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1.
Microemulsions based on five-component mixtures for food applications and improved oil solubilization have been studied. The compositions included water, oil phase [such as R(+)-limonene and medium-chain triglycerides (MCT)], short-chain alcohols (such as ethanol), polyols (propylene glycol and glycerol), and several surfactants and their corresponding mixtures (nonionic, such as ethoxylated sorbitan esters, polyglycerol esters, sugar ester, and anionic, such as phosphatidylcholine). The phase behavior of these systems is discussed with respect to the influence of polyols and short-chain alcohols on the degree of solubilization of oils in the aqueous phase. The alcohol and polyols modify the interfacial spontaneous curvature and the flexibility of the surfactant film, enhancing the oil solubilization capacity of the microemulsions. The solubilization of R(+)-limonene was dramatically improved in the presence of the alcohol and polyols, whereas the improvement of solubilization for triglycerides containing MCT was less pronounced. In some systems high oil solubilization was achieved, and some of them can be easily diluted to infinity both with the aqueous phase and with the oil phase. Viscosity measurements along selected dilution lines [characterized by a single continuous microemulsion region starting from a pseudo binary solution (surfactant/oil phase) to the microemulsion (water/polyol corner)] indicate that at a certain composition the system inverts from a W/O to an O/W microemulsion.  相似文献   

2.
This study explores some characteristics of microemulsions composed of sucrose monostearate (SMS), medium-chain triglycerides (MCT), or R-(+)-limonene, alcohols, and water. The systems are homogeneous, soft, and waxy solids at room temperature but liquefy and structure into homogeneous microemulsions when heated to >40 degrees C. The amount of solubilized water is enhanced as a function of the alcohol/oil ratio and is inversely proportional to the alcohol chain length. Over 60 wt % water can be solubilized in systems consisting of propanol/MCT/SMS at a weight ratio of 3:1:4 (initial weight ratio). These microemulsions are unique and differ from nonionic ethoxylated-based microemulsions in that their viscosity is very low and is reduced with increasing amounts of solubilized water. The electrical conductivity increases only slightly as a function of the water content and does not show typical bicontinuous or percolated behavior. The water in the core of the microemulsion strongly binds to the headgroups of the surfactant. Only at >15 wt % solubilization of water was free or bulk water detected in the core of the microemulsions. Such unique behavior of the core water might have a possible application in systems requiring monitoring of enzymatic (lipase) reactions carried out in the microemulsions as microreactors.  相似文献   

3.
Water-dilutable food-grade microemulsions consisting of ethoxylated sorbitan esters, and in some cases blended with other emulsifiers, water, (R)-(+)-limonene, ethanol, and propylene glycol, have been prepared. These microemulsions are of growing interest to the food industry as vehicles for delivering and enhancing solubilization of natural food supplements with nutritional and health benefits. Lycopene, an active natural lipophilic antioxidant from tomato, has solubilized in water-in-oil, bicontinuous, and oil-in-water types of microemulsions up to 10 times the oil [(R)-(+)-limonene] dissolution capacity. The effects of aqueous-phase dilution, nature of surfactant (hydrophilic-lypophilic balance), and mixed surfactant on solubilization capacity and solubilization efficiency were studied. Structural aspects studied by self-diffusion NMR were correlated to the solubilization capacity, and transformational structural changes were identified.  相似文献   

4.
Microemulsions are of growing interest to the food industry as vehicles for delivering and enhancing solubilization of natural food supplements with nutritional and health benefits. The incorporation of molecular phytosterols, cholesterol-lowering agents, in food products is of great interest to the food industry. In this work is demonstrated the use of water dilutable food-grade microemulsions consisting of ethoxylated sorbitan ester (Tween 60), water, R-(+)-limonene, ethanol, and propylene glycol as vehicles for enhancing the phytosterols solubilization. Phytosterols were solubilized up to 12 times more than the dissolution capacity of the oil [R-(+)-limonene] for the same compounds. The solubilization capacity of phytosterols and cholesterol along a dilution line in a pseudo-ternary phase diagram [on this dilution line the weight ratio of R-(+)-limonene/ethanol/Tween 60 is constant at 1:1:3] was correlated to the microstructure transitions along the dilution line. Structural aspects were studied by self-diffusion NMR spectroscopy. The ability of phytosterols to compete with cholesterol for penetration into bile salt micelles in the gut may be limited to rich aqueous systems (O/W microemulsion).  相似文献   

5.
A new microemulsions system of curcumin (CUR-MEs) was successfully developed to improve the solubility and bioavailability of curcumin. Several formulations of the microemulsions system were prepared and evaluated using different ratios of oils, surfactants, and co-surfactants (S&CoS). The optimal formulation, which consists of Capryol 90 (oil), Cremophor RH40 (surfactant), and Transcutol P aqueous solution (co-surfactant), could enhance the solubility of curcumin up to 32.5 mg/mL. The pharmacokinetic study of microemulsions was performed in rats compared to the corresponding suspension. The stability of microemulsions after dilution was excellence. Microemulsions have significantly increased the C(max) and area under the curve (AUC) in comparison to that in suspension (p < 0.05). The relative bioavailability of curcumin in microemulsions was 22.6-fold higher than that in suspension. The results indicated that the CUR-MEs could be used as an effective formulation for enhancing the oral bioavailability of curcumin.  相似文献   

6.
Purified lutein diesters deposited on commercial nonporous glass beads were solubilized in supercritical CO(2) in a computerized batch extractor, and their solubilities were compared to their solubilities in hexane. Densities of 0.7, 0.8, and 0.9 g/mL were evaluated without modifiers. Both pressure and temperature increased solubility, although temperatures >50 degrees C promoted carotenoid loss as determined by mass balance. Solubility was enhanced by the use of modifiers and was related to their log P. Chloroform (log P = 2) increased 2.8 times the amount of solubilized lutein diesters compared to pure CO(2) at the same extraction conditions (0.9 g/mL and 40 degrees C) to yield 65% of the amount extracted with hexane. Supercritical CO(2) extraction of lutein diesters could represent a cleaner technology as compared to the current industrial use of hexane with important ecological and health-related implications.  相似文献   

7.
Epidemiological studies have consistently demonstrated that there is an association between carotenoid-rich food intakes with a low incidence in chronic diseases. Nevertheless, there is not an association between the intake of total dietary carotenoids and chronic health incidence in the European population, probably because of different carotenoid food sources and bioavailability. The objective of this study was to evaluate the small and large intestine bioaccessibilities of major dietary carotenoids from fruits and vegetables in a common diet. A bioaccessibility model that includes enzymatic digestion and in vitro colonic fermentation was employed. Lutein presented greater small intestine bioaccessibility (79%) than beta-carotene (27%) or lycopene (40%). With regard to large intestine bioaccessibility, similar amounts of lycopene and beta-carotene were released from the food matrix (57%), whereas small amounts of lutein (17%) were released. These results suggest that 91% of the beta-carotene, lutein, and lycopene contained in fruits and vegetables is available in the gut during the entire digestion process. Colonic fermentation is shown to be important for carotenoid availability in the gut.  相似文献   

8.
Chlorella is a nutrient-rich microalga that contains protein, lipid, minerals, vitamins, and high levels of lutein. This study evaluated the bioavailability of lutein from Chlorella vulgaris using a coupled in vitro digestion and human intestinal Caco-2 cell model. Lutein bioaccessibility was low, and approximately 75% of total C. vulgaris lutein was not micellized during the digestion process but remained in the insoluble digestate. Microfluidization improved lutein micellization efficiency during C. vulgaris digestion. C. vulgaris was microfluidized at a pressure exceeding 10000 psi, and the cell surface disruption was visualized by scanning electron microscopy. The mean C. vulgaris particle size was reduced from 3.56 to 0.35 μm with the microfluidization treatment. C. vulgaris microfluidization at 20000 psi was three times more efficient for aqueous lutein micelles production as compared with untreated C. vulgaris, and the final lutein content accumulated by intestinal Caco-2 cells was also higher with microfluidization. C. vulgaris lutein stability was not affected by microfluidization. These results indicate that microfluidization may be useful for improving lutein bioaccessibility from C. vulgaris during food processing.  相似文献   

