Bioavailability, Health Benefits, and Delivery Systems of Allicin: A Review.

Garlic has been used worldwide as a spice due to its pungent taste and flavor-enhancing properties. As a main biologically active component of the freshly crushed garlic extracts, allicin (diallyl thiosulfinate) is converted from alliin by alliinase upon damaging the garlic clove, which has been reported to have many potent beneficial biological functions. In this work, allicin formation, stability, bioavailability, and metabolism process are examined and summarized. The biological functions of allicin and potential underlying mechanisms are reviewed and discussed, including antioxidation, anti-inflammation, antidiabetic, cardioprotective, antineurodegenerative, antitumor, and antiobesity effects. Novel delivery systems of allicin with enhanced stability, encapsulation efficiency, and bioavailability are also evaluated, such as nanoparticles, gels, liposomes, and micelles. This study could provide a comprehensive understanding of the physiochemical properties and health benefits of allicin, with great potential for further applications in the food and nutraceutical industries.

Surfactant-free oleogel-based emulsion stabilized by co-assembled ceramide/lecithin crystals with controlled digestibility.

BACKGROUND: There is increasing interest in the development of oleogel-based emulsions. However, they usually contained surfactants for stabilization, especially small-molecular weight surfactants, which may have adverse health impacts. RESULTS: Herein, a surfactant-free oleogel-based emulsion stabilized by co-assembled ceramide/lecithin (CER/LEC) crystals was developed. The formation and stabilization mechanisms were explored. The different molar ratios of gelator (LEC and CER) in emulsions resulted in different crystal morphology, crystallinity as well as different emulsion properties. This suggested that appropriate crystallinity, crystal size, and interfacial distribution of these crystals provided higher surface coverage against droplets coalescence, thus better emulsion stabilization. Both X-ray diffractograms and contact angle results confirmed that the crystals which were primarily responsible for emulsion stabilization, are co-assembled crystals consisted of both gelators (CER and LEC). Furthermore, the percentage of free fatty acids (FFAs%) results revealed a negative relationship between lipid digestibility and crystal concentration. CONCLUSIONS: This strategy greatly enriched surfactant-free oleogel-based emulsion formulations, as well as their potential applications in healthy lipid-based products and novel food delivery systems with controlled lipid digestibility. © 2022 Society of Chemical Industry.

Gelation and foaming properties of fatty acid mixtures in sunflower oil.

BACKGROUND: The development of lipid-lowering products has become the focus of the food industry due to increasing consumer awareness of the relationship between diet and health. Recently, edible oleofoams have drawn attention due to their enormous potential in reformulating food products with reduced fat content and unique mouth feel. RESULTS: We have developed an edible oleofoam system by whipping oleogel composed of fatty acid mixtures in sunflower oil. The crystal morphology, gelation properties, and foaming properties of these oleogels could be tailored by changing the ratio of stearic acid (SA) and myristic acid (MA). Specifically, SA/MA = 2:8 (2S8M) was demonstrated to have superior foaming capability and foam stability, likely due to the densely packed and uniformly distributed crystals formed at this fatty acid ratio. Small lipid crystals in 2S8M absorbed to the air-oil interface more efficiently, and together with the strengthened network established in the bulk phase, helped stabilize the foam structure. As a result, the 2S8M oleofoam showed excellent foaming properties: strong plasticity, significantly increased overrun (up to 63.56 ± 2.58%), and significantly improved foam stability. The X-ray diffraction (XRD) results indicated that the diffraction pattern observed for 2S8M samples at d-spacing of 4.20 and 3.79 Å was related to the characteristic peak of ß' type crystals, which were responsible for the enhanced foaming capability of 2S8M oleogels. Oleophobic property of 2S8M increased, as indicated by wettability in oil phase, which could possibly drive crystals to the air-oil interface. CONCLUSIONS: These results highlighted the importance of lipid crystal morphology in determining the whippability of oleogels. © 2021 Society of Chemical Industry.

Effect of Momordica saponin- and Cyclocarya paliurus polysaccharide-enriched beverages on oxidative stress and fat accumulation in Caenorhabditis elegans.

