海藻酸钠-乳清蛋白复合益生菌微胶囊的构建及性能评价

将两歧双歧杆菌包埋在海藻酸钠和乳清蛋白中制成微胶囊,探索影响制备益生菌微胶囊的因素,通过正交实验确定最佳的工艺参数及条件,并对益生菌微胶囊的耐酸、肠溶性等特性展开研究。制备微胶囊的最佳工艺参数:海藻酸钠浓度为3%,乳清蛋白浓度为10%,氯化钙浓度为2%,搅拌速度800r/min。此条件下包埋率达到(78.0±2.0)%。经人工胃液处理后菌体存活率≥70%,在模拟肠液中60min后能够完全释放出来,可显著提高两歧双歧杆菌在模拟消化液处理后或在4℃储藏期内的存活率。本研究为益生菌微胶囊的进一步开发利用奠定基础。     

抗氧化型壁材包埋番茄红素微胶囊的研究

研究了新型抗氧化性壁材制备番茄红素微胶囊的生产工艺。采用番茄红素为芯材,乳清分离蛋白与低聚木糖的美拉德反应产物(MRPs)为壁材,通过均质和喷雾干燥制得番茄红素微胶囊。优化的工艺参数为乳清分离蛋白与低聚木糖的质量比1∶2,加热时间3 h,p H 10,均质压力40 MPa。在此条件下得到的微胶囊产率和包埋效率分别为86.28%和94.11%。通过保留率的数据分析,结果表明壁材能够有效保护芯材成分,提高番茄红素微胶囊的储存稳定性。     

乳清蛋白-海藻酸钠的制备及其特性的测定

将海藻酸钠通过糖基化反应引入乳清蛋白,制备乳清蛋白-海藻酸钠复合物,探讨干法条件下反应时间、反应温度、海藻酸钠与乳清蛋白质量配比对复合物接枝度和溶解度的影响,确定了最佳糖基化条件为反应时间6.3 d,反应温度56.1℃,海藻酸钠与乳清蛋白质量配比4.1∶1。在此条件下,乳清蛋白-海藻酸钠共价复合物的接枝度为75.89%、溶解度为32.56%与理论预测值基本相符。     

羊乳清蛋白包埋微藻油DHA微胶囊粉末的制备与评价

DHA是具有多个不饱和双键的天然脂肪酸,因为它们具有健脑益智、促进视力发育等功能,而被广泛应用到婴幼儿配方奶粉中。因为DHA结构中含有多个不饱和双键,极易受光、氧、热、金属元素以及自由基的影响而发生氧化。为了避免DHA应用过程中发生氧化现象,一般将其制成微胶囊的形式利用。乳品市场中,针对婴幼儿奶粉中使用的DHA微胶囊粉末大部分采用的壁材为牛乳成分,但是,牛乳作为壁材的使用,根据国家食品药品监督管理局2016年10月1日起正式实行的《婴幼儿配方乳粉产品配方注册管理办法》第31条要求,难以满足纯羊奶配方粉生产的要求。本论文主要在制备DHA微胶囊中,通过对常规壁材原料牛乳清粉进行替换,采用羊乳清蛋白对DHA油脂进行包埋,从而使其可以应用到婴幼儿纯羊乳配方奶粉中,并在替换后,表面油极低,抗氧化稳定性得到进一步的增强。     

益生菌微胶囊化壁材与方法的研究进展

益生菌微胶囊技术因其能显著提高益生菌在胃肠道中的存活率而备受关注。本文介绍了益生菌微胶囊技术中所使用的包埋材料及方法,并提出益生菌微胶囊新的研究方向。      

植物蛋白微胶囊对益生菌包埋的研究进展

益生菌对宿主健康具有一定的益生作用而被广泛应用于食品领域。然而益生菌对外界环境比较敏感,且进入机体后不耐胃液、胆盐等恶劣环境,导致其存活率大大下降。微胶囊技术对益生菌包埋可以解决这一问题,且将植物蛋白作为益生菌的包埋壁材,不仅可以提高益生菌在不良环境中的存活率,还可以作为载体用于益生菌肠道的定位释放。本文综述了大豆蛋白、豌豆蛋白等对益生菌的包埋以及益生菌微胶囊在食品中的应用,为植物蛋白微胶囊技术包埋益生菌提供参考依据。      

