Amino acid composition, foaming, emulsifying properties and surface hydrophobicity of mustard protein isolate as affected by pH and NaCl

Enhacing emulsification of meat broth system mixed with myofibrillar proteins and type I collagen: The role of NaCl and heat

A mixed system with a 5:1 ratio of beef myofibrillar protein to type I collagen was prepared to mimic meat broths. The study aimed to determine the combined effects of various NaCl concentrations (0, 0.2 M, 0.4 M, 0.6 M) and heat treatment on solubility, emulsifying properties (EAI, ESI), viscosity, and particle size of the mixed protein system. Mechanistic changes were examined through molecular interactions, intrinsic fluorescence, protein molecular weight, and Raman spectroscopy. The results showed that, without heat treatment, NaCl enhanced solubility, EAI, ESI, emulsion viscosity, and hydrogen bonding. After heating (90 °C, 30 min), elevated 0.4-0.6 M NaCl created an unstable, crowded environment, resulting in protein aggregation and reduced solubility and emulsifying performance. The results indicated that heating at 90 °C with 0.2 M NaCl was beneficial for meat emulsification, providing valuable production guidance for optimizing the formulation of meat products with low salt and high emulsifying properties.

Impact of pH on the structure, interfacial and foaming properties of pea protein isolate: Investigation of the structure - Function relationship

This study explored the relationship between pea protein foaming properties and their structure and physicochemical properties under neutral and acidic pH. Results showed that pH modified the zeta potential, particle size and surface tension due to electrostatic changes. FT-MIR and fluorescence spectra revealed pH-induced conformational changes, exposing hydrophobic groups and increasing sulfhydryl content, promoting protein aggregation. At pH 3, the highest foaming capacity (1.273) and lowest foam expansion (6.967) were observed, associated with increased surface hydrophobicity and net charges, ideal for creating light foams with high liquid incorporation for acidic beverages or fruit-based mousses. Pea protein isolate generated stable foams with foam volume stability between 86.662 % and 94.255 %. Although neutral pH conditions showed the highest foam volume stability, their air bubbles increased in size and transitioned from spherical to polyhedral shape, suitable for visual-centric applications, like cappuccino foam and beer-head retention. Foams at pH 5 exhibited the smallest bubbles and maintained their spherical shape, enhancing drainage resistance, beneficial for whipped toppings. Strong correlations (Pearson correlation coefficient higher than 0.600) were noted between the structure, surface and foaming properties, providing crucial insights into optimizing pea protein functionality across various pH conditions, enabling the development of plant-based foamed products with tailored properties.

A comprehensive review on nutritional, nutraceutical, and industrial perspectives of perilla (Perilla frutscens L.) seeds - An orphan oilseed crop

There is a growing need to mainstream orphan or underutilized crops to enhance nutritional security and sustainable agriculture. Among these, Perilla frutescens L. is an important crop due to its rich nutritional and phytochemical content which makes it significant in nutrition, medicine, and industrial sector. Perilla seeds are mainly rich in ω-3 fatty acids, dietary fiber, amino acids, vitamins, and minerals, high α-linolenic acid, which contributes to their health benefits. This review explores the nutritional profile of perilla seeds and highlights its unique composition compared to other oilseed crops. It also analyzes the phytochemical components of perilla seeds and their various biological activities, including antioxidant, antidiabetic, antiobesity, cardioprotective, anticancer, antimicrobial, neuroprotective, and anti-inflammatory effects. These activities demonstrate the potential of perilla seeds in both pharmaceutical and food sectors. The review also covers recent advancements in genomics and transgenic research discussing potential areas for crop improvement. Additionally, it explores the use of perilla seeds in functional foods, blending perilla oil with other oils, and their applications in enhancing product formulations. This review offers valuable insights for researchers, students, policymakers, environmentalists, and industry professionals by detailing the potential of perilla seeds across various sectors. The findings support sustainable agriculture, crop diversification, and innovative product development, thus contributing to the integration of perilla into mainstream agriculture.

Structural and Physicochemical Characterization of Extracted Proteins Fractions from Chickpea (Cicer arietinum L.) as a Potential Food Ingredient to Replace Ovalbumin in Foams and Emulsions

Chickpeas are the third most abundant legume crop worldwide, having a high protein content (14.9-24.6%) with interesting technological properties, thus representing a sustainable alternative to animal proteins. In this study, the surface and structural properties of total (TE) and sequential (ALB, GLO, and GLU) protein fractions isolated from defatted chickpea flour were evaluated and compared with an animal protein, ovalbumin (OVO). Differences in their physicochemical properties were evidenced when comparing TE with ALB, GLO, and GLU fractions. In addition, using a simple and low-cost extraction method it was obtained a high protein yield (82 ± 4%) with a significant content of essential and hydrophobic amino acids. Chickpea proteins presented improved interfacial and surface behavior compared to OVO, where GLO showed the most significant effects, correlated with its secondary structure and associated with its flexibility and higher surface hydrophobicity. Therefore, chickpea proteins have improved surface properties compared to OVO, evidencing their potential use as foam and/or emulsion stabilizers in food formulations for the replacement of animal proteins.

