Nanostructure Formation in Glycerolipid Films during Enzymatic Hydrolysis: A GISAXS Study.

Responsive nanostructured films from food-grade lipids can be valuable for food, pharmaceutical, and biotechnological science. Lyotropic liquid crystalline structures that respond to enzymes in their environment can, for instance, be innovated as drug delivery platforms or biosensors. However, the structural changes that such films undergo during enzymatic reactions with lipase are not yet understood. This work demonstrates the preparation of mesostructured lipid films from the food-grade lipids glycerol monooleate (GMO) and triolein on silicon wafers and their digestion with pancreatic lipase using time-resolved synchrotron grazing incidence small-angle X-ray scattering (GISAXS). The film structure is compared with the corresponding GMO/triolein bulk phases in excess water. Increasing the GMO/triolein ratio in the film makes it possible to modulate the structure of the films from oil coatings to inverse hexagonal and inverse bicontinuous cubic films. Pancreatic lipase triggered swelling of the internal film nanostructure and eventually structural transformation inside the film. Orientation and reorientation of the internal film structure relative to the silicon wafer surface were observed during the preparation of the films and their digestion. The findings contribute to the understanding of self-assembly in thin films and guide the development of enzyme-responsive coatings for the functional modification of various substrates.

Assessment of in Vivo Performance of Lipid-Based Formulations: Correlation between in Vitro Drug Release Profiles and in Vivo Absorption Rate Profiles.

The purpose of this study was to assess the in vivo absorption enhancement effects of lipid-based formulations (LBFs) through in vitro release studies. The type IIIA-MC (medium-chain) and type IIIA-LC (long-chain) formulations containing a Biopharmaceutics Classification System (BCS) Class II drug (dipyridamole or ketoconazole) were used as model LBFs. The type IIIA-MC formulation, but not the type IIIA-LC formulation, showed a higher initial absorption rate than the control suspension for both model drugs in rats. An in vitro side-by-side chamber system coupled with a lipid digestion model was used to measure free drugs, available for intestinal absorption, that are released from a model LBF. The profiles of free drug concentration on the donor side were determined by calculating the ratio of permeation rate (LBF/suspension) at every sampling interval. The in vitro free drug concentration was immediately supersaturated when the digestion of type IIIA-MC formulation was initiated for both drugs, which would cause the initially high absorption rate in rats. In contrast, the free concentration of the type IIIA-LC formulation became lower than the equilibrium solubility over time for both drugs. Overall, the profiles of in vitro free concentrations were consistent with those of in vivo absorption rates for both drugs and all LBFs. These findings would help predict the in vivo performance and establish an in vitro-in vivo correlation (IVIVC) of LBFs.

Engineering surfactant-free pickering double emulsions gels with different structures as low-calorie fat analogues: Tunable oral perception, inhibiting lipid digestion, and potent co-delivery for lycopene and epigallocatechin gallate.

Structural design has been as a transformative strategy to create clean-label and well-nourished fat-based foods. Herin, surfactant-free, plant-based oil-in-water-in-oil (O/W/O) and water-in-oil-in-water (W/O/W) emulsions gels (EGs) were designed using protein microgels and fat crystals formed in situ, which achieved dual-interface Pickering stabilization. The suitability and difference of O/W/O and W/O/W EGs as fat analogues in maintaining fat texture, inhibiting lipid digestion, target release and bioactivity of co-loading epigallocatechin gallate (EGCG) and lycopene were examined. O/W/O and W/O/W EGs displayed own unique characteristics, and could be tailored to optimize their performance. O/W/O EGs provided smoother oral perception similar to butter. The multi-structure and interface modulation for double EGs achieved inhibiting lipid digestion, fat phase position mainly controlled the digestive process. Co-delivery systems exhibited synchronous release profiles, allowing a more obvious in-time sustained release of lycopene in O/W/O and EGCG in W/O/W EGs. Both co-delivery O/W/O and W/O/W showed anti-inflammatory bioactivity.

