Special Issue "Effect of Processing on the Structure, Techno-Functional Properties and Nutritional Quality of Animal- and Plant-Based Food Proteins"

A special issue of Foods (ISSN 2304-8158). This special issue belongs to the section "Food Quality and Safety".

Deadline for manuscript submissions: 30 October 2023 | Viewed by 11805

Special Issue Editors

Department of Food Science, Aarhus University, Aarhus, Denmark
Interests: food physics; food biomacromecules; soft materials; colloidal systems; processing–structure–function interrelations; circular food systems; rheology
Department of Food Science, Aarhus University, Aarhus, Denmark
Interests: food biopolymers; microstructure; rheology; colloidal systems; dairy technology; functionality; soft materials
Department of Food Science, Aarhus University, Aarhus, Denmark
Interests: food biopolymers; macromolecular biochemistry; hydrothermal processing; food rheology; structure–function–digestion relationships; carbohydrates chemistry; plant proteins

Special Issue Information

Dear Colleagues,

Proteins play an outstanding role in foods: they are import macronutrients, but also relevant to confer foods with their textural properties, as they are involved in structure formation processes at multiple length scales. Proteins from both plant and animal origins can form supramolecular structures with each other or other food compounds, naturally or processing-induced, which affects their functional properties to a large extent. It is therefore important to understand the structural changes that occur in food proteins on a supramolecular level when they aggregate and interact with fibers, lipids or other macro- and micronutrients during food processing, and how this affects their techno-functional properties (e.g., gelation, emulsification) and nutritional quality (e.g., digestibility, bioavailability). This Special Issue aims to gather research papers and review articles describing the interrelations between various processing technologies and structure, function, and nutritional quality of different animal- and plant-based food proteins. Submissions dealing with protein blends and multi-component systems are particularly welcome.

Dr. Norbert Raak
Dr. Ruifen Li
Dr. Laura Roman
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Foods is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2900 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • food proteins
  • food processing
  • structure–function interrelations
  • protein digestibility
  • biopolymers interactions

Published Papers (8 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

Article
Dietary Supplementation with Popped Amaranth Modulates the Gut Microbiota in Low Height-for-Age Children: A Nonrandomized Pilot Trial
Foods 2023, 12(14), 2760; https://doi.org/10.3390/foods12142760 - 20 Jul 2023
Viewed by 684
Abstract
Amaranth has been recognized as a nutraceutical food because it contains high-quality proteins due to its adequate amino acid composition that covers the recommended requirements for children and adults. Since pre-Hispanic times, amaranth has been consumed as popped grain; the popping process improves [...] Read more.
Amaranth has been recognized as a nutraceutical food because it contains high-quality proteins due to its adequate amino acid composition that covers the recommended requirements for children and adults. Since pre-Hispanic times, amaranth has been consumed as popped grain; the popping process improves its nutritive quality and improves its digestibility. Popped amaranth consumption has been associated with the recovery of malnourished children. However, there is no information on the impact that popped amaranth consumption has on gut microbiota composition. A non-randomized pilot trial was conducted to evaluate the changes in composition, structure, and function of the gut microbiota of stunted children who received four grams of popped amaranth daily for three months. Stool and serum were collected at the beginning and at the end of the trial. Short-chain fatty acids (SCFA) were quantified, and gut bacterial composition was analyzed by 16S rRNA gene sequencing. Biometry and hematology results showed that children had no pathology other than low height-for-age. A decrease in the relative abundance of Alistipes putredinis, Bacteroides coprocola, and Bacteroides stercoris bacteria related to inflammation and colitis, and an increase in the relative abundance of Akkermansia muciniphila and Streptococcus thermophiles bacteria associated with health and longevity, was observed. The results demonstrate that popped amaranth is a nutritious food that helps to combat childhood malnutrition through gut microbiota modulation. Full article
Show Figures

Graphical abstract

Article
Rework Potential of Soy and Pea Protein Isolates in High-Moisture Extrusion
Foods 2023, 12(13), 2543; https://doi.org/10.3390/foods12132543 - 29 Jun 2023
Viewed by 1087
Abstract
High-moisture extrusion (HME) is an effective process to make fibrous products that can be used as meat analogues. In this study, the effect of extrusion of already extruded products (i.e., re-extrusion) was tested with the aim to explore the potential of rework in [...] Read more.
High-moisture extrusion (HME) is an effective process to make fibrous products that can be used as meat analogues. In this study, the effect of extrusion of already extruded products (i.e., re-extrusion) was tested with the aim to explore the potential of rework in HME. The rework of material is important because it is a route to reduce waste, which is always produced, for example during the start or at the end of a production run. Pea and soy protein isolates (PPI and SPI) were first extruded, then freeze-dried and ground, and extruded again. The visual and textural properties of the fibrous products were evaluated. Also, the rheological properties, solubility, and water-holding capacity (WHC) of the ingredients and the products after the first and second extrusion were quantified. The obtained freeze-dried powders after the first HME cycle had a reduction in solubility of 15% for PPI and 74% for SPI. Furthermore, WHC was reduced by 65% and 17% for PPI and SPI, respectively. After the second HME cycle, the reduction in solubility and WHC was augmented to 22% and 90% for PPI, and 79% and 63% for SPI. No effect on stock and loss moduli after heating and cooling were found, even after two HME cycles. SPI fibrous products did not differ in cutting strength, anisotropy index, or visual appearance after re-extrusion. Only, a decrease in hardness was detected, from 62.0 N to 51.1 N. For PPI, re-extrusion did reduce the cutting force and hardness but not the anisotropy index. It was concluded that even though HME induces a loss of solubility and WHC, this did not affect the fibrous texture formation of the protein. This means that the texture formed during HME does not depend on the process history and that rework is thus possible for fibrous products. Full article
Show Figures

