Formation of semi-solid lipid phases by aggregation of protein microspheres in water-in-oil emulsions

Research progress of water-in-oil emulsion gelated with internal aqueous phase: gel factors, gel mechanism, application fields, and future direction of development

The W/O emulsion is a promising system. Its special structure can keep the sensory properties of fat while reducing the fat content. Improving the stability and physical properties of W/O emulsions is generally oriented toward outer oil-phase modified oil gels and inner water-phase modified inner hydrogels. In this paper, the research progress of internal aqueous gel was reviewed, and some gel factors suitable for internal aqueous gel and the gel mechanism of main gel factors were discussed. The advantages of this internal aqueous gel emulsion system allow its use in the field of fat substitutes and encapsulating substances. Finally, some shortcomings and possible research directions in the future were proposed, which would provide a theoretical basis for the further development of internal water-phase gelled W/O emulsion in the future.

Study on stability of grape seed oil/rice hydrolyzed protein emulsion

In this study, the stability mechanism of grape seed oil/rice hydrolyzed protein emulsion was studied. The grape seed oil (10% v/v) and rice hydrolyzed protein (2% w/v) were homogenized under high pressure to prepare the emulsion. It was observed by CLSM and Multiple light scatterometer that the emulsion had long-term storage stability, and the average particle size of droplets was 0.984–1.363 µm. ζ-potential ranged from −37.733 mV to −25.633 mV. It is found that the emulsion has strong resistance to temperature, ions and other environmental factors from the macroscopic and microscopic structure, and no emulsion stratification phenomenon occurs. The composite emulsion can be used in the field of food industry and fine chemical industry, which can provide nutrition and functionality of products, its research has certain value and has a wide space for development.

Whey Proteins as a Potential Co-Surfactant with Aesculus hippocastanum L. as a Stabilizer in Nanoemulsions Derived from Hempseed Oil

The use of natural surfactants including plant extracts, plant hydrocolloids and proteins in nanoemulsion systems has received commercial interest due to demonstrated safety of use and potential health benefits of plant products. In this study, a whey protein isolate (WPI) from a byproduct of cheese production was used to stabilize a nanoemulsion formulation that contained hempseed oil and the Aesculus hippocastanum L. extract (AHE). A Box-Behnken experimental design was used to set the formulation criteria and the optimal nanoemulsion conditions, used subsequently in follow-up experiments that measured specifically emulsion droplet size distribution, stability tests and visual quality. Regression analysis showed that the concentration of HSO and the interaction between HSO and the WPI were the most significant factors affecting the emulsion polydispersity index and droplet size (nm) (p < 0.05). Rheological tests, Fourier transform infrared spectroscopy (FTIR) analysis and L*a*b* color parameters were also taken to characterize the physicochemical properties of the emulsions. Emulsion systems with a higher concentration of the AHE had a potential metabolic activity up to 84% in a microbiological assay. It can be concluded from our results that the nanoemulsion system described herein is a safe and stable formulation with potential biological activity and health benefits that complement its use in the food industry.

Recent advances on food-grade water-in-oil emulsions: Instability mechanism, fabrication, characterization, application, and research trends

Owing to their promising application prospects, water-in-oil (W/O) emulsions have aroused continuous attention in recent years. However, long-term stability of W/O emulsions remains a particularly challenging problem in colloid science. With the increasing demand of consumers for natural, green, and healthy foods, the heavy reliance on chemically synthesized surfactants to achieve long-term stability has become the key technical defect restricting the application of W/O emulsions in food. To design and manufacture W/O emulsions with long-term stability and clean label, a comprehensive understanding of the fundamentals of the W/O emulsion system is required. This review aims to demystify the field of W/O emulsions and update its current research progress. We first provide a summary on the essential basic knowledge regarding the instability mechanisms, including physical and chemical instability in W/O emulsions. Then, the formulation of the W/O emulsion system is introduced, particularly focusing on the use of natural stabilizers. Besides, the characterization and application of W/O emulsions are also discussed. Finally, we propose promising research trends, including (1) developing W/O high internal phase emulsions (HIPEs) as fat mimetic and substitute, (2) promising formulation routine for long-term stable double emulsions, and (3) searching for novel plant-derived stabilizers of W/O emulsions.

Effect of Water Content and Pectin on the Viscoelastic Improvement of Water-in-Canola Oil Emulsions

This study aimed to investigate gelation in glycerol monooleate (GMO)-stabilized water-in-canola oil (W/CO) emulsions by increasing water content (20–50 wt.%) and the addition of low methoxyl pectin (LMP) in the aqueous phase. A constant ratio of GMO to water was used to keep a similar droplet size in all emulsions. Hydrogenated soybean oil (7 wt.%) was used to provide network stabilization in the continuous phase. All fresh emulsions with LMP in the aqueous phase formed a stable and self-supported matrix with higher viscosity and gel strength than emulsions without LMP. Emulsion viscosity and gel strength increased with an increase in water content. All emulsions showed gel-like properties (storage moduli (G’) > loss moduli (G’’)) related to the presence of LMP in the aqueous phase and increased water content. Freeze/thaw analysis using a differential scanning calorimeter showed improved stability of the water droplets in the presence of LMP in the aqueous phase. This study demonstrated the presence of LMP in the aqueous phase, its interaction with GMO at the interface, and fat crystals in the continuous phase that could support the water droplets’ aggregation to obtain stable elastic W/CO emulsions that could be used as low-fat table spreads.

Protein microspheres as structuring agents in lipids: potential for reduction of total and saturated fat in food products

Excess consumption of total and saturated fats is linked to the development of chronic diseases, such as obesity, heart disease, diabetes, and cancer. There is therefore considerable interest in the development of foods containing lower levels of total and saturated fats, but that still have the same desirable physicochemical and sensory characteristics as the original foods. Solid fats normally contribute a number of key functional attributes to foods due to their ability to form crystalline networks that alter texture (such as elasticity, plasticity, and spreadability) and appearance (such as opacity and creaminess). The aim of this review is to provide an overview and to discuss the potential applications of food proteins as fat structuring agents that may be able to offer some of the desirable attributes normally supplied by saturated and trans fats. Previous studies have shown that globular proteins (such as whey proteins) trapped inside water-in-oil emulsions form protein microspheres when they are thermally denatured, which leads to the creation of highly viscous or solid-like lipid phases, having higher rheological properties. These protein microspheres may therefore be useful for the development of reduced fat margarines and spreads with reduced level of saturated/trans-fat contents. © 2020 Society of Chemical Industry.

Tea from the Food Science Perspective: An Overview

Tea (Camelia sinensis L.) is one of the main beverages known and consumed all around the world. Quality of tea is not only linked to the raw material but also to the processing steps that influence on the biochemical and sensory characteristics of each type of tea. This overview is focused on the differences in the production and composition of the main types of teas present in the market, highlighting not only their chemical and sensory characteristics, but also the importance of this plant from the food science viewpoint related to its several applications.