Potato protein: An emerging source of high quality and allergy free protein, and its possible future based products

Engineering Patatin for enhanced lipase activity and long-chain fatty acid specificity via rational design

Patatin, a multifunctional glycoprotein from potatoes, is a promising lipase for industrial applications due to its emulsifying, antioxidant, and lipid-modifying properties. However, its low expression efficiency and preference for short-chain substrates limit practical utility. Here, we addressed these challenges by heterologously expressing patatin in Pichia pastoris X-33, achieving a yield of 121 mg/L through optimized fermentation. The enzyme showed optimal activity at 35 °C and pH 10.0, with methanol enhancing activity, while Fe2+/Fe3+ inhibited it. Rational design of the D286A mutant significantly improved long-chain substrate specificity (3.2-fold higher activity for pNP-C16) and thermal stability (ΔTm = +5.4 °C). Molecular dynamics revealed that the mutation disrupted an α-helix (residues 280-286), forming a flexible loop to accommodate long-chain substrates via hydrogen bonding and π-alkyl interactions. Structural integrity was confirmed by circular dichroism. This work provides a scalable platform for engineering patatin, with future studies targeting industrial-scale production and applications in functional lipids and biocatalysis.

Supplementation with Potato Protein Concentrate and Saccharomyces boulardii to an Antibiotic-Free Diet Improves Intestinal Health in Weaned Piglets

Many countries have banned the use of antibiotics in livestock feed due to the development of antibiotic-resistant bacteria. Therefore, it is necessary to identify suitable alternatives to antibiotics in order to maintain intestinal health and improve piglet performance after weaning. The objective of this study was to evaluate how the intake of two functional foods-potato protein concentrate (PP) and Saccharomyces boulardii (Sb), either isolated or combined-would affect productive performance and some digestive morphophysiological responses after two weeks post-weaning. We evaluated five diets: SB, with Sb; PPC, with PP; PPC-SB, with a combination of PP and Sb; C-, without antibiotics, Sb, or PP; and C+, with antibiotics. Neither the absence of antibiotics in the diet nor the inclusion of PP and Sb affected performance or digestive organ development during the post-weaning phase. Piglets fed the C+ diet and the PP-Sb combination had higher concentrations of occludin proteins and longer villi in the jejunum compared to those fed C-, PPC, and SB. The use of Sb alone or in combination with PP increased fecal Lactobacillus, while antibiotics reduced coliform bacteria. The PP-Sb combination prevented the atrophy of the jejunal villi and promoted adhesion between enterocytes in the jejunum. Including these functional foods in piglet diets contributed to maintaining intestinal health during the critical post-weaning phase. However, further research is needed to validate and enhance the conclusions of this study.

Enhancing the Functional and Emulsifying Properties of Potato Protein via Enzymatic Hydrolysis with Papain and Bromelain for Gluten-Free Cake Emulsifiers

In recent years, plant-derived food proteins have gained increasing attention due to their economic, ecological, and health benefits. This study aimed to enhance the functional properties of potato protein isolate (PPI) through enzymatic hydrolysis with papain and bromelain, evaluating the physicochemical and emulsifying characteristics of the resulting potato protein hydrolysates (PPHs) for their potential use as plant-based emulsifiers. PPHs were prepared at various hydrolysis times (0.25-2 h), resulting in reduced molecular weights and improved solubility under acidic conditions (pH 4-6). PPHs exhibited higher ABTS radical-scavenging activity than PPI. The foaming stability (FS) of bromelain-treated PPI was maintained, whereas papain-treated PPI showed decreased FS with increased hydrolysis. Bromelain-treated PPHs demonstrated a superior emulsifying activity index (EAI: 306 m2/g), polydispersity index (PDI), higher surface potential, and higher viscosity compared to papain-treated PPHs, particularly after 15 min of hydrolysis. Incorporating PPHs into gluten-free chiffon rice cake batter reduced the batter density, increased the specific volume, and improved the cake's textural properties, including springiness, cohesiveness, and resilience. These findings suggest that bromelain-treated PPHs are promising plant-based emulsifiers with applications in food systems requiring enhanced stability and functionality.