9.
The preparation of nonaqueous microemulsions using food-acceptable components is reported. The effect of oil on the formation of microemulsions stabilized by lecithin (Epikuron 200) and containing propylene glycol as immiscible solvent was investigated. When the triglycerides were used as oil, three types of phase behavior were noted, namely, a two-phase cloudy region (occurring at low lecithin concentrations), a liquid crystalline (LC) phase (occurring at high surfactant and low oil concentrations), and a clear monophasic microemulsion region. The extent of this clear one-phase region was found to be dependent upon the molecular volume of the oil being solubilized. Large molecular volume oils, such as soybean and sunflower oils, produced a small microemulsion region, whereas the smallest molecular volume triglyceride, tributyrin, produced a large, clear monophasic region. Use of the ethyl ester, ethyl oleate, as oil produced a clear, monophasic region of a size comparable to that seen with tributyrin. Substitution of some of the propylene glycol with water greatly reduced the extent of the clear one-phase region and increased the extent of the liquid crystalline region. In contrast, ethanol enhanced the clear, monophasic region by decreasing the LC phase. Replacement of some of the lecithin with the micelle-forming nonionic surfactant Tween 80 to produce mixed lecithin/Tween 80 mixtures of weight ratios (Km) 1:2 and 1:3 did not significantly alter the phase behavior, although there was a marginal increase in the area of the two-phase, cloudy region of the phase diagram. The use of the lower phosphatidylcholine content lecithin, Epikuron 170, in place of Epikuron 200 resulted in a reduction in the LC region for all of the systems investigated. In conclusion, these studies show that it is possible to prepare one-phase, clear lecithin-based microemulsions over a wide range of compositions using components that are food-acceptable.  相似文献   

10.
We investigated an improved method for the separation of high-purified lutein from a commercially available spray-dried Chlorella powder (CP) using fine grinding by jet mill and flash column chromatography on a silica gel. Saponification and extraction of lutein were enhanced 2.3-2.9-fold in jet mill-treated CP (mean particle size, 20 microm) as compared to untreated CP (mean particle size, 67 microm). The carotenoid extract was dissolved in ether-hexane (1:1 v/v) and subjected to flash column chromatography on silica gel. A mixture of alpha- and beta-carotene was eluted with hexane, followed by elution with hexane-acetone-chloroform (7:2:1 v/v). Lutein (dark-orange band) was collected after the elution of an unknown colorless compound (detected based on UV absorbance). The purity of lutein in this fraction was over 99%, and the yield was 60%. The present study provides key information for obtaining highly purified lutein using flash column chromatography on a silica gel.  相似文献   

11.
Quantitative data with regard to dietary (3R,3'R,6'R)-lutein, (3R,3'R)-zeaxanthin, and their (E/Z)-geometrical isomers are scarce, and in most cases, only the combined concentrations of these two carotenoids in foods are reported. Lutein and zeaxanthin accumulate in the human macula and have been implicated in the prevention of age-related macular degeneration (AMD). The qualitative and quantitative distributions of lutein, zeaxanthin, and their (E/Z)-isomers in the extracts from some of the most commonly consumed fruits, vegetables, and pasta products were determined by HPLC employing a silica-based nitrile-bonded column. Green vegetables had the highest concentration of lutein (L) and zeaxanthin (Z), and the ratios of these carotenoids (L/Z) were in the range 12-63. The yellow-orange fruits and vegetables, with the exception of squash (butternut variety), had much lower levels of lutein in comparison to greens but contained a higher concentration of zeaxanthin. The ratio of lutein to zeaxanthin (L/Z) in two North American bread varieties of wheat (Pioneer, Catoctin) was 11 and 7.6, respectively, while in a green-harvested wheat (Freekeh) imported from Australia, the ratio was 2.5. Between the two pasta products examined, lasagne and egg noodles, the latter had a much higher concentration of lutein and zeaxanthin. The levels of the (E/Z)-geometrical isomers of lutein and zeaxanthin in these foods were also determined.  相似文献   

12.
The higher carotenoid content (commonly referred as "yellow pigment content") of tritordeum seeds as compared to wheat and the potential of this species as a donor of useful traits to wheat led us to investigate the detailed carotenoid composition of 53 accessions of hexaploid tritordeums originating from different stages of the tritordeum breeding program developed at IAS-CSIC. In addition, seven durum wheat accessions were also studied for comparison. Lutein was the unique carotenoid detected, either free or esterified with fatty acids. On average, tritordeum had 5.2 times more carotenoids than durum wheat, which suggests a high potential of this species to become a functional food. In addition, the most outstanding result of this work is the high esterification degree of lutein found in tritordeums as compared to durum wheat. This difference may indicate the differential esterification ability between tritordeum and durum wheat species. The implications of this high level of lutein esterification on both carotenoid accumulation and stability are discussed.  相似文献   

