Encapsulation systems for lutein: A review

BackgroundThe increased demand by consumers for clean labels has encouraged industry to search for replacements of synthetic ingredients in food products, and in particular, colorants. Lutein, a xanthophyll found in marigolds and corn, can be used in food products as a natural colorant replacing yellow food dyes. Moreover, lutein is considered a nutraceutical due to its potentially beneficial health effects, such as prevention of macular degeneration, role in the development of the visual and nervous systems of fetuses, and its antioxidant properties. However, incorporation of lutein into foods is often limited because of its low-water solubility, chemical instability, and poor oral bioavailability. For this reason, colloidal encapsulation systems have been developed to facilitate the incorporation of lutein into aqueous food and beverage products.Scope and approachThis review focuses on exploring encapsulation options for lutein using various emulsion-based, nanoparticle- and microparticle-based and molecular inclusion encapsulation systems, as well as additives that can be used to increase its chemical stability in these systems. This review covers all aspects of lutein encapsulation, including both food-grade and pharmaceutical-grade encapsulation systems.Key findings and conclusionsThough lutein-loaded encapsulation systems are extensively explored in this review, emulsions are of the most interest in industry as they are cost efficient and can be designed to increase the stability of lutein by selecting the proper emulsifiers and emulsification techniques. Despite the extensive amount of research carried out on the encapsulation of hydrophobic bioactive molecules such as lutein, there are still opportunities to develop encapsulation systems that further protect these molecules during storage and also increase their bioavailability after ingestion.     

耐盐及耐茶汁西藏酥油微胶囊乳化体系研究

通过比较不同种类、配比及用量的乳化剂制备的酥油乳状液稳定性及酥油微胶囊化效果,建立了牛油单甘酯-二乙酰酒石酸单双甘酯-酪朊酸钠的西藏酥油微胶囊乳化体系,最佳配比为2.3:0.7:3。结果表明:用该乳化体系制备的酥油乳状液性质稳定,产品酥油微胶囊在喷雾干燥过程中无转型破乳现象。同时,该乳化体系制备的酥油微胶囊加水复原乳状液色白、稳定,添加高浓度(5%)食盐和高浓度茶汁(含1%红茶提取物),乳状液无分层及粒子粘壁现象。     

微胶囊型酸化剂与抗生素联合使用对断奶仔猪生产性能及腹泻率的影响

选用28日龄断奶的长白猪(♂)×大白猪(♀)二元杂交仔猪64头,研究在玉米-豆粕-膨化大豆型基础日粮中单独添加和联合使用包被酸化剂与抗生素对断奶仔猪生产性能和腹泻率的影响。结果表明:与基础日粮组相比,"基础日粮+酸化剂+抗生素"组仔猪平均日增重和饲料利用率极显著提高,腹泻率降低;与"基础日粮+酸化剂"组、"基础日粮+抗生素"组相比,"基础日粮+酸化剂+抗生素"组仔猪平均日增重和饲料利用率提高显著,腹泻率进一步降低。     

Simplified optimization for microcapsule preparation by complex coacervation based on the correlation between coacervates and the corresponding microcapsule

A close correlation between coacervates and the corresponding microcapsule was established using gelatin and gum arabic as a model system. Through turbidimetric titration and zeta-potential measurement, the optimum coacervates were obtained at pH 4.1 with the mixing ratio of 1:1 (w/w). Comparisons on morphology, yield and internal characteristic of heat-resistance were performed to testify the correlation between coacervates and the corresponding microcapsule. A simplified method for optimization of microcapsule preparation by complex coacervation was then proposed, in which the zeta-potential measurement helps to establish the approximate mixing ratios of wall materials; the turbidity analysis facilitates the finding of suitable pH corresponded to the highest turbidity to make the perfect microcapsule. Then, gelatin and sodium carboxymethyl cellulose was provided as a new combination of wall materials for the verification.     

