An overview of structure engineering to tailor the functionality of monoglyceride oleogels.

Monoglyceride (MG)-based oleogelation is an effective strategy to create soft matter structures with the functionality of fats, but with a nutritional profile similar to edible oils. MG oleogels are mainly studied to replace or reduce trans and saturated fats as well as to develop novel products with improved physical and organoleptic properties. The process consists of direct dispersion of MGs into the oil at temperatures above the melting point. This is followed by a cooling period in which the gelator network is formed, entrapping the oil in a crystalline structure. MG composition and concentration, oil type, process temperatures, stirring speed, shear rate during cooling, and storage time play a role in the kinetics of MG crystallization within an MG-oil system, which leads to the formation of lipid materials with different properties. A deep understanding of MG oleogelation processing parameters allows for the tailoring of oleogel properties to meet desirable characteristics as solid fat replacers. This review provides insight regarding manipulating physical process parameters to engineer structures with specific functionality. Furthermore, ultrasound technologies and optimization methodologies are discussed as tools for the production of oleogels with specific properties based on their potential use as well as the development of bi- and multi-gelators oleogels using MGs. Finally, the food applications in which MG oleogels have been tested are summarized in addition to the identified gaps that require further research.

Preparation of highly stable oleogel-based nanoemulsions for encapsulation and controlled release of curcumin.

Oleogels have been proposed as suitable systems for the encapsulation and delivery of lipophilic bioactive compounds. This work aimed to produce stable nanoemulsions of gelled-oil particles using monoglyceride (MG) oleogels loaded with curcumin. High-speed homogenization followed by ultrasonication was used for obtaining colloidal dispersions. The effects of ultrasonication processing parameters and formulation were evaluated to optimize particle size, polydispersity index (PDI), and stability during storage. All sonication parameters had a significant effect on particle size and PDI. A Pluronic F-68 + Tween 80 surfactant mixture with the lowest oleogel/aqueous phase ratio (5/95) produced nanoemulsions which were at least 10-month stable. The nanoemulsions showed a higher encapsulation efficiency than the sample without the gelator (73.85-91.05% vs. 56.99%). Furthermore, it was corroborated that structuring oil particles with MG crystals produces a matrix that entraps curcumin molecules and slows down their release. These findings provide useful information for the development of new nutraceutical products.

Monoglyceride oleogels as fat replacers in filling creams for sandwich cookies.

BACKGROUND: Many food products need to be reformulated to reduce the intake of saturated and trans fats which are considered unhealthy. In particular, the reformulation of filling creams (FCs) is challenging as these fats cannot be directly replaced with liquid oil without affecting the final product properties. This research studied the formulation and characterization of FCs for sandwich cookies using monoglyceride oleogel as fat material. RESULTS: FC formulated with 260 g kg-1 oleogel showed viscoelastic moduli values that did not differ significantly from those measured in a filling cream of commercial sandwich cookies (FC-CSCs) used as reference. The oil binding capacity of the FCs decreased with the increase of oleogel content. The increase of the oleogel amount in the formulation produced a decrease in hardness but an increase in adhesiveness and cohesiveness. Hardness, adhesiveness, and cohesiveness ranged from 0.66 to 3.48 N, 0.44 to 0.86 N s, and 0.07 to 0.29, respectively. When FCs were used for assembling cookies into sandwiches, an oil loss of about 9 g kg-1 FC after 21 days of storage was found in FCs containing 220 and 260 g kg-1 oleogel. The nutritional improvement due to the use of oleogel in FCs led to a reduction in saturated fatty acids between 64.5% and 35.2% and from 1.0 to 0.0% trans fatty acids in comparison with FC-CSC. CONCLUSION: Full fat replacement with monoglyceride oleogel in FC formulations allows the obtention of products with good quality and some similar characteristics to those obtained for FC-CSC, with the added benefit of a healthier nutritional profile. © 2020 Society of Chemical Industry.

A process parameters dataset for the extrusion 3D printing of nutraceutical oral dosage forms formulated with monoglycerides oleogels and phytosterols mixtures.

We report the parameter settings used in different 3D printing tests carried out to evaluate the production of nutraceutical oral forms by using mixtures of monoglycerides oleogels and phytosterols as printing materials. The printer employed was an ad-hoc extrusion 3D printing system adapted from a Prusa printer. The dataset here informed would serve as a starting point for the implementation of the 3D printing process to fabricate products using oleogels or printing materials with similar characteristics. This data is related to our recent research article entitled "Extrusion 3D printing of nutraceutical oral dosage forms formulated with monoglycerides oleogels and phytosterols mixtures" [1].

Extrusion 3D printing of nutraceutical oral dosage forms formulated with monoglycerides oleogels and phytosterols mixtures.

