Formulation of phytosterols in emulsions for increased dose response in functional foods

The effect of water on the crystallization of phytosterols and phytostanols in organic solutions

Phytosterols (C29H50O), also known as plant sterols and stanols, are valuable biomolecules with a variety of applications in the pharma, food, and cosmetics industries. Phytosterols are typically manufactured from vegetable oil and tall oil feedstocks through a cooling crystallization process. Depending on the feedstock used, the composition regarding individual phytosterols and phytostanols (saturated analogs of phytosterols), also varies to a large extent. In the current research it was observed that by adding a small amount of water to the organic solvent [i.e., n(water)/n(acetone) of 0.17, n(water)/n(ethanol) of 0.13, and n(water)/n(ethyl acetate) of 0.10], the final phytosterol profile regarding phytosterol and phytostanol concentrations can be modified. This can be explained by the different solubility behavior of phytosterols and phytostanols in the studied solvent systems, based on experimental results obtained from transmissivity measurements. Phytostanols have surprisingly low solubility when compared to phytosterols in all the studied solvent systems. However, in the presence of water, phytosterol solubility decreased more compared to phytostanols. To the best of our knowledge, this is the first time that phytostanol solubility has been systematically studied. Moreover, phytosterol and phytostanol concentrations in a crystallized product with varying binary solvent systems containing water has not previously been reported. The measured experimental solubility data correlated well with the studied solubility models (van't Hoff, modified Apelblat, Buchowski-Ksiazaczak (λh), and polynomial equations). Understanding the solubility behavior of phytosterols and phytostanols allows to optimize the crystallization process itself toward a broader raw material selection, and better yield and quality in the production of phytosterols from plant-based raw materials. In addition, these findings can potentially be further utilized in phytosterol formulations for various applications.

Co-sonicated coacervation for high-efficiency green nanoencapsulation of phytosterols by colloidal non-biotoxic solid lipid nanoparticles

Plant sterols are used as a supplement or an additive to reduce LDL cholesterol. The poor dispersibility and instability of phytosterols are the main limitations of their application. So, we tried to overcome these problems through nanoencapsulation of them with colloidal natural RSs (SLNs) using an effective approach to achieve higher efficiency and less intrinsic coagulation. Phytosterols extracted from flax seeds oil with caffeine by a new method were encapsulated with a stable colloid of sheep fat and ostrich oil (1:2), soy lecithin, and glucose through co-sonicated coacervation. Characterization of the obtained SLNs was conducted using FTIR, UV-Vis, SEM, DLS, and GC analysis. The three-factor three-level Behnken design (BBD) was used to prioritize the factors affecting the coacervation process to optimize particle size and loading capacity of SLNs. Operational conditions were examined, revealing that the size of SLNs was below 100 nm, with a phytosterols content (EE %) of 85.46% with high positive zeta potential. The nanocapsules' anti-microbial activity and drug-release behavior were then evaluated using the CFU count method and Beer-Lambert's law, respectively. The controlled release of nanocapsules (below 20%) at ambient temperature has been tested. The stability of nano-encapsulated phytosterols was investigated for six months. All results show that this green optimal coacervation is a better way than conventional methods to produce stable SLNs for the nanoencapsulation of phytosterols.

Current and New Insights on Delivery Systems for Plant Sterols in Food

Plant sterols are minor bioactive components of food lipids, which are often used for the formulation of functional foods due to their cholesterol-lowering properties. However, they have low solubility and tend to crystallize, which may affect their biological effects, the sensory profile of the sterol-enriched food, and its consumer acceptability. Moreover, due to the unsaturated structure of sterols, they are susceptible to oxidation, so different encapsulation systems have been developed to improve their dispersibility/solubility, stability, delivery, and bioaccessibility. This chapter provides an overview of the main encapsulation systems currently used for plant sterols and their application in model and food systems, with a particular focus on their efficiency and impact on sterol bioaccessibility.

