Flexible control of bigel microstructure for enhanced stability and flavor release during oral consumption

Recent advances in nutraceutical delivery systems constructed by protein-polysaccharide complexes: A systematic review

Most nutraceuticals have low stability and solubility, making it difficult to achieve ideal bioavailability by directly incorporating into food. Therefore, constructing delivery systems to protect nutraceuticals is an essential strategy. Proteins and polysaccharides have become ideal materials for encapsulating nutraceuticals due to their superior nutritional value, edible safety, and physicochemical properties. This review first introduces the binding methods of protein-polysaccharide complexes and analyzes their respective merits, defects, and applications. Then, various protein-polysaccharide complex-based nutraceutical delivery systems are systematically summarized, including emulsions, gels, nanoparticles, microcapsules, complexes, and films, which can improve the stability, encapsulation efficiency, and bioaccessibility of nutraceuticals. In addition to traditional globular proteins mentioned in previous reviews, this review also introduces the advantages of another morphology of proteins (protein fibrils with linear structure) in the formation of protein-polysaccharide complexes and the construction of nutraceutical delivery systems. Next, the affecting factors are analyzed to achieve the precise control of protein-polysaccharide complex-based nutraceutical delivery systems. To improve public acceptability of protein-polysaccharide complex-based nutraceutical delivery systems, the safety and regulatory aspects are also discussed in detail. Moreover, the applications of such delivery systems are presented, including dietary supplements, food ingredients, food packaging, and food detection. Finally, several promising research directions that had not been provided before are innovatively proposed, including cell-cultured meat scaffolds, plant-based meat analogs, three-dimensional printing inks, and "three reductions" foods. Overall, this review provides guidance for designing protein-polysaccharide complex-based nutraceutical delivery systems with customized nutrition and superior bioavailability.

Development and characterisation of a novel bigel based on pea protein hydrogel and rice bran wax oleogel: Enhancement of rheological properties and freeze-thaw stability

In this study, a novel pea protein (PP)-based bigel was developed, featuring a high internal phase emulsion. The impact of gelling agent concentration on the gel properties and freeze-thaw stability of the bigel was investigated. The bigel was comprised of two distinct gel phases: an aqueous-phase gel with a covalent network formed by PP and transglutaminase (TGase), and an oil-phase gel with a crystal network structure of rice bran wax (RBW). Microstructural analysis revealed a bi-continuous network structure in the bigel, with network density increasing as TGase and RBW concentrations rose. Rheological analysis showed that storage modulus (G'), apparent viscosity, and structural recovery of the bigel increased with higher TGase and RBW concentrations. Temperature scanning experiments confirmed that the bigel maintained its elastic solid behavior even at elevated temperatures. Optimal sensory properties and low coefficient of friction were achieved at 0.4 % TGase and 7 % RBW concentrations. Additionally, the bigel exhibited notable freeze-thaw stability at TGase and RBW concentrations exceeding 0.2 % and 5 %, respectively. These findings highlight the excellent gelation properties and stability of the PP-RBW-based bigel, suggesting its potential as a fat substitute in the food industry.

Novel bigel based on nanocellulose hydrogel and monoglyceride oleogel: Preparation, characteristics and application as fat substitute

In the present study, bigels containing nanocellulose hydrogel and monoglyceride oleogel were prepared as a novel fat substitute. The nanocellulose was derived from chestnut shells via TEMPO oxidation, resulting a yield of 59.6 %. The impact of varying the oleogel/hydrogel ratio on the macroscopic and microscopic structures, chemical interactions, and the textural, thermal and rheological properties of the bigels was explored. As the hydrogel content increased from 20 % to 50 %, the average droplet diameter in the bigels increased. The bigels transitioned from a water-in-oil structure to a bi-continuous structure, and the textural hardness, cohesiveness, and rheological properties improved significantly. Shortbread cookies were prepared by incorporating different proportions of the bigels to replace animal butter as shortening, and the color, spreadability, hardness and baking loss rate of cookies were analyzed. The result showed that replacing butter with bigels in cookie preparation could reduce fat content without significantly altering the appearance or properties of the cookies. These prepared bigel have the potential to serve as a healthy and sustainable solid fat substitute in the food industry.