BACKGROUND: As an edible and medicinal herb in Chinese folk medicine, Cyclocarya paliurus (Batal.) Iljinskaja leaves are traditionally widely used in the treatment of metabolic disorders. The vegetable Momordica charantia L. has been consumed worldwide for thousands of years as a traditional drug due to its activities against obesity and diabetes. In view of the therapeutic value of Momordica saponins (MSs) and C. paliurus polysaccharides (CPPs), an independently developed MSs- and CPPs-containing beverage (MC) was evaluated for its efficacy in controlling oxidative stress and obesity in Caenorhabditis elegans. RESULTS: First, we found that MC could promote the nuclear localization of DAF-16 and the translation of SOD-3. Further exploring its antioxidant properties, the oxidative stress by-products reactive oxygen species, malondialdehyde, and nonesterified fatty acids were significantly inhibited in C. elegans. Moreover, damage due to diseases related to oxidative stress (age pigments and neurodegenerative diseases) was alleviated. Furthermore, fat accumulation was significantly reduced in normal and high-fat models. Finally, the lipid-lowering effects of MC might involve reductions in the size and number of lipid droplets without impairing basic physiological functions in C. elegans. CONCLUSION: These results provide promising data indicating MC as an innovative health beverage for the pharmacological management of oxidative stress and obesity. © 2020 Society of Chemical Industry.

Assembly pattern of multicomponent supramolecular oleogel composed of ceramide and lecithin in sunflower oil: self-assembly or self-sorting?

Ceramide (CER) is a novel food-grade organogelator with beneficial health effects. Lecithin (LEC) is not an effective gelator; however, it may alter the crystal morphology of the host gelator in a multicomponent system. In this paper, LEC and CER were mixed at various molar ratios in sunflower oil leading to different gelation behaviors. It was interesting since in this multicomponent system, gels formed when there was more less-effective gelator (LEC), while gels hardly formed when there was more effective gelator (CER). This drew our attention since there might not be only one kind of assembly mode between the LEC and the CER. A comprehensive rheological investigation was conducted. It was found that at specific ratios (6L4C and 5L5C), strong gels (G' > 1.0 × 105 Pa) formed with superior oil binding capacity (up to 99.84%). Meanwhile, these gels exhibited higher tolerance level to permanent deformation than the monocomponent gel. However, weak gels were observed off the optimal ratio (8L2C, 7L3C, 4L6C and 3L7C). The crystal morphology of gels drastically changed with change in gelator proportion. Short needle-like crystals and small rosette crystals were observed in 6L4C and 5L5C, respectively, while other samples exhibited spherulite-shaped crystals (8L2C, 7L3C, 4L6C, and 3L7C), which differed from any of the monocomponent gel structures (10L0C and 0L10C). Results from differential scanning calorimetry and polarized light microscopy suggested that the macroscopic properties are determined by the morphology and distribution of crystals rather than the crystallinity of the matrix. Fourier transform infrared spectroscopy results indicated the presence of van der Waals forces and the formation of hydrogen bonding between the phosphate of the LEC and the amide group of the CER. The above results indicated that the LEC and CER co-assembled at approximately equal molar ratio, and the redundant LEC or CER at other ratios self-sorted to combine with the co-assembled fibers by lateral association, leading to potentially different underlying microstructures. These multicomponent supramolecular oleogels with high tunability may further broaden their applicability in various healthy lipid-based product formats.

Hepatic Lipidomics Analysis Reveals the Antiobesity and Cholesterol-Lowering Effects of Tangeretin in High-Fat Diet-Fed Rats.

Tangeretin (TAN) exhibited antilipogenic, antidiabetic, and lipid-lowering effects. However, the lipid biomarkers and the underlying mechanisms for antiobesity and cholesterol-lowering effects of TAN have not been sufficiently investigated. Herein, we integrated biochemical analysis with lipidomics to elucidate its efficacy and mechanisms in high-fat diet-fed rats. TAN at supplementation levels of 0.04 and 0.08% not only significantly decreased body weight gain, serum total cholesterol, and low-density lipoprotein cholesterol levels but also ameliorated hepatic steatosis. These beneficial effects were associated with the declining levels of fatty acids, diacylglycerols (DGs), triacylglycerols, ceramides, and cholesteryl esters by hepatic lipidomics analysis, which were attributed to downregulating lipogenesis-related genes and upregulating lipid oxidation- and bile acid biosynthesis-related genes. Additionally, 21 lipids were identified as potential lipid biomarkers, such as DGs and phosphatidylethanolamines. These findings indicated that the modulation of lipid homeostasis might be the key pathways for the mechanisms of TAN in the antiobesity and cholesterol-lowering effects.

