Physicochemical characterization of protein isolates of amaranth and common bean and a study of their compatibility with xanthan gum

Amaranth proteins: From extraction to application as nanoparticle-based delivery systems for bioactive compounds

Amaranth proteins can be produced more sustainably than animal proteins, and they have amino acid compositions that are nutritionally balanced, which makes them attractive candidates for various applications in the food and pharmaceutical industries. This article provides an overview of the composition and techno-functional properties of amaranth protein, including its solubility, emulsification, gelation, foaming, and binding properties. These properties play an important role in the use of amaranth proteins for formulating nanoparticle-based delivery systems with good functional attributes. Amaranth proteins have structural and physicochemical properties suitable for fabricating protein-based nanoparticles. These nanoparticles can be used to encapsulate and control the release of bioactive compounds. However, challenges associated with the presence of anti-nutritional factors in amaranth proteins need to be addressed. These antinutrients negatively affect the bioavailability and digestibility of proteins and bioactive compounds. Hence, strategies to mitigate these challenges are discussed, including processing technologies and genetic engineering methods.

Effect of polysaccharide concentration on heat-induced Tremella fuciformis polysaccharide-soy protein isolation gels: Gel properties and interactions

The formation of a single soybean protein isolate (SPI) gel is limited by the processing conditions, and has the disadvantages of poor gel property, and it is usually necessary to add other biomacromolecules to improve its property. In this study, we investigated the effects of polysaccharide concentration on gel properties and interaction mechanisms of Tremella fuciformis polysaccharide (TFP)-SPI complexes. It was found that (1) the rheological properties, texture properties, water-holding properties, and thermal stability of TFP-SPI composite gels were improved with the addition of TFP (0.25-2.0 %, w/v) in a concentration-dependent manner; (2) hydrogen bond, the electrostatic interaction, hydrophobic interaction, and disulfide bond in the gel system increased with the increase of TFP concentration; (3) the electrostatic and hydrophobic interactions played an important role in the formation of the TFP-SPI composite gel while hydrogen bond formation was the least contributor to the binary composite gel network. Overall, TFP is not only a critical health food but also a promising structural component for improving the gel properties of SPI.

Water in water emulsion stabilized by liposomes developed from whey protein isolate and xanthan gum: Environmental stability and photoprotection effect for riboflavin

The purpose of this work is to explore the feasibility of water in water (W/W) emulsion stabilized with liposomes as a water-soluble nutraceutical carrier. A W/W emulsion system composed of xanthan gum (XG) and whey protein isolate (WPI) with different amount (0.2 %, 0.4 %, and 0.6 %) of liposomes as stabilizer was constructed. Fast green staining observation showed that XG was the internal phase and WPI was the continuous phase respectively. Confocal laser scanning microscopy revealed that with the increase of liposomes concentration from 0.4 % to 0.6 %, the interface thickness of the W/W emulsions was approximately twice that of the 0.2 % liposome-stabilized emulsion.The emulsions remained stable under neutral and weakly alkaline conditions. The droplet sizes of the emulsions were little affected by ionic strength. The binding constant (Ka) for XG to riboflavin (12.22) was approximately 5 times that for WPI to riboflavin (2.46), suggesting that riboflavin had a stronger binding affinity for the XG molecule compared to WPI. The fluorescence spectra of riboflavin showed that 0.4 % and 0.6 % liposome stabilized emulsions could effectively retard the photodegradation of riboflavin under ultraviolet irradiation. The successful construction of liposomes stabilized W/W emulsion provides a novel strategy for delivering water-soluble bioactive substances.

Assessment of Soy Protein Acid Hydrolysate-Xanthan Gum Mixtures on the Stability, Disperse and Rheological Properties of Oil-in-Water Emulsions

There is a growing need for natural ingredients that could be utilized for the production of food, pharmaceutical, and cosmetic emulsions. Soy protein acid hydrolysate (SPAH) is a plant-based additive used in the food industry mainly as a flavor enhancer. For the purpose of this work, however, it was mixed with a well-known natural polysaccharide, xanthan gum (XG), to produce stable 30% (w/w) sunflower oil-in-water emulsions using a rotor-stator homogenizer. In order to assess the emulsifying properties of the SPAH and its mixtures with XG, the surface tension properties of their water solutions, particle size, creaming stability, and rheological properties of the emulsions were investigated. Since the emulsions prepared using only SPAH, in various concentrations, were not stable, systems containing 5% of SPAH and 0.1, 0.2, 0.3, 0.4, or 0.5% of XG were then studied. The increase in concentration of the macromolecule led to an increase in creaming stability. The emulsions with 5% SPAH and 0.5% XG were stable for at least 14 days. The increase in XG concentration led to a decrease in d_4,3, while consistency index and non-Newtonian behavior increased. The systems containing SPAH, in the absence of XG, showed shear-thinning flow behavior, which was changed to thixotropic with the addition of XG. Viscoelastic properties of emulsions containing over 0.2% of XG were confirmed by oscillatory rheological tests, demonstrating the dominance of elastic (G') over viscous (G") modulus.