Solubilization of free β-sitosterol in milk sphingomyelin and polar lipid vesicles as carriers: Structural characterization of the membranes and sphingosome morphology

High consumption of plant sterols reduces the risk of cardiovascular diseases in humans and provides health benefits. Increasing the amount of plant sterols in the diet is therefore necessary to reach the recommended daily dietary intake. However, food supplementation with free plant sterols is challenging because of their low solubility in fats and water. The objectives of this study were to investigate the capacity of milk-sphingomyelin (milk-SM) and milk polar lipids to solubilise β-sitosterol molecules in bilayer membranes organised as vesicles called sphingosomes. The thermal and structural properties of milk-SM containing bilayers composed of various amounts of β-sitosterol were examined by differential scanning calorimetry (DSC) and temperature-controlled X-ray diffraction (XRD), the molecular interactions were studied using the Langmuir film technique, the morphologies of sphingosomes and β-sitosterol crystals were observed by microscopy. We showed that the milk-SM bilayers devoid of β-sitosterol exhibited a gel to fluid L_α phase transition for T_m = 34.5 °C and formed facetted spherical sphingosomes below T_m. The solubilisation of β-sitosterol within milk-SM bilayers induced a liquid-ordered L_o phaseabove 25 %mol (1.7 %wt) β-sitosterol and a softening of the membranes leading to the formation of elongated sphingosomes. Attractive molecular interactions revealed a condensing effect of β-sitosterol on milk-SM Langmuir monolayers. Above 40 %mol (25.7 %wt) β-sitosterol, partitioning occured with the formation of β-sitosterol microcrystals in the aqueous phase. Similar results were obtained with the solubilization of β-sitosterol within milk polar lipid vesicles. For the first time, this study highlighted the efficient solubilization of free β-sitosterol within milk-SM based vesicles, which opens new market opportunities for the formulation of functional foods enriched in non-crystalline free plant sterols.

DHA loaded nanoliposomes stabilized by β-sitosterol: Preparation, characterization and release in vitro and vivo

DHA loaded nanoliposomes, stabilized by β-sitosterol, were prepared by thin film hydration-sonication method. The characteristics and membranes properties of DHA-NLs with different β-sitosterol content were measured. The samples with the same formulation were used to measure the resistance of environment stress and controlled release & absorption of DHA in vitro and in vivo. The results showed that the maximal encapsulation efficiency of DHA-NLs was (86.95 ± 0.95)%, when the ratio of soybean lecithin to β-sitosterol was 5:1. The particle size of all samples was within 200 nm and relative retention rate was more than 60% after 3 weeks storage. The area under the curve of DHA concentration of DHA-NLs and DHA-emulsion groups was 1.32 and 1.08, respectively. In summary, the nanoliposomes were promising to improve the absorption of DHA in form of ethyl ester.

Prospects of Marine Sterols against Pathobiology of Alzheimer's Disease: Pharmacological Insights and Technological Advances

Alzheimer's disease (AD) is a degenerative brain disorder characterized by a progressive decline in memory and cognition, mostly affecting the elderly. Numerous functional bioactives have been reported in marine organisms, and anti-Alzheimer's agents derived from marine resources have gained attention as a promising approach to treat AD pathogenesis. Marine sterols have been investigated for several health benefits, including anti-cancer, anti-obesity, anti-diabetes, anti-aging, and anti-Alzheimer's activities, owing to their anti-inflammatory and antioxidant properties. Marine sterols interact with various proteins and enzymes participating via diverse cellular systems such as apoptosis, the antioxidant defense system, immune response, and cholesterol homeostasis. Here, we briefly overview the potential of marine sterols against the pathology of AD and provide an insight into their pharmacological mechanisms. We also highlight technological advances that may lead to the potential application of marine sterols in the prevention and therapy of AD.

β-Sitosterol Loaded Nanostructured Lipid Carrier: Physical and Oxidative Stability, In Vitro Simulated Digestion and Hypocholesterolemic Activity

The objective of the present study was to explore the potential of nanostructured lipid carriers (NLCs) for improving the oral delivery of β-sitosterol, a poorly water-soluble bioactive component with hypocholesterolemic activity. Two β-sitosterol formulations with different solid lipid compositions were prepared by melt emulsification, followed by the sonication technique, and the effect of storage conditions and simulated digestion on the physical, chemical and oxidative stability, bioaccessibility and release were extensively studied. Both NLC preparations remained relatively stable during the four weeks of storage at different conditions (4, 25 and 40 °C), with more superior stability at lower temperatures. The in vitro digestion experiment indicated a high physical stability after exposure to the simulated mouth and stomach stages and an improved overall β-sitosterol bioaccessibility at the end of the digestion. The NLCs presented an increased solubility and gradual release which could be justified by the remarkable affinity of β-sitosterol to the complex lipid mixture. An in vivo study demonstrated an improved reduction in the total cholesterol and low-density lipoprotein cholesterol plasma levels in mice compared with the drug suspension. These investigations evidenced the potential of the developed NLC formulations for the enhancement of solubility and in vivo performance of β-sitosterol.