Unveiling the potential of bean proteins: Extraction methods, functional and structural properties, modification techniques, physiological benefits, and diverse food applications

Bean proteins, known for their sustainability, versatility, and high nutritional value, represent a valuable yet underutilized resource, receiving less industrial attention compared to soy and pea proteins. This review examines the structural and molecular characteristics, functional properties, amino acid composition, nutritional value, antinutritional factors, and digestibility of bean proteins. Their applications in various food systems, including baked goods, juice and milk substitutes, meat alternatives, edible coatings, and 3D printing inks, are discussed. The physiological benefits of bean proteins, such as antidiabetic, cardioprotective, antioxidant, and neuroprotective effects, are also presented, highlighting their potential for promoting well-being. Our review emphasizes the diversity of bean proteins and highlights ultrasound as the most effective extraction method among available techniques. Beyond their physiological benefits, bean proteins significantly enhance the structural, technological, and nutritional properties of food systems. The functionality can be further improved through various modification techniques, thereby expanding their applicability in the food industry. While studies have explored the impact of bean protein structure on their nutritional and functional properties, further research is needed to investigate advanced modification techniques and the structure-function relationship. This will enhance the utilization of bean proteins in innovative and sustainable food applications.

Physical stability of oil-in-water multi-layered coenzyme Q10 nano-emulsions

As a lipophilic antioxidant, coenzyme Q10 (CoQ10) has limited application owing to its low water solubility and instability. In the present study, potato protein (PP) and soybean soluble polysaccharide (SSPS) were used as carriers to prepare a multilayer SSPS-PP-CoQ10 nano-emulsion using the reversed-phase emulsification method; further, the water solubility, stability, and formation mechanism of the nano-emulsion were analyzed. The results showed that the particle size of SSPS-PP-CoQ10 nano-emulsions was 253-422 nm with good polydispersity. The encapsulation efficiency (EE) could reach up to 88.87 %. When the concentration of SSPS was 0.1 wt%, the decrease in interfacial tension and increase in viscoelasticity indicated that nano-emulsion improved CoQ10 physical stability. SSPS incorporation altered the microscopic environment of the hydrophobic residues, rendering them more hydrophilic and enhancing their water solubility. According to molecular docking results, hydrogen bonds promote binding among SSPS, PP, and CoQ10, and increase emulsion stability.

Design and fabrication of plant-based milk fat globule mimetics: Flaxseed oil droplets coated with potato, soy, or pea protein

An increasing number of plant-based milk products are appearing on the market as substitutes for dairy milk. These products are becoming more popular due to growing consumers concerns about environmental, health, or ethical issues linked to dairy milk. Typically, plant-based milks are produced using top-down approaches that involve mechanical disruption of plant tissues. In this study, we examined the possibility of using a bottom-up approach to mimic the structural and physicochemical properties of milk fat globules (MFGs) in homogenized milk. Plant-based MFGs (PB-MFGs) were prepared using flaxseed oil as an omega-3 fatty acid rich oil phase, and potato, soy, or pea protein as emulsifiers to create the interfacial membranes. PB-MFGs were prepared with the same oil content (10 %) but different protein contents (0.5, 1, 1.5, and 2 %). The mean particle diameters (d4,3 and d3,2) of the three types of PB-MFGs were slightly smaller than those of dairy MFGs, while their surface charges were somewhat more negative under neutral conditions. There was no significant difference in the shear viscosity of PB-MFGs and MFGs. In terms of stability, PB-MFGs prepared with potato protein exhibited the smallest particle size change after 30 days of storage. Moreover, the pH stability of these PB-MFGs was closest to that of dairy MFGs. Our results provide valuable insights into the design and development of plant-based milks with more dairy-like properties, which may increase their more widespread acceptance and application.