Capsaicin-the major bioactive ingredient of chili peppers: bio-efficacy and delivery systems.

Capsaicin is the primary bioactive substance in red chili peppers, which produces the pungent flavor. During the past few decades, pharmacological benefits of capsaicin and its underlying mechanisms have been examined extensively. In this paper, major biological efficacies of capsaicin are reviewed, including analgesic, antioxidant, anti-inflammatory, anti-cancer, anti-obesity, cardio-protective, and metabolic modulation effects. Novel delivery systems, such as liposomes, micelles, micro/nano-emulsions, colloidal capsules and solid nanoparticles, for enhancing the oral bioavailability of capsaicin are also evaluated depending on the stability, encapsulation efficiency and biological properties. This review provides a theoretical basis for capsaicin to be further developed into a multi-functional ingredient with health-promoting functions in the nutraceutical industry.

Engineering water-induced ceramide/lecithin oleogels: understanding the influence of water added upon pre- and post-nucleation.

A mixture of ceramide (CER) and lecithin (LEC) at specific ratios was capable of forming oleogels in sunflower oil triggered by adding a trace amount of water. It was noted that the addition of water at different temperatures (TW) resulted in different gelation behaviors and microstructures. To better illuminate the assembly mechanism at different TW, samples with water added at different TW (20 °C, 45 °C, 70 °C and 95 °C) were prepared. The viscoelastic properties, microstructures, and the crystal packing of these samples were investigated. It was observed that all samples prepared at TW of 20 °C and 95 °C formed gels, while most samples prepared at TW of 45 °C and 70 °C were too weak to form gels. Gels prepared at 95 °C were stronger but more fragile in texture compared to gels produced at 20 °C. The crystal morphology of gels drastically changed with TW. Spindle-shaped crystals were observed in gels prepared at low TW (20 °C), while gels prepared at high TW (95 °C) exhibited a network with packed oil droplets stabilized by lamellar shells together with fibrillar crystals in the bulk phase. X-ray diffractograms showed a different reflection peak (d-spacing of 14.5 Å) in gel prepared at 20 °C, compared to the d-spacing in oleogels with a single gelator (13.14 Å and 15.33 Å, respectively, for CER and LEC). Gel prepared at 95 °C showed two long-spacing characteristic peaks, which correspond to the characteristic peaks of CER gel (∼13 Å) and LEC gel (∼12 Å). Fourier transform infrared spectroscopy results indicated that the different gelation behaviors at different TW were mainly caused by vibrational changes in the amide bond of CER. Our hypothesized assembly mechanism can be concluded as: increasing TW resulted in the conversion of CER and LEC crystallization from co-assembly (TW = 20 °C) to self-sorting by individual gelators (TW = 95 °C). In this study, novel water-induced oleogels were produced by manipulating TW, and such information further assists the rational design of lipid-based healthy fat products.

HPLC fingerprint analysis of Phyllanthus emblica ethanol extract and their antioxidant and anti-inflammatory properties.