Nanoemulsion- and emulsion-based delivery systems for curcumin: Encapsulation and release properties

Curcumin has been reported to have many biological activities, but its application as a functional ingredient is currently limited because of its poor water-solubility and bioaccessibility. This study investigated the impact of different lipid-based formulations on curcumin encapsulation and bioaccessibility. Oil-in-water nanoemulsions (r < 100 nm), or conventional emulsions (r > 100 nm), were prepared with different lipids: long, medium, and short chain triacylglycerols (LCT, MCT and SCT, respectively). An in vitro model simulating small intestine digestion conditions characterised rate and extent of lipid phase digestion. A centrifugation method determined fraction of curcumin released into mixed micelles after digestion (bioaccessibility). Initial digestion rate decreased in the order SCT > MCT > LCT, while final digestion extent decreased in the order MCT > SCT > LCT. The bioaccessibility of curcumin decreased in the order MCT > LCT ? SCT and appeared to be slightly higher in conventional emulsions than in nanoemulsions.     

Development of an immobilization system for in situ micronutrients release

An immobilization system constituted by coated microcapsules was developed aiming at immobilizing probiotic bacteria capable of producing folate and release it in a sustained manner into the intestine. Despite no probiotic folate-producers have been immobilized so far, the system has been developed with this goal and this work reports its stability and ability to release folate under gastro-intestinal conditions.Microcapsules were made of alginate with three consecutive coatings of poly-l-lysine, sodium alginate and chitosan. Turbidity experiments showed a strong electrostatic interaction between these polymers. Fourier transform infrared spectroscopy (FTIR) and confocal analysis showed the stability of the coating materials when applied on the microcapsules, even after they were immersed in solutions simulating conditions in the stomach and small intestine (i.e. pH 2, 60 min and pH 7.2, 120 min, respectively). Coated microcapsules have an average diameter size ranged from 20 and 40 μm, and swelled upon exposure to a neutral medium, without dissolution as showed by microscopy analyses. Release experiments proved the ability of the coated microcapsules to release folic acid, at different rates, depending on the applied coating. Release experiments showed that the first coating (Ɛ-PLL) is characterized by Fickian diffusion as the main release mechanism of folic acid. Fickian rate constant (k_F) decreased with the number of consequent coatings, reflecting the decrease of predominance of Fick's behavior. Results showed that the developed coated microcapsules have suitable characteristics for encapsulation of folic acid aiming in situ release in the intestine.     

Development and validation of a short-term, serum-free culture system for bovine granulosa cells: evaluation of the effects of somatotropin and growth hormone-releasing factor on estradiol production

The objective of this study was to develop and validate a short-term, serum-free culture system to determine whether recombinant bovine somatotropin (rbST) or recombinant bovine growth hormone-releasing factor (rbGRF) altered the estradiol-producing capacity of bovine granulosa cells isolated from dominant or subordinate follicles of the first follicular wave. Thus, ovaries were obtained at an abattoir from cows that were between d 2 to 5 or 6 to 10 of the estrous cycle. Three size classes of follicles were isolated from each cow's ovaries: small (2 to 5 mm in diameter), medium (6 to 14 mm), or the largest (6 to 19 mm). In vivo steroid-producing capacity of follicles was assessed by measuring concentration of estradiol, progesterone, androstenedione and 5alpha-dihydrotestosterone in each follicle. In vitro steroid-producing capacity was assessed by culturing granulosa cells from the different follicle sizes for 48 h in serum-free media with 19-OH androstenedione and measuring the estradiol and progesterone concentrations in media at the end of culture. The effect of different doses of FSH, rbST, or rbGRF on estradiol and progesterone production by granulosa cells from each follicle size class during d 2 to 5 or 6 to 10 was also evaluated. A high percentage (91.7%) of the largest follicles obtained on d 2 to 5 was estrogen-active (estradiol > progesterone) compared with other follicle classifications (d 2 to 5, small = 0%, medium = 13.8%; d 6 to 10, small = 0%, medium = 3.3%, largest = 33.3%). Estradiol was highest (P < 0.05) in the largest follicle on d 2 to 5 and correlated positively with follicle diameter. The pattern of in vitro production of estradiol by granulosa cells from the different follicle size classes reflected the original in vivo capacity of follicles to produce estradiol. However, only granulosa cells from the largest estrogen-active follicle on d 2 to 5 produced more estradiol than progesterone in vitro. Progesterone production by granulosa cells from all follicle classifications was increased by FSH, but FSH only enhanced estradiol production by granulosa cells from the largest estrogen-active follicles on d 2 to 5. Recombinant bST blocked the FSH-induced increase in estradiol by granulosa cells from the largest estrogen-active follicles on d 2 to 5, whereas rbGRF had no effect on steroid production. Based on these results, we concluded that short-term, serum-free culture of bovine granulosal cells obtained from first-wave follicles at an abattoir could be used to reflect reliably the original in vivo estradiol-producing capacity of granulosal cells, and that neither rbST nor rbGRF enhance basal or FSH-induced estradiol production by bovine granulosa cells from first-wave follicles.     

