不同制备方式的鱼油微胶囊挥发性成分及贮藏稳定性的比较

本文研究了不同干燥工艺对鱼油和两种微胶囊挥发性成分以及贮藏稳定性的影响。以鱼油作为芯材,魔芋葡甘聚糖和大豆分离蛋白作为壁材,制备成纳米乳液后通过喷雾干燥和真空冷冻干燥工艺制备微胶囊。试验发现,鱼油、喷雾干燥微胶囊和冷冻干燥微胶囊共鉴定出80种挥发性风味物质,其中鱼油42种,喷雾干燥微胶囊41种,冷冻干燥微胶囊20种,共有成分包括十四烷酸乙酯、9-十六碳烯酸乙酯、1-甲基-4-异丙基苯和1-甲基-4-异丙基苯。加速贮藏实验中两种鱼油微胶囊的过氧化值（POV）增长速率均较鱼油低,当贮藏时间达到30 d时,鱼油、喷雾干燥微胶囊和真空冷冻干燥微胶囊POV值分别为15.65 mmol/kg、8.89 mmol/kg和8.14 mmol/kg,喷雾干燥所得鱼油微胶囊包埋率下降速率较冷冻干燥鱼油微胶囊快,包埋率分别为34.29%和40.90%。综合分析,两种鱼油微胶囊制备方法均能够延缓鱼油氧化和掩蔽不良风味,但冷冻干燥制备鱼油微胶囊更佳,对制备鱼油微胶囊具一定的参考意义。     

壳聚糖微胶囊对鱼油品质的影响

为探究微胶囊化对鱼油品质的影响,以壳聚糖为壁材,金枪鱼油为芯材,采用喷雾干燥法制备鱼油微胶囊,分别检测鱼油及鱼油微胶囊的理化指标、脂肪酸组成及挥发性成分,并通过加速贮藏试验考察以上指标的变化。结果显示:鱼油微胶囊过氧化值高,不饱和脂肪含量低,与腥味相关的关键挥发性成分多,品质较低。贮藏期间鱼油微胶囊能明显抑制过氧化值的增长和关键挥发性成分含量的升高,对DHA和EPA的保留率影响不大,说明鱼油微胶囊制备过程会在一定程度上降低鱼油品质,然而对延缓鱼油氧化、掩蔽不良风味确实有一定作用。     

沙棘籽油微胶囊的制备及其性质研究

以沙棘籽油为芯材,采用CAS/MD、OSA/MD、WPI/GA/MD 3种壁材配方,通过喷雾干燥制备沙棘籽油微胶囊,并对微胶囊的性质和微观结构进行研究,用气相色谱法测定微胶囊化前后沙棘籽油脂肪酸含量变化。结果表明:3种配方的微胶囊产品均具有较低的含水量和较高的溶解性,其中以CAS/MD为壁材制备的沙棘籽油微胶囊包埋率最高,微胶囊粒径小,表面光滑,热稳定性良好,壁厚度均一,沙棘籽油在胶囊中分布均匀,喷雾干燥制备过程未对沙棘籽油中的功能性成分产生影响。     

Impact of Wall Materials on Physicochemical Properties of Microencapsulated Fish Oil by Spray Drying

The aim of the present study was to investigate the effect of wall materials composition on physicochemical characteristics of fish oil microcapsules produced by spray drying (180 °C). Four different combination of coating materials (fish gelatin, chitosan, combination of gelatin and chitosan, and a mixture of microbial transglutaminase (MTGase) with maltodextrin) were applied to two different fish oils to produce 40 % solid emulsions. Scanning electron microscopy and extraction of surface and encapsulated oils revealed that fish gelatin provided the highest preserving effect on the covering fish oil. Meantime, addition of MTGase to gelatin could also increase this ability and reveled less surface oil than chitosan treatment (2.63 and 2.80 % versus 4.66 and 5.23 %, respectively; P?<?0.05). Mixture of gelatin and maltodextrin with MTGase as wall material led to the highest encapsulation efficiency, being selected as the best microencapsulation condition; meantime, application of chitosan with maltodextrin provided the worse encapsulation efficiency (P?<?0.05). All indices of powders (encapsulation efficiency, surface morphology, and particle size) showed that powders prepared from gelatin and gelatin with MTGase increased the encapsulation efficiency and would increase the stability of microcapsule powders.     