Tamarindus indica seeds improve carbohydrate and lipid metabolism: An in vivo study

BACKGROUND

The tamarind seeds have a lot of nutrients that may be used to control cholesterol or glucose levels.

OBJECTIVE(S)

The effects of tamarind seeds (T) on lipid and carbohydrate metabolism in rats were studied. Rats were offered basal diet (BD) with T (2%, 4% or 8%) or without T.

MATERIALS AND METHODS

Feeding and growth performance in rats were measured and samples of liver and blood were analyzed for glycogen content and levels of cholesterol and glucose respectively.

RESULTS

The inclusion of T in the diet influences the feeding and growth performance in rats. The serum cholesterol level was reduced (p < 0.05) in Sprague Dawley (SD) rats fed on basal diet (BD) containing 4% and 8% T (0.24 ± 0.14 g/l and 0.31 ± 0.06 g/l respectively) compared to control (0.79 ± 0.04 g/l). The serum glucose levels in the spontaneous hypertensive rats (SHR) was lower (50.74 ± 2.50 mg/dl; p < 0.05) than control (93.52 ± 10.83 mg/dl) at 4% T. Incorporation of increasing doses of T resulted in linear increase of glycogen storage in livers of SD rats fed on BD and high sucrose diet.

CONCLUSION

Tamarind seeds can lower blood glucose and serum cholesterol and enhance storage of glycogen in rats.

Optimization of Emulsifying Effectiveness of Phytosterol in Milk Using Two-Level Fractional Factorial Design

In this paper emulsifying effects of seven emulsifiers including Tween 80, Span 80, tripolyglycerol monostearate, sodium stearoyl lactylate, sucrose ester, soy lecithin and monoglyceride on phytosterol in milk were investigated using single factor test and fractional factorial design. The addition for seven emulsifiers were in the following concentrations: 0.1%, 0.2%, 0.3%, 0.4%, 0.5% and 0.6%. The results revealed that tripolyglycerol monostearate, sucrose ester and monoglyceride had a significant emulsifying effect on phytosterol in milk, Tripolyglycerol monostearate showed a positive emulsifying effect on phytosterol in milk, while sucrose ester and monoglyceride exhibited a negative emulsifying effect on phytosterol in milk.

Mass Spectrometric Approaches for the Analysis of Phytosterols in Biological Samples

Plant sterols (phytosterols) are important structural components of plant cellular membranes, and they play a major role during development and metabolism. They have health-associated benefits, especially in lowering blood cholesterol levels. Because of their many health claims, there is a growing interest in their analysis. Although various analytical strategies have been employed in analyzing phytosterols, chromatography linked to mass spectrometry (MS) is superior due to its sensitivity. Furthermore, specificity and selectivity are enhanced by utilizing tandem mass spectrometry (MS/MS). This article reviews the various mass spectrometric strategies used for the analysis of phytosterols. It highlights the applications and limitations associated with each MS strategy in various sample matrixes such as plant, human, animal, food, and dietary supplements. GC-MS was historically the method of choice for analysis; however, the derivatization step rendered it tedious and time-consuming. On the other hand, liquid chromatography coupled to MS (LC-MS) simplifies the analysis. Many ionization techniques have been used, namely, electrospray ionization (ESI), atmospheric pressure chemical ionization (APCI), and atmospheric pressure photoionization (APPI). APCI showed superiority in terms of ion intensity and consistency in ion formation, primarily forming [M + H - H₂O]⁺ ions rather than [M + H]⁺. In addition, matrix assisted laser desorption ionization (MALDI) as well as ambient mass spectrometry such as direct analysis in real time (DART) have also been evaluated.

Phytosterols-induced viscoelasticity of oleogels prepared by using monoglycerides