13.
Curcumin is a bioactive compound with poor oral bioavailability. Low water solubility and rapid metabolism are two known limiting factors, but the absorption mechanism of solubilized curcumin remains unclear. This study investigated the permeation mechanism of solubilized curcumin using an in vitro Caco-2 cell monolayer model. It was shown that curcumin permeated across the monolayers fairly rapidly [P(app)(A-B) = (7.1 ± 0.7) × 10(-6) cm/s] and the permeation mechanism was found as passive diffusion [P(app)(B-A)/P(app)(A-B) = 1.4]. Furthermore, the permeation rates of curcumin complexed with bovine serum albumin and in the bile salts-fatty acids mixed micelles were also determined as P(app)(mixed micelle) > P(app)(DMSO) > P(app)(protein complex). These results suggested that solubilization agents play an important role in the permeation of solubilized curcumin, and stronger binding between the solubilization agents and curcumin may decrease the permeation rate. The results further suggest that lipid-based formulations, which solubilize curcumin in mixed micelles after lipid digestion, are promising vehicles for curcumin oral delivery.  相似文献   

14.
The thermal reaction between cysteine and furfural was investigated at 65 degrees C in five-component food grade oil/water (O/W) microemulsions of R-(+)-limonene/ethanol, EtOH/water/propylene glycol, PG/Tween 60 as apart of a systematic study on the generation of aroma compounds by utilizing structured W/O and O/W fluids. The furfural-cysteine reaction led to the formation of unique aroma compounds such as 2-furfurylthiol (FFT), 2-(2-furanyl)thiazolidine (main reaction product), 2-(2-furanyl)thiazoline, and N-(2-mercaptovinyl)-2-(2-furanyl)thiazolidine. These products were determined and characterized by GC-MS. Enhancement in flavor formation is termed "microemulsion catalysis". The chemical reaction occurs preferably at the interfacial film, and therefore a pseudophase model was assumed to explain the enhanced flavor formation. The product internal composition is dictated by process conditions such as temperature, time, pH, and mainly the nature of the interface. Increasing water/PG ratio leads to a dramatic increase in the initial reaction rate (V(0)). V(0) increased linearly as a function of the aqueous phase content, which could be due to the increase in the interfacial concentration of furfural. Microemulsions offer a new reaction medium to produce selective aroma compounds and to optimize their formation.  相似文献   

15.
This study determined the lutein level in various green leafy vegetables (GLVs) and the influence of olive and sunflower oils on the postprandial plasma and eye response of dietary lutein in adult rats, previously induced with lutein depletion (LD). Fresh GLVs (n = 35) were assessed for lutein (L) and its isomer zeaxanthin (Z) levels by high-performance liquid chromatography and liquid chromatography-mass spectrometry. Among GLVs analyzed, Commelina benghalensis L. contained a higher level of L + Z (183 mg/100 g dry wt) and was used as a lutein source for feeding studies. Rats with LD were fed a diet containing powdered C. benghalensis (2.69 mg lutein/kg diet) with either olive oil (OO group), sunflower oil (SFO group), or groundnut oil (GNO group) for 16 days. The L + Z levels of the OO group were markedly (p > 0.05) higher than those of SFO and GNO groups, in plasma (37.6 and 40.9%) and eyes (22.7 and 30.8%), respectively. These results suggest that oleic acid or OO can be used as a suitable fat source to modulate the absorption of dietary lutein to manage age-related macular degeneration.  相似文献   

16.
The present study was conducted to determine the influence of an ozonation process on lutein and protein in clean and contaminated corns. This study aimed to determine the levels of lutein and protein in corn before and after ozonation and to verify the antimutagenic potential of the extracted lutein against aflatoxin using the Ames test. The lutein content was analyzed by high-performance liquid chromatography. Nitrogen analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were used to analyze protein. Clean ozone-treated corn had a total lutein content of 28.36 microg/g, which was higher than that of 22.75 microg/g in the untreated clean corn. However, the lutein content was 11.69 microg/g in the ozone-treated contaminated corn, which was lower than that of 16.42 microg/g in the untreated contaminated corn. In both corn samples, the protein content of ozone-treated corn was lower than that of untreated corn, indicating that protein could be destroyed by the ozonation process, which may influence the nutritious value of the corn. Lutein extracts alone showed no mutagenic potential against Salmonella typhimurium tester strains TA100. Lutein extracts from corn inhibited the mutagenicity of AFB1 in a dose-response manner more efficiently than lutein standard. Lutein extracts from different corn samples had similar antimutagenic potentials against AFB1, so the ozone treatment did not affect the antimutagenic potentials of lutein extracts.  相似文献   

17.
Synthetic mixtures of 24 mono- and diesters of the asymmetric hydroxylated carotenoid lutein with lauric, myristic, palmitic, and stearic acids were analyzed by liquid chromatography-ultraviolet/visible spectroscopy (LC-UV-vis) and characterized by LC-mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). These compounds were then used for identifying the composition of a commercial lutein supplement. This is the first report of chromatographic separation of mixed fatty acid lutein diesters. Preferential MS loss of fatty acids or water occurred initially at the 3'-hydroxy position in the epsilon-ionone ring and subsequently at the 3-hydroxy position in the beta-ionone ring. This selective fragmentation leads to facile assignment of the specific fatty acids to the appropriate regioisomeric ionone ring. A commercial lutein supplement contained low levels of two pairs of regioisomeric monoesters and nearly equal levels of three homogeneous diesters and five pairs of mixed diesters. Palmitic acid was the predominant fatty acid, with lower amounts of myristic, stearic, and lauric acids.  相似文献   

18.
Quillaja saponin in aqueous solution enhanced cholesterol solubility by as much as a factor of 10(3) at room temperature. Increased temperature and [NaCl] increased cholesterol solubility, whereas solubility was greatest at an aqueous pH of 4.6 at 298 K. Although various saponin sources were observed to differ in their abilities to solubilize cholesterol, trends in their solubilization properties with changing aqueous phase parameters were consistent. Surfactant molecules containing fused-ring structures as their hydrophobic portion, such as sodium cholate, sodium deoxycholate, and quillaja saponin, solubilized cholesterol significantly better than the linear hydrocarbon chain surfactants Tween 20 and Triton X-100. Mixtures of surfactants studied were found to exhibit synergistic effects: they formed micelles at lower concentrations than did those formed by the individual surfactants themselves, and they had a better ability to solubilize cholesterol. The knowledge obtained from these studies improves our understanding of cholesterol association with saponin and other types of surfactants and enhances the potential for using saponins for the solubilization and extraction of hydrophobic solutes in various pharmacological and industrial applications.  相似文献   

19.
The carotenoid composition of sarsaparilla ( Smilax aspera L.) berries has been analyzed for the first time. Lycopene was found to be the main carotenoid (242.44 μg/g fresh wt) in the pulp, followed by β-carotene (65.76 μg/g fresh wt) and β-cryptoxanthin (42.14 μg/g fresh wt; including the free and esterified forms). Other minor carotenoids were lycophyll (13.70 μg/g fresh wt), zeaxanthin (8.56 μg/g fresh wt; including the free and esterified forms), lutein (0.94 μg/g fresh wt), and antheraxanthin (0.58 μg/g fresh wt). β-Cryptoxanthin and zeaxanthin were present in free and esterified forms. β-Cryptoxanthin was mainly esterified with saturated fatty acids (capric, lauric, myristic, palmitic, and stearic), although a low amount of β-cryptoxanthin oleate was also detected. In the case of zeaxanthin, only a monoester with myristic acid (zeaxanthin monomyristate) was identified. The diverse carotenoid profile, some with provitamin A activity, together with the relatively high content, up to 375 μg/g fresh wt, makes sarsaparilla berries a potential source of carotenoids for the food, animal feed, and pharmaceutical industries.  相似文献   

20.
Chitosan, a partially deacetylated derivative of chitin, was solubilized by bipolar membrane electroacidification (BMEA). Bipolar/monopolar (anionic or cationic) configuration and chitosan addition mode (single step or stepwise) were examined. Chitosan solubility and electroacidification parameters were monitored during the process to determine the optimal conditions. Bipolar/anionic configuration and stepwise feeding mode led to chitosan solubilization yield of 91% in 60 min at 20 mA/cm(2). In this configuration, chitosan solution had a pH of 2.5, a conductivity of 8.5 mS/cm, and an ash content of 0.2%. Relative energy consumption was 0.05 kWh/L of 1% chitosan solution prepared. Although some chitosan particles were aggregated in the electrodialysis stack, limiting chitosan solubilization, BMEA allowed complete solubilization of chitosan circulating in the system.  相似文献   

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