Spray Drying for the Production of Nutraceutical Ingredients—A Review

Contributions of spray drying to food processing applications are increasing as compared to other conventional drying methods. Spray drying has not only contributed in drying of fluids but also has played a vital role in encapsulation and microencapsulation of valuable foods and functional–nutraceutical ingredients. Microencapsulation by spray drying is a cost-effective one-step process as compared to other encapsulation methods. Encapsulation using spray drying is mainly used in the food sector to protect bioactive compounds or functional foods from light, temperature, oxidation, etc. This paper reviews the work done in past years in the functional food and nutraceutical sector using spray drying. The paper focuses on the role of spray drying in vitamins, minerals, flavouring substances, antioxidant compounds and fatty acids encapsulation.     

大豆蛋白和鱼油双层微囊化SOD优化条件的研究

以大豆可溶性蛋白、鱼油为双层壁材 ,采用喷雾干燥法制备出SOD微胶囊 ,考察了SOD包埋率、活性和鱼油的过氧化值 ,结果显示产品的包埋率和抗氧化性均有提高 ,微囊在 45℃条件下 ,较大豆蛋白单层微囊的稳定性显著增加。经正交法优化选择 ,微囊的最佳制备条件为 :进风温度 1 95℃ ,均质压力 5 0MPa ,出风温度 1 1 0℃ ,外层壁材选择大豆可溶性蛋白和麦芽糊精 ,鱼油与SOD溶液比 (g∶mL)为 4∶1 ,鱼油占外层壁材百份比为 40 % ,SOD包封率达 3 8 65 %。     

乳酸菌微胶囊包埋技术与常用壁材的研究进展

从提高乳酸菌在人体胃肠道的生存率出发,概述了微胶囊包埋技术的定义和发展历史,对几种微胶囊包埋技术界面聚合法、相分离法、喷雾干燥法、锐孔法、高压静电喷雾干燥法等的优缺点进行分析;并结合乳酸菌微胶囊的常用壁材和乳酸菌包埋方法进行探讨,指出复配包埋、多层包埋和添加益生元等对乳酸菌的影响。     

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。     

高压静电场制备蛋白类物质微胶囊的研究(二)

通过对高压静电场制备的海藻酸盐/BSA蛋白类物质微胶囊基本性质的研究，结果表明，BSA在微胶囊中仍以晶体的形式存在；配料比、壳聚糖浓度、CaCl2溶液的pH对包封率和芯材载入率有直接的影响；壳聚糖能显著改善微胶囊的体外释放性能，同时，干燥方式的不同，也会对释放性能产生一定的影响。     

乳液粒径对橙皮精油微胶囊物理性质和氧化稳定性的影响

本文以橙皮精油为芯材,变性淀粉和麦芽糊精为壁材,通过高压(1000、2500、3500和22000 psi)均质制备了不同粒径橙油乳液,从而探讨乳液粒径对喷雾干燥橙油微胶囊平均粒径、包埋率、总油量、含水量、微观形貌以及重组乳液粒径分布的影响。同时以柠檬烯氧化程度评价微胶囊稳定性并预测其货架期。结果表明,均质压力越高,乳液粒径越小。乳液粒径对微胶囊的总油量(1.5 g/20 g)、包埋率(>95%)和含水量(<4%)没有明显影响,但会影响微胶囊的平均粒径、微观形貌以及重组乳液的粒径分布。乳液粒径越小,微胶囊平均粒径越小,表面越光滑,重组乳液也具有更窄的粒径分布。微胶囊在37 ℃贮藏5周,经零级动力学方程拟合氧化柠檬烯/柠檬烯(mg/g)变化的结果表明,以22000 psi制备的微胶囊货架期可长达11周左右,是其余微胶囊货架期的2.97~4.63倍。研究结果可为喷雾干燥精油微胶囊的工艺优化及质量控制提供理论参考。     

黑枸杞花青素微胶囊优化及理化特性分析

为提高黑枸杞花青素的稳定性,对其进行微胶囊化,同时采用包埋率、DPPH清除活性、花青素含量和水分活度为评价指标对微胶囊喷雾干燥工艺进行优化。并对微胶囊的理化性质进行分析,采用红外光谱、X射线衍射、扫描电镜和差示扫描量热法(differential scanning calorimetry,DSC)对微胶囊化颗粒的结构、结晶度、表面形貌和热性能进行了综合研究。研究发现微胶囊的最佳制备工艺为:壁材浓度6%、温度157℃、进样泵速6%。在该工艺条件下,黑枸杞花青素微胶囊的包埋率为93.4%、DPPH清除率为45.41%、花青素含量为63.04 mg/L、水分活度为0.49。微胶囊中芯材与壁材包埋成功并形成了淀粉-花青素-明胶聚合体,呈圆球形,无裂纹或孔洞,热稳定性提高。微胶囊化是一种提高花青素稳定性的有效技术,为花青素在食品工业中的应用提供一定的参考。     

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.     

