β-Lactoglobulin and sorghum phenolic compounds molecular binding: Interaction mechanism and thermal stability impact.

The mechanism of molecular interaction between β-lactoglobulin (β-lg) and sorghum bran phenolic compounds from 4 genotypes was studied. Catechin (CA) and ferulic acid (FA) were used as model systems. Higher affinity for β-lg:FA interaction (K ≈ 10 M) compared with β-lg:CA interaction (K ≈ 10 M) was revealed, with different preferable binding sites identified through molecular docking.

Lentil protein isolate (Lens culinaris) subjected to ultrasound treatment combined or not with heat-treatment: structural characterization and ability to stabilize high internal phase emulsions.

This study evaluated the effect of ultrasound treatment combined or not with heat treatment applied to lentil protein isolate (LPI) aiming to enhance its ability to stabilize high internal phase emulsions (HIPE). LPI dispersion (2%, w/w) was ultrasound-treated at 60% (UA) and 70% (UB) amplitude for 7 min; these samples were subjected to and then heat treatments at 70 °C (UAT70 and UBT70, respectively) or 80 °C (UAT80 and UBT80, respectively) for 20 min. HIPEs were produced with 25% untreated and treated LPI dispersions and 75% soybean oil using a rotor-stator (15,500 rpm/1 min).

Does protein deamidation enhance rice protein concentrate's ability to produce and stabilize high internal phase emulsions?

Rice is one of the most consumed grains in the world. Rice protein has great nutritional value as a hypoallergenic protein and due to its high lysine content, a limiting amino acid in several other plant protein sources. However, rice protein has low solubility, hampering its use in many applications in the food industry.

Thermo-induced changes in the structure of lentil protein isolate (Lens culinaris) to stabilize high internal phase emulsions.

This study aims to assess the impact of heat treatment on the emulsifying properties of lentil protein isolate (LPI) dispersion to produce high internal phase emulsions (HIPEs). The heat-treated LPI dispersion was characterized by size, turbidity, solubility, zeta potential, free sulfhydryl group, electrophoresis, differential scanning calorimetry, circular dichroism, Fourier transforms infrared spectroscopy and intrinsic fluorescence. HIPEs were produced with 25% of LPI dispersion (2%, w/w) and soybean oil (75%) using a rotor-stator (15,500 rpm/1 min).

Compartmentalization of lutein in simple and double emulsions containing protein nanoparticles: Effects on stability and bioaccessibility.

Delivery systems designed through protein stabilized emulsions are promising for incorporating carotenoids in different products. Nevertheless, the versatility in structures of such systems raises questions regarding the effect of the bioactive compound localization on their bio-efficacy, in particular for double emulsions. In this context, the aims of this study were to determine the impact of the localization of lutein in different water/oil/water double emulsions versus a single oil/water emulsion on the stability and in vitro bioaccessibility of lutein, a lipophilic carotenoid.

Effects of processing technologies on the antioxidant properties of common bean (Phaseolus vulgaris L.) and lentil (Lens culinaris) proteins and their hydrolysates.

The effects of ultrasound (280 W, 5 min), heat treatment (75 °C and 90 °C for 10 min) and microfluidization (125 MPa, 4 cycles) as pre or post treatments and their combination with enzymatic hydrolysis on the antioxidant properties of common bean and lentil protein hydrolysates were investigated. In general, hydrolysis resulted in increases of antioxidant activity, both in the presence and absence of processing technologies. The increases reached maximum values of 158% (ABTS), 105% (DPPH), 279% (FRAP) and 107% (TAC) for the bean protein hydrolysates submitted to post-treatment with ultrasound (ABTS, FRAP and TAC) and pre-treatment with microfluidization (DPPH), compared to their respective controls (untreated samples).

Stability of milk proteins subjected to UHT treatments: challenges and future perspectives.

Ultra-high temperature (UHT) treatments are of high economic relevance for food industries because they contribute to extending the shelf life of food products and facilitating their distribution. In the dairy segment, UHT treatments are applied to a wide range of products containing variable protein amounts. In this sense, the changes in the molecular structure of milk proteins induced by the severity of UHT treatments may lead to fouling in equipment during processing or sedimentation and/or gelation during storage.

Co-aggregation between whey proteins and carotenoids from yellow mombin (Spondias mombin): Impact of carotenoids' self-aggregation.

The interaction between whey proteins and carotenoid is reported to improve carotenoid solubility and stability, however, the strong trend of carotenoids to aggregate when in polar systems is often neglected in papers addressing their molecular interaction. Therefore, this study focused on characterizing the aggregative behavior of the carotenoids from yellow mombin (Spondias mombin) and to understand how these carotenoids behave when added to aqueous dispersions of whey proteins. Carotenoids-rich extract, containing mainly β-cryptoxanthin and lutein, was obtained from freeze-dried yellow mombin pulp and its aggregative behavior in ethanol/water medium was studied.

Lutein bioaccessibility in casein-stabilized emulsions is influenced by the free to acylated carotenoid ratio, but not by the casein aggregation state.

Considering that carotenoids are found acylated to fatty acids in most edible fruits, the influence of the ratio of free to acylated lutein on the hydrolysis extent and bioaccessibility was evaluated by in vitro digestion. For this purpose, for the first time, esterified, free, or a mixture of both carotenoid forms was used in the lipid phase of emulsions stabilized by sodium caseinate (NaCas) and native phosphocaseinate (PPCN). Marigold petals was used as a source of lutein-rich extracts.

Designing covalent sodium caseinate-quercetin complexes to improve emulsifying properties and oxidative stability.

The complexation of proteins with phenolic compounds has been considered a promising route to improve the oxidative stability of oil-in-water (O/W) emulsions. In this context, physicochemical and techno-functional properties of sodium caseinate (SC) chemically modified by the interaction with quercetin (Q) under alkaline conditions were evaluated using different molar ratios of the components (SC:Q). The formation of covalent complexes was analysed by the changes in SC structure and properties.

High-pressure microfluidization of whey proteins: Impact on protein structure and ability to bind and protect lutein.

Dynamic high-pressure homogenization microfluidization (DHPM) is a versatile emerging technology that may be applied to food processing to achieve several goals. DHPM may, depending on nature of the molecules and the working parameters, induce changes in protein structure, which may improve or impair their techno-functional properties and ability to bind other molecules. In this context, DHPM (12 passes, 120 MPa), coupled or not to a cooling device, was applied to β-lactoglobulin (β-lg) and whey protein isolate (WPI) dispersions.

Structural and foaming properties of whey and soy protein isolates in mixed systems before and after heat treatment.

The partial replacement of proteins from animal sources by plant proteins in formulated food products has been proposed as useful to improve sustainability aspects of the products without dramatically changing their techno-functional properties. Although several research groups have published on the gelling properties of mixed systems containing whey and soy protein isolates (WPI and SPI), their foaming properties are much less described. In this context, the main objective of this paper was to evaluate the structural and foaming properties of samples containing different mass ratios of WPI:SPI (100:0, 75:25, 50:50, 25:75 and 0:100) before and after heat treatment.

Unraveling the molecular mechanisms underlying interactions between caseins and lutein.

Understanding the food protein binding to bioactive compounds is of utmost importance for the development of efficient protein-based delivery systems. The binding of lutein to sodium caseinate (NaCas) or native casein micelle (PPCN) was investigated at pH 7 to evaluate the effect of casein supramolecular structures on the interaction. Fluorescence quenching, UV-vis spectroscopy, and dynamic light scattering were carried out.

Complexation of chitosan with gum Arabic, sodium alginate and κ-carrageenan: Effects of pH, polymer ratio and salt concentration.

The effects of pH, ionic strength and polymer ratio in the complexation of chitosan (CHI) with different anionic polysaccharides, namely gum Arabic (GA), sodium alginate (ALG) and κ-carrageenan (CRG), were investigated. This was made using titration techniques, which allowed the determination of stoichiometry and binding constant of complexes. The sulfated polysaccharide interacted more strongly with CHI than carboxylated polysaccharides.

Technological aspects of lactose-hydrolyzed milk powder.

Few reports describe the effect of lactose hydrolysis on the properties of milk powder during production and storage. Hence, the aim of this study was to evaluate the effects of five different levels of enzymatic lactose hydrolysis during the production and storage of milk powder. As the lactose hydrolysis rate increased, adhesion to the drying chamber also increased, due to higher levels of particle agglomeration.

How the presence of a small molecule affects the complex coacervation between lactoferrin and β-lactoglobulin.

Heteroprotein complex coacervation corresponds to the formation of two liquid phases in equilibrium induced by the interaction of two oppositely charged proteins. The more concentrated phase known as coacervate phase, has attracted interest from several fields of science due to its potential applications for example for encapsulation and delivery of bioactives. Prior such application, it is necessary to understand how the presence of small ligands affects the complex coacervation.

Heteroprotein complex coacervation: A generic process.

Proteins exhibit a rich diversity of functional, physico-chemical and biodegradable properties which makes them appealing for various applications in the food and non-food sectors. Such properties are attributed to their ability to interact and assemble into a diversity of supramolecular structures. The present review addresses the updated research progress in the recent field of complex coacervation made from mixtures of oppositely charged proteins (i.

Structure and Dynamics of Heteroprotein Coacervates.

Under specific conditions, mixing two oppositely charged proteins induces liquid-liquid phase separation. The denser phase, or coacervate phase, can be potentially applied as a system to protect or encapsulate different bioactive molecules with a broad range of food and/or medical applications. The optimization of the design and efficiency of such systems requires a precise understanding of the structure and the equilibrium of the nanocomplexes formed within the coacervate.

Binding of Folic Acid Induces Specific Self-Aggregation of Lactoferrin: Thermodynamic Characterization.

In the study presented here, we investigated the interaction at pH 5.5 between folic acid (FA) and lactoferrin (LF), a positively charged protein. We found a binding constant Ka of 10(5) M(-1) and a high stoichiometry of 10 mol of FA/mol of LF.