Figure 1

Communication
Transmembrane Pressure during Micro- and Diafiltration of Milk Affects the Release of Non-Sedimentable Caseins
Foods 2023, 12(11), 2234; https://doi.org/10.3390/foods12112234 - 01 Jun 2023
Cited by 1 | Viewed by 800
Abstract
Membrane filtration, especially in combination with diafiltration, can affect the colloidal structure of casein micelles in milk and concentrated milks. The partial dissociation of casein proteins from the casein micelles into the serum phase has been shown to depend on diafiltration conditions. This [...] Read more.
Membrane filtration, especially in combination with diafiltration, can affect the colloidal structure of casein micelles in milk and concentrated milks. The partial dissociation of casein proteins from the casein micelles into the serum phase has been shown to depend on diafiltration conditions. This dissociation can affect the technological functionality of the milk concentrates. The present study aimed at determining the contribution of the gel layer deposited onto the membrane during filtration in the colloidal equilibrium between soluble and micellar caseins. Skimmed milk was concentrated by microfiltration combined with diafiltration using a cross-flow spiral-wound membrane at two transmembrane pressure (TMP) levels, causing differences in the extent of the gel layer formed. Non-sedimentable casein aggregates were formed to a greater extent at a low TMP compared to a high operating TMP. This difference was attributed to the greater compression of the deposit layer during filtration at a high TMP. This study contributes new knowledge to the understanding of how to modulate the functionality of milk concentrates through the control of processing conditions. Full article
Show Figures

Figure 1

Article
Ionic Strength Dependence of the Complex Coacervation between Lactoferrin and β-Lactoglobulin
Foods 2023, 12(5), 1040; https://doi.org/10.3390/foods12051040 - 01 Mar 2023
Viewed by 1076
Abstract
Heteroprotein complex coacervation is an assembly formed by oppositely charged proteins in aqueous solution that leads to liquid–liquid phase separation. The ability of lactoferrin and β-lactoglobulin to form complex coacervates at pH 5.5 under optimal protein stoichiometry has been studied in a previous [...] Read more.
Heteroprotein complex coacervation is an assembly formed by oppositely charged proteins in aqueous solution that leads to liquid–liquid phase separation. The ability of lactoferrin and β-lactoglobulin to form complex coacervates at pH 5.5 under optimal protein stoichiometry has been studied in a previous work. The goal of the current study is to determine the influence of ionic strength on the complex coacervation between these two proteins using direct mixing and desalting protocols. The initial interaction between lactoferrin and β-lactoglobulin and subsequent coacervation process were highly sensitive to the ionic strength. No microscopic phase separation was observed beyond a salt concentration of 20 mM. The coacervate yield decreased drastically with increasing added NaCl from 0 to 60 mM. The charge-screening effect induced by increasing the ionic strength is attributed to a decrease of interaction between the two oppositely charged proteins throughout a decrease in Debye length. Interestingly, as shown by isothermal titration calorimetry, a small concentration of NaCl around 2.5 mM promoted the binding energy between the two proteins. These results shed new light on the electrostatically driven mechanism governing the complex coacervation in heteroprotein systems. Full article
Show Figures

Figure 1

Article
Effect of Oxidative Modification by Peroxyl Radical on the Characterization and Identification of Oxidative Aggregates and In Vitro Digestion Products of Walnut (Juglans regia L.) Protein Isolates
Foods 2022, 11(24), 4104; https://doi.org/10.3390/foods11244104 - 19 Dec 2022
Viewed by 1011
Abstract
Walnut protein is a key plant protein resource due to its high nutritional value, but walnuts are prone to oxidation during storage and processing. This article explored the oxidative modification and digestion mechanism of walnut protein isolates by peroxyl radical and obtained new [...] Read more.
Walnut protein is a key plant protein resource due to its high nutritional value, but walnuts are prone to oxidation during storage and processing. This article explored the oxidative modification and digestion mechanism of walnut protein isolates by peroxyl radical and obtained new findings. SDS-PAGE and spectral analysis were used to identify structural changes in the protein after oxidative modification, and LC-MS/MS was used to identify the digestion products. The findings demonstrated that as the AAPH concentration increased, protein carbonyl content increased from 2.36 to 5.12 nmol/mg, while free sulfhydryl content, free amino content, and surface hydrophobicity decreased from 4.30 nmol/mg, 1.47 μmol/mg, and 167.92 to 1.72 nmol/mg, 1.13 μmol/mg, and 40.93 nmol/mg, respectively. Furthermore, the result of Tricine-SDS-PAGE in vitro digestion revealed that protein oxidation could cause gastric digestion resistance and a tendency for intestinal digestion promotion. Carbonyl content increased dramatