceutical, food and chemical use. However, its application is limited due to the loss of its bioactive components. Microencapsulation may be an alternative to reduce such problems. A step-by-step optimization approach was used in this work for preservation of bioactive compounds. The applied technique to microencapsulate the Acrocomia aculeata oil was efficient, producing between 64% and 99% of microcapsules and 59% to 97% of encapsulated oil. In the experimental design, temperature was the parameter that significantly influenced the carotenoids of microcapsules. Complex coacervation helped to preserve carotenoids and the antioxidant activity, and an interaction between the temperature and the content was observed for such preservation.

Microencapsulation of Lipase and Savinase Enzymes by Spray Drying Using Arabic Gum as Wall Material

Enzymes have been used in detergents over the years. They can improve the detergent’s efficiency due to their activities against hard stains. Nevertheless, enzymes cannot maintain their properties indefinitely, since they are exposed to stress factors, like temperature, pH, mechanical processes and others. Consequently, enzymes lose their structure and they are not functional. For this reason, microencapsulating these proteins is a feasible solution to improve their use in industrial processes and commercial products. Spray drying technology has been selected because a lot of scientific literature proved its useful application in a variety of industries. In particular, savinase and lipase are the two encapsulated enzymes in this work. Savinase attacks proteins and lipase removes fats, so they are suitable enzymes for detergent industry. Arabic gum has been used as wall material. Morphology, size and activity of the obtained microcapsules have been analyzed in order to find the best conditions to produce them. In conclusion, useful microcapsules of lipase and savinase can be obtained with the mentioned technology.

Microencapsulation of L-Ascorbic Acid by Spray Drying Using Sodium Alginate as Wall Material

L-ascorbic acid is a water soluble vitamin (vitamin C) widely used as an additive in foods and cosmetics. It has high instability against certain environmental factors;the main cause of its deterioration is oxidation. Microencapsulation is an effective protection technique of L-ascorbic acid from its degradation reactions. This work is focused on the encapsulation of L-ascorbic acid by spray drying technique using sodium alginate as wall material. The microcapsules morphology was observed by scanning electron microscopy (SEM) and the encapsulation efficiency was determined by spectrophotometric analysis. Results showed that encapsulation efficiency was of 93.48% and after 30 days was of 92.55%;differences were not significant, so that the stability of L-ascorbic acid was not affected. Encapsulation yields obtained were low, at around 30%, but the microcapsules morphology obtained is spherical.

植物乳杆菌和嗜酸乳杆菌微胶囊酸奶的研制

以鲜牛乳为原料,添加植物乳杆菌和嗜酸乳杆菌微胶囊制备酸奶。以产品的酸度、黏度、pH、感官评分为评价指标,通过单因素试验、正交试验和主成分分析(PCA)对结果进行综合分析,优化酸奶工艺,且通过体外模拟胃肠液试验,探究微胶囊酸奶中乳酸菌的存活率。结果表明,酸奶的最佳配方为以鲜牛乳为原料,发酵剂添加量0.2%,白砂糖添加量8%,果胶添加量0.2%,微胶囊添加量2%,发酵温度41℃,发酵时间9 h。在此优化条件下制作的酸奶质地细腻,组织状态均匀,感官评分为85分,其黏度、酸度、pH值分别为410 m Pa·s、137°T、5.2,其理化和微生物指标均符合国家标准。体外模拟试验结果表明,与添加乳酸菌菌粉制成的酸奶相比,添加乳酸菌微胶囊制成的酸奶经胃液和肠液后,存活率达到67.60%和62.00%,分别增加了36.21%和33.94%。乳酸菌微胶囊添加到酸奶中,为新型酸奶食品的研发提供参考依据。

多重包埋技术在微囊化姜黄素中的应用

姜黄素较差的溶解性和对氧化的高度敏感性,使其存在很大的应用局限,为此对多重包埋技术在微囊化姜黄素中的应用进行了研究。通过单因素试验,分析溶剂类别、溶解温度和时间以及油相蠕动泵频率、真空乳化机转速等因素对微囊化姜黄素产品的影响,确定了姜黄素最佳溶解工艺条件和一次包埋工艺条件;然后通过正交实验分析,针对产品感观质量和稳定性等因素,确定了合理的多重包埋技术微囊化姜黄素10%冷水溶性(Cold Water Solubility,CWS)产品配方。结果表明:最佳工艺条件是以丙酮作溶剂,溶解温度55℃、时间少于45 min,蠕动泵频率20 Hz,真空乳化机转速控制在15000 r/min;产品配方为12%姜黄素、25%聚乙二醇6000、3.5%吐温-60、35%辛烯基琥珀酸淀粉钠、4.5%dl-α生育酚、20%玉米淀粉。此项技术的应用很大程度上提高了姜黄素的水溶性、稳定性与生物利用度,拓宽了其应用范围和领域。

共封装硒肽和VE微胶囊制备及其理化特性

通过乳化-冷冻干燥联合技术构建微胶囊体系,以实现对具有不同极性的物质(亲水性硒肽和亲脂性VE)的稳态化共封装。以包埋率作为参考,通过单因素试验考察壁材浓度、硒肽和VE含量等工艺参数对包埋效果的影响。傅里叶变换红外光谱和扫描电子显微镜图像表明微胶囊能够有效封装硒肽和VE,并且具有较好的水分散性,复溶后仍保持双重乳液结构。热稳定性分析和2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除实验结果证实,相比于硒肽粉末,微胶囊具有更高的热稳定性和抗氧化活性。电子鼻分析结果进一步证实微胶囊体系对硒肽自身异味具有较好的遮掩效果。体外模拟消化实验表明,微胶囊封装提高了硒肽在模拟胃液中的稳定性,并且硒肽在模拟肠液具有更低的保留率,能够被有效释放。相关研究结论将为富硒功能性食品营养补充剂的开发提供理论依据。

微胶囊相变材料改良粉砂土的导热系数及预测模型

【目的】针对季节冻土地区渠道冻融破坏,分析微胶囊相变材料(microencapsulated phase change materials,mPCM)改良粉砂土层渠基的温度场,对改良粉砂土的导热系数进行研究。【方法】以mPCM为改良剂,掺入渠基粉砂土形成mPCM改良粉砂土;对mPCM改良粉砂土进行导热系数实验和内部结构表征;采用多元线性回归和支持向量机(support vector machine,SVM)方法分别建立mPCM改良粉砂土的导热系数预测模型。【结果】mPCM改良粉砂土导热系数与含水率、干密度、mPCM掺量有关,且受冰水相对含量、冰水相变潜热、mPCM相变潜热和mPCM填充密实作用的影响,具有明显的温度效应;mPCM改良粉砂土导热系数的变化与实验温度和mPCM相变温度有关,可分为快速降低、缓慢降低和逐步上升3个阶段;多元线性回归和SVM模型均能较好地拟合预测mPCM改良粉砂土的导热系数,但SVM模型更适用于表征mPCM改良粉砂土导热系数各影响因素间的非线性关系。【结论】mPCM改良粉砂土的导热系数提高能够有效调控渠基土温度场,减轻渠道冻害,且SVM模型能更加准确地进行导热系数预测。

基于文献计量分析益生菌微胶囊化研究现状及发展趋势

益生菌产品对维护肠道健康的重要性不断被揭示,但无论是加工、贮藏、运输中的物理损伤还是摄入之后胃酸、胆汁盐等的胁迫,都会导致益生菌活力损失。为解决这些问题,利用微胶囊技术对益生菌进行包埋已经成为重要议题。该研究借助CiteSpace6.1.R6、VOSviewer1.6.19和Bibliometrix等文献计量工具,对1438篇中英文文献进行了分布特征分析。结果显示,益生菌微胶囊化研究正处于高速发展期,中国发文量领先,展现了未来发展的巨大潜力。包埋材料正在从壳聚糖与藻酸盐为主走向多元化发展,喷雾干燥技术取代冷冻干燥技术成为最常使用的微胶囊化手段。同时,各类生物活性材料的应用愈发频繁,多酚与人工酶将助力高自由度纳米封装。此外,益生菌与益生元的共封装或成为研究热点。结合关键词演变知识图谱,可以推测该领域未来研究热点,为研究者提供参考。

杏仁油的功能特性、提取和微胶囊化研究综述

杏仁油营养丰富,是一种功能性食用油,同时具有很高的药用价值。本文在介绍杏仁油抗氧化、降血糖和预防心血管疾病等多种功能特性的基础上,对国内外杏仁油的提取和微胶囊化制备技术进行综述和展望。通过对杏仁油机械压榨法、溶剂萃取法、水萃取法等多种不同提取方法比较,以及喷雾干燥法、复合凝聚法、挤压法和冷冻干燥法等微胶囊化制备技术进行分析,明确不同技术方法的优缺点,以期为稳定杏仁油的制备及其合理利用提供理论参考,建立一种方便、快捷、高效、安全的杏仁油产业化生产和制备技术。