再生丝素蛋白与明胶为壁材的大蒜油微胶囊的制备研究

以再生丝素蛋白与明胶复配作为壁材,利用喷雾干燥法制备大蒜油微胶囊。论文以乳状液的乳化能力、稳定性和微观形态、微胶囊的包埋率和产率为指标,探讨了壁材种类、芯材/壁材比例和乳化剂的亲水亲油平衡值(HLB)对微胶囊形成的影响。结果表明:再生丝素蛋白与明胶以1∶1(g/g)复合配制为壁材溶液,加入壁材质量50%的大蒜油及HLB值为12.9的复合乳化剂,该体系的乳状液性质稳定,喷雾干燥前不发生相分离。经喷雾干燥制备的大蒜油微胶囊的包埋率和产率最大,分别为85%和88%。大蒜油微胶囊表面光滑,为直径10~20μm均匀球状颗粒;当储存至21 d时,微胶囊中的大蒜油保留率为88.2%。结论:再生丝素蛋白是一种理想的大蒜油微胶囊壁材,对大蒜油起到较好的保护作用。      

喷雾干燥法制备微胶囊化大豆胚芽油粉末油脂

为提高大豆胚芽油的氧化稳定性,本文采用喷雾干燥法制备微胶囊化大豆胚芽油粉末油脂,并研究了不同芯材、壁材比例及喷雾干燥条件变化对微胶囊化大豆胚芽油理化特性、微观结构及氧化稳定性的影响,采用的表征方法包括:粒径分布、乳液稳定性、喷雾干燥制得的微胶囊包埋率、水分含量、扫描电镜及氧化稳定性等。结果显示:喷雾干燥前,3号（壁材∶芯材为3∶5）和6号（壁材∶芯材为2∶3）样品稳定性较高,平均粒径分布均匀且较小。在单因素实验的基础上,采用Design-Expert软件对实验结果建立数学模型,喷雾干燥后样品条件:当壁材含量25%、油脂含量15%及出口温度为160℃时样品的状态最佳。外形颗粒较圆整、饱满,且表面光滑、裂纹较少,并且在室温下非常稳定,此时包埋率为97.15%。该结果说明壁材阿拉伯胶与芯材大豆胚芽油具有最适比例,可制备成微胶囊化大豆胚芽油,在此条件下所制取的微胶囊可防止大豆胚芽油氧化,延长油脂保质期。      

A process for turning pomegranate peels into a valuable food ingredient using ultrasound-assisted extraction and encapsulation

A new method for pomegranate peel application in food industries was developed based on the ultrasound-assisted extraction of phenolic compounds and their subsequent encapsulation by spray drying. The effects of various parameters on extraction yield, on encapsulation efficiency/yield, and on the main physical properties of the microcapsules (moisture content, bulk density, rehydration ability) were studied. Ultrasound was found to increase extraction yield, but mainly to shorten the treatment time by over 20 times. The maximum encapsulation efficiency was 99.80% and the optimum operating conditions were found to be: wall material, maltodextrin/whey protein isolate (50:50); inlet air temperature, 150 °C; drying air flow rate, 17.5 m³/h; ratio of wall to core material, 9/1; feed solid concentration, 30% (w/w). The encapsulated phenolic extract was found efficient in improving the shelf life of hazelnut paste, in spite of the limited solubility of the crude extract in such a high lipid content matrix.Industrial relevancePomegranate peels, a by-product of pomegranate juice and concentrate industries, present a wide range of pharmaceutical and nutraceutical properties. Therefore, the peels could have more beneficial applications in food industries instead of being used as animal feed or in commercial cosmetic products. In this work, a new method for pomegranate peel application was developed based on the ultrasound-assisted extraction of phenolics and their subsequent encapsulation by spray drying.     

复凝聚法鼠李糖乳杆菌微胶囊工艺优化及储藏稳定性

为提高鼠李糖乳杆菌在贮藏过程中的稳定性,以明胶、阿拉伯胶为壁材,采用复凝聚法制备鼠李糖乳杆菌微胶囊。研究以湿态微胶囊的包埋率为指标,考察pH、壁材浓度、转速和菌添加量对复凝聚法微胶囊制备的影响,在单因素试验的基础上进行正交试验,优化最佳工艺。将最优条件下的湿微胶囊进行喷雾干燥和真空冷冻干燥,并在不同水分活度和不同温度条件下研究了喷雾干燥和真空冷冻干燥鼠李糖乳杆菌微胶囊的储藏稳定性。结果表明,pH 3.75、壁材浓度1.5%、转速200 r/min、菌添加量109 CFU,此条件下制备的鼠李糖乳杆菌微胶囊包埋率最高,为93.21%;复凝聚法制备的鼠李糖乳杆菌湿微胶囊干燥后,每克真空冷冻干燥微胶囊的活菌数比喷雾干燥微胶囊高1.9个对数值;储藏时水分活度越低,温度越低,鼠李糖乳杆菌微胶囊的储藏性越好;与喷雾干燥微胶囊相比,储藏时真空冷冻干燥微胶囊在高水分活度下较稳定,且在不同水分活度、不同温度条件下的活性均高于喷雾干燥微胶囊。因此复凝聚法制备的鼠李糖乳杆菌微胶囊真空冷冻干燥后能更好的保护鼠李糖乳杆菌,延长其储藏期。     

