植物乳杆菌微胶囊化研究

为保护植物乳杆菌的活性以增强乳杆菌在动物肠道内的益生功能,以天然发酵玉米青贮饲料中优良植物乳杆菌作为芯材,乳清蛋白和明胶为壁材,利用喷雾干燥法制成微胶囊,并以植物乳杆菌包埋率为响应值,研究壁材配比、壁材添加量、进风温度、进料量4个因素,进行中心组合实验(Box-Behnken),通过响应面分析对喷雾干燥法制备植物乳杆菌微胶囊条件进行优化。结果表明:最优条件为壁材配比(乳清蛋白与明胶质量比)1:2、壁材添加量22%、进风温度127℃、进料量35%,在此条件下,植物乳杆菌包埋率为62.15%。结论:本研究为应用喷雾干燥法制备植物乳杆菌微胶囊奠定了基础。     

采用复凝聚法和二次包埋工艺制备DHA微胶囊

一种新型DHA微胶囊制备方法,即采用复凝聚法和二次包埋工艺相结合来制备DHA微胶囊。复凝聚法是以明胶和阿拉伯胶为壁材,DHA油脂为芯材,制备DHA微胶囊。二次包埋技术是指将复凝聚法制成的DHA微胶囊湿囊产品选用某种壁材进行再次包埋,在复凝聚法所用壁材的基础上进行加固,改善微胶囊在喷雾干燥过程中囊壁产生的部分裂缝和孔洞,达到提高DHA微胶囊的贮藏稳定性以及延长其货架期的目的。通过研究微胶囊的包埋率和收率,可以得到高品质的微胶囊产品。影响微胶囊包埋率和收率的因素有很多,本文主要研究芯材壁材比例、明胶/阿拉伯胶比率和二次包埋工艺中的壁材组成对DHA微胶囊收率和包埋率的影响。实验结果表明,采用复凝聚法和二次包埋工艺制备DHA微胶囊的优化配方为芯材壁材比1∶2,明胶/阿拉伯胶比率1∶1,二次包埋壁材选用变性淀粉。     

干燥方式对鼠李糖乳杆菌微胶囊的活力及储藏稳定性的影响

为了提高鼠李糖乳杆菌在人体胃肠道传递中的活力,以乳清蛋白和低聚异麦芽糖美拉德反应产物为壁材,通过內源乳化冷凝胶方法制作出微胶囊,研究不同干燥方式微胶囊储藏稳定性。研究结果表明:美拉德产物壁材组微观结构更光滑,无缝隙、破裂现象。乳清蛋白与低聚异麦芽糖混合壁材组和美拉德产物壁材组微胶囊经喷雾干燥菌活力下降3.26 g~(-1)和3.15 g~(-1)(对数值),4℃冷藏储藏30 d后微胶囊菌活力分别为6.23 g~(-1)和6.61 g~(-1)(对数值),而冷冻干燥菌活力损失为1.62 g~(-1)和1.51g~(-1)(对数值),4℃冷藏储藏30 d两种壁材微胶囊菌活力分别为7.31 g~(-1)和8.26 g~(-1)(对数值)。美拉德产物壁材微胶囊冷冻干燥后水活度较低,拥有较好的储藏稳定性。     

复凝聚法青鱼内脏鱼油微胶囊的制备及其性能研究

为提高鱼油稳定性,以青鱼内脏鱼油为芯材,大豆分离蛋白(SPI)和壳聚糖(CS)为壁材,制备鱼油微胶囊。采用单因素实验考察了均质速度、pH、壁材总质量分数、SPI/CS比值、芯壁比等因素对鱼油微胶囊制备效果的影响,结合响应面法优化鱼油微胶囊制备工艺,并比较研究了鱼油微胶囊湿囊分别经喷雾干燥和冷冻干燥两种干燥方法所得产品的包埋率、水分含量、贮藏稳定性。结果表明,最佳鱼油微胶囊制备工艺条件为:pH7、壁材总质量分数2%、SPI/CS比值1.3∶1、芯壁比1.3∶1,在此条件下鱼油包埋率为71.98%±0.16%。喷雾干燥法表面含油率为0.73%±0.04%,低于冷冻干燥法3.62%±0.09%,包埋率为71.98%±0.16%,高于冷冻干燥法56.76%±0.37%,说明喷雾干燥法效果优于冷冻干燥法,鱼油微胶囊贮藏期可较未包埋的鱼油延长6 d以上。通过微胶囊化,改善了青鱼内脏鱼油的性能,提高了使用范围和应用价值。     