High-level production of patatin in Pichia pastoris and characterization of N-glycosylation modification in food processing properties

Patatin is an acidic protein found in potatoes that is commonly used in food and pharmaceutical industries due to its excellent emulsifying and gelation abilities. Pichia pastoris is widely used as a host for recombinant protein production because it can incorporate post-translational modifications. In this study, a patatin titre of 2189.8 mg/L was achieved in a 5 L bioreactor using P. pastoris GS115 with signal peptide mutation, dual promoter construction, co-expression of chaperone proteins and optimised fermentation. To enhance the application of recombinant patatin in the food processing field, the level of N-glycosylation was elevated by genetic engineering. Properties of natural patatin, recombinant patatin and patatinL109T (N-glycosylated modified patatin) were investigated including foaming, hydrophobicity and emulsifying abilities. The functional properties of recombinant patatin were enhanced by introducing N-glycosylation, which also improved the water-holding capacity of its gel. The patatinL109T gel exhibited superior elasticity and water retention properties. The findings provide valuable insight and serve as a reference for the utilisation of recombinant patatin. The established enhancement strategy could be applied to other recombinant proteins.

Advancements in emulsion systems for specialized infant formulas: Research process and formulation proposals for optimizing bioavailability of nutraceuticals

With the rapid advancements in nutrition and dietary management, infant formulas for special medical purposes (IFSMPs) have been developed to cater to the unique nutraceutical requirements of infants with specific medical conditions or physiological features. However, there are various challenges in effectively preserving and maximizing the health benefits of the specific nutraceuticals incorporated in IFSMPs. This review provides an overview of the nutritional compositions of various IFSMPs and highlights the challenges associated with the effective supplementation of specific nutraceuticals for infants. In addition, it emphasizes the promising potential of emulsion delivery systems, which possess both encapsulation and delivery features, to significantly improve the solubility, stability, oral acceptance, and bioavailability (BA) of nutraceutical bioactives. Based on this information, this work proposes detailed strategies for designing and developing model IFSMP emulsions to enhance the BA of specially required nutraceuticals. Key areas covered include emulsion stabilization, selective release mechanisms, and effective absorption of nutraceuticals. By following these proposals, researchers and industry professionals can design and optimize emulsion-based IFSMPs with enhanced health benefits. This review not only outlines the developmental states of IFSMP formulations but also identifies future research directions aimed at improving the physiological health benefits of IFSMPs. This effort lays the theoretical groundwork for the further development of emulsion-type IFSMP in infant formula (IF) industry, positioning the IF industry to better meet the complex needs of infants requiring specialized nutrition.

Biofortification of potato nutrition

BACKGROUND

Potato (Solanum tuberosum L.) is the fourth most important food crop after rice, wheat and maize in the world with the potential to feed the world's population, and potato is a major staple food in many countries. Currently, potato is grown in more than 100 countries and is consumed by more than 1 billion people worldwide, and the global annual output exceeds 300 million tons. With the rapid increase in the global population, potato will play a key role in food supply. These aspects have driven scientists to genetically engineer potato for yield and nutrition improvement.

AIM OF REVIEW

Potato is an excellent source of carbohydrates, rich in vitamins, phenols and minerals. At present, the nutritional fortification of potato has made remarkable progress, and the biomass and nutrient compositions of potato have been significantly improved through agronomic operation and genetic improvement. This review aims to summarize recent advances in the nutritional fortification of potato protein, lipid and vitamin, and provides new insights for future potato research.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review comprehensively summarizes the biofortification of potato five nutrients from protein, lipid, starch, vitamin to mineral. Meanwhile, we also discuss the multilayered insights in the prospects of edible potato fruit, vaccines and high-value products synthesis, and diploid potato seeds reproduction.