Impact of chitosan and oregano extract on the physicochemical properties of microencapsulated fish oil stored at different temperature

Fish oil is an excellent source of omega-3 fatty acids and is easily susceptible to oxidation. Microencapsulation is a commonly employed technique to protect fish oil against oxidation. In the present study, the potential of chitosan in combination with bovine gelatin and maltodextrin as wall material for microencapsulation of fish oil by spray drying was evaluated. To improve the oxidative stability of the fish oil microencapsulates, oregano (Origanum vulgare L) extract was added at 0.50 g/100 g of emulsion. The spray-dried powder showed a moisture content of 2.8 – 3.2 g/100 g of spray-dried powder. The powder contained spherical microparticles with different sizes as indicated by scanning electron microscope images. Encapsulation efficiency of microencapsulates ranged between 68.94% and 81.88%. Differential scanning calorimetry and Fourier-transformed infrared spectroscopy analysis of microencapsulates revealed the possible structural stabilization of core and wall material. The oxidative stability of fish oil microencapsulates were monitored under three different temperature (60°C, 28 ± 2°C, and 4°C). Incorporation of oregano extract minimized the generation of secondary and tertiary oxidation products as indicated by lower peroxide value and thiobarbituric acid reactive substance values compared to control. Overall, the results suggested that combination of chitosan along with bovine gelatin and maltodextrin as wall material improved the surface morphology of the microparticle and encapsulation efficiency, whereas incorporation of oregano extract in fish oil before spray drying enhanced the oxidative stability during storage.     

复凝聚法制备白术挥发油微胶囊及表征

以白术挥发油为芯材,壳聚糖和海藻酸钠为壁材,采用复凝聚法制备微胶囊,通过单因素实验研究工艺参数对挥发油包埋率的影响,采用激光粒度分析仪、扫描电镜(SEM)、傅里叶变换红外光谱(FT-IR)、热重分析仪(TG-DTA)对微胶囊的粒径分布、表面形貌、化学结构、芯材含量进行表征。结果表明:在芯壁比为1∶2,乳化剂用量为5%,复凝聚温度为40℃,壳聚糖质量分数为1%,海藻酸钠质量分数为2%,pH 1.5,乳化转速6 000 r/min条件下制备的微胶囊包埋效果最好。微胶囊颗粒大致呈球状,表面结构致密,无明显的裂缝和洞孔,包埋率高,热稳定性能好,研究结果可为白术挥发油微胶囊的制备、鉴定、质量控制和制剂学性质的研究提供依据。     

Taste Detection Thresholds of Resveratrol

Resveratrol is a polyphenol that is associated with numerous health benefits related to heart disease, cancer, diabetes, and neurological function. The addition of this compound to food products would help to deliver these health benefits to the consumer. However, bitterness associated with resveratrol may impart negative sensory qualities on the food products into which resveratrol is added; thus, decreasing consumer acceptability. This concern may be resolved by encapsulating resveratrol through spray drying, an innovative processing technique. The objectives of this research were to (1) compare taste detection thresholds of unencapsulated resveratrol and encapsulated resveratrol and (2) determine if the inclusion of anhydrous milk fat in the formulation of the encapsulation wall material affects the taste detection threshold of resveratrol within the microcapsules. Resveratrol microcapsules were produced by encapsulating resveratrol in a protein matrix through spray drying. R‐index measure by the rating method was used to determine the average taste detection threshold and the pooled group taste detection threshold. The average and pooled group taste detection thresholds of unencapsulated resveratrol, sodium‐caseinate‐based resveratrol microcapsule without fat (SC), and sodium‐caseinate‐based resveratrol microcapsule with fat (SCAMF) were 90 and 47 mg resveratrol/L (unencapsulated), 313 and 103 mg resveratrol/L (SC), 334 and 108 mg resveratrol/L (SCAMF), respectively. The findings demonstrate that the encapsulation of resveratrol decreased the detection of the compound and provided a means to incorporate resveratrol into food products without imparting negative sensory properties.