鱼油的微胶囊化及其影响因素

鱼油微胶囊化不仅可实现鱼油的均匀分散,避免其氧化,而且还可掩盖鱼腥味,提高消化吸收率,扩大其应用范围。阐述了鱼油微胶囊化的发展现状及适用于鱼油的微胶囊化方法,包括喷雾干燥法、复合凝聚法、分子包埋法、冷冻干燥法、锐孔凝固浴法及脂质体包埋法。重点归纳了影响喷雾干燥法制备鱼油微胶囊包埋率的因素,包括壁材的物理化学特性、固形物浓度、乳化方式和乳化条件(温度、压力、次数)及喷雾干燥条件(进出风温度)。最后对鱼油微胶囊化的发展方向进行了展望。     

藏灵菇源干酪乳杆菌微胶囊喷雾干燥工艺条件的优化

为了降低从藏灵菇中筛选的产胆盐水解酶的干酪乳杆菌微胶囊菌粉的水分活度及保持其高活菌数量,采用三因素三水平[L_9(3~4)]正交实验,研究不同喷雾干燥工艺条件对微胶囊菌粉水分活度和活菌数量的影响。结果表明:在阿拉伯胶浓度为40%、进/出口风温度为170/75℃、蠕动泵流速为75 m L/min的条件下进行微胶囊化,其菌粉的水分活度为0.096,活菌数量为2.37×10~9CFU/g。既降低了微胶囊菌粉的水分活度,又保持了其高活菌数量,为制备干酪乳杆菌微胶囊产品提供实践依据。     

大豆分离蛋白—海藻酸钠复凝聚法制备芥末油微胶囊

以大豆分离蛋白和海藻酸钠为壁材,采用复凝聚法制备芥末油微胶囊的最佳工艺条件为:壁材浓度3％,大豆分离蛋白与海藻酸钠的比例3∶1,芯壁比1∶1;复凝聚反应pH 3.0,温度40℃,时间20 min,转速400 r/min,戊二醛的添加量3 mL.在此工艺条件下得到的微胶囊产品的包埋率为97.28％.     

壁材对真空低温喷雾干燥制备乳双歧杆菌Probio-M8微胶囊的影响

目的:研究不同壁材对真空低温喷雾干燥制备乳双歧杆菌Probio-M8微胶囊的影响。方法:对不同壁材微胶囊粉末的溶解度、再水合时间、粉末流动性以及粉末水分和水分活度的物理性质进行测定，使用荧光显微镜观测干燥前、后菌体细胞膜完整性的变化，扫描电镜观察微胶囊粉的形态结构，差示扫描量热仪测定微胶囊粉的玻璃化转变温度，并测定了不同壁材菌体的DPPH自由基清除能力和总抗氧化能力。结果:复合壁材的Probio-M8微胶囊粉末表现出较高的存活率，为73.8%，且具有较低的水分含量(4.85%)和水分活度(0.17)，粉末流动性也优于其它3种微胶囊粉末，然而，由于复合壁材组分复杂，复合壁材的微胶囊粉具有较低的溶解度和较长的再水合时间。此外，复合壁材保护的Probio-M8细胞膜的完整性也高于其它3种壁材保护的Probio-M8，有效地保护了菌体细胞膜的完整性，并具有较高的玻璃化转变温度和较强的抗氧化能力，有利于Probio-M8微胶囊粉的贮藏稳定性。结论:通过比较不同壁材对Probio-M8真空低温喷雾干燥后菌体活性的影响，发现不同的壁材对菌体有不同的保护效果，其中复合壁材可更有效保护菌体的活性。研究结果对乳双歧杆菌Probio-M8微胶囊的工业化生产有一定的参考意义。     

复凝聚法制备黄酮类化合物微胶囊研究

以明胶和CMC(羧甲基纤维素)为壁材,采用复凝聚法制备黄酮类化合物微胶囊。通过单因素和正交试验确定影响制备黄酮类化合物微胶囊主要因素,经实验确定最优工艺条件为:壁材浓度1.5%、明胶∶CMC为8∶1、芯壁比1∶5、复凝聚pH值4.6、复凝聚温度40℃;在此条件下,黄酮类化合物微胶囊平均包埋率可达78.2%。     