In Vitro Gastrointestinal Digestion of Corn-Oil-in-Water Pickering Emulsions: Influence of Lignin-Containing Cellulose Nanofibrils Loading.

There is a growing trend in incorporating biomass-based engineered nanomaterials into food products to enhance their quality and functionality. The zeta potential, droplet size, microstructure, and content of free fatty acid (FFA) release were determined to investigate the influence of a plant-derived particle stabilizer, i.e., lignin-containing cellulose nanofibrils (LCNFs). Remarkable differences were observed during digestion stages, which were found to be correlated with the concentrations of LCNFs. The gradual FFA release in the small intestine stage from LCNF-coated lipid droplets was monitored over time, with a final lowest release of FFAs amounting to 26.3% in the emulsion containing 20.0% (v/v) of the dispersed phase stabilized by 3 mg/mL of LCNFs. This release can be attributed to the physical barrier at lipid droplet surfaces and the network effect created by the free LCNFs in the continuous phase. This work provides a foundation for the potential application of nature-derived LCNF materials in reducing fat absorbance.

Modulation of Lipid Digestion by Nanoarchitectonics of Complex Interfacial Structures with Tween 80 and Lecithin.

In recent years, there has been a growing interest in regulating lipid digestion through the construction of various interfacial structures. In the present work, a series of complex interfacial structures were designed by combining Tween 80 in the aqueous phase and lecithin in the oil phase at different concentration ratios. The emulsification properties, the roles in regulating lipid digestion, and the interfacial dilatational rheological properties of the composite emulsifying systems were characterized. The results showed that the combination of Tween 80 and lecithin at different ratios could effectively modulate the rate of lipid digestion. The polyoxyethylene chains of Tween 80 formed a network, that provided a spatial obstacle for the adsorption of bile salts and lipases. Thus, Tween 80 significantly delayed the lipid digestion. The introduction of lecithin gradually replaced Tween 80 molecules at the interface, thus providing space for the adsorption of bile salts and lipases. In addition, as the ratio of lecithin concentration to Tween 80 increased, lecithin gradually became the dominant factor in the interfacial properties. As a result, the rate of lipid digestion was accelerated. Therefore, by compounding different ratios of lecithin and Tween 80, a series of emulsions with different lipid digestion rates were obtained. This research provides a basis for rationally designing food emulsions according to specific needs.

Interfacial Protein Fibril Polymorphisms Regulate In Vivo Adipose Expansion for Control of Obesity.

Obesity is becoming a worldwide pandemic. Interfacial engineering of food lipid is expected to inhibit diet-induced obesity without damage to the eating enjoyment brought by high-fat diets. Unfortunately, this strategy has not been achieved yet. After screening different plant proteins, bromelain and papain were found to form wormlike and long-straight protein fibrils, respectively. The conversion of long-straight amyloid-like fibrils to wormlike fibrils was demonstrated in the fibrillation of bromelain. Using oil-in-water high internal phase emulsions (HIPEs) as a proof of concept, bromelain fibrils showed dramatically stronger interfacial stabilization capabilities than papain fibrils with high application potentials in the real-world formulation of high-fat food products such as mayonnaise. Compared with papain fibrils, oral administration of HIPEs stabilized by bromelain fibrils resulted in substantially higher fecal lipid contents and significantly decreased expression levels of the genes related to lipid absorption and transport in the intestine, including CD36, FATP-2, FATP-4, and APOA-4, without a difference in intervening gut microbiota. Consequently, dramatically less lipid absorption in the small intestine, markedly smaller chylomicron particles in the plasma, lower serum triglycerides, and controlled energy and lipid metabolism, as well as the inhibition of adipose expansion and overweight, were observed in the group with gavage of HIPEs stabilized by the bromelain fibrils rather than the papain fibrils. Furthermore, with the same calorie, substitution of all the fat in the standard high-fat feed of mice with the HIPEs emulsified by the bromelain fibrils showed a significantly stronger effect than the ones prepared by the papain fibrils on preventing high-fat-diet (HFD)-induced obesity including alleviation of adipose expansion and inflammation as well as fatty liver, also via inhibiting the absorption and transport of lipid in the intestine. The effect is ascribed to the suppressed lipolysis caused by a more compact and elastic interfacial layer formed by the wormlike fibrils than that of the long-straight fibrils, which are resistant to gastric environments and replacement by bile acids in digestion. Therefore, we provide an appealing and general strategy for controlling obesity by reducing the supply of free fatty acids (FAs) for absorption in the enteric lumen through protein fibril polymorphisms at the interface.

