Microstructural Analysis of Whey/Soy Protein Isolate Mixed Gels Using Confocal Raman Microscopy

Protein-Protein Interactions and Structure of Heat-Set Gels Based on Pea Protein and Egg White Mixtures

The substitution of animal proteins with plant-based ones to fit environmental and economic demands is a challenge in gel applications. This study examined the thermal elation of mixtures of pea protein isolate (PPI) and egg white proteins (EWPs) at different PPI/EWP weight ratios (100/0, 75/25, 50/50, 25/75, 0/100) at pH 7.5 and 9.0. Viscoelastic and texture properties of the composite gels, along with the microstructure and molecular interactions involved in the gel network, were investigated. Except for PPI-EWP 100/0 at pH 9.0, all systems gelled with increasing gel hardness, springiness, and cohesiveness when EWP content increased. This was explained by the microstructure of the gels, wherein the presence of PPI enhanced the formation of aggregates embedded in the EWP network, thus loosening it. The rheological properties of the mixed gels were primarily influenced by the EWP network, involving disulfide bonds. However, upon the addition of PPI, hydrogen bonds and hydrophobic interactions predominated and the structure of the gel became more sensitive to pH as electrostatic repulsions interfered. Adjusting the ratio of PPI/EWP allows the production of gels with varying textures, and suggests the possibility of partially substituting egg white with pea proteins in food gel formulation.

Development and characterization of soy protein-based custard-like soft foods for elderly individuals with swallowing difficulties

There is growing interest in developing protein-rich foods for the elderly using plant proteins. The application of soy protein isolate (SPI) as a model protein to create protein-rich, custard-like soft foods presents a unique opportunity for innovative formulations tailored to those within the aging population suffering from swallowing difficulties. This study investigated the physicochemical and textural properties of custard-type soft food formulations developed using SPI for dysphagic elderly individuals, with the goal of achieving characteristics similar to those of optimal milk protein-based counterparts. The protein content in the SPI-based custards varied from 8.9 % to 13.9 % and the milk-protein based custards had 8.9 % protein content. There was a substantial difference in textural, rheological and creep resistance and other properties between SPI and milk protein-based formulations. The SPI-based custards also had lower water-holding capacity, looser structure, and higher level of insoluble protein aggregates. The SPI-based custards imparted a more spreadable mouthfeel suitable for the aging population. The custards containing 13.9 % SPI had higher gel strength, viscosity, texture, and product stability. All of these custards were classified as Level 6 - Soft & Bite-sized dysphagia diet, based on International Dysphagia Diet Standardisation Initiative (IDDSI) tests. Instrumental IDDSI tests for Level 6 foods corroborated these observations, yielding reliable and consistent data. This research provides insights for developing protein-rich plant-based soft foods intended for the elderly population that have characteristics close to milk protein-based custards and comply with IDSSI criteria.

Effect of glycosylation modification on structure and properties of soy protein isolate: A review

Soybean protein isolate (SPI) is a highly functional protein source used in various food applications, such as emulsion, gelatin, and food packaging. However, its commercial application may be limited due to its poor mechanical properties, barrier properties, and high water sensitivity. Studies have shown that modifying SPI through glycosylation can enhance its functional properties and biological activities, resulting in better application performance. This paper reviews the recent studies on glycosylation modification of SPI, including its quantification method, structural improvements, and enhancement of its functional properties, such as solubility, gelation, emulsifying, and foaming. The review also discusses how glycosylation affects the bioactivity of SPI, such as its antioxidant and antibacterial activity. This review aims to provide a reference for further research on glycosylation modification and lay a foundation for applying SPI in various fields.

Recent advances and applications of laser-based imaging techniques in food crops and products: a critical review

To meet the growing demand for food quality and safety, there is a pressing need for fast and visible techniques to monitor the food crop and product production processing, and to understand the chemical changes that occur during these processes. Herein, the fundamental principles, instruments, and characteristics of three major laser-based imaging techniques (LBITs), namely, laser-induced breakdown spectroscopy, Raman spectroscopy, and laser ablation-inductively coupled plasma-mass spectrometry, are introduced. Additionally, the advances, challenges, and prospects for the application of LBITs in food crops and products are discussed. In recent years, LBITs have played a crucial role in mapping primary metabolites, secondary metabolites, nanoparticles, toxic metals, and mineral elements in food crops, as well as visualizing food adulteration, composition changes, pesticide residue, microbial contamination, and elements in food products. However, LBITs are still facing challenges in achieving accurate and sensitive quantification of compositions due to the complex sample matrix and minimal laser sampling quantity. Thus, further research is required to develop comprehensive data processing strategies and signal enhancement methods. With the continued development of imaging methods and equipment, LBITs have the potential to further explore chemical distribution mechanisms and ensure the safety and quality of food crops and products.

Topologically directed confocal Raman imaging (TD-CRI): Advanced Raman imaging towards compositional and micromeritic profiling of a commercial tablet components

Particle size distribution (PSD), spatial location and particle cluster size of ingredients, polymorphism, compositional distribution of a pharmaceutical product are few of the most important attributes in establishing the drug release-controlling microstructural and solid state properties that would be used to (re)design or reproduce similar products. There are numerous solid-state techniques available for PSD analysis. Laser diffraction (LD) is mostly used to study PSD of raw materials. However, a constraint of LD is the interference between the active pharmaceutical ingredients (API) and excipients, where it is very challenging to measure API size in a tablet. X-ray powder diffraction (XRPD) is widely employed in establishing the polymorphism of API and excipients. This research examined a commercial osmotic tablet in terms of extracting solid state properties of API and functional excipient by Raman Imaging. Establishing repeatability, reproducibility, and sample representativeness when the samples are non-uniform and inhomogeneous necessitates multiple measurements. In such scenarios, when employing imaging-based techniques, it can be time-consuming and tedious. Advanced statistical methodologies are used to overcome these disadvantages and expedite the characterization process. Overall, this study demonstrates that Raman imaging can be employed as a non-invasive and effective offline method for assessing the solid-state characteristics of API and functional excipients in complex dosage forms like osmotic tablets.