双歧杆菌微囊肠溶胶囊的制备

目的:制备全封闭的双歧杆菌活菌微囊胶囊。方法:采用胶囊肠溶包衣新技术和微囊化技术,将不同的高分子材料用于制备全封闭的双歧杆菌活菌微囊胶囊。结果:微囊和微囊胶囊在模拟人工胃液(pH1.5～2.0)中处理4h,活菌数分别保持在27.6%和84.4%以上,而在人工肠液中处理30min,微囊全部溶出释放出活性菌,释放率达90%以上。微囊胶囊在37℃下保存3个月(相当于常温下1年以上),其中的活菌数仍大于109个·g-1。结论:制备的微囊对活性菌有保护作用,有效地提高了活性菌体的耐酸性能,微囊中的菌体仍保持较高的活性且能在微囊中继续增殖。     

保加利亚乳杆菌微囊化活菌制剂的研究

制备保加利亚乳杆菌的微囊化制剂。液体发酵法制备保加利亚乳杆菌,以海藻酸钠为囊材制备保加利亚乳杆菌微囊。微囊化保加利亚乳杆菌的冻干存活率为45.07%,与传统方法(冻干存活率为44.35%)相比,差异无统计学意义。人体胃液和肠液耐受性试验结果显示,在人体胃液中微囊化的菌体3 h后菌体存活率达到71.16%,而对照的存活率仅为16.47%;在人体肠液中微囊化的菌体6 h后菌体存活率达到71.67%,而对照的存活率仅为30.46%。微囊起到了保护保加利亚乳杆菌免受人体胃液和肠液破坏的作用。     

乳糖酶纳米粒的制备及水解牛乳中乳糖的研究

以具有良好生物相容性和生物降解性的聚乳酸作为壳材,采用改进的5步复乳法制备载乳糖酶纳米粒。对其外观形貌、粒径、包封率和悬浮稳定性等理化性质进行了评价,进一步考察了乳糖酶纳米粒在人工肠液(含胰酶)中的稳定性和水解牛乳中乳糖的效率。结果表明,制备的纳米粒粒径大小均匀(100~200 nm)、包封率高(85%)且悬浮稳定性好。乳糖酶纳米粒在人工肠液中3 h,其活性保留可达(75.63±2.51)%,而对照组游离乳糖酶则几乎完全失活。乳糖酶纳米粒显示了良好的水解乳糖的能力,37℃条件下水解3 h,乳糖水解率可达100%,有望成为解决乳糖不耐受症的有效制剂。     

免疫磁珠的制备及其在食品安全检测中的应用

目的 研究胃肠液对纳豆激酶纤溶活性的影响。方法 模拟人体胃液、肠液中的生理过程, 采用纤维蛋白平板法, 对粗酶液和含豆固体粉碎样品2种形态的纳豆激酶进行纤溶活性研究。结果 粗酶液和含豆固体粉碎样品在人工胃液处理5 h左右时, 活性分别下降到对照组的28%和35%, 说明2种状态的酶在酸性的胃液中都不稳定, 大部分活性丧失; 粗酶液和含豆固体粉碎样品在人工胃液处理4 h后, 再用人工肠液处理 5 h, 活性分别下降到对照组的89%和91%; 说明在人工肠液中2种状态的酶都较稳定, 都保持较高的酶活性。结论 为避免胃酸的破坏作用, 建议将纳豆激酶制成肠溶性的产品服用。     

采用微囊化技术研制新型高效双歧杆菌活菌制剂

采用流化床技术与喷咀结合的微型包囊法,将三种双歧杆菌、高效活菌保护剂和双歧促生因子一起作为核心物质,包封于无毒囊材中制成耐酸肠溶微囊（或微球）。微囊在人工模拟胃液（ｐＨ１．５～２．０）中处理２ｈ,其中的双歧杆菌活菌数仍保持在９０％ 以上;在人工肠液中处理１５ｍ ｉｎ,微囊全部崩解释放出活性菌,在３７℃下保存３ 个月（相当于常温下一年）,其中的活菌数仍大于１０９ 个／ｇ。用上述耐酸肠溶微胶囊制成的新型高效微生态活菌制剂和功能食品在经口服时,其中的活性双歧杆菌能顺利通过人体胃和小肠,到达大肠释放,从而有效地解决了胃酸、消化酶和抗生素等对活性双歧杆菌引起的灭活问题和产品常温保存期太短的问题。     