Technical note: validation of a system for monitoring individual feeding and drinking behavior and intake in group-housed cattle

The objective of this study was to validate a system for monitoring individual feeding and drinking behavior and intake in group-housed cattle. A total of 42 Holstein cows were tested with access to 24 feed bins and 4 water bins. For the purposes of this validation experiment, we focused our observations on 4 water bins and 13 feed bins. When the cow approached the feed or water bin, an antenna detected the cow's unique passive transponder and lowered the barrier, allowing the cow access to the feed or water. For each visit to the bin, the system recorded the cow number, bin number, initial and final times and weight and calculated the visit duration and intake. Bins were also monitored by direct observation and time-lapse video recording for 2 d per bin, with observations for 4 and 6 h/d for the feed and water bins, respectively. Data from direct observations were compared with the electronic data recorded by the system. Feed disappearance over 24 h was assessed by using an external scale over 3 consecutive 24-h periods, and these values were compared with the sum of intakes across all visits to that bin for the same time periods. The system showed a high specificity (100%) and sensitivity (100 and 99.76% for the feed and water bins, respectively) for cow identification. The duration of the feeding and drinking visits and the feed and water intake per visit, as estimated by the monitoring system, were highly correlated with those obtained by direct observation (R² ≥ 0.99 in all the cases). The comparison of the total feed that disappeared from each bin in 24 h with the sum of the feed cows consumed from that bin during the same period differed by less than 1 kg (29.92 ± 0.90 kg and 29.24 ± 0.90 kg as estimated by manual weighing and by the electronic system, respectively). This difference could be attributed to changes in feed moisture during the 24-h period. In conclusion, this electronic system is a useful tool for monitoring intakes and feeding and drinking behavior of loose-housed cows.     

Possibilities for an in vitro meat production system

Meat produced in vitro has been proposed as a humane, safe and environmentally beneficial alternative to slaughtered animal flesh as a source of nutritional muscle tissue. The basic methodology of an in vitro meat production system (IMPS) involves culturing muscle tissue in a liquid medium on a large scale. Each component of the system offers an array of options which are described taking into account recent advances in relevant research. A major advantage of an IMPS is that the conditions are controlled and manipulatable. Limitations discussed include meeting nutritional requirements and large scale operation. The direction of further research and prospects regarding the future of in vitro meat production will be speculated.Industrial relevanceThe development of an alternative meat production system is driven by the growing demand for meat and the shrinking resources available to produce it by current methods. Implementation of an in vitro meat production system (IMPS) to complement existing meat production practices creates the opportunity for meat products of different characteristics to be put onto the market. In vitro produced meat products resembling the processed and comminuted meat products of today will be sooner to develop than those resembling traditional cuts of meat. While widening the scope of the meat industry in practices and products, the IMPS will reduce the need for agricultural resources to produce meat.     

新式的香肠生产技术

随着西方食品的不断引进,我国人民的生活模式与饮食习惯渐渐受到影响,如我国传统的早餐食品——馒头,已开始被西式面包逐渐取代。而快餐店的涌现,更为加工肉制品如香肠、火腿、午餐肉等产品提供了广阔的发展空间,带动了肉类加工工业的迅猛发展,这又要求质量更高的生产工艺与设备。     

叶黄素微囊粉中叶黄素、玉米黄质检测方法的建立

目的是建立叶黄素微囊粉中叶黄素和玉米黄质测定方法。前处理方法:称0.05g样品至100mL容量瓶中,加入5mL水,超声溶解,加10mL甲醇于该容量瓶中,摇匀,加50mL流动相,摇匀,10%无水硫酸钠溶液定容,摇晃1min(200次/min),静止15min;液相色谱条件:色谱柱:WelchUltimateSiO_2,4.6mm×250mm,粒度5μm,流动相:正己烷:乙酸乙酯=70∶30,柱温:28℃,流速:1.5mL/min,进样量:20μL,检测波长:446nm。方法学验证:叶黄素在0.3166～10.1320μg/mL范围内线性关系良好,相关系数R~2=0.9998;玉米黄质在0.6175～9.8795μg/mL范围内线性关系良好,相关系数R~2=0.9995;加标回收率叶黄素在98.2%～102.3%之间,玉米黄质在97%～100%之间;相对标准偏差RSD叶黄素在1%以内,玉米黄质在2%以内。该方法处理简单,准确度高,适用于叶黄素微囊粉中叶黄素和玉米黄质的同时测定。     