复凝聚法制备橄榄油微胶囊

目的:优选以乳清蛋白和阿拉伯胶为壁材的橄榄油微胶囊最佳工艺。方法:通过壁材凝聚率选出最佳壁材配比及最适浓度,采用复凝聚法制备微胶囊。首先对壁芯比、复凝聚pH、凝聚时间做单因素试验,然后通过响应面试验筛选制备微胶囊的最佳工艺。结果:在壁材质量分数3%、壁芯比3、pH 4、凝聚60 min条件下制备微胶囊,最高包埋率为87.95%,包埋效果较好。     

Microencapsulated Lactobacillus rhamnosus GG powders: relationship of powder physical properties to probiotic survival during storage

Freeze-dried commercial Lactobacillus rhamnosus GG (LGG) were encapsulated in an emulsion-based formulation stabilized by whey protein and resistant starch and either spray-dried or freeze-dried to produce probiotic microcapsules. There was no difference in loss of probiotics viability after spray drying or freeze drying. Particle size, morphology, moisture sorption, and water mobility of the powder microcapsules were examined. Particle size analysis and scanning electron microscopy showed that spray-dried LGG microcapsules (SDMC) were small spherical particles, whereas freeze-dried LGG microcapsules (FDMC) were larger nonspherical particles. Moisture sorption isotherms obtained using dynamic vapor sorption showed a slightly higher water uptake in spray-dried microcapsules. The effect of water mobility, as measured by nuclear magnetic resonance (NMR) spectroscopy, at various water activities (a(w) 0.32, 0.57, and 0.70) and probiotic viability during storage at 25 °C was also examined. Increasing the relative humidity of the environment at which the samples were stored caused an increase in water mobility and the rate of loss in viability. The viability data during storage indicated that SDMC had better storage stability compared to FDMC. Although more water was adsorbed for spray-dried than freeze-dried microcapsules, water mobility was similar for corresponding storage conditions because there was a stronger water-binding energy for spray-dried microcapsule. This possibly accounted for the improved survival of probiotics in spray-dried microcapsules.     

Preparation of Acid‐Resistant Microcapsules with Shell‐Matrix Structure to Enhance Stability of Streptococcus Thermophilus IFFI 6038

Microencapsulation is an effective technology used to protect probiotics against harsh conditions. Extrusion is a commonly used microencapsulation method utilized to prepare probiotics microcapsules that is regarded as economical and simple to operate. This research aims to prepare acid‐resistant probiotic microcapsules with high viability after freeze‐drying and optimized storage stability. Streptococcus thermophilus IFFI 6038 (IFFI 6038) cells were mixed with trehalose and alginate to fabricate microcapsules using extrusion. These capsules were subsequently coated with chitosan to obtain chitosan‐trehalose‐alginate microcapsules with shell‐matrix structure. Chitosan‐alginate microcapsules (without trehalose) were also prepared using the same method. The characteristics of the microcapsules were observed by measuring the freeze‐dried viability, acid resistance, and long‐term storage stability of the cells. The viable count of IFFI 6038 in the chitosan‐trehalose‐alginate microcapsules was 8.34 ± 0.30 log CFU g^?1 after freeze‐drying (lyophilization), which was nearly 1 log units g^?1 greater than the chitosan‐alginate microcapsules. The viability of IFFI 6038 in the chitosan‐trehalose‐alginate microcapsules was 6.45 ± 0.09 log CFU g^?1 after 120 min of treatment in simulated gastric juices, while the chitosan‐alginate microcapsules only measured 4.82 ± 0.22 log CFU g^?1. The results of the long‐term storage stability assay indicated that the viability of IFFI 6038 in chitosan‐trehalose‐alginate microcapsules was higher than in chitosan‐alginate microcapsules after storage at 25 °C. Trehalose played an important role in the stability of IFFI 6038 during storage. The novel shell‐matrix chitosan‐trehalose‐alginate microcapsules showed optimal stability and acid resistance, demonstrating their potential as a delivery vehicle to transport probiotics.     