番茄红素脂质体生物利用率的比较研究

番茄红素的理化性质极大地限制了其生理活性功能的发挥,脂质体作为一种常见药物载体,考虑将其作为番茄红素的产品剂型,提高番茄红素的生物利用率。选取薄膜- 超声法制备番茄红素脂质体,经体外实验及体内实验研究可知：油溶番茄红素在人工胃液和无胆酸盐的人工肠液中无释放,但在添加胆酸盐的人工肠液中释放率达91%;番茄红素脂质体和番茄红素微胶囊在人工胃液中释放率低于22%,在添加胆酸盐和无胆酸盐的人工肠液中24h 释放率均达80%～90%。以油溶番茄红素为参照剂型,自制番茄红素脂质体与市售番茄红素微胶囊均具有较长的体内滞后时间和较低的清除率,延长了有效作用时间;自制番茄红素脂质体相对生物利用率为154.42%,大大优于油溶番茄红素,接近市售番茄红素微胶囊(205.03%)。     

酸奶中超氧化物歧化酶对模拟胃肠道消化液的稳定性

以超氧化物歧化酶（superoxide dismutase,SOD）为功能因子,以牛奶为载体制备了SOD酸奶,考察SOD酸奶在4 ℃贮藏过程中SOD活性的变化及其在模拟胃肠道环境中的稳定性。结果表明：贮藏6 d后,酸奶中SOD剩余活性为84.5%,贮藏14 d后,剩余活性为64%;SOD及SOD酸奶中的SOD在pH 2的人工胃液中作用3 h后,SOD剩余活性为0.1%和8.7%,而在pH值为3和4的人工胃液中能保持较高的活性,分别为50.4%、60.7%和65.4%、84.4%;在人工肠液中作用4 h后,SOD剩余活性为44.8%;在不同浓度的胆盐溶液中作用4 h后,SOD剩余活性均在87.4%以上;在人工胃液、肠液的连续消化结束后,SOD及SOD酸奶中SOD剩余活性分别为15.4%和72.4%。可见,SOD对pH 3以上的人工胃液、人工肠液、胆盐具有较好的耐受性,而SOD酸奶中的SOD对模拟胃肠道消化液具有更高的稳定性。     

益生菌副干酪乳杆菌R8双层包埋工艺研究

目的:以益生菌副干酪乳杆菌R8为研究对象,进行双层包埋关键工艺参数的研究,以提高菌体的稳定性,并实现在肠道定向释放的目的。方法:筛选冻干保护剂、益生元;优化微胶囊包埋材料海藻酸钠和固化液中氯化钙浓度;检测和分析制得的微胶囊在人工胃液和人工肠液中的释放特性。结果:筛选出的最佳冻干保护剂为20%全蛋液;最佳益生元为菊粉;最佳包埋液配方为:5%益生菌、2%菊粉、20%全蛋液,1%海藻酸钠;最佳固化液配方为2.5%氯化钙。所得微囊颗粒可耐受胃液破坏,在模拟肠环境中45 min内释放完毕,人工肠液中活菌数为原微囊活菌数的65.6%。全蛋液在制备工艺过程起到保护作用,并提高在储存过程中的稳定性;将菌体/蛋白质/海藻酸钠微胶囊进一步用壳聚糖材料进行覆膜,可实现在肠道定向释放。     

乳糖酶生物黏附纳米微囊的制备及黏附性评价

采用复乳法制备生物黏附乳糖酶纳米微囊,以壳聚糖和卡波姆作为黏附材料,分别考察了壳聚糖和卡波姆单独表面修饰以及协同表面修饰对纳米微囊理化性质的影响,采用外翻肠囊法考察纳米微囊在离体大鼠小肠黏膜的滞留程度。相对分子质量为120 kDa、脱乙酰度为95%的壳聚糖和934P型号的卡波姆作为修饰材料制备的纳米微囊粒径大小均匀、Zeta电位绝对值和包封率较高。体外黏附试验结果表明,壳聚糖、卡波姆修饰的纳米微囊在小肠黏膜的滞留率显著高于未修饰纳米微囊,壳聚糖/卡波姆(质量比为2∶1)协同修饰纳米微囊的黏附性最高,小肠黏膜滞留率可达(91.1±3.4)%。     

采用微型包囊技术研制活性双歧联菌微囊微生态制剂

针对双歧杆菌活菌制剂在口服时,不耐受强胃酸,活性菌在有氧条件下容易失活,常温下保存期短等存在问题,将微型包囊技术应用于微生态制剂中,并已研制成活性双歧联菌株耐酸肠溶微囊微生态制剂, 获得较理想的效果.本文介绍了双歧联菌株混合培养工艺条件的优化研究, 活性双歧杆菌冻干保护剂和冻干条件的确定, 微型包囊复合囊材配方的优化研究, 最佳微型包囊方法的确定及微囊化条件的研究, 含活性菌微囊的耐酸肠溶试验, 含活性菌微囊的保存稳定性试验, 50升发酵罐中试结果,以及活性双歧联菌株微囊微生态制剂的研制等.     