喷雾减压冷冻干燥法生产孜然精油微胶囊

介绍了喷雾减压冷冻干燥法生产孜然精油微胶囊的工艺技术，通过实验分别对壁材的选择组合、心材的填加量、均质压力次数及喷雾减压冷冻干燥法各项参数的研究，最终确定了最佳的工艺条件，微胶囊产品达到了预期的效果。     

Screening of a natural biodiversity of lactic and propionic acid bacteria for folate and vitamin B12 production in supplemented whey permeate

Lactic acid bacteria (LAB) and propionic acid bacteria (PAB) are known for the production of several important nutraceuticals. We screened 151 LAB and 100 PAB of different origins (fermented foods and feeds) for extracellular folate and intracellular vitamin B12 production in supplemented whey permeate using a standardized microbiological assay (folate) and HPLC (vitamin B12). Five LAB strains belonging to the species Lactobacillus plantarum, Lactobacillus reuteri, Lactobacillus brevis and Lactobacillus fermentum exhibited high extracellular folate productions, with a maximum yield of 397 ± 60 ng mL^?1 for L. plantarum SM39. The highest vitamin B12 production was measured for Propionibacterium freudenreichii DF15 with 2.5 μg mL^?1. Screening a large biodiversity of LAB and PAB led to a representative image of the distribution of folate and vitamin B12 production by these genera and enabled the identification of high natural folate and vitamin B12 producing strains with high potential for applications in fermented foods.     

Description of a simple detection assay for in situ production of bacteriocin on meat

Using a modification of the agar diffusion assay, in situ bacteriocin production on meat was analyzed using cooked meat medium (CMM) and sterile pork tissue (lean and fat) with Carnobacterium piscicola LV17 as the producer and Carnobacterium divergens LV13 as the indicator strains. Contrary to what is observed in APT broth, bacteriocin production by C. piscicola LV17 occurred with growth at low inoculum levels (< or =10(4) CFU/cm2 or g of meat) on disks (10 cm2) of pork fat tissue (pH 6.58) and on CMM particles (pH 7.0) but not on disks of lean tissue (pH 5.61). The assays described in this study do not required sophisticated equipment and would be useful to study bacteriocin production on meat products stored under various conditions.     

Fatty acid content and composition of UK beef and lamb muscle in relation to production system and implications for human nutrition

Although ruminant meats normally have a low ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (P:S ratio), the muscle contains a range of C(20) and C(22) PUFA of both the n-6 and n-3 series of potential significance in human nutrition. However, information on the amounts of these fatty acids in muscle and how they are modified by production system is limited In this study, the content and composition of fatty acids was determined in several muscles from beef steers fed grass (grazed) and bulls fed cereal concentrates. These are the two main types of beef production in the UK and Europe. Muscle fatty acids were also determined in lambs fed grass (grazed on pasture). The total fatty acid content of all muscles studied was less than 35 g kg(-1). The percentages in total fatty acids of all n-3 PUFA were higher in muscles from steers fed grass than from bulls fed concentrates whereas all n-6 PUFA were higher in the latter. The gluteobiceps muscle contained the largest amounts of fatty acids including PUFA and the m. longissimus dorsi the least amounts of PUFA in beef and lamb, and m. longissimus contained the lowest percentages of PUFA. Arachidonic acid was the major fatty acid in the C(20) + C(22) PUFA in beef from both production systems with twice as much in muscles from bulls fed concentrates. The P:S ratios were higher in the latter animals, range 0.21-0.34 compared with 0.08-0.13 in the steers fed grass. However, the n6:n-3 ratio was much less desirable in the bulls, 15.6-20.1 compared with 2.0-2.3 in the steers fed grass. These effects of production system in ruminants are larger than previously reported. Lamb muscle P:S ratios resembled those in grass-fed beef but the n-6:n-3 ratios were lower. The percentage of trans unsaturated 18:1 fatty acids was similar in both cattle production systems but lamb muscles contained twice as much as beef. Although the concentrations of the C(20) and C(22) PUFA are much lower than in fish, maintaining high n-3 levels in ruminant meats through grass feeding may be advantageous in human nutrition since meat is more widely consumed.     