Among the potential applications of 3D printing, the development of products with personalized characteristics in the area of food and nutraceuticals represents an important field that must still be explored. The aim of this work was to evaluate the production of nutraceutical oral forms by extrusion-based 3D printing (E3DP) using mixtures of monoglycerides (MG) oleogels and phytosterols (PS) as printing materials. These materials were obtained using MG (10 or 20%wt), high oleic sunflower oil, and variable amounts of PS (20-50%wt PS/oleogel). An ad-hoc extrusion 3D printer composed of a heated syringe and a cooling build platform was used. Rheological tests were carried out to determine the mixtures gel point, in order to select appropriate printing temperatures, as well as the yield stress of the final materials. Hardness of printed forms was obtained by compression tests. Additionally, oral forms were produced by manual extrusion using molds for comparison. It was found that oral forms were successfully printed when using mixtures containing a maximum of 30 and 40%wt PS/oleogel for oleogels formulated with 10 and 20%wt of MG, respectively. Moreover, the best printed forms corresponded to the mixtures with the lowest gelation temperatures. These printed forms were structurally stable, with uniform weight and shape, and maximum hardness of 12.55 N. Hardness values of printed oral forms did not show a correlation with those obtained by manual extrusion using molds, indicating that this parameter was affected by solid composition, cooling rate, and the fragility generated for layers superposition. In conclusion, it was demonstrated that mixtures of MG oleogels and PS can be used for E3DP production of nutraceutical oral forms suggesting that oleogels have excellent potential as materials able to incorporate liposoluble active ingredients to be used as extrusion printing materials.

Physical Properties of Monoglycerides Oleogels Modified by Concentration, Cooling Rate, and High-Intensity Ultrasound.

The aim of this study was to investigate the effects of monoglycerides (MG) concentration (3, 4.5, and 6 wt%), cooling rate (0.1 and 10 °C/min), and high-intensity ultrasound (HIU) application on physical properties of oleogels from MG and high oleic sunflower oil. Microstructure, melting profile, elasticity (G'), and solid fat content (SFC) were measured immediately after preparation of samples (t = 0) and after 24 hr of storage at 25 °C. Samples' textural properties (hardness, adhesiveness, and cohesiveness) and oil binding capacity (OBC) were evaluated after 24 hr at 25 °C. In general, samples became less elastic over time. Slow cooling rate resulted in lower G' after 24 hr compared to the ones obtained using 10 °C/min. Network OBC was improved by increasing MG concentration and cooling rate, and by applying HIU. After storage, oleogel melting enthalpy increased with MG concentration. In general, this behavior was not correlated with an increase in SFC. An improvement in the network structure was generally reached with the increase in cooling rate, according to texture and rheology results, for both sonicated and nonsonicated conditions. At the highest MG concentration, HIU application was more efficient at increasing OBC and hardness of the network at 0.1 °C/min. Microscopy images showed that the oleogels microstructure was changed as a consequence of HIU application and cooling rate, evidencing smaller crystals both in sonicated and faster cooled samples. Obtained results demonstrate that cooling rate, MG concentration, and HIU can be used satisfactorily to tailor physical properties of MG oleogels. PRACTICAL APPLICATION: Oleogels have been studied in the last years as semisolid fat replacers in food products. Cooling rate is an important processing parameter in the oleogel preparation because it affects their final physical properties, while high-intensity ultrasound (HIU) is a relatively novel technique to tailor lipid properties. This study is focused on the application of a slow/fast cooling rate in combination with/without HIU treatment at different monoglycerides and high oleic sunflower oil mixtures as a successful strategy to obtain oleogels with different physical properties and with potential applications in the food industry, such as fat substitutes in bakery.

Muffins Elaborated with Optimized Monoglycerides Oleogels: From Solid Fat Replacer Obtention to Product Quality Evaluation.

This study demonstrates the effectiveness of using oleogels from high oleic sunflower oil (HOSO) and monoglycerides as solid fat replacers in a sweet bakery product. Firstly, a methodology to obtain oleogels with desired properties based on mathematical models able to describe relationships between process and product characteristics variables followed by multi-objective optimization was applied. Later, muffins were prepared with the optimized oleogels and their physicochemical and textural properties were compared with those of muffins formulated using a commercial margarine (Control) or only HOSO. Furthermore, the amount of oil released from muffins over time (1, 7, and 10 days) was measured to evaluate their stability. The replacement of commercial margarine with the optimized oleogels in muffin formulation led to the obtention of products with greater spreadability, higher specific volume, similar hardness values, and a more connected and homogeneous crumb structure. Moreover, these products showed a reduction of oil migration of around 50% in contrast to the Control muffins after 10 days of storage, which indicated that the optimized oleogels can be used satisfactorily to decrease oil loss in this sweet baked product. Fat replacement with the optimized monoglycerides oleogels not only had a positive impact on the quality of the muffins, but also allowed to improve their nutritional profile (without trans fat and low in saturated fat). PRACTICAL APPLICATION: The food industry demands new ways to reduce the use of saturated and trans fats in food formulations. To contribute to this search, oleogels from high oleic sunflower oil and saturated monoglycerides were prepared under optimized conditions in order to obtain a product with similar functionality to margarine, and its potential application as a semisolid fat ingredient in muffins was evaluated. Muffins formulated with oleogels showed an improved quality compare with those obtained using a commercial margarine with the added benefit of a healthier nutritional profile.