The emulsifying capacity and stability of potato proteins and peptides: A comprehensive review

The potato has recently attracted more attention as a promising protein source. Potato proteins are commonly extracted from potato fruit juice, a byproduct of starch production. Potato proteins are characterized by superior techno-functional properties, such as water solubility, gel-forming, emulsifying, and foaming properties. However, commercially isolated potato proteins are often denatured, leading to a loss of these functionalities. Extensive research has explored the influence of different conditions and techniques on the emulsifying capacity and stability of potato proteins. However, there has been no comprehensive review of this topic yet. This paper aims to provide an in-depth overview of current research progress on the emulsifying capacity and stability of potato proteins and peptides, discussing research challenges and future perspectives. This paper discusses genetic diversity in potato proteins and various methods for extracting proteins from potatoes, including thermal and acid precipitation, salt precipitation, organic solvent precipitation, carboxymethyl cellulose complexation, chromatography, and membrane technology. It also covers enzymatic hydrolysis for producing potato-derived peptides and methods for identifying potato protein-derived emulsifying peptides. Furthermore, it reviews the influence of factors, such as physicochemical properties, environmental conditions, and food-processing techniques on the emulsifying capacity and stability of potato proteins and their derived peptides. Finally, it highlights chemical modifications, such as acylation, succinylation, phosphorylation, and glycation to enhance emulsifying capacity and stability. This review provides insight into future research directions for utilizing potato proteins as sustainable protein sources and high-value food emulsifiers, thereby contributing to adding value to the potato processing industry.

Advancements in plant based meat analogs enhancing sensory and nutritional attributes

The burgeoning demand for plant-based meat analogs (PBMAs) stems from environmental, health, and ethical concerns, yet replicating the sensory attributes of animal meat remains challenging. This comprehensive review explores recent innovations in PBMA ingredients and methodologies, emphasizing advancements in texture, flavor, and nutritional profiles. It chronicles the transition from soy-based first-generation products to more diversified second- and third-generation PBMAs, showcasing the utilization of various plant proteins and advanced processing techniques to enrich sensory experiences. The review underscores the crucial role of proteins, polysaccharides, and fats in mimicking meat's texture and flavor and emphasizes research on new plant-based sources to improve product quality. Addressing challenges like production costs, taste, texture, and nutritional adequacy is vital for enhancing consumer acceptance and fostering a more sustainable food system.

Smart proteins as a new paradigm for meeting dietary protein sufficiency of India: a critical review on the safety and sustainability of different protein sources

India, a global leader in agriculture, faces sustainability challenges in feeding its population. Although primarily a vegetarian population, the consumption of animal derived proteins has tremendously increased in recent years. Excessive dependency on animal proteins is not environmentally sustainable, necessitating the identification of alternative smart proteins. Smart proteins are environmentally benign and mimic the properties of animal proteins (dairy, egg and meat) and are derived from plant proteins, microbial fermentation, insects and cell culture meat (CCM) processes. This review critically evaluates the technological, safety, and sustainability challenges involved in production of smart proteins and their consumer acceptance from Indian context. Under current circumstances, plant-based proteins are most favorable; however, limited land availability and impending climate change makes them unsustainable in the long run. CCM is unaffordable with high input costs limiting its commercialization in near future. Microbial-derived proteins could be the most sustainable option for future owing to higher productivity and ability to grow on low-cost substrates. A circular economy approach integrating agri-horti waste valorization and C1 substrate synthesis with microbial biomass production offer economic viability. Considering the use of novel additives and processing techniques, evaluation of safety, allergenicity, and bioavailability of smart protein products is necessary before large-scale adoption.

Analysis of ingredient list and nutrient composition of plant-based burgers available in the global market

The nutrient composition of plant-based burgers is a key factor when making their purchase/consumption decision to maintain a balanced diet. For this reason, ingredient list and nutritional information of burgers launched in the global market were retrieved from their labels. Products were classified based on the technology development, market position and region of the manufacturer. From the ingredient analysis, we observed a high heterogeneity in the ingredients used, a predominance of soy and wheat as main sources of proteins, and the increasing use of new protein sources (e.g. peas, other types of beans and pseudo-cereals). Oil was the most cited ingredient followed by salt. Nutritional composition varied mainly depending on the region with no clear pattern among countries. To less extent, technology development resulted in traditional products with lower amounts of protein and higher amounts of carbohydrates. Vegan and vegetarian products showed limited differences due to the high intra-heterogenicity.