利用微胶囊双水相体系萃取百里香精油的研究

文章把微胶囊技术和双水相萃取技术相结合,采用β-环糊精-硫酸钠双水相萃取体系提取百里香精油,并对精油萃取工艺进行了优化,实验结果表明最佳萃取条件为:β-环糊精0.45g/mL,硫酸钠0.20g/mL,萃取温度45℃,精油平均收率高达95%以上。     

Encapsulation of all-trans retinoic acid into wheat ceramides micro vesicles enhanced influence on collagenase and tissue inhibitor of metalloproteinase-1 production by human skin fibroblasts

The influence of all-trans retinoic acid (RA), either in its free or encapsulated form into wheat ceramides (CER), on the production of collagenase (MMP-1), and tissue inhibitor of metalloproteinase (TIMP-1) by human skin fibroblasts (HSF) at early and late stages of their proliferative life span (PLS) was examined. The level of MMP-1 was elevated and that of TIMP-1 decreased in late as compared to early passage cells. All-trans retinoic acid significantly decreased and increased the secretions of MMP-1 and TIMP-1 respectively, in a dose-dependent manner, from 10-7 m to 10-5 m. Entrapment of RA into CER vesicles potentiated its effect on MMP-1 and TIMP-1 secretions by HSF, independently of cell passages. The extent of variations obtained on MMP-1 and TIMP-1 levels, when HSF culture medium was supplemented with 10-5 m RA, could be obtained using a 100-fold lower concentration of RA encapsulated into CER vesicles. CER had no effect on TIMP-1 and MMP production by HSF in culture, and simultaneous addition of CER and RA did not potentiate the effects of RA alone, indicating that formation of RA-CER liposomes was responsible for the enhancing effects. The rate of internalization of RA into HSF was increased when used in its CER encapsulated form. Therefore, the use of retinoid within CER potentiates its beneficial influence on the MMP-1:TIMP-1 imbalance with fibroblastageing.     

纳米胶囊的包埋方法与表征

综述了纳米胶囊的形式与壁材选择、应用领域及其独特的优势,重点介绍了纳米胶囊的多种包埋方法以及特性的表征,希望能进步加强食品领域对纳米胶囊的相关研究,以确保食品原料和活性组分在加工贮藏和消化吸收过程中的稳定性,提高生物利用性,提高抗氧化和保健功能,增强在食品配方中的可溶性,防止物质分子间因相互作用而产生的失活和有害反应等。     

Adhesion studies for probiotics: need for validation and refinement

Adhesion of probiotic bacteria to intestinal epithelial cells is regarded as a prerequisite to exert beneficial health effects. Human intestinal epithelial lines, like Caco-2 or HT-29 cells, have been extensively used to select for adhesive strains in vitro. Adhesion to intestinal mucus has been used to a lesser extent. However, to date, there has been no standardization of the conditions used in in vitro adhesion assays. As a consequence, results obtained in different laboratories using identical strains, but different assay conditions, show great variability. This lack of standardization complicates the interpretation of data and discrepancies emerge on what is meant by effective adhesion. A critical validation of in vitro adhesion is essential for the food industry, using adhesion assays as predicitve screening tools to assess new probiotic strains. In this review we summarize a comparative study on adhesion of the well characterized probiotic bacteria L. johnsonii La1 and L. rhamnosus GG with respect to the influence of bacterial growth conditions, growth phase, buffer, pH, and mucus on adhesion properties. The results are employed in the current scientific discussion to allow a critical evaluation on the reliability of the in vitro assays.     

食品运载体系包埋姜黄素的研究进展

姜黄素具有抗氧化、抗肿瘤、降血脂和预防老年痴呆等多种生理功能,还可以用作天然着色剂、食品防腐剂、抗氧化剂等;然而水溶性差、不稳定、代谢速度快、生物利用率低等缺陷限制了其在食品领域中的应用。利用食品运载体系,以天然生物分子为材料制备姜黄素的传递载体可以解决上述问题。本文介绍了姜黄素的结构特征和理化性质,以及限制其利用的主要因素和原理,对现有的运载体系及其在提高姜黄素生物利用度方面的研究现状进行综述,最后针对目前研究中存在的问题对未来姜黄素运载体系的研究方向提出合理建议。