The effect of physical stability and modified gastrointestinal tract behaviour of resveratrol-loaded NLCs encapsulated alginate beads.

Nanostructured lipid carriers (NLC) have low storage and gastrointestinal stability, limiting their applicability. The work aimed to elevate the stability and behaviour of NLC in the alimentary tract by creating an alginate bead. Through the extrusion dropping procedure, Resveratrol (RES)-loaded NLC were efficiently integrated into alginate beads. The incorporation had no significant impact on the particle size, morphology, or inner structure of NLC, as assessed using DLS (Dynamic Light Scattering), SEM (Scanning Electron Microscopy), Differential Scanning Calorimetry (DSC) and FT-IR (Fourier Transform Infra-Red). Incorporating NLC into alginate beads improves its physical stability compared to dispersion of NLC as well as NLC-Sol. An in vitro release investigation found that the NLC-alginate beads released RES more slowly than optimized NLC formulation (RES-NLCs-opt) and NLC-alginate sol. Research on simulated in vitro digestive models revealed that just a small amount of integrated NLC may permeate stomach fluid due to its tiny size. The slow diffusion of NLC from alginate to intestinal fluid prevented aggregation and allowed for gentle hydrolysis of the lipid matrix. Incorporating NLC in alginate beads shows promise for improving stability, modifying gastrointestinal behaviour, and controlling release throughout the process of digestion.

ß-Glucan-based superabsorbent hydrogel acts as a gastrointestinal exoskeleton enhancing satiety and interfering fat hydrolysis.

Fat and its hydrolysis products, fatty acids, are indispensable nutritional components; however, prolonged excessive fat consumption, particularly in western diets, contributes to the onset of obesity and multiple metabolic disorders. In this study, we propose a daily-ingestible hydrogel (denoted as ßC-MA hydrogel) composed of natural ß-glucan and sodium carboxymethylcellulose crosslinked by malic acid at 120 °C. This hydrogel exhibits rapid swelling performance, up to 24-fold within 1 min and 176-fold after 1 h in deionized water. It also lengthens gastric retention and increases endogenous satiety signal levels, potentially controlling appetite and reducing food intake. Furthermore, ßC-MA hydrogels that enter the small intestine can effectively inhibit fat hydrolysis and decrease triglyceride synthesis and transport. Specifically, the hydrogels inhibit the release of free fatty acids (FFAs) by approximately 50 % during digestion, influence the translocation of triglycerides and FFAs across the intestinal epithelium, and reduce the serum triglyceride levels by 22.2 %. These findings suggest that ßC-MA hydrogels could serve as a noninvasive gastrointestinal device for weight control, with the advantage of reducing food intake and restoring lipid metabolism homeostasis.

In Vitro Digestion-In Situ Absorption Setup Employing a Physiologically Relevant Value of the Membrane Surface Area/Volume Ratio for Evaluating Performance of Lipid-Based Formulations: A Comparative Study with an In Vitro Digestion-Permeation Model.