Vegan grade medium component screening and concentration optimization for the fermentation of the probiotic strain Lactobacillus paracasei IMC 502® using Design of Experiments

Lactobacillus paracasei IMC502® is a commercially successful probiotic strain. However, there are no reports that investigate growth medium composition in relation to improved biomass production for this strain. The major outcome of the present study is the design and optimization of a growth medium based on vegan components to be used in the cultivation of Lactobacillus paracasei IMC502®, by using Design of Experiments. Besides comparing different carbon sources, the use of plant-based peptones as nitrogen sources was considered. In particular, the use of guar peptone as the main nitrogen source, in the optimization of fermentation media for the production of probiotics, could replace other plant peptones (e.g. potato, rice, wheat, and soy) which are part of the human diet, thereby avoiding an increase in product and process prices. A model with R2 and adjusted R2 values higher than 95% was obtained. Model accuracy was equal to 94.11%. The vegan-optimized culture medium described in this study increased biomass production by about 65% compared to growth on De Man-Rogosa-Sharpe (MRS) medium. Moreover, this approach showed that most of the salts and trace elements generally present in MRS are not affecting biomass production, thus a simplified medium preparation can be proposed with higher probiotic biomass yield and titer. The possibility to obtain viable lactic acid bacteria at high density from vegetable derived nutrients will be of great interest to specific consumer communities, opening the way to follow this approach with other probiotics of impact for human health.

Carbohydrate confusion and dietary patterns: unintended public health consequences of "food swapping"

The 2025-2030 United States Dietary Guidelines process is currently underway, and the 2025 Dietary Guidelines Advisory Committee is examining and evaluating a list of prioritized scientific questions identified by the United States Department of Health and Human Services and the United States Department of Agriculture. One of the questions that will be evaluated is if changes should be made to USDA Dietary Patterns based on whether starchy vegetables and grains are, or can be, consumed interchangeably. These foods have historically been classified in distinct food groups. Menu modeling analyses evaluating the impact of replacing starchy vegetables with grains result in declines in key nutrients of concern. Given their unique nutrient contributions and the fact that many cultural foodways within the United States population include both starchy vegetables and grains, it is important for dietary recommendations to continue to categorize starchy vegetables and grains separately.

Genetic architecture of tuber-bound free amino acids in potato and effect of growing environment on the amino acid content

Free amino acids in potato tubers contribute to their nutritional value and processing quality. Exploring the natural variation in their accumulation in tubers across diverse genetic backgrounds is critical to potato breeding programs aiming to enhance or partition their distribution effectively. This study assessed variation in the tuber-bound free amino acids in a diversity panel of tetraploid potato clones developed and maintained by the Texas A&M Potato Breeding Program to explore their genetic basis and to obtain genomic-estimated breeding values for applied breeding purposes. Free amino acids content was evaluated in tubers of 217 tetraploid potato clones collected from Dalhart, Texas in 2019 and 2020, and Springlake, Texas in 2020. Most tuber amino acids were not affected by growing location, except histidine and proline, which were significantly lower (- 59.0%) and higher (+ 129.0%), respectively, at Springlake, Texas (a location that regularly suffers from abiotic stresses, mainly high-temperature stress). Single nucleotide polymorphism markers were used for genome-wide association studies and genomic selection of clones based on amino acid content. Most amino acids showed significant variations among potato clones and moderate to high heritabilities. Principal component analysis separated fresh from processing potato market classes based on amino acids distribution patterns. Genome-wide association studies discovered 33 QTL associated with 13 free amino acids. Genomic-estimated breeding values were calculated and are recommended for practical potato breeding applications to select parents and advance clones with the desired free amino acid content.

Plant protein-based emulsions for the delivery of bioactive compounds

Emulsion-based delivery systems (EBDSs) can be used as effective carriers for bioactive compounds (bioactives). Recent studies have shown that plant proteins (PLPs) have the potential to be utilized as stabilizers of emulsions for loading, protection and delivery of bioactives. Different strategies combining physical, chemical and biological techniques can be applied for alteration of the structural characteristics and improving the emulsification and encapsulation performance of PLPs. The stability, release, and bioavailability of the encapsulated bioactives can be tailored via optimizing the processing conditions and formulation of the emulsions. This paper presents cutting-edge information on PLP-based emulsions carrying bioactives in terms of their preparation methods, physicochemical characteristics, stability, encapsulation efficiency and release behavior of bioactives. Strategies applied for improvement of emulsifying and encapsulation properties of PLPs used in EBDSs are also reviewed. Special emphasis is given to the use of PLP-carbohydrate complexes for stabilizing bioactive-loaded emulsions.

The properties of potato gluten-free doughs: comparative and combined effects of propylene glycol alginate and hydroxypropyl methyl cellulose or flaxseed gum

Different methods are often used to make gluten-free (GF) bread to get better bread characteristics. To explore the effects of emulsifiers and hydrocolloids on the characteristics of GF dough, different esterification levels of propylene glycol alginate (PGA), hydroxypropyl methyl cellulose (HPMC), flaxseed gum with (FG) different molecular weight, and the binary blends of HPMC/PGA and FG/PGA were added to GF dough, made with potato starch and potato protein in a ratio of 6:4. The results showed that the potato GF dough with FG and FG/PGA obtained a higher viscoelasticity than the other doughs. HPMC and FG promoted to the formation of network structure, but the network structure formed by PGA and their combination was more developed. It was found that all PGA, HPMC, FG and their combination could improve the softness of GF breads. The results provided a basis for optimizing the quality of potato GF bread.

Novel zero waste tactics for commercial vegetables – recent advances

Commercial vegetables include tomatoes, potatoes, onions, and eggplant due to their surplus production, availability, and affordability. The valorisation of the massive wastage of commercial vegetables and providing a long-term solution has been challenging. The review addresses the implications of biowastes on the environment and fosters the recent investigations into valorising commercial vegetable waste to develop multiple value-added products. It discussed the outcomes of the multiple technologies, majorly on green chemistry extraction, while outlining other methods such as fermentation, enzymatic treatments, 3D printing foods, high-pressure homogenisation, microencapsulation, bio-absorption method, and pyrolysis for their respective vegetable wastes. Agri-residues can be a valuable source for formulating functional ingredients, natural additives, biodiesel, dyes, and animal feed. This comprehensive review proposes a strategy to upcycle low-cost biowaste to boost the economic and ecological benefits. The current review captures the interests and great collaborations between researchers, industrialists, policymakers, waste management bodies, and eco-activists.

Structural Analysis and Study of Gel Properties of Thermally-Induced Soybean Isolate-Potato Protein Gel System

Heat-induced composite gel systems consisting of different soybean protein isolate (SPI) and potato protein (PP) mixtures were studied to elucidate their "backbone" and property changes. This was achieved by comparing the ratio of non-network proteins, protein subunit composition, and aggregation of different gel samples. It was revealed that SPI was the "gel network backbone" and PP played the role of "filler" in the SPI-PP composite gel system. Compared with the composite gels at the same ratio, springiness and WHC decrease with PP addition. For hardness, PP addition showed a less linear trend. At the SPI-PP = 2/1 composite gel, hardness was more than doubled, while springiness and WHC did not decrease too much and increased the inter-protein binding. The hydrophobic interactions and electrostatic interactions and hydrogen bonding of the SPI gel system were enhanced. The scanning electron microscopy results showed that the SPI-based gel system was able to form a more compact and compatible gel network. This study demonstrates the use of PP as a potential filler that can effectively improve the gelling properties of SPI, thus providing a theoretical basis for the study of functional plant protein foods.