Monoglycerides (MGs) and phytosterols (PS) are known to form firm oleogels with liquid oil. However, the oleogels are prone to undergo polymorphic transition over time that lead to crystals' aggregation thus, compromises physical properties. Thus, we combined MGs with PS to control the crystallization and modify the morphology of the combination oleogels, as both components are reported to interact together. The oleogels were prepared at different ratio combinations and characterized in their rheological, thermal, morphology, and diffraction properties. The results showed that the 8:2 MGP:PS exhibited higher storage modulus (G') than the MGP mono-component. The combination oleogels exhibited effects on the crystallization and polymorphic transition. Consequently, the effects led to change in the morphology of the combination oleogels which was visualized using optical and electron microscope. The resultant effect on the morphology is associated with crystal defect. Due to observable crystals of MGP and PS, it is speculated that the combination oleogels formed a mixed crystal system. This was confirmed with diffraction analysis in which the corresponding peaks from MGP and PS were observed in the combination oleogels. However, the 8:2 oleogel exhibited additional peak at 35.41Å. Ultimately, the 8:2 was the optimum combination observed in our study. Interestingly, this combination is inspired by nature as sterols (phytosterols) are natural component of lipid membrane whilst MGP has properties similar to phospholipids. Hence, the results of our study not only beneficial for oil structuring, but also for the fields of biophysical and pharmaceutical.

Effect of Phytosterols on the Crystallization Behavior of Oil-in-Water Milk Fat Emulsions

Milk has been used commercially as a carrier for phytosterols, but there is limited knowledge on the effect of added plant sterols on the properties of the system. In this study, phytosterols dispersed in milk fat at a level of 0.3 or 0.6% were homogenized with an aqueous dispersion of whey protein isolate (WPI). The particle size, morphology, ζ-potential, and stability of the emulsions were investigated. Emulsion crystallization properties were examined through the use of differential scanning calorimetry (DSC) and Synchrotron X-ray scattering at both small and wide angles. Phytosterol enrichment influenced the particle size and physical appearance of the emulsion droplets, but did not affect the stability or charge of the dispersed particles. DSC data demonstrated that, at the higher level of phytosterol addition, crystallization of milk fat was delayed, whereas, at the lower level, phytosterol enrichment induced nucleation and emulsion crystallization. These differences were attributed to the formation of separate phytosterol crystals within the emulsions at the high phytosterol concentration, as characterized by Synchrotron X-ray measurements. X-ray scattering patterns demonstrated the ability of the phytosterol to integrate within the milk fat triacylglycerol matrix, with a concomitant increase in longitudinal packing and system disorder. Understanding the consequences of adding phytosterols, on the physical and crystalline behavior of emulsions may enable the functional food industry to design more physically and chemically stable products.

Super-cooled and amorphous lipid-based colloidal dispersions for the delivery of phytosterols

Super-cooled and amorphous lipid-based colloids are highly desirable delivery systems because of their ability to encapsulate compounds in a soluble or in a non-crystalline state. In this study, we demonstrate the preparation and characterization of super-cooled and amorphous lipid-based nanoscale colloidal dispersions containing high concentrations of phytosterols (PSs). PSs are highly hydrophobic natural bioactive compounds that are known to significantly reduce blood cholesterol levels in humans, but are insoluble in water and are poorly soluble in common lipids such as triacylglycerols (TAGs). Using the ultrahigh pressure homogenization of pre-heated dispersions, followed by temperature quenching, colloidal dispersions with varying concentrations of PSs in the lipid phase are prepared. Long and medium chain TAGs in combination with a non-ionic surfactant are used. The particle size, morphology and stability are analysed by dynamic and static light scattering, electron microscopy, and X-ray diffraction. Rapid temperature quenching enables the formation of stable colloidal dispersions of 10 wt% PSs, more than five times the equilibrium solubility at room temperature. Super-cooled emulsions are formed using liquid TAG, whereas amorphous particles are formed in the case of solid TAG. In both cases, the complete suppression of the crystallization of both PSs and lipids is observed due to the nanoscale confinement. The colloidal dispersions are stable for at least four months. The insights of this work will help understand the colloid formation and particle morphology control in the development of delivery systems for hydrophobic bio-actives such as drugs, cosmeceuticals, nutraceuticals, nutritional and agricultural nanoscale formulations.

Food protein-based phytosterol nanoparticles: fabrication and characterization

Phytosterols are a group of plant sterols with well-recognized LDL-cholesterol lowering effects. The water solubility and bioaccessibility of these compounds can be greatly improved by encapsulation within food protein-based nanoparticles.

Phytosterol colloidal particles as Pickering stabilizers for emulsions

Water-insoluble phytosterols were developed into a kind of colloidal particle as Pickering stabilizers for emulsions by a classic anti-solvent method using 100% ethanol as the organic phase to solubilize the phytosterols and whey protein concentrate (WPC) as the emulsifier. The colloidal particles in the dispersion, with morphology of stacked platelet-like sheets, had a mean diameter of 44.7 and 24.7 μm for the volume- and surface-averaged sizes, respectively. The properties and stability of the emulsions stabilized by these colloidal particles were highly dependent upon the applied total solid concentration (c; in the dispersion) and oil fraction (ø). The results indicated that (1) at a low c value (<1.0%, w/v) the emulsions were susceptible to phase separation, even at a low ø of 0.2, (2) at low ø values (e.g., 0.2 or 0.3) and a relatively high c value (1.0%, w/v, or above), a severe droplet flocculation occurred for the emulsions, and (3) when both c and ø were appropriately high, a kind of self-supporting gel-like emulsions could be formed. More interestingly, a phase inversion of the emulsions from the oil-in-water to water-in-oil type was observed, upon the ø increasing from 0.2 to 0.6 (especially at high c values, e.g., 3.0%, w/v). The elaborated Pickering emulsions stabilized by the phytosterol colloidal particles with a gel-like behavior would provide a candidate to act as a novel delivery system for active ingredients.

Enhanced oral bioavailability and tissue distribution of a new potential anticancer agent, Flammulina velutipes sterols, through liposomal encapsulation

This study innovatively investigated the anticancer effect of Flammulina velutipes sterols (FVSs), the in vivo pharmacokinetics, and the tissue distribution of FVS-loaded liposomes. The FVS consisting of mainly 54.8% ergosterol and 27.9% 22,23-dihydroergosterol exhibited evident in vitro antiproliferative activity (liver HepG-2, IC50 = 9.3 μg mL(-1); lung A549, IC50 = 20.4 μg mL(-1)). To improve the poor solubility of FVS, F. velutipes sterol liposome (FVSL) was originally prepared. The encapsulation efficiency of ergosterol was 71.3 ± 0.1% in FVSL, and the encapsulation efficiency of 22,23-dihydroergosterol was 69.0 ± 0.02% in FVSL. In comparison to its two free sterol counterparts, the relative bioavailability of ergosterol and 22,23-dihydroergosterol in FVSL was 162.9 and 244.2%, respectively. After oral administration in Kunming mice, the results of tissue distribution demonstrated that the liposomal FVS was distributed mostly in liver and spleen. The drug was eliminated rapidly within 4 h. These findings support the fact that FVS, a potential nutraceutical and an effective drug for the treatment of liver cancer, could be encapsulated in liposomes for improved solubility and bioavailability.

Lipase-mediated synthesis of water-soluble plant stanol derivatives in tert-butanol

The effects of solvents with different log P values, and of lipases on the synthesis of water-soluble plant stanol derivatives were investigated. Results showed that conversion in solvents with log P<0.37 was mainly controlled by the hydrophobicity of the solvent and subsequent complete or partial deactivation of the enzyme. The solubility of substrate was the leading factor for the conversion in solvents with log P>0.37. Lipozyme RM IM and tert-butanol was the most suitable biocatalyst and solvent, respectively. The highest yield (>51%) of plant stanyl sorbitol succinate was obtained under the selected conditions: 50 μmol/mL plant stanyl hemisuccinate, 1:3 molar ratio of plant stanyl hemisuccinate to d-sorbitol, 80 mg/mL 3 Å molecular sieves and 100mg/mL Lipozyme RM IM in tert-butanol, 150 r/min and 55 °C. Fourier transform infrared spectroscopy, mass spectroscopy and nuclear magnetic resonance spectroscopy were adopted to determine the structure of product, suggesting that water-soluble plant stanol derivatives were successfully synthesized.

Characteristics and pathways of bioactive 4-desmethylsterols, triterpene alcohols and 4α-monomethylsterols, from developing Tunisian cultivars and wild peanut (Arachis hypogaea L.)

Seven 4-desmethylsterols, five triterpene alcohols and three 4α-monomethylsterols were identified by GC-MS during the development of wild peanut, which is Arbi (AraA), and cultivars peanut, which are Trabelsia (AraT) and Chounfakhi (AraC). Our results showed that the maximum level of 4-desmethylsterols (881.07 mg/100 g of oil) was reached at 12 days after flowering (DAF) date of peanut plant in AraA, as well as the highest level of triterpene alcohols (31.51 mg/100 g of oil) was reached at 23 DAF in AraA, whilst, the highest level of 4α-monomethylsterols (15.11 mg/100 g of oil) was reached at 41 DAF in AraC. Herein, the level of triterpene alcohols and 4α-monomethylsterols was overwhelmed by the amount of 4-desmethylsterols at each stage of peanut maturity. Differences were observed in each sterol contents among the studied cultivars and wild one especially in immature stage.

Gas chromatography-mass spectrometry screening for phytochemical 4-desmethylsterols accumulated during development of Tunisian peanut kernels (Arachis hypogaea L.)

4-Desmethylsterols, the main component of the phytosterol fraction, have been analyzed during the development of Tunisian peanut kernels ( Arachis hypogaea L.), Trabelsia (AraT) and Chounfakhi (AraC), which are monocultivar species, and Arbi (AraA), which is a wild species, by gas chromatography-mass spectrometry. Immature wild peanut (AraA) showed the highest contents of beta-sitosterol (554.8 mg/100 g of oil), campesterol (228.6 mg/100 g of oil), and Delta(5)-avenasterol (39.0 mg/100 g of oil) followed by peanut cultivar AraC with beta-sitosterol, campesterol, and Delta(5)-avenasterol averages of 267.7, 92.1, and 28.6 mg/100 g of oil, respectively, and similarly for AraT 309.1, 108.4, and 27.4 mg/100 g of oil, respectively, were found. These results suggest that, in immature stages, phytosterol contents can be important regulator factors for the functional quality of peanut oil for the agro-industry chain from plant to nutraceuticals.

n-3 Oil sources for use in aquaculture--alternatives to the unsustainable harvest of wild fish

The present review examines renewable sources of oils with n-3 long-chain (> or = C20) PUFA (n-3 LC-PUFA) as alternatives to oil from wild-caught fish in aquafeeds. Due to the increased demand for and price of wild-caught marine sources of n-3 LC-PUFA-rich oil, their effective and sustainable replacement in aquafeeds is an industry priority, especially because dietary n-3 LC-PUFA from eating fish are known to have health benefits in human beings. The benefits and challenges involved in changing dietary oil in aquaculture are highlighted and four major potential sources of n-3 LC-PUFA for aquafeeds, other than fish oil, are compared. These sources of oil, which contain n-3 LC-PUFA, specifically EPA (20:5n-3) and DHA (22:6n-3) or precursors to these key essential fatty acids, are: (1) other marine sources of oil; (2) vegetable oils that contain biosynthetic precursors, such as stearidonic acid, which may be used by fish to produce n-3 LC-PUFA; (3) single-cell oil sources of n-3 LC-PUFA; (4) vegetable oils derived from oil-seed crops that have undergone genetic modification to contain n-3 LC-PUFA. The review focuses on Atlantic salmon (Salmo salar L.), because it is the main intensively cultured finfish species and it both uses and stores large amounts of oil, in particular n-3 LC-PUFA, in the flesh.

Effects of hydrophilic and lipophilic beta-sitosterol derivatives on cholesterol absorption and plasma cholesterol levels in rats

The effects of two phytosterol derivatives of beta-sitosterol, a lipophilic derivative (LPSS) and a hydrophilic derivative (HPSS), on cholesterol uptake and blood lipoprotein levels in rats were compared with those of beta-sitosterol. LPSS and HPSS have solubilities of up to 0.05 g/mL in edible oil and 0.15 g/mL in water at 25 degrees C, respectively. The intragastric administration of either 30 or 50 mg of phytosterols with 10 mg of [4- (14)C]-cholesterol per kg of body weight once a day for 3 consecutive days reduced cholesterol uptake by approximately 30% compared to controls that received cholesterol alone. Feeding a cholesterol-enriched diet containing 1% or 3% beta-sitosterol, LPSS, or HPSS for 2 and 4 weeks resulted in lowered levels of total blood cholesterol and reduced the atherogenic index in all groups. These results indicate that LPSS and HPSS have comparable effects to beta-sitosterol in lowering blood cholesterol levels but they differ from beta-sitosterol in having a solubility advantage.

Phytosterols: applications and recovery methods

Phytosterols, or plant sterols, are compounds that occur naturally and bear close structural resemblance to cholesterol, but have different side-chain configurations. Phytosterols are relevant in pharmaceuticals (production of therapeutic steroids), nutrition (anti-cholesterol additives in functional foods, anti-cancer properties), and cosmetics (creams, lipstick). Phytosterols can be obtained from vegetable oils or from industrial wastes, which gives an added value to the latter. Considerable efforts have been recently dedicated to the development of efficient processes for phytosterol isolation from natural sources. The present work aims to summarize information on the applications of phytosterols and to review recent approaches, mainly from the industry, for the large-scale recovery of phytosterols.