The aim of this study is to establish and test an in vitro digestion-in situ absorption model that can mimic in vivo drug flux by employing a physiologically relevant value of the membrane surface area (S)/volume (V) ratio for accurate prediction of oral drug absorption from lipid-based formulations (LBFs). Three different types of LBFs (Type IIIA-MC, Type IIIA-LC, and Type IV) loaded with cinnarizine (CNZ), a lipophilic weak base with borderline permeability, and a control suspension were prepared. Subsequently, a simultaneous in vitro digestion-permeation experiment was conducted using a side-by-side diffusion cell with a dialysis membrane having a low S/V value. During digestion, CNZ partially precipitated for Type IV, while it remained solubilized in the aqueous phase for Type IIIA-MC and Type IIIA-LC in the donor compartment. However, in vitro drug fluxes for Type IIIA-MC and Type IIIA-LC were lower than those for Type IV due to the reduced free fraction of CNZ in the donor compartment. In pharmacokinetic studies, a similar improvement in in vivo oral exposure relative to suspension was observed, regardless of the LBFs used. Consequently, a poor correlation was found between in vitro permeation and areas under the plasma concentration-time curve (AUCoral) (R2 = 0.087). A luminal concentration measurement study revealed that this discrepancy was attributed to the extremely high absorption rate of CNZ in the gastrointestinal tract compared to that across a dialysis membrane evaluated by the in vitro digestion-permeation model, i.e., the absorption of CNZ in vivo was completed regardless of the extent of the free fraction, owing to the rapid removal of CNZ from the intestine. Subsequently, we aimed to predict the oral absorption of CNZ from the same formulations using a model that demonstrated high drug flux by employing the physiologically relevant S/V value and rat jejunum segment as an absorption sink (for replicating in vivo intestinal permeability). Predigested formulations were injected into the rat intestinal loop, and AUCloop values were calculated from the plasma concentration-time profiles. A better correlation was found between AUCloop and AUCoral (R2 = 0.72), although AUCloop underestimated AUCoral for Type IV due to the precipitation of CNZ during the predigestion process. However, this result indicated the importance of mimicking the in vivo drug absorption rate in the predictive model. The method presented herein is valuable for the development of LBFs.

Natural antioxidants (rosemary and parsley) in microwaved ground meat patties: effects of in vitro digestion.

BACKGROUND: Minimizing food oxidation remains a challenge in several environments. The addition of rosemary extract (150 mg kg-1) and lyophilized parsley (7.1 g kg-1) at equivalent antioxidant activity (5550 µg Trolox equivalents kg-1) to meat patties was assessed in terms of their effect during microwave cooking and after being subjected to an in vitro digestion process. RESULTS: Regardless of the use of antioxidants, cooking caused a decrease of the fat content as compared to raw samples, without noticing statistical differences in the fatty acid distribution between raw and cooked samples [44%, 47% and 6.8%, of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA), respectively]. However, the bioaccessible lipid fraction obtained after digestion was less saturated (around 34% SFA) and more unsaturated (35% MUFA +30% PUFA). Cooking caused, in all types of samples, an increased lipid [thiobarbituric acid reactive substances (TBARS)] and protein (carbonyls) oxidation values. The increase of TBARS during in vitro digestion was around 7 mg malondialdehyde (MDA) kg-1 for control and samples with parsley and 4.8 mg MDA kg-1 with rosemary. The addition of parsley, and particularly of rosemary, significantly increased the antioxidant activity (DPPH) of cooked and digested microwaved meat patties. CONCLUSION: Whereas rosemary was effective in minimizing protein oxidation during cooking and digestion as compared to control samples, parsley could only limit it during digestion. Lipid oxidation was only limited by rosemary during in vitro digestion. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Development of lipid-based SEDDS using digestion products of long-chain triglyceride for high drug solubility: Formulation and dispersion testing.

A self-emulsifying drug delivery system (SEDDS) containing long chain lipid digestion products (LDP) and surfactants was developed to increase solubility of two model weakly basic drugs, cinnarizine and ritonavir, in the formulation. A 1:1.2 w/w mixture of glyceryl monooleate (Capmul GMO-50; Abitec) and oleic acid was used as the digestion product, and a 1:1 w/w mixture of Tween 80 and Cremophor EL was the surfactant used. The ratio between LDP and surfactant was 1:1 w/w. Since the commercially available Capmul GMO-50 is not pure monoglyceride and contained di-and-triglycerides, the digestion product used would provide 1:2 stoichiometric molar ratio of monoglyceride and fatty acid after complete digestion in gastrointestinal fluid. Both cinnarizine and ritonavir had much higher solubility in oleic acid (536 and 72 mg/g, respectively) than that in glyceryl monooleate and glyceryl trioleate. Therefore, by incorporating oleic acid in place of glyceryl trioleate in the formulation, the solubility of cinnarizine and ritonavir could be increased by 5-fold and 3.5-fold, respectively, as compared to a formulation without the fatty acid. The formulation dispersed readily in aqueous media, and adding 3 mM sodium taurocholate, which is generally present in GI fluid, remarkably improved the dispersibility of SEDDS and reduced particle size of dispersions. Thus, the use of digestion products of long-chain triglycerides as components of SEDDS can enhance the drug loading of weakly basic compounds and increase dispersibility in GI fluids.

