Cold plasma hydrophilization of soy protein isolate and milk protein concentrate enables manufacturing of surfactant-free water suspensions. Part I: Hydrophilization of food powders using cold plasma

Plasma technology modifies the surface properties of desalted duck egg white and applied as a novel oleogel stabilizer

Salted duck egg white (SDEW) is often discarded due to its high salt content. In this work, low-temperature plasma (LTP) technology was used to modify the functional properties of gelatinized desalted SDEW (gd-SDEW) through physical and chemical changes. After LTP treatment at 35 v for 3 min, gd-SDEW showed an increase in oil holding capacity. The analytical results indicated that the increase of β-sheets in the secondary structure, the surface hydrophobicity and the carbonyl content, the significant increase of BET surface area and decrease of adsorption mean pore size, and the increase of surface roughness were responsible for the increase of its oil holding capacity. LTP-treated gd-SDEW microgels can be used to stabilize the oleogels with excellent oil holding capacity, higher viscosity and gelation characteristics. This study offers the possibility of LTP as a novel technique to modify the surface properties of gd-SDEW for the reuse of SDEW.

Protein fractions in cow milk inhibit decontamination by cold atmospheric plasma

There is a growing body of research on the infection of cow milk by Prototheca algae, a potential human pathogen. This study presents investigations on plasma treatment to inactivate Prototheca directly in milk. However, microbiological tests revealed a surprisingly high survival rate of Prototheca in milk compared to saline solution treated under the same conditions. This phenomenon appears to be due to presence of proteins that act as scavengers of plasma reactive species, with OH• radicals playing a major role. Studies using MALDI-TOF MS, FTIR, XPS and UV-VIS on a model solution of peptone K (simulating the molecular structure of milk protein fractions) confirmed the high reactivity of peptides with OH• radicals, leading primarily to the substitution of hydrogen atoms with hydroxyl groups and cleavage of peptide chains. The obtained results encourage a broader consideration of proteins' role in plasma treatment processes, including applications in food products and plasma medicine.

Soy protein-gellan gum noncovalent complexes stabilized emulsion: Effect of heating and pH on emulsion stability

This paper investigated the effects of heating and pH on the stability of emulsions of non-covalent complexes of gellan gum (GG) and soy protein isolate (SPI). As a result, the GG-SPI complexes stabilized emulsion exhibited a minimum emulsion particle size (945 ± 23 nm), a maximum absolute values of zeta-potential (-32.7 ± 0.81 mV), the highest values of emulsion activity index (EAI) and stability index (ESI) (132 ± 4.7 min) when emulsion was prepared under the following conditions: oil phase ratio of 18 %, polysaccharide-protein proportion of 1:8 (w/w), homogeneous pressure at 80 MPa and homogeneous time at 4 min. GG-SPI emulsion had the best emulsification performance at pH 9.0 and 75 °C owing to the protein defolding occurred, the content of α-Helix increased, hydrophobic groups were exposed, and the number of negative groups on the surface of proteins increased under the high pH and high temperature conditions. The experimental results revealed the key role of heating and pH treatment for protein emulsion stability regulation, which will enrich the application of gellan gum in soy protein emulsions and provide an important theoretical basis for the future application of emulsion modification.

Cold plasma reengineers peanut protein isolate: Unveiling changes in functionality, rheology, and structure

This study investigates the effects of cold plasma (CP) treatment on peanut protein isolate (PPI), focusing on functionality, rheology, and structural modifications across various treatment times (0, 90, 180, 270, 360, and 450 s) and voltages (120, 140, and 160 kV). Key findings include a significant increase in solubility from 9.99 mg/mL to 15.98 mg/mL, as well as 161.07 % enhanced water-holding capacity (WHC) and 448.45 % oil-holding capacity (OHC). CP treatment also improved foaming capacity (FC) to 186.46 % and increased emulsion capacity (EC) and emulsion stability (ES) by 185.90 % at 160 kV. Rheological analysis showed shear-thinning behaviour, with viscosity decreasing as the shear rate increased-higher voltages (140 kV and 160 kV) further reduced viscosity, indicating lower resistance to flow. Additionally, CP-treated PPI exhibited viscoelasticity, with increased storage and loss moduli at higher frequencies, indicating greater stiffness. Spectroscopic studies demonstrated shifts in the protein's secondary structure, altering the balance among alpha-helix, beta-sheet, and random coil components, which highlights CP's role in reengineering PPI. FTIR-ATR spectra revealed reductions in the 3200-3400 cm-1 range, suggesting changes in protein backbone vibrations and hydrogen bonding. Particle size analysis showed significant increases, especially at higher voltages and longer treatment times, stabilizing after 270 s. Zeta potential assays indicated a gradual decrease in negative surface charge, suggesting enhanced protein aggregation. Overall, CP treatment significantly improves the functional and rheological properties of PPI while inducing structural changes, making it more suitable for applications in the food and pharmaceutical industries.