4种多糖益生元对鼠李糖乳杆菌微胶囊稳定性的影响

为提高鼠李糖乳杆菌（Lactobacillus rhamnosus GG,LGG）的稳定性，采用复合凝聚法制备LGG微胶囊，探究菊糖、低聚果糖、普鲁兰多糖和水苏糖4种益生元对LGG微胶囊性能的影响，并结合扫描电镜和差示扫描量热仪分析微胶囊的微结构和热稳定性。结果表明：益生元对LGG微胶囊的性能均有积极影响。模拟胃肠液处理后，菊糖活菌数存活率最高，达9.5(lg(CFU/g))；水苏糖对LGG微胶囊在胆盐和高温下的保护能力最强，75℃、30 min后活菌数达8.7(lg(CFU/g))；水分活度0.75条件下低聚果糖的加入提高了LGG微胶囊的贮藏稳定性；差示扫描量热分析结果表明益生元提高了LGG微胶囊的热稳定性，水苏糖的微胶囊熔融温度达172℃，但低聚果糖降低了LGG微胶囊的熔融温度；扫描电镜分析表明添加益生元后微胶囊结构没有变化。本研究为后续添加益生元对LGG微胶囊性能的影响研究提供理论基础。     

Stability of probiotic Lactobacillus plantarum in dry microcapsules under accelerated storage conditions

This study investigated the stability of freeze dried and fluid bed dried alginate microcapsules coated with chitosan containing model probiotic bacteria, Lactobacillus plantarum, during storage for up to 45 days at different water activities (0.11, 0.23, 0.40 and 0.70) and temperatures (4, 30 and 37 °C). The loss in cell viability was around 0.8 log in the case of fluid bed drying and around 1.3 in the case of freeze drying, with the former method resulting in dried capsules of smaller size (~ 1 mm vs 1.3 mm), more irregular shape, and with a rougher surface. In both cases, the water activity and water content were less than 0.25 and 10% w/w, respectively, which favours high storage stability. The storage stability studies demonstrated that as the water activity and temperature decreased the survival of the dried encapsulated cells increased. Considerably better survival was observed for fluid bed dried encapsulated cells compared to freeze dried encapsulated cells and freeze dried free cells with 10% sucrose (control), and in some cases, e.g. at 4 and 30 °C at water activities of 0.11, 0.23 and 0.40, there was more than 1 log difference after 45 days, with concentrations higher than 10⁸ CFU/g after 45 days of storage. The results indicate that fluid bed drying is an effective and efficient manufacturing method to produce probiotic containing capsules with enhanced storage stability.     

干燥方式对不同接枝度的大豆分离蛋白-麦芽糊精聚合物性质影响

以大豆分离蛋白(SPI)和麦芽糊精(MD)为原料制备不同接枝度的SPI-MD聚合物,研究比较喷雾干燥和冷冻干燥两种处理方式对不同接枝度下的SPI-MD聚合物性质的影响,如溶解度、疏水性、持水性、乳化性、乳化稳定性及起泡性、泡沫稳定性等的影响。实验表明,喷雾干燥样品的溶解性,表面疏水性和乳化性高于冷冻干燥样品;冷冻干燥样品则具有较好的持水性。另外,两种干燥样品的乳化稳定性非常接近。不同接枝度的两种干燥样品起泡性差异较大,且泡沫稳定性都相对较差。     

The Viability of Lactobacillus rhamnosus GG and Lactobacillus acidophilus NCFM Following Double Encapsulation in Alginate and Maltodextrin

Lactobacillus rhamnosus GG (LGG) and Lactobacillus acidophilus NCFM (LNCFM) were encapsulated in alginate microgel particles (microbeads) by a novel dual aerosols method. The encapsulated probiotics in microbead gel matrix were further stabilized in maltodextrin solids by either spray or freeze-drying to form probiotic microcapsule powders. The free cells of probiotics were also sprayed and freeze-dried in maltodextrin only without microgel encapsulation. After rehydration of microgel-encapsulated powder, gel particles regained their shape. There was no difference in the loss of viability between encapsulated and unencapsulated probiotics during spray drying or freeze-drying. For LNCFM, spray-dried bacteria with or without gel encapsulation exhibited less death (3.03 and 3.07 log CFU/g reduction, respectively) than those of freeze-dried bacteria (4.36 and 4.89 log CFU/g reduction, respectively) after 6 months storage at 4 °C. The same trend was also observed in spray-dried LGG without gel encapsulation which showed 5.87 log CFU/g reduction in viability after 6 months at 4 °C; however, freeze-dried LGG without gel encapsulation exhibited a rapid reduction in viability of 5.91 log CFU/g within just 2 months. Gel-encapsulated LGG which was freeze-dried exhibited less death (3.32 log CFU/g reduction) after 6 months at 4 °C. This work shows that spray drying results in improved subsequent probiotic survivability compared to freeze-drying and that alginate gel encapsulation can improve the survivability following freeze-drying in a probiotic-dependent manner.     