复合海藻酸钠益生菌微胶囊研究进展

海藻酸钠微胶囊制备的研究一直是微胶囊技术的重要组成部分。由海藻酸钠制成的益生菌胶囊有孔隙和裂缝,通过利用不同壁材与海藻酸钠组合形成复合海藻酸钠微胶囊,可对益生菌起到更有效的保护作用。本文概述了三类材料对海藻酸钠微胶囊复合的研究进展,包括添加益生元刺激益生菌增长,共混纳米材料来提升机械性能,利用涂层成膜材料减少外部物质进入或内部芯材渗透。总结不同包埋结构的优缺点,并对益生菌微胶囊包埋的发展趋势进行了展望,以期为复合海藻酸钠益生菌微胶囊的科学研究提供参考。

微流控法制备载卵母细胞水凝胶微球及其玻璃化保存

目的通过微流控法制备载卵母细胞海藻酸钠微球,在低浓度保护剂下实现卵母细胞玻璃化保存。方法采用流动聚焦型微流控芯片,通过调整芯片结构、海藻酸钠溶液浓度和流速比,制备大小均匀、空包率低、低温耐受的载卵母细胞海藻酸钠水凝胶微球。在低浓度低温保护剂下将微球玻璃化保存,复温后检测存活率,采用细胞松弛素B和氯化锶孤雌激活卵母细胞,与Cryotop玻璃化法对比卵母细胞存活率和卵裂率、囊胚率。结果制备的海藻酸钠微球在冷冻复温前后的体积稳定且结构完整,在将卵母细胞包封在海藻酸钠水凝胶中后,空包率低,存活率、卵裂率和囊胚率与新鲜组相比无显著差异。在低浓度低温保护剂10%DMSO+10%乙二醇(EG)+0.5 mol/L海藻糖中玻璃化冻存后卵母细胞的存活率达到92.48%,卵裂率70.80%,囊胚率20.42%,与高浓度保护剂15%DMSO+15%EG+0.5 mol/L海藻糖中Cryotop玻璃化法相比无显著性差异。结论本文设计制作了三通道内部交联芯片并用于卵母细胞玻璃化保存的微流控系统,可生成大小均匀、空包率低、低温耐受的载卵母细胞海藻酸钠水凝胶微球,在低浓度保护剂下实现玻璃化保存,为卵母细胞玻璃化保存方法提供新思路。

PGPR微胶囊菌剂研发及其对玉米的促生效果评价

【目的】为了提高植物根际促生菌(Plant growth-promoting rhizobacteria,PGPR)对作物促生作用的稳定性,研制出以PGPR复合菌液为原料的微胶囊菌剂,探究其对玉米的促生效果。【方法】从玉米根际土壤中分离得到2株PGPR菌株并制备成复合液体菌液。分别用海藻酸钠(SA)和CaCl2作为包埋剂和交联剂,对复合菌液进行包埋以制备微胶囊菌剂。以复合微胶囊菌剂制备的难易程度和菌株包埋率、增殖前活菌数及增殖后活菌数为评价指标,确定微胶囊菌剂制备的最优条件。通过分析微胶囊菌剂在不同聚乙二醇含量、温度、pH、存储时间以及盐含量下的菌株生长及其对玉米生长和根系形态的影响确定PGPR微胶囊菌剂的特性。【结果】分离得到了2株PGPR菌株,具有多种植物促生功能。使用质量分数为1%SA-3%CaCl2制备的微胶囊菌剂稳定性较好,包埋率达91.27%,增殖后的微胶囊活菌数达到8.73×10^(9)cfu·g^(-1),增殖7.79倍。微胶囊菌剂在不同干旱、温度、pH、存储时间和盐浓度条件下对PGPR菌株具有较好的保护作用。PGPR微胶囊菌剂对玉米有显著的促生作用,施用微胶囊菌剂使玉米株高、苗干重和根干重分别增加91.83%、81.82%和29.57%。同时微胶囊菌剂也显著提高了玉米总根长、根表面积、根平均直径、根体积和根尖数。【结论】探明了一种PGPR微胶囊菌剂的制备方法,施用该PGPR微胶囊剂能够显著促进玉米生长、改善玉米根系形态,对玉米的促生效果优于液体菌剂。