On the modification of plant proteins: Traditional methods and the Hofmeister effect

With increasing consumer health awareness and demand from some vegans, plant proteins have received a lot of attention. Plant proteins have many advantages over animal proteins. However, the application of plant proteins is limited by a number of factors and there is a need to improve their functional properties to enable a wider range of applications. This paper describes the advantages and disadvantages of traditional methods of modifying plant proteins and the appropriate timing for their use, and collates and describes a method with fewer applications in the food industry: the Hofmeister effect. It is extremely simple but efficient in some respects compared to traditional methods. The paper provides theoretical guidance for the further development of plant protein-based food products and a reference value basis for improving the functional properties of proteins to enhance their applications in the food industry, pharmaceuticals and other fields.

Ingredients, structure and reconstitution properties of instant powder foods and the potential for healthy product development: a comprehensive review

Instant foods are widely presented in powder forms across different food segments, which potentially can be formulated with functional or beneficial compounds to provide health benefits. Many reconstituted instant powder foods form colloidal suspensions with complex structures. However, designing instant powder food could be challenging due to the structural complexity and high flexibility in formulation. This review proposed a new classification method for instant powder foods according to the solubility of ingredients and the structure of the reconstituted products. Instant powder foods containing insoluble ingredients are discussed. It summarised challenges and current advances in powder treatments, reconstitution improvement, and influences on food texture and structure to facilitate product design in related industries. The characteristics and incorporation of the main ingredients and ingredients with health benefits in product development were reviewed. Different products vary significantly in the ratios of macronutrients. The macronutrients have limited solubility in water. After being reconstituted by water, the insoluble components are dispersed and swell to form colloidal dispersions with complex structures and textures. Soluble components, which dissolve in the continuous phase, may facilitate the dispersing process or influence the solution environment. The structure of reconstituted products and destabilising factors are discussed. Both particle and molecular structuring strategies have been developed to improve wettability and prevent the formation of lumps and, therefore, to improve reconstitution properties. Various types of instant food have been developed based on healthy or functional ingredients and exhibit positive effects on the prevention of non-communicable diseases and overall health. Less processed materials and by-products are often chosen to enhance the contents of dietary fibre and phenolic compounds. The enrichment of phenolic compounds, dietary fibres and/or probiotics tend to be simultaneous in plant-based products. The process of the ingredients and the formulation of products must be tailored to design the desired structure and to improve the reconstitution property.

Recent advance in modification strategies and applications of soy protein gel properties

Soy protein gel can be developed into a variety of products, ranging from traditional food (e.g., tofu) to newly developed food (e.g., soy yogurt and meat analog). So far, efforts are still needed to be made on modifying the gel properties of soy protein for improving its sensory properties as animal protein-based food substitutes. Furthermore, there is always a need to regulate its gel properties for designing novel and tailored products of soy protein gels due to the fast-growing plant protein-based product market. This review gave an emphasis on the latest modification strategies and applications of gel properties of soy protein. The modifying methods of soy protein gel properties were reviewed from an aspect of composition or processing. Compositional modification included changing protein composition and gelling conditions and using additives, whereas processing strategies can be achieved through physical, chemical, and enzymatic treatments. Several compositional modification and processing strategies have been both proven to alter the gel properties of soy protein effectively. So far, soy protein gel has been applied in the field of food and biomedicine. In the future, more mechanistic studies on the modification methods are still needed to facilitate the full application of soy protein gel.

Efficacy of cold plasma technology on the constituents of plant-based food products: Principles, current applications, and future potentials

Cold plasma (CP) is one of the novel non-thermal food processing technologies, which has the potential to extend the shelf-life of plant-based food products without adversely affecting the nutritional value and sensory characteristics. Besides microbial inactivation, this technology has been explored for food functionality, pesticide control, and allergen removals. Cold plasma technology presents positive results in applications related to food processing at a laboratory scale. This review discusses applications of CP technology and its effect on the constituents of plant-based food products including proteins, lipids, carbohydrates, and polar and non-polar secondary plant metabolites. As proven by the publications in the food field, the influence of CP on the food constituents and sensory quality of various food materials are mainly based on CP-related factors such as processing time, voltage level, power, frequency, type of gas, gas flow rate as well as the amount of sample, type, and content of food constituents. In addition to these, changes in the secondary plant metabolites depend on the action of CP on both cell membrane breakdown and increase/decrease in the scavenging compounds. This technology offers a good alternative to conventional methods by inactivating enzymes and increasing antioxidant levels. With a waterless and chemical-free property, this sustainable and energy-efficient technology presents several advantages in food applications. However, scaling up CP by ensuring uniform plasma treatment is a major challenge. Further investigation is required to provide information regarding the toxicity of plasma-treated food products.