Food-Grade Bigel Systems: Formulation, Characterization, and Applications for Novel Food Product Development

Bigels are characterized as biphasic systems consisting of two structured phases of different polarity, namely the oleogel and hydrogel phases. These systems have been widely used in pharmaceuticals and cosmetics, owing to their enhanced physicochemical stability compared to other structured systems and their ability to simultaneously deliver both hydrophilic and lipophilic compounds. Considering the above advantages, bigels could have considerable potential for the food industry. This review aims to provide a detailed description of the edible components used for structuring the oleogel and hydrogel phases and the preparation methods applied for the formation of food-grade bigels with application-specific tailored properties. The impact of the processing parameters, such as the oleogel-to-hydrogel ratio, methodology used for component mixing, and cooling rates, is presented. Moreover, the most applicable bigel characterization techniques, such as rheology, DSC, texture analysis, etc., are critically discussed. Finally, different bigel applications in foods as animal fat substitutes or as complex delivery systems for both polar and non-polar bioactive compounds are examined.

Hydrogel delivery systems of functional substances for precision nutrition

Hydrogel delivery systems based on polysaccharides and proteins have the ability to protect functional substances from chemical degradation, control/target release, and increase bioavailability. This chapter summarizes the recent progress in the utilization of hydrogel delivery systems for nutritional interventions. Various hydrogel delivery systems as well as their preparation, structure, and properties are given. The applications for the encapsulation, protection, and controlled delivery of functional substances are described. We also discuss their potential and challenges in managing chronic diseases such as inflammatory bowel disease, obesity, liver disease, and cancer, aiming at providing theoretical references for exploring novel hydrogel delivery systems and their practical prospects in precise nutritional interventions.

Novel Pickering bigels stabilized by whey protein microgels: Interfacial properties, oral sensation and gastrointestinal digestive profiles

In the ongoing quest to formulate sensory-rich, low-fat products that maintain structural integrity, this work investigated the potential of bigels, especially those created using innovative Pickering techniques. By harnessing the unique properties of whey protein isolate (WPI) and whey protein microgel (WPM) as interfacial stabilizers, WPM-based Pickering bigels exhibited a remarkable particle localization at the interface due to specific intermolecular interactions. The rise in protein concentration not only intensified particle coverage and interface stabilization but also amplified attributes like storage modulus, yield stress, and adhesiveness, owing to enhanced intermolecular forces and a compact gel matrix. Impressively, WPM-based Pickering bigels outshone in practical applications, showcasing exceptional oil retention during freeze-thaw cycles and extended flavor release-a promising indication for frozen food product applications. Furthermore, these bigels underwent a sensory evolution from a lubricious texture at lower concentrations to a stable plateau at higher ones, offering an enriched consumer experience. In a comparative digestibility assessment, WPM-based Pickering bigels demonstrated superior prowess in decelerating the release of free fatty acids, indicating slowed lipid digestion. This study demonstrates the potential to fine-tune oral sensations and digestive profiles in bigels by modulating Pickering particle concentrations.

Effect of the gelling mechanism on the physical properties of bigels based on whey protein isolate

The effect of the cold-set and heat-set gelling mechanism of whey protein isolate on bigel production was assessed. For this purpose, hydrogel phase was produced with whey protein isolated (10 % w/v) and for oleogel sunflower oil and glycerol monostearate (7.5 % w/v) were used. Bigels were produced by hot emulsification of different hydrogel:oleogel ratios (from 90:10 up to 10:90). For cold-set bigels (CSB) NaCl (200 mM) was added to the aqueous phase prior to the emulsification and the emulsion was cooled to promote the 3D network formation. On the other hand, heat-set bigels (HSB) were produced by heating the emulsion (80 °C, 60 min). Bigels were evaluated through microscopy, FTIR, thermal and texture analyzes. Results showed that depending on the hydrogel:oleogel ratio and gelling mechanism different structures organization were obtained. CSB were more organized, showing that the rate of gelation was the mechanism responsible for the structure. However, for HSB the heat treatment destabilized the emulsion and disorganized structures were observed for high oleogel content. FTIR corroborates the visual observation and showed that the arrangement was purely physical. In addition, the structural arrangement led to different mechanical properties. In general, HSB produced gels with rubber-like behavior, higher elasticity modulus and the presence of a breaking point. In contrast, CSB behaves as squeezing gel, with no breaking point and lower values of elasticity modulus. Moreover, for O/W bigels the dispersed oleogel particles disrupted the WPI network decreasing the gel strength in comparison to pure hydrogels. However, for systems where oleogel was the continuous phase, the gel strength was recovered due to the metastable and dynamic character of these systems. Thus, results showed that the gelling mechanism of the protein exerted an effect on the physical properties of bigels. In addition, the mechanical properties also can be modulated according to the bigel composition, allowing its application in products with different sensorial characteristics.