Improvement of O/W emulsion performance by adjusting the interaction between gelatin and bacterial cellulose nanofibrils

Applications of bacterial cellulose in the food industry and its health-promoting potential

Bacterial cellulose (BC) is a naturally occurring biomaterial with a wide range of potential applications in the food industry because of its exceptional mechanical qualities, unique nanofiber structure, high purity, and outstanding biocompatibility. Beyond its physical attributes, BC has gained interest recently due to research demonstrating its potential health benefits as a functional food ingredient. This article examines the many uses of BC in the food business, with a focus on how it may enhance food texture, operate as a bioactive carrier, and have promise in the packaging sector. Further research was done on the health-promoting properties of BC in functional foods, particularly with regard to its functions as a blood glucose regulator, and gastrointestinal health. This review seeks to bring fresh ideas for the study of bioactive components in the food industry by providing a summary of the existing research and demonstrating the possible role of BC in food. It also suggests future paths for research.

Study on the stability, functional activity and preservation effect of oregano essential oil Pickering emulsion with different proportions of chicken bone gelatin/bacterial cellulose during storage

In this study, chicken bone gelatin (CBG) was extracted as a new substitute for traditional pig bone gelatin, and bacterial cellulose (BC) was used as the compound to prepare Oregano essential oil (OEO) Pickering emulsion. To explore a protein/polysaccharide emulsion system that can effectively prolong the functional activity of OEO during storage. The results indicated that the variation in CBG and BC content significantly influenced the physicochemical properties of the emulsions. The optimal formulation of OEO Pickering emulsion, prepared with a CBG-BC ratio of 6:2 (v/v), exhibited superior characteristics including appearance, encapsulation efficiency, and stability during preservation. After 7 d of storage at 4 °C, the rheological properties remained stable, with no significant differences observed in antioxidant and antibacterial activities. It was verified in the beef fresh-keeping experiment that the shelf life of beef samples in the 6-2-2 treatment group was 6 d longer than that in the control group and 3 d longer than that in the pure OEO group. This experiment enhanced the utilization of poultry by-products and provided a valuable reference for exploring suitable protein-polysaccharide systems embedding active substances for food preservation.

Enhancement of Pickering effect of ovalbumin with bacterial cellulose nanofibers prepared by electron beam irradiation and encapsulation of curcumin

In this study, the enhancement of Pickering effect of ovalbumin (OVA) with bacterial cellulose nanofibers (BCNFs) prepared by electron beam irradiation was investigated and the environmental stability of oil-in-water Pickering emulsions stabilized by OVA/BCNFs complexes was explored by varying ratios of OVA/BCNFS (1:0.2, 1:0.4, 1:0.6, 1:0.8, 1:1) and oil phase concentrations (10 %, 20 %, 30 %, 40 %, 50 %, 60 %). Droplet sizes of Pickering emulsions were decreased with the increase of the proportion of BCNFs, while the viscosity and storage modulus (G') of Pickering emulsions were increased. The gel strength of Pickering emulsions was positively correlated with the oil phase content. Pickering emulsions stabilized by OVA/BCNFs complexes were endowed excellent environmental stability under varying pH, ionic strength, and thermal conditions. Moreover, after encapsulating curcumin in Pickering emulsions, the retention rates of curcumin were improved significantly during room temperature, UV light, and thermal treatment. The present study would contribute to the advancement of novel protein/polysaccharide stabilizers and offer novel insight for investigating the stability of Pickering emulsions and delivering lipophilic bioactive compounds.

Advances of protein-based emulsion gels as fat analogues: Systematic classification, formation mechanism, and food application

Fat plays a pivotal role in the appearance, flavor, texture, and palatability of food. However, excessive fat consumption poses a significant risk for chronic ailments such as obesity, hypercholesterolemia, and cardiovascular disease. Therefore, the development of green, healthy, and stable protein-based emulsion gel as an alternative to traditional fats represents a novel approach to designing low-fat food. This paper reviews the emulsification behavior of proteins from different sources to gain a comprehensive understanding of their potential in the development of emulsion gels with fat-analog properties. It further investigates the emulsifying potential of protein combined with diverse substances. Then, the mechanisms of protein-stabilized emulsion gels with fat-analog properties are discussed, mainly involving single proteins, proteins-polysaccharides, as well as proteins-polyphenols. Moreover, the potential applications of protein emulsion gels as fat analogues in the food industry are also encompassed. By combining natural proteins with other components such as polysaccharides, polyphenols, or biopolymers, it is possible to enhance the stability of the emulsion gels and improve its fat-analog texture properties. In addition to their advantages in protecting oil oxidation, limiting hydrogenated oil intake, and delivering bioactive substances, protein-based emulsion gels have potential in food 3D printing and the development of specialty fats for plant-based meat.

Emulsification properties of ovalbumin-fucoidan (OVA-FUC) binary complexes

The poor thermal stability and emulsifying properties of ovalbumin (OVA) limit its functional performance, but these limitations may be overcome by forming binary complexes. We prepared binary complexes of OVA and fucoidan (FUC) through electrostatic self-assembly and investigated the emulsifying properties of the complex by measuring the particle size, interfacial membrane thickness, zeta potential, and stability of the emulsion prepared with camellia oil and the complex. The OVA-FUC emulsions have a thicker interfacial membrane, lower mobility, higher viscosity, and better stability compared with the OVA emulsions. The emulsion prepared with 1.5 % OVA-FUC remained stable and homogeneous during storage. They tended to become unstable with freeze-thaw, but the oil encapsulated did not leak after coalescence occurred. With the addition of Ca2+, the OVA-FUC emulsion will be converted into a gel state. These findings indicate that OVA-FUC binary complexes can be used to prepare high-performance emulsions with great potential for development.

Gelatin-nanocellulose stabilized emulsion-filled hydrogel beads loaded with curcumin: Preparation, encapsulation and release behavior

In this study, the curcumin was firstly encapsulated in gelatin (GLT) and/or cellulose nanocrystals (CNC) stabilized emulsions, then further mixed with sodium alginate (SA) to form emulsion-filled hydrogel beads loaded with curcumin (Cur). The Cur-loaded emulsions showed a droplet size of 20.3-24.4 μm with a uniform distribution. Introducing CNC and/or SA increased the viscosity of emulsions accompanied by viscoelastic transition, while the modulus was reduced due to destruction of GLT gel. Cur was doubly immobilized in the hydrogel beads with >90 % of encapsulation efficiency. The results of simulated gastrointestinal tract experiments revealed that the beads possessed a good pH sensitivity and controlled release behavior to prolong the retention of Cur in the gastrointestinal tract. After 6 h of UV irradiation, the Cur-loaded emulsion-filled hydrogel beads showed a higher antioxidant activity than that of pure Cur, effectively delaying the photodegradation of Cur. In addition, the beads had better stability in aqueous and acidic environments, which was favorable for prolonging the release of Cur. These results suggest that the emulsion-filled hydrogel beads have great potential for the delivery of lipophilic bioactive molecules.

Gelatin/carboxymethyl chitosan/aloe juice hydrogels with skin-like endurance and quick recovery: Preparation, characterization, and properties

Gelatin-based hydrogels have gained considerable attention due to their resemblance to the extracellular matrix and hydrophilic three-dimensional network structure. Apart from providing an air-permeable and moist environment, these hydrogels optimize the inflammatory microenvironment of the wounds. These properties make gelatin-based hydrogels highly competitive in the field of wound dressings. In this study, a series of composite hydrogels were prepared using gelatin (Gel) and carboxymethyl chitosan (CMCh) as primary materials, glutaraldehyde as a crosslinker, and aloe vera juice as an anti-inflammatory component. The properties of the hydrogel, including its rheological properties, microscopic structures, mechanical properties, swelling ratios, thermal stability, antibacterial properties, and biocompatibility, were investigated. The results demonstrate that the gelatin-based hydrogels exhibit good elasticity and rapid self-healing ability. The hydrogels exhibited slight shear behavior, which is advantageous for skin care applications. Furthermore, the inclusion of aloe vera juice into the hydrogel resulted in a dense structure, improved mechanical properties and enhanced swelling ratio. The Gel/CMCh/Aloe hydrogels tolerate a compressive strength similar to that of human skin. Moreover, the hydrogels displayed excellent cytocompatibility with HFF-1 cells, and exhibited antibacterial activity against E. coli and S. aureus. Lomefloxacin was used as a model drug to study the releasing behavior of the Gel/CMCh/aloe hydrogels. The results showed that the drug was released rapidly at the initial stage, and could continue to be released for 12 h, the maximum releasing rate exceeded 20 %. These findings suggest that the gelatin-based hydrogels hold great promise as effective wound dressings.