Studies on the role of gelatin as a cryo- and lyo-protectant in the stability of capsicum oleoresin nanocapsules in gelatin matrix

The purpose of this study was to determine the effect of freezing process in the absence or presence of excipients on the stability of capsicum loaded nanocapsules (NC) during freeze-thawing and freeze-drying procedures. Capsicum loaded nanocapsules were prepared by the modified-emulsion-diffusion method combined with the microfluidization method. The prepared samples were frozen at freezing temperatures of −40, −20, and −15 °C to study the effects of cooling temperature on the properties of the capsicum oleoresin loaded nanoparticles. From results, a relatively high freezing temperature had an effect on the maintenance of nanocapsule size after freeze-thawing and freeze-drying. Regarding the addition of excipients, gelatin and κ-carrageenan played roles as cryoprotectants and lyoprotectants, and represented R values of 1.01 and 1.13 in size comparisons before and after treatment, respectively. Furthermore, the morphologies of NC made with gelatin or κ-carrageenan were conserved after freeze-drying showing spherical forms according to electron microscope observations.     

Evaluation of enzymes produced from yeast

Pichia pinus was found to be capable of growing on mango wastes, producing pectinase (pectin lyase, EC-4.2.2.10) and lactase (beta-galactosidase, EC-3.2.1.23) enzymes. The two enzymes were successively purified by precipitation with ammonium sulfate followed by chromatography on Sephadex G-120. The purification procedure provided 1,846 and 929 fold purification with 20.6 and 24% yield recovery of pectinase and lactase, respectively. the km value of pectinase was 0.33% for pectin at pH 4.5 and that for lactase was 0.166% for lactose at pH 7.0. The purified enzymes, pectinase and lactase are stable up to 50 degrees C for 60 and 45 min, respectively, with 20 and 35% loss of their activity. Gel filtration on Sephadex G-200 indicated that the molecular weights of the purified pectinase was 90 x 10(3) Dalton and of lactase 115 x 10(3) Dalton. On the basis of the evaluation tests done, the enzymes were considered to have a potential technological interest as treating mango pastes (residues left after mango juice preparation) with the two prepared enzymes resulted in an increase of the colour intensity, total carbohydrate content and juice yield. Treating milk with the purified lactase also showed an increase in the total carbohydrate and reducing sugar produced.     

Fmoc-FF多肽杂化水凝胶对乳糖酶的控释作用研究

探讨Fmoc-FF(Phe)多肽与卡拉胶形成的凝胶对乳糖酶在模拟胃液中的保护作用以及对包埋物的控制释放作用。结果表明:在Fmoc-FF与卡拉胶的质量比为1∶15、卡拉胶的质量浓度为48%时,经模拟胃肠道后,杂化水凝胶包埋的乳糖酶的酶活可以达到未经过胃肠道处理的酶活的67.63%,远高于同样实验条件下未经包埋的乳糖酶的酶活(0%)。因此,Fmoc-FF/卡拉胶杂化水凝胶能有效保护乳糖酶不被胃液破坏,且对包埋物有控制释放的作用,可作为口服乳糖酶的控释包埋材料。     

Production of novel vitamin D3 loaded lipid nanocapsules for milk fortification

Lipid nanoparticles are carriers to improve stability, solubility, and efficacy of bioactive compounds. In this paper, novel vitamin D₃ loaded lipid nanocapsules (LNC) were produced by phase inversion method. The produced nanocapsules were characterised by particle size, polydispersity index, zeta potential, encapsulation efficiency, and encapsulation load. LNC showed sizes in the range of 31.43 to 36.66 nm. Optimum LNC formulation was selected for further analysis (such as morphological study, analysis of chemical structure, release study, and sensory evaluation). Transmission electron microscopy revealed that particles had approximately spherical shape. The Fourier transform infrared spectra indicated that no adverse reactions occurred between vitamin D₃ and lipid nanocapsules. About 9.6% of vitamin released in gastric simulated solution (pH: 1.2), which indicated that LNC can protect vitamin against acidic conditions. Sensory evaluation revealed the potential application of produced vitamin D₃ loaded LNC for development of fortified milk.     

Halloysite Nanocapsules Containing Thyme Essential Oil: Preparation,Characterization, and Application in Packaging Materials

Halloysite nanotubes (HNTs), which are natural nanomaterials, have a hollow tubular structure with about 15 nm inner and 50 nm outer diameters. Because of their tubular shape, HNTs loaded with various materials have been investigated as functional nanocapsules. In this study, thyme essential oil (TO) was encapsulated successfully in HNTs using vacuum pulling methods, followed by end‐capping or a layer‐by‐layer surface coating process for complete encapsulation. Nanocapsules loaded with TO were mixed with flexographic ink and coated on a paper for applications as food packaging materials. Scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of the nanocapsules and to confirm the TO loading of the nanocapsules. Fourier transform infrared spectroscopy and thermogravimetric analyses analysis were used to complement the structural information. In addition, the controlled release of TO from the nanocapsules showed sustained release properties over a period of many days. The results reveal that the release properties of TO in these nanocapsules could be controlled by surface modifications such as end‐capping and/or surface coating of bare nanocapsules. The packaging paper with TO‐loaded HNT capsules was effective in eliminating against Escherichia coli during the first 5 d and showed strong antibacterial activity for about 10 d.     