Inhibitory effects of nobiletin-mediated interfacial instability of bile salt emulsified oil droplets on lipid digestion.

Previous lipase inhibitors studies mainly focus on the binding between inhibitors and lipase, ignoring the impact of inhibitors on the oil-water interface of lipid droplets. This study aimed to investigate the effect of nobiletin (NBT) from Citri Reticulatae Pericarpium on the oil-water interface properties and lipid digestion. Here, we found that NBT could destroy bile salt (BS)-stabilized lipid droplets and thus inhibited free fatty acid release, owing to the interaction between NBT and BS at the oil-water interface, and reducing the stability of the oil-water interface (the stability index decreased from 91.15 ± 2.6 % to 66.5 ± 3.6 %). Further, the molecular dynamics simulation and isothermal titration calorimetry revealed that NBT could combine with BS at oil-water interface through intermolecular interactions, including hydrogen bonds, Van der Waals force, and steric hindrance. These results suggest that the interfacial instability of NBT mediated BS emulsified oil droplets may be another pathway to inhibit lipid digestion.

Physical properties and in-vitro gastrointestinal digestion of oil-in-water emulsions stabilized by single- and dual-modified cassava starches with cross-linking and octenylsuccinylation.

The different modified cassava starches (MCS) obtained by either single or dual modifications with cross-linking (CL) and octenylsuccinylation (OS), including 2%CL, 3%OS, 2%CL-3%OS, and 3%OS-2%CL, were used to stabilize soybean oil-in-water emulsions (oil content 10% (w/w)) at a concentration of 4.5% (w/w) compared to native cassava starch (NCS) and their physical properties and in-vitro gastrointestinal digestion were investigated. The emulsions stabilized with NCS and 2%CL-MCS had larger oil droplet sizes, higher viscosity, and lower negative charge than the emulsions stabilized by single- or dual-MCS with 3%OS. All MCS-stabilized emulsions showed a higher emulsion stability against creaming than the NCS-stabilized emulsion. Under a simulated gastrointestinal tract, all 3%OS-MCS promoted droplet flocculation, while the less ionic NCS and the 2%CL-MCS showed a decrease in droplet size after passing through the mouth and stomach stages. The lipid digestion rate of emulsions stabilized with different MCS and NCS followed the following order: 3%OS >2%CL-3%OS > 3%OS-2%CL > 2%CL > NCS. The NCS- and 2%CL-stabilized emulsions had a lower lipid digestion rate, possibly due to the larger droplet sizes and higher viscosity of the initial emulsions, which delays access of lipase enzymes to lipid droplet surfaces, compared to all 3%OS-MCS-stabilized emulsions.

Structure-activity relationship of Caulerpa lentillifera polysaccharide in inhibiting lipid digestion.

Caulerpa lentillifera polysaccharide (CLP) has been characterized as a sulfated polysaccharide which can effectively inhibit lipid digestion. However, little information was known regarding its inhibitory mechanisms. In the present study, desulfation and degradation were conducted to prepare the derivatives of CLP, and a series of chemical and spectroscopic methods were used to elucidate the structure-activity relationship of CLP on the inhibitory effect of lipid digestion. Results revealed that CLP possessed excellent binding capacities for sodium cholate, sodium glycocholate, and sodium taurocholate. In addition, CLP can effectively inhibit lipase activity by quenching the fluorescence intensity, changing the secondary structure, and decreasing the UV-Vis absorbance. Of note, sulfate groups in CLP took a vital role in inhibiting lipase activity, while the molecular weight of CLP showed a positive correlation with the binding activities of bile acids. Furthermore, adding CLP into the whey protein isolate (WPI) emulsion system also impeded lipid digestion, indicating that CLP can be a potential reduced-fat nutraceutical used in food emulsion systems.