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。     

不同蛋白质包埋壁材对益生菌在人体模拟胃液中的保护效果

为了提高益生菌在人体胃液中的存活率,本研究以大豆蛋白(SPI)、乳清蛋白(WPI)、酪蛋白(Casein)、明胶(Gelatin)为壁材,采用转谷氨酰胺酶交联的乳化凝胶方法,将Lactobacillus gasseri和Bifidobacterium bifidum包埋于蛋白质胶囊中,通过测定这两种益生菌在人体模拟胃液中的存活率,结果表明:相比于未经过包埋处理的细胞,包埋于蛋白质微胶囊中的细胞具有较高的存活率,并且还发现大豆蛋白微胶囊对菌的保护效果最好,明胶微胶囊最差。对于Lactobacillus gasseri,在加和未加胃蛋白酶的模拟胃液中,菌在这四种蛋白质微胶囊中的D值分别为:73.1、59.7、63.9、47.3min及246.6、240.5、220.0、90.2min。对于Bifidobacterium bifidum,在加和未加胃蛋白酶的模拟胃液中,菌在这四种蛋白质微胶囊中的D值分别为:31.7、24.2、22.7、18.7min和124.3、103.5、97.6、47.8min。除此之外,还比较了蛋白质的四种理化特性(乳化能力,凝胶强度,乳化稳定性、渗透性),其结果:乳化能力大小为SPI>Casein>WPI>Gelatin,凝胶强度大小为Gelatin>SPI>Casein>WPI,模拟胃液的渗透性大小为Gelatin>SPI=Casein>WPI,缓冲能力大小为Casein>WPI=SPI>Gelatin。通过上述结果可以推测蛋白质的缓冲能力与保护效果有很大的相关性,但缓冲能力并不是唯一决定因素,蛋白质其它的理化性质都有可能影响其保护效果。      

益生菌发酵乳清饮料的工艺研究

以乳清粉为原料研制出益生菌发酵乳清饮料,优化了包括菌种配比、发酵条件和稳定性在内的工艺与配方。结果表明:嗜酸乳杆菌和干酪乳杆菌配比为1:1、接种量为3%、发酵温度为35℃、发酵时间为8h时,益生菌发酵乳清饮料风味最好。稳定剂的配比为:CMC0.25%、PGA0.15%、果胶0.1%。     

Optimization of Incorporated Prebiotics as Coating Materials for Probiotic Microencapsulation

ABSTRACT: The purpose of this research was to improve probiotic microencapsulation using prebiotics and modern optimization techniques to determine optimal processing conditions, performance, and survival rates. Prebiotics (fructooligosaccharides or isomaltooligosaccharides), growth promoter (peptide), and sodium algi-nate were incorporated as coating materials to microencapsulate 4 probiotics ( Lactobacillus acidophilus, Lacto-bacillus casei, Bifidobacterium bifidum , and Bifidobacterium longum ). The proportion of the prebiotics, peptide, and sodium alginate was optimized using response surface methodology (RSM) to 1st construct a surface model, with sequential quadratic programming (SQP) subsequently adopted to optimize the model and evaluate the survival of microencapsulated probiotics under simulated gastric fluid test. Optimization results indicated that 1% sodium alginate mixed with 1% peptide and 3% fructooligosaccharides as coating materials would produce the highest survival in terms of probiotic count. The verification experiment yielded a result close to the predicted values, with no significant difference ( P > 0.05). The storage results also demonstrated that addition of prebiotics in the walls of probiotic microcapsules provided improved protection for the active organisms. These probiotic counts remained at 10⁶ to 10⁷ colony-forming units (CFU)/g for microcapsules stored for 1 mo and then treated in simulated gastric fluid test and bile salt test.     