Impact of the Structural Modifications of Potato Protein in the Digestibility Process under Semi-Dynamic Simulated Human Gastrointestinal In Vitro System

The raising consumer demand for plant-derived proteins has led to an increased production of alternative protein ingredients with varying processing histories. In this study, we used a commercially available potato protein ingredient with a nutritionally valuable amino acid profile and high technological functionality to evaluate if the digestibility of a suspension with the same composition is affected by differences in the structure. Four isocaloric (4% protein, w/w) matrices (suspension, gel, foam and heat-set foam) were prepared and their gastrointestinal fate was followed utilizing a semi-dynamic in vitro digestion model. The microstructure was observed by confocal laser scanning microscopy, protein breakdown was tested by electrophoresis and free amino acids after intestinal digestion was estimated using liquid chromatography/triple-quadruple-mass spectrometry (LC-TQMS). The heat-treated samples showed a higher degree of hydrolysis and lower trypsin inhibitory activity than the non-heat-treated samples. An in vitro digestible indispensable amino acid score was calculated based on experimental data, showing a value of 0.9 based on sulfur amino acids/valine as the limiting amino acids. The heated samples also showed a slower gastric emptying rate. The study highlights the effect of the food matrix on the distribution of the peptides created during various stages of gastric emptying.

Effect of high-intensity ultrasound on the structural, rheological, emulsifying and gelling properties of insoluble potato protein isolates

The denaturation and lower solubility of commercial potato proteins generally limited their industrial application. Effects of high-intensity ultrasound (HIU) (200, 400, and 600 W) and treatment time (10, 20, and 30 min) on the physicochemical and functional properties of insoluble potato protein isolates (ISPP) were investigated. The results revealed that HIU treatment induced the unfolding and breakdown of macromolecular aggregates of ISPP, resulting in the exposure of hydrophobic and R-SH groups, and reduction of the particle size. These active groups contributed to the formation of a dense and uniform gel network of ISPP gel and insoluble potato proteins/egg white protein (ISPP/EWP) hybrid gel. Furthermore, the increase of solubility and surface hydrophobicity and the decrease of particle size improved the emulsifying property of ISPP. However, excessive HIU treatment reduced the emulsification and gelling properties of the ISPP. Meanwhile, HIU treatment changes the secondary structure of ISPP. It could be speculated that the formation of a stable secondary structure of ISPP initiated by cavitation and shearing effect might play a dominant role on gel strengthens and firmness. Meanwhile, the decrease in relative content of β-turn had a positive effect on the formation of small particle to improve emulsifying property of ISPP.

Emulsifying activity of potato proteins in the presence of k-carrageenan at different pH conditions

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The emulsifying activity of potato proteins was tested in different conditions.

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Potato proteins presented a higher emulsifying activity at pH 4.8.

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Electrostatic attraction occurs between Potato proteins and k-carrageenan at pH 3.

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k-carrageenan strengthens the structure of Potato proteins - stabilised emulsions.

Oil in Water (3:1) emulsions were prepared using potato proteins in the presence or absence of 0.2% k-carrageenan at different pH conditions (3.0, 7.0, and 4.8). These emulsions showed different droplet sizes, stability, appearance, and rheological properties. The best emulsion stability was achieved combining potato proteins and k-carrageenan at pH 3.0, where uniform and small oil droplets (30 µm) were observed. The rheological properties of the emulsions were also different. The highest viscosity and G’ were shown by the emulsion prepared with the addition of k-carrageenan at pH 3.0, this being attributed to the onset of a gel-like viscoelastic structure in these conditions. SDS-PAGE indicated that the superior properties of the emulsion prepared with k-carrageenan at pH 3.0 can be attributed to an electrostatic interaction between the positively charged potato proteins and the anionic polysaccharide. This interaction allowed the formation of a strong molecular network able to stabilize the system.