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.