Digestive characteristics of astaxanthin oil in water emulsion stabilized by a casein-caffeic acid-glucose ternary conjugate.

To overcome the barrier of poor oral bioavailability of astaxanthin, a stable oil-in-water emulsion was constructed using casein-caffeic acid-glucose ternary conjugates (CSC) to deliver astaxanthin, and its gastrointestinal behavior was evaluated in vitro with sodium caseinate (CSN) as a control. Results showed that, CSC-stabilized emulsion shower better resistance to the adverse conditions of the gastric environment than CSN-stabilized emulsion, and exhibited lower average particle size and aggregation (4972.33 nm, -5.93 mv) after simulated gastric digestion. Besides, after simulated intestinal digestion, the reducing capacity and astaxanthin transfer efficiency of CSC emulsion into the micellar phase were 686.74 µmol Trolox/100 mL and 26.2 %, which were 2.6 and 4.05-fold higher than that of CSN emulsion. The above results suggest that CSC can be used for better delivery of astaxanthin, which could be useful in designing foods such as functional beverages, pharmaceuticals and nutritional supplements for delivery of lipophilic bioactives.

The digestion fates of lipids with different unsaturated levels in people with different age groups.

The digestion behavior of lipids plays a crucial role in their nutritional bioaccessibility, which subsequently impacts human health. This study aims to investigate potential variations in lipid digestion profiles among individuals of different ages, considering the distinct physiological functions of the gastrointestinal tract in infants, aging populations, and healthy young adults. The digestion fates of high oleic peanut oil (HOPO), sunflower oil (SO), and linseed oil (LINO) were investigated using in vitro digestion models representing infants, adults, and elders. Comparatively, lipid digestion proved to be more comprehensive in adults, leading to free fatty acid (FFA) levels of 64.53%, 62.32%, and 57.90% for HOPO, SO, and LINO, respectively. Besides, infants demonstrated propensity to selectively release FFAs with shorter chain lengths and higher saturation levels during the digestion. In addition, in the gastric phase, particle sizes among the elderly were consistently larger than those observed in infants and adults, despite adults generating approximately 15% FFAs within the stomach. In summary, this study enhances our fundamental comprehension of how lipids with varying degrees of unsaturation undergo digestion in diverse age groups.

Developing an in vitro lipolysis model for real-time analysis of drug concentrations during digestion of lipid-based formulations.

Understanding the effect of digestion on oral lipid-based drug formulations is a critical step in assessing the impact of the digestive process in the intestine on intraluminal drug concentrations. The classical pH-stat in vitro lipolysis technique has traditionally been applied, however, there is a need to explore the establishment of higher throughput small-scale methods. This study explores the use of alternative lipases with the aim of selecting digestion conditions that permit in-line UV detection for the determination of real-time drug concentrations. A range of immobilised and pre-dissolved lipases were assessed for digestion of lipid-based formulations and compared to digestion with the classical source of lipase, porcine pancreatin. Palatase® 20000 L, a purified liquid lipase, displayed comparable digestion kinetics to porcine pancreatin and drug concentration determined during digestion of a fenofibrate lipid-based formulation were similar between methods. In-line UV analysis using the MicroDISS ProfilerTM demonstrated that drug concentration could be monitored during one hour of dispersion and three hours of digestion for both a medium- and long-chain lipid-based formulations with corresponding results to that obtained from the classical lipolysis method. This method offers opportunities exploring the real-time dynamic drug concentration during dispersion and digestion of lipid-based formulations in a small-scale setup avoiding artifacts as a result of extensive sample preparation.