Noncovalent interactions between biomolecules facilitated their application in food emulsions' construction: A review

The use of biomolecules, such as proteins, polysaccharides, saponins, and phospholipids, instead of synthetic emulsifiers in food emulsion creation has generated significant interest among food scientists due to their advantages of being nontoxic, harmless, edible, and biocompatible. However, using a single biomolecule may not always meet practical needs for food emulsion applications. Therefore, biomolecules often require modification to achieve ideal interfacial properties. Among them, noncovalent interactions between biomolecules represent a promising physical modification method to modulate their interfacial properties without causing the health risks associated with forming new chemical bonds. Electrostatic interactions, hydrophobic interactions, and hydrogen bonding are examples of noncovalent interactions that facilitate biomolecules' effective applications in food emulsions. These interactions positively impact the physical stability, oxidative stability, digestibility, delivery characteristics, response sensitivity, and printability of biomolecule-based food emulsions. Nevertheless, using noncovalent interactions between biomolecules to facilitate their application in food emulsions still has limitations that need further improvement. This review introduced common biomolecule emulsifiers, the promotion effect of noncovalent interactions between biomolecules on the construction of emulsions with different biomolecules, their positive impact on the performance of emulsions, as well as their limitations and prospects in the construction of biomolecule-based emulsions. In conclusion, the future design and development of food emulsions will increasingly rely on noncovalent interactions between biomolecules. However, further improvements are necessary to fully exploit these interactions for constructing biomolecule-based emulsions.

Effect of oil phases on the stability of myofibrillar protein microgel particles stabilized Pickering emulsions: The leading role of viscosity

The Pickering emulsion may be restricted in the foods owing to the unreasonable use of oils. Herein, the effect of different oil phases on the stability of myofibrillar protein microgel particles stabilized Pickering emulsions was investigated. Results showed sunflower oil Pickering emulsions with high stability have the smallest droplet size (-26.17 μm). While peanut oil Pickering emulsions have the largest droplet size (-77.00 μm) and poor emulsion stability. The fatty acid analysis showed sunflower oil had low content of saturated (15.68 %) and super-long-chain (0) fatty acids, while peanut oil had high content of saturated (23.67 %) and super-long-chain (9.02 %) fatty acids, leading to a difference in viscosity. Low viscosity was more conducive to dispersing oil droplets and inhibiting the floating and gathering of droplets, thus enhancing the emulsion stability. Therefore, the oil with low content of super-long-chain and saturated fatty acids could be suitable for preparing MMP Pickering emulsions.

Bacterial Cellulose Nanofibril-Based Pickering Emulsions: Recent Trends and Applications in the Food Industry

The Pickering emulsion stabilized by food-grade colloidal particles has developed rapidly in recent decades and attracts extensive attention for potential applications in the food industry. Bacterial cellulose nanofibrils (BCNFs), as green and sustainable colloidal nanoparticles derived from bacterial cellulose, have various advantages for Pickering emulsion stabilization and applications due to their unique properties, such as good amphiphilicity, a nanoscale fibrous network, a high aspect ratio, low toxicity, excellent biocompatibility, and sustainability. This review provides a comprehensive overview of the recent advances in the Pickering emulsion stabilized by BCNF particles, including the classification, preparation method, and physicochemical properties of diverse BCNF-based particles as Pickering stabilizers, as well as surface modifications with other substances to improve their emulsifying performance and functionality. Additionally, this paper highlights the stabilization mechanisms and provides potential food applications of BCNF-based Pickering emulsions, such as nutrient encapsulation and delivery, edible coatings and films, fat substitutes, etc. Furthermore, the safety issues and future challenges for the development and food-related applications of BCNFs-based Pickering emulsions are also outlined. This work will provide new insights and more ideas on the development and application of nanofibril-based Pickering emulsions for researchers.