Microencapsulation of Bifidobacterium bifidum F‐35 in Whey Protein‐Based Microcapsules by Transglutaminase‐Induced Gelation

Abstract: Bifidobacterium bifidum F‐35 was microencapsulated into whey protein microcapsules (WPMs) by a transglutaminase (TGase)‐induced method after optimization of gelation conditions. The performance of these WPMs was compared with that produced by a spray drying method (WPMs‐A). WPMs produced by the TGase‐induced gelation method (WPMs‐B) had larger and denser structures in morphological examinations. Native gel and SDS‐PAGE analyses showed that most of the polymerization observed in WPMs‐B was due to stable covalent crosslinks catalyzed by TGase. The degradation properties of these WPMs were investigated in simulated gastric juice (SGJ) with or without pepsin. In the presence of pepsin, WPMs‐A degraded more quickly than did WPMs‐B. Finally, survival rates of the microencapsulated cells in both WPMs were significantly better than that of free cells and varied with the microencapsulation method. However, WPMs‐B produced by TGase‐induced gelation could provide better protection for microencapsulated cells in low pH conditions and during 1 mo of storage at 4 °C or at ambient temperature.     

Optimizing Preparation Conditions for Heat-denatured Whey Protein Solutions to be Used as Cold-gelling Ingredients

Heat-denatured whey protein solutions are used to make ingredients that gel at low temperatures. This study examines the influence of holding temperature (65 to 90°C), holding time (5 to 30 min), protein concentration (2 to 12 wt%) and pH (3 to 8) on the rheology and appearance of heat-denatured whey protein solutions. The optimum preparation conditions required to produce non-gelled transparent solutions of heat-denatured proteins were established. The rate of cold-gelation after the addition of 200 mM NaCl to the heat-denatured whey protein solutions increased as their initial viscosity increased. It was possible to produce gels with different cold-gelling characteristics by altering the thermal preparation conditions.     

Growth of Probiotic and Traditional Yogurt Cultures in Milk Supplemented with Whey Protein Hydrolysate

ABSTRACT: Growth of some probiotic bacteria was significantly improved in milk supplemented with whey protein hydrolysate (WPH). However, WPH had no effect on the growth of Lactobacillus delbrueckii ssp. bulgaricus 18, L. delbrueckii ssp. bulgaricus 10442, and Streptococcus thermophilus 1. When the probiotic bacteria were grown in combination with different yogurt cultures in milk, WPH caused significant increases in growth of Bifidobacterium longum S9, L. acidophilus O16, and L. acidophilus L-1. However, by day 28 of refrigerated storage, the populations of the probiotic cultures that had been grown in samples supplemented with WPH were similar or below those in the control samples.     

Effect of Various Encapsulating Materials on the Stability of Probiotic Bacteria

ABSTRACT:  Ten probiotic bacteria, including Lactobacillus rhamnosus , Bifidobacterium longum , L. salivarius , L. plantarum , L. acidophilus , L. paracasei , B. lactis type Bl-04, B. lactis type Bi-07, HOWARU L. rhamnosus , and HOWARU B. bifidum , were encapsulated in various coating materials, namely alginate, guar gum, xanthan gum, locust bean gum, and carrageenan gum. The various encapsulated probiotic bacteria were studied for their acid and bile tolerance. Free probiotic organisms were used as a control. The acid tolerance of probiotic organisms was tested at pH 2 over a 2-h incubation period. Bile tolerance was tested with taurocholic acid over an 8-h incubation period. The permeability of the capsules was also examined using a water-soluble dye, 6-carboxyflourescin (6-CF). The permeability was monitored by measuring the amount of 6-CF released from the capsules during a 2-w storage period. Results indicated that probiotic bacteria encapsulated in alginate, xanthan gum, and carrageenan gum survived better ( P < 0.05) than free probiotic bacteria, under acidic conditions. When free probiotic bacteria were exposed to taurocholic acid, viability was reduced by 6.36 log CFU/mL, whereas only 3.63, 3.27, and 4.12 log CFU/mL was lost in probiotic organisms encapsulated in alginate, xanthan gum, and carrageenan gum, respectively. All encapsulating materials tested released small amounts of 6-CF; however, alginate and xanthan gum retained 22.1% and 18.6% more fluorescent dye than guar gum. In general, microcapsules made of alginate, xanthan gum, and carrageenan gum greatly improved the survival of probiotic bacteria when exposed to acidic conditions and bile salts.     