The colloid and interface strategies to inhibit lipid digestion for designing low-calorie food.

Although fat is one of the indispensable components of food flavor, excessive fat consumption could cause obesity, metabolism syndromes and an imbalance in the intestinal flora. In the pursuit of a healthy diet, designing fat reducing foods by inhibiting lipid digestion and calorie intake is a promising strategy. Altering the gastric emptying rates of lipids as well as acting on the lipase by suppressing the enzymatic activity or limiting lipase diffusion via interfacial modulation can effectively decrease lipolysis rates. In this review, we provide a comprehensive overview of colloid-based strategies that can be employed to retard lipid hydrolysis, including pancreatic lipase inhibitors, emulsion-based interfacial modulation and fat substitutes. Plants-/microorganisms-derived lipase inhibitors bind to catalytic active sites and change the enzymatic conformation to inhibit lipase activity. Introducing oil-in-water Pickering emulsions into the food can effectively delay lipolysis via steric hindrance of interfacial particulates. Regulating stability and physical states of emulsions can also affect the rate of hydrolysis by altering the active hydrolysis surface. 3D network structure assembled by fat substitutes with high viscosity can not only slow down the peristole and obstruct the diffusion of lipase to the oil droplets but also impede the transportation of lipolysis products to epithelial cells for adsorption. Their applications in low-calorie bakery, dairy and meat products were also discussed, emphasizing fat intake reduction, structure and flavor retention and potential health benefits. However, further application of these strategies in large-scale food production still requires more optimization on cost and lipid reducing effects. This review provides a comprehensive review on colloidal approaches, design, principles and applications of fat reducing strategies to meet the growing demand for healthier diet and offer practical insights for the low-calorie food industry.

The lipid digestion behavior of oil-in-water emulsions stabilized by different particle-sized insoluble dietary fiber from citrus peel.

In this study, oil-in-water emulsions stabilized by insoluble dietary fibre from citrus peel (CIDF) exhibited an obviously delayed lipid digestion property through gastrointestinal tract (GIT) model. Our results suggested that the rate and extent of lipid digestion greatly relied on particle sizes and concentrations of CIDF, and the inhibition effect of lipolysis was markedly enhanced with decreasing particle sizes and increasing CIDF levels. Furthermore, compared with Tween80-stabilized emulsion, the maximum inhibition extent of lipolysis was 38.77% for CIDF400-stabilized one at 0.4 wt% concentration. Effects of CIDFs on lipid digestion was mainly due to the formation of protective layers around oil droplets, further blocking the entry of lipase to the internal lipids, and/or attributed to the increasing viscosity of emulsions caused by CIDFs, finally limiting the transportation of some substances in the simulated small intestine digestion. Our research would provide useful references for the application of CIDF-stabilized emulsions in low-calorie food.

Pancreatic lipase digestion: The forgotten barrier in oral administration of lipid-based delivery systems?

This review highlights the importance of controlling the digestion process of orally administered lipid-based delivery systems (LBDS) and their performance. Oral LBDS are prone to digestion via pancreatic lipase in the small intestine. Rapid or uncontrolled digestion may cause the loss of delivery system integrity, its structural changes, reduced solubilization capacity and physical stability issues. All these events can lead to uncontrolled drug release from the digested LBDS into the gastrointestinal environment, exposing the incorporated drug to precipitation or degradation by luminal proteases. To prevent this, the digestion rate of orally administered LBDS can be estimated by appropriate choice of the formulation type, excipient combinations and their ratios. In addition, in vitro digestion models like pH-stat are useful tools to evaluate the formulation digestion rate. Controlling digestion can be achieved by conventional lipase inhibitors like orlistat, sterically hindering of lipase adsorption on the delivery system surface with polyethylene glycol (PEG) chains, lipase desorption or saturation of the interface with surfactants as well as formulating LBDS with ester-free excipients. Recent in vivo studies demonstrated that digestion inhibition lead to altered pharmacokinetic profiles, where Cmax and Tmax were reduced in spite of same AUC compared to control or even improved oral bioavailability.