Amaranth proteins and peptides: Biological properties and food uses

Amaranthus grains have attracted great attention due to its attractive health benefits. The grains have processing properties (e.g., starch related properties) similar to those of common cereals. Amaranth grains are gluten free and protein is a significant component of these grains. Proteins of the grains have been used in various food applications such as formulations of edible films and emulsions for controlled release of bioactive compounds. The proteins have been hydrolyzed using different enzymes to produce peptides and hydrolysates, which showed a range of biological functions including anti-hypertensive and antioxidant activities among others. They have been formulated into staple foods including breads and pastas for improved nutritional quality. This review summarizes the recent advances of the last 5 years in understanding the biological functions and food applications of proteins, protein hydrolysates and peptides from the grains of different Amaranthus species. Limitations in the studies summarized are critically discussed with an aim to improve the efficiency in amaranth grain protein and peptide research.

Trends in millet and pseudomillet proteins - Characterization, processing and food applications

Millets are small-seeded crops which have been well adopted globally owing to their high concentration of macro and micronutrients such as protein, dietary fibre, essential fatty acids, minerals and vitamins. Considering their climate resilience and potential role in nutritional and health security, the year 2023 has been declared as 'International Year of Millets' by the United Nations. Cereals being the major nutrient vehicle for a majority population, and proteins being the second most abundant nutrient in millets, these grains can be a suitable alternative for plant-based proteins. Therefore, this review was written with an aim to succinctly provide an overview of the available literature take on the characterization, processing and applications of millet-based proteins. This information would play an important role in realizing the research gap restricting the utilization of complete potential of millet proteins. This can be further used by researchers and food industries for understanding the scope of millet proteins as an ingredient for novel food product development.

Long-Term Refrigerated Storage of Beef Using an Active Edible Film Reinforced with Mesoporous Silica Nanoparticles Containing Oregano Essential Oil (Lippia graveolens Kunth)

Beef is a fundamental part of the human diet, but it is highly susceptible to microbiological and physicochemical deterioration which decrease its shelf life. This work aimed to formulate an active edible film (AEF) incorporated with amino-functionalized mesoporous silica nanoparticles (A-MSN) loaded with Mexican oregano (Lippia graveolens Kunth) essential oil (OEO) and to evaluate its effect as a coating on fresh beef quality during refrigerated storage. The AEF was based on amaranth protein isolate (API) and chitosan (CH) (4:1, w/w), to which OEO emulsified or encapsulated in A-MSN was added. The tensile strength (36.91 ± 1.37 MPa), Young's modulus (1354.80 ± 64.6 MPa), and elongation (4.71%) parameters of AEF made it comparable with synthetic films. The antimicrobial activity of AEF against E. coli O157:H7 was improved by adding 9% (w/w) encapsulated OEO, and interactions of glycerol and A-MSN with the polymeric matrix were observed by FT-IR spectroscopy. In fresh beef, after 42 days, AEF reduced the population growth (Log CFU/cm², relative to uncoated fresh beef) of Brochothrix thermosphacta (5.5), Escherichia coli (3.5), Pseudomonas spp. (2.8), and aerobic mesophilic bacteria (6.8). After 21 days, odor acceptability of coated fresh beef was improved, thus, enlarging the shelf life of the beef and demonstrating the preservation capacity of this film.

Proteins from pseudocereal seeds: solubility, extraction, and modifications of the physicochemical and techno-functional properties

Pseudocereals (amaranth, buckwheat and quinoa) are emerging as popular gluten-free crops. This may be attributed to their wide-ranging health benefits, including antioxidant, hypoglycemic and serum-cholesterol reducing properties. Proteins of these crops have a high nutritional quality as a result of the presence of essential amino acids. Additionally, amaranth, buckwheat and quinoa proteins (AP, BP and QP, respectively) have physicochemical properties that are useful for the manufacture of different types of food. However, native pseudocereal proteins demonstrate a low solubility in water, mainly because of their composition. The major components of these proteins are albumins (water-soluble) and globulins (salt-soluble), although some proportions of glutelin (alkali-soluble) and prolamins (alcohol-soluble) are also found. The most commonly used method for extracting pseudocereal proteins is the alkaline extraction method, which may contribute to the low solubility of pseudocereal protein. Fortunately, different methods for modifying physicochemical (or techno-functional) properties have been proposed to extend their industrial application. For example, high-intensity ultrasound (HIUS) proved useful for improving the solubility of API and QP. Heating can allow for the formation of soluble aggregates of QP. The combination of heating and HIUS can improve the digestibility, solubility and foam properties of AP. Conjugation through the Maillard reaction can improve BPI and QP interfacial properties. Thus, present study provides a review of the solubility, extraction and modification of the techno-functional properties of AP, BP and QP. © 2022 Society of Chemical Industry.