Impact of emerging food processing technologies on structural and functional modification of proteins in plant-based meat alternatives: An updated review

In the past decade, the plant-based meat alternative industry has grown rapidly due to consumers' demand for environmental-friendly, nutritious, sustainable and humane choices. Consumers are not only concerned about the positive relationship between food consumption and health, they are also keen on the environmental sustainability. With such increased consumers' demand for meat alternatives, there is an urgent need for identification and modification of protein sources to imitate the functionality, textural, organoleptic and nutritional characteristics of traditional meat products. However, the plant proteins are not readily digestible and require more functionalization and modification are required. Proteins has to be modified to achieve high quality attributes such as solubility, gelling, emulsifying and foaming properties to make them more palatable and digestible. The protein source from the plant source in order to achieve the claims which needs more high protein digestibility and amino acid bioavailability. In order to achieve these newer emerging non-thermal technologies which can operate under mild temperature conditions can reach a balance between feasibility and reduced environmental impact maintaining the nutritional attributes and functional attributes of the proteins. This review article has discussed the mechanism of protein modification and advancements in the application of non-thermal technologies such as high pressure processing and pulsed electric field and emerging oxidation technologies (ultrasound, cold plasma, and ozone) on the structural modification of plant-based meat alternatives to improve, the techno-functional properties and palatability for successful food product development applications.

Conjugation of soy protein isolate with carboxymethyl cellulose through dielectric barrier discharge (DBD) plasma

The present study aimed to evaluate the physicochemical properties of dielectric barrier discharge (DBD) plasma grafted carboxymethyl cellulose (CMC) and soy protein isolate (SPI). Therefore, the mixture of SPI and CMC was treated at 16, 18 and 20 kV for 5, 10 and 15 min with DBD plasma. The results of FTIR, XRD, FESEM and SDS-PAGE confirmed the SPI-CMC conjugate formation after plasma treatment, and a glycation degree of about 21 % was obtained after 15 min treatment at 18 kV. Significantly higher levels of emulsifying activity and stability, as well as solubility, were obtained for the conjugates, as compared with the SPI-CMC mixture. Also, the smaller droplet sizes were observed in emulsions obtained from conjugate produced at 18 kV for 5 min, which had the most stability after 14 days of storage at 4 °C. Eventually, it was detected that DBD plasma could graft SPI and CMC in a short time.

Cold plasma: a promising technology for improving the rheological characteristics of food

At the beginning of the 21st century, many consumers show interest in purchasing safe, healthy, and nutritious foods. The intent requirement of end-users and many food product manufacturers are trying to feature a new processing technique for the healthy food supply. The non-thermal nature of cold plasma treatment is one of the leading breakthrough technologies for several food processing applications. The beneficial response of cold plasma processing on food quality characteristics is widely accepted as a substitution technique for new food manufacturing practices. This review aims to elaborate and offer crispy innovative ideas on cold plasma application in various food processing channels. It highlights the scientific approaches on the principle of generation and mechanism of cold plasma treatment on rheological properties of foods. It provides an overview of the behavior of cold plasma in terms of viscosity, crystallization, gelatinization, shear stress, and shear rate. Research reports highlighted that the cold plasma treated samples demonstrated a pseudoplastic behavior. The published literatures indicated that the cold plasma is a potential technology for modification of native starch to obtain desirable rheological properties. The adaptability and environmentally friendly nature of non-thermal cold plasma processing provide exclusive advantages compared to the traditional processing technique.

Soy protein isolates: A review of their composition, aggregation, and gelation

Considering that a series of complex issues such as environmental problems, sustainable development, animal welfare, and human health are on a global scale, the development of vegetable protein-based meat substitutes provides a potential solution to the disparity between meat consumption demand and supply. The research and development of vegetable protein-based meat substitutes have become a major commercial activity, and the market is expanding to meet the growing consumer demand. Soy protein isolates (SPI) are often used as a raw material for vegetable meat substitutes because of their potential to form fiber structures. Although significant initial success has been achieved, it is still a challenge to explain how the composition and aggregation of SPI influence gel properties and the mechanism(s) involved. This article reviews the latest research about SPI. The relationship between the composition, aggregation, and gelation properties of SPI is based on a through literature search. It focused on the application of SPI in heat- and cold-induced gels, given the diversified market demands. The research on cold gel has helped expand the market. The methods to improve the properties of SPI gels, including physical, chemical, and biological properties, are reviewed to provide insights on its role in the properties of SPI gels. To achieve environmentally friendly and efficient ways for the food industry to use SPI gel properties, the research prospects and development trends of the gel properties of SPI are summarized. New developments and practical applications in the production technology, such as for ultrasound, microwave and high pressure, are reviewed. The potential and challenges for practical applications of cold plasma technology for SPI gel properties are also discussed. There is a need to transfer the laboratory technology to actual food production efficiently and safely.