Demonstration of anti-oxidant properties of mustard seed (Brassica juncea) protein isolate in orange juice

Previous research has shown that formulated and natural beverages containing mixtures of anti-oxidants can produce stable levels of hydrogen peroxide (H₂O₂). The aim of this study was to demonstrate the ultimate anti-oxidant effects of proteins for suppressing H₂O₂, using a protein extract from mustard seed (Brassica juncea). The mustard seed protein isolate (MPI) contained ∼51% protein, and 6.4 mg GAe/g TS of total reducible substances, presumably representing secondary metabolites, including polyphenolics. Dose-dependent suppression of H₂O₂ (present at 110 µM and 550 µM), in fresh and thermally-processed orange juice was complete in the presence of 0.1 mg/mL MPI after 24 hr, with slightly higher anti-oxidant efficacy than the fruit juice-derived reference protein, thaumatin. The combination of thiol-rich amino acid (methionine and cysteine)-containing proteins and other anti-oxidant species in the MPI were highly effective for inhibiting autoxidation-mediated production of H₂O₂ in orange juice, and may be useful for other manufactured beverages.

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

This study was designed to improve the stability of medium internal phase emulsion by adjusting the electrostatic interaction between gelatin (GLT) and TEMPO-oxidized bacterial cellulose nanofibrils (TOBC). The influences of polysaccharide-protein ratio (1:10, 1:5, and 1:2.5) and pH (3.0, 4.7, 7.0, and 11.0) on the emulsion properties were investigated. The droplet size of TOBC/GLT-stabilized emulsion was increased with the TOBC proportion increasing at pH 3.0-11.0. Additionally, emulsion had a larger droplet size at pH 4.7 (the electrical equivalence point pH of mixtures). However, the addition of TOBC significantly improved the emulsion stability. The emulsions prepared with TOBC/GLT mixtures (mixing ratio of 1:2.5) at pH 3.0-7.0 were stable without creaming during the storage. It was because the formation of nanofibrils network impeded the droplet mobility, and the emulsion viscosity and viscoelastic modulus were increased with the addition of TOBC. These findings were meaningful to modulate the physical properties of emulsions.

Characterisation, physicochemical and functional properties of protein isolates from Amygdalus pedunculata Pall seeds

Amygdalus pedunculata Pall is a kind of desert woody oil plant, and its seeds are high in protein. The protein of Amygdalus pedunculata Pall (API) was identified by SDS-PAGE, 2-DE and MS. More than 300 proteins were identified. The improved solubility, emulsifying properties and foaming properties of API were observed in a pH range of 2.0-12.0 and a sodium chloride concentration of 0-1.0 M. The results showed that API had a good solubility (94.2%), bulk density (0.107 g/mL), oil absorption capacity (3.54 g/g), thermal stability (91.58 °C), emulsifying property (70 m²/g) and foaming property (83.7%). The conformation changes of API were studied by fluorescence and differential scanning calorimetry (DSC). The degree of denaturation of denaturants for API was guanidine hydrochloride > urea > SDS. These results showed that API has good processing performance and can be used as a new type of plant protein resource.

Relationship between Secondary Structure and Surface Hydrophobicity of Soybean Protein Isolate Subjected to Heat Treatment

This study investigated relationship between secondary structure and surface hydrophobicity of soy protein isolate (SPI) subjected to a thermal treatment at 70~90°C. Heat denaturation increased the surface hydrophobicity and surface hydrophobicity decreased as aggregate formed. Heat caused an increase in the relative amount ofα-helix structures and an overall decrease in the amount ofβ-sheet structures when compared with nontreated SPI. The relative amounts of secondary structures varied with time, temperature, and intensity of heat treatment applied. Theβ-sheet structure was most important for its significant role in denaturation of 7S globulin and following formed aggregates and even in denaturation of 11S globulin. The amount ofβ-sheet structure in SPI had an inverse correlation with the surface hydrophobicity when the temperature was kept below 90°C. Besides,β-turn structure increased asβ-7S/B-11S aggregate formated.