Whey Protein Coating Effect on The Oxygen Uptake of Dry Roasted Peanuts

A procedure was developed to coat peanuts with aqueous whey protein isolate (WPI) solutions based on increasing coating-solution viscosity. Oxygen uptake of WPI-coated nuts and uncoated nuts were compared. WPI coatings delayed oxygen uptake of dry roasted peanuts at intermediate (53%) and low (21%) storage relative humidity. They had similar results at 29°C and 37°C. The effects of coating thickness and storage relative humidity indicate that the mechanism of protection of the coatings was through their oxygen barrier properties.     

Whey Protein Coating Efficiency on Mechanically Roughened Hydrophobic Peanut Surfaces

ABSTRACT:  Mechanical roughening of commercially blanched-and-roasted peanuts efficiently improved whey protein coating efficiency. However, increased coating coverage varied significantly among peanuts, likely due to variable change of peanut surfaces during commercial processing and storage before coating. Coating efficiency was further improved and was more consistent on mechanically roughened freshly blanched-and-roasted peanuts compared to the commercially blanched-and-roasted peanuts. The improved coating efficiency without large variation on mechanically roughened freshly blanched-and-roasted peanuts may be the result of avoiding the re-formation of a waxy cuticle layer on peanut surfaces, which occurs during storage between commercial blanching/roasting process and the coating application. Scanning electron microscope (SEM) micrographs of treated peanuts confirmed the effect of roughening, as well as disruption of the parenchyma cell structure of peanuts and the creation of channels that could allow oil migration to the peanut surface and subsequent formation of a waxy layer with long enough storage.     

乳清蛋白与老年肌肉衰减征研究进展

肌肉衰减征(Sarcopenia)是伴随衰老而出现的一种以肌肉质明显减少、肌肉力量下降为特点的常见病征,同时伴随功能下降和多种慢性病发生。摄入充足的膳食蛋白质和能量,以及加强抗阻力运动和有氧运动是防治老年人肌肉衰减征的重要措施。乳清蛋白富含亮氨酸等支链氨基酸和谷氨酰胺,在防治老年肌肉衰减征中具有独特而重要的作用。     

Whey Protein Solution Coating for Fat-Uptake Reduction in Deep-Fried Chicken Breast Strips

ABSTRACT:  This study investigated the use of whey protein, as an additional coating, in combination with basic, well-described predust, batter, and breading ingredients, for fat-uptake reduction in fried chicken. Chicken breasts were cut into strips (1 × 5 × 10 cm) and coated with wheat flour (WF) as a predust, dipped in batter, coated with WF as a breading, then dipped in 10% denatured whey protein isolate (DWPI) aqueous solution (wet basis). A WF-batter-WF treatment with no DWPI solution dip was included as a control. Coated chicken strips were deep-fried at 160 °C for 5 min. A Soxhlet-type extraction was performed to determine the fat content of the meat fraction of fried samples, the coating fraction of fried samples, raw chicken, and raw coating ingredients. The WF-batter-WF-10% DWPI solution had significantly lower fat uptake than the WF-batter-WF control, by 30.67% (dry basis).
Practical Application: This article describes applied research involving fat reduction in coated deep-fried chicken. The methods used in this article were intended to achieve maximized fat reduction while maintaining a simple procedure applicable to actual food processing lines.