Improvement of colour stability of pear juice concentrate by heat treatment

Clarified pear juice concentrates were prepared from ascorbic acid treated juices that had been boiled for 0, 1, 2, 3 and 5 min and an unheated control. Boiling of pear juice for 1 min was required for complete inactivation of pear juice polyphenol oxidase (EC 1.14.18.1, monophenol monooxygenase). During 6 months of storage at 0,20 and 38°C concentrates prepared from boiled juice were characterized by greater colour stability as indicated by slower rates of browning and changes in the Hunter 'L' values when compared to these changes in concentrates prepared from unheated juice.
Colour stability of the concentrates was also improved by storage at 0°C.     

复合凝聚法制备枸杞玉米黄质纳米胶囊及其性质研究

本文以宁夏枸杞提取的玉米黄质为芯材,明胶、羧甲基纤维素钠(sodium carboxymethyl cellulose,CMC)作为壁材,利用复合凝聚法制备枸杞玉米黄质纳米胶囊,优化其制备工艺,并对纳米胶囊的性质表征及贮藏稳定性进行研究。结果表明,玉米黄质纳米胶囊的最佳制备工艺为:芯材溶剂浓度0.5%,玉米黄质浓度15 mg/mL芯材溶剂,壁材浓度0.5%,乳化剂浓度0.5%(Tween 80:Span 80=1:1,w/w),固化剂浓度20 U/g明胶。该条件下包埋率为92.60%±2.91%,平均粒径210.7 nm,多分散指数(polydispersity index,PDI)为0.063,Zeta电位为-11.5 mV。显微图像显示其呈现规则的球形结构;X-射线衍射分析结果表明,玉米黄质经包埋后以无定形的状态存在,水溶性得到了改善;贮藏稳定性结果表明,纳米胶囊结构能有效保护玉米黄质,从而抵抗温度、光照、氧气引起的氧化降解,防腐剂山梨酸钾和苯甲酸钠可与玉米黄质纳米胶囊在体系中共存。     

Simple and complex coacervation methods for the nanoencapsulation of Rosa damascena mill L. anthocyanin in zein/potato starch: A new approach to enhance antioxidant and thermal properties

The structure and antioxidant properties of zein and potato starches as well as the stability of anthocyanins strongly depend on the pH. However, due to the stability of anthocyanins in at acidic medium, their encapsulation has been limited to low pHs. In the present work, an encapsulation of anthocyanins extracted from Rosa damascena mill L. (as a model) into zein, starch, and their binary mixtures by simple and complex coacervation methods over a wide range of pH (especially higher pHs), and different encapsulating agent doses and different initial volumes of anthocyanin were studied in order to obtain new conditions for the preservation of anthocyanins and to improve the antioxidant activities of zein and potato starches. High levels of antioxidant activity and encapsulation efficiency for zein/starch/anthocyanin nanocapsules and maximum antioxidant activity for zein/starch nanocapsules (without anthocyanin) were obtained at pHs 8 and 2, respectively. Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray powder diffraction, and thermal gravimetric analysis techniques were used to analyze simple and complex coacervates biopolymer interactions, morphology, and thermal stability. The size of zein nanocapsules (283–366 nm) decreased in the range of 50–175 nm after the encapsulation of anthocyanin (pH 8), which makes them suitable for drug delivery processes. The prepared nanocapsules showed a high scavenging ability.     

新型果蔬汁饮料的研制

研究了混合蔬菜汁的制作工艺、配方以及稳定性。以市售的各类新鲜蔬菜为原料,通过清洗、热烫、打浆榨汁、浓缩取得浓缩汁,对不同蔬菜的特性采取不同的取汁工艺条件。以100%蔬菜和水果混合汁为研究目标,通过对物料配比的研究以及糖酸比的调整,确定最佳蔬菜汁配方。在获得合适的配方后,重点对混合蔬菜汁的悬浮稳定性做了研究。结果表明添加黄原胶、酸性CMC和高甲酯果胶可以提高体系稳定性。综合口感和经济性,最终确定采用黄原胶作为稳定剂。常温放置3个月实验证明以0.12%(W∶V)黄原胶和0.08%(W∶V)VC作为稳定剂的混合蔬菜汁稠度适中、色泽和悬浮稳定性良好。