ETHNOPHARMACOLOGICAL RELEVANCE: Phyllanthus emblica L. (P. emblica) as a medical plant has been used to treat diseases in Asia. It is famous for a wide range of biological activities, especially for its antioxidant and anti-inflammatory activity. However, quality control underlying the bioactivity of P. emblica fruits remains to be studied. MATERIALS AND METHODS: In this study, we evaluated the HPLC fingerprint and bioactivity of polyphenols extracted from P. emblica fruits grown in different habitats. RESULTS: P. emblica fruits collected from 10 different habitats in Guangdong, Fujian, Yunnan, and Guangxi provinces in China were used to establish a simple and reliable HPLC fingerprint assay. Simultaneous quantification of three monophenols was also performed to determine assay quality and consistency. Additionally, chemical assessment of the different ethanolic extract (PEEE) from 10 P. emblica fruits demonstrated that they exhibited antioxidant activity by enhancing reducing power and total antioxidant capacity, scavenging hydroxyl radical and superoxide anion. PEEE protected RAW264.7 cells from oxidative damage by increasing glutathione content and total superoxide dismutase activity, suppressing MDA content. PEPE also alleviated lipopolysaccharide-induced inflammation in RAW 264.7 cells by decreasing release of pro-inflammatory mediators. Notably, the PEEE samples from Yunnan province showed the optimal antioxidant and anti-inflammatory effects among all the PEEE samples. CONCLUSION: In conclusion, The PEEE HPLC fingerprint may help improve P. emblica quality control, and P. emblica with antioxidant and anti-inflammatory activities may be potentially applied in functional foods or in adjuvant therapy for medicinal development.

Water-induced self-assembly of mixed gelator system (ceramide and lecithin) for edible oil structuring.

Ceramide (CER) is a highly effective organogelator with numerous health implications. Lecithin (LEC) is often used as a crystal modifier to improve gel properties. It was found in this study that in the presence of a small amount of water, CER and LEC self-assembled at specific ratios and form oleogels in sunflower oil (SFO), and the structure of which differed from any of the mono-component gel structures. To the best of our knowledge, this is the first water-induced multi-component oleogelation reported to date. To clarify when gelation occurs, a phase diagram of the four-component system SFO/CER/LEC/water was established and characterized. In the gel region, confocal laser scanning microscopy revealed that water was evenly distributed in the self-assembled microstructure. To clarify the vital role of water in formation of stable gel, a series of samples with varying ratios in CER and LEC with and without water were explored. The thermal properties, viscoelastic properties, microstructures, as well as crystal packing were investigated. With water added, the microscopic structures of CER/LEC gels changed from three-dimensional dendritic crystals to two-dimensional rod-like or platelet-like crystals, which are more effective at structuring liquid oil. A different reflection was observed (d-spacing of 14.9 Å), suggesting the rearrangement in crystal packing of ceramide and lecithin molecules, compared to the d-spacing in oleogels with single gelator (13.1 Å and 15.3 Å, respectively for ceramide and lecithin). Fourier transform infrared spectroscopy results indicated the presence of interaction between water and gelators, which confirmed the importance of water in self-assembly of this mixed-gelator system. Water-induced conversion of oleogelation provides alternatives in producing hard-stock fat replacers as well as possibilities to incorporate water-soluble nutrients into oil-based products.

Rational design of food-grade polyelectrolyte complex coacervate for encapsulation and enhanced oral delivery of oenothein B.

Oenothein B (OeB), a dimeric macrocyclic ellagitannin isolated from eucalyptus leaves has been demonstrated as a promising natural bioactive compound for its remarkable antitumor, antioxidant, anti-inflammatory and immunomodulating effects. Unfortunately, early study indicates that OeB has quite low bioaccessibility for oral consumption due to their susceptibility to decomposition both in vitro and in vivo. Herein, we report the design and synthesis of food-grade polyelectrolyte complex coacervate using caseinophosphopeptides (CPPs) and chitosan (CS) to encapsulate OeB for enhanced protection through gastrointestinal (GI) tract. Turbidimetric titration, dynamic light scattering (DLS), ζ-potential and scanning electric microscopy (SEM), as well as theoretical calculations based on principle of charge neutralization, were conducted to provide tentative and quantitative description for phase behavior in formation and disassociation of the complex. The optimum fabrication conditions were found to be at pH 5.5, with CPP : CS at 1 : 1, using CS of high molecular weight (980 kDa). The genipin cross-linking protected the system from disassembling in harsh acidic environments. The best cross-linking conditions were found to be 0.6 mg ml-1 genipin addition at 4 h cross-linking reaction time. The particle size and zeta potential of the nanoparticles varied from 200 to 300 nm and +20 to +24.2 mV, respectively. Scanning electron microscopy (SEM) revealed a spherical coacervate phase. Results from in vitro release study proved that controlled release of OeB through GI tract using CPP-CS nanoparticles cross-linked with genipin was achievable.