植物乳杆菌CICC 20270微胶囊的制备及其特性

以植物乳杆菌CICC 20270(Lactobacillus plantarum)及椰子油/玉米油为芯材,添加到以葡萄糖值即DE值分别为25、18糖浆为壁材的乳状液中,通过喷雾干燥法制备益生菌微胶囊,考察微胶囊的菌细胞存活率、表面结构、耐热性、储藏稳定性及在模拟胃肠液中的菌细胞存活率情况。结果表明:制得的微胶囊中植物乳杆菌存活率均在90%以上。在55℃热处理条件下,各微胶囊菌活无显著性差异(p>0.05);65℃处理1、10 min后,活菌数最低的分别是DE25/椰子油和DE18/椰子油微胶囊,存活率为75.66%、49.82%;75℃热处理1、10 min后,DE18/椰子油微胶囊中活菌数均最低,存活率分别为38.40%、15.08%。在4、25、37℃储藏条件下,玉米油微胶囊储藏性质较椰子油更为稳定,活菌数更高;而在33%、52%、75%湿度条件下,糖浆的DE值不同比油脂对益生菌的存活率影响更大,且DE25糖浆给益生菌提供了更好的保护效果。在6 h体外模拟消化中,DE25糖浆/椰子油微胶囊整个过程活菌数只下降了3.88 lg CFU/g。因此,DE25糖浆更适作为益生菌壁材;添加玉米油后使得微胶囊具有更好的耐热性;而添加椰子油更有利于提高微胶囊在模拟胃肠液中的菌活数。     

不同干燥方式对西番莲果皮中湿法改性膳食纤维品质的影响

本实验以西番莲果皮中湿法改性膳食纤维为原料,探讨了热风干燥、微波干燥、真空冷冻干燥、喷雾干燥和冷冻喷雾干燥五种干燥方式对其色泽形貌、粉体性质及理化性质的影响。结果表明,湿法改性后,纤维组织破坏严重,再经不同干燥方式处理,膳食纤维的形貌和色泽都产生很大变化;真空冷冻干燥和冷冻喷雾干燥处理的膳食纤维表现出极佳的持水力、持油力及吸湿性,结果分别为:持水力24.1、16.4 g/g;持油力11.8、8.3 g/g;吸湿性19.3%、19.8%;真空冷冻干燥和冷冻喷雾干燥振实密度较小,其分散性、溶解性和吸附性能较佳;喷雾干燥处理的膳食纤维休止角为38.5°,表现出最佳的流动性;另外各处理间的膨胀力和阳离子交换能力差异不明显。综上,真空冷冻干燥和冷冻喷雾干燥处理对西番莲果皮中湿法改性膳食纤维品质改善最为显明显。     

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。     

基于变异系数权重法对怀山药干燥全粉品质的评价

以怀山药为原料,通过热风干燥、真空冷冻干燥、喷雾干燥、喷雾冷冻干燥、微波真空冷冻干燥5种干燥方式对其进行干燥制粉,并对其物理性质和多糖含量进行测定,利用变异系数权重法获取5种怀山药全粉制品的综合评分,以确定其最佳的干燥方式。结果表明:干燥方式对各指标影响显著(P0.05);溶解度、多糖含量、干燥能耗和吸湿性在全粉制品评价中占较大比重,分别为0.227、0.162、0.204、0.201。综合评分结果表明:喷雾干燥全粉品质最优,其次是喷雾冷冻和微波真空冷冻干燥,真空冷冻干燥次之,热风干燥全粉品质最差,对应的综合评分分别为0.624、0.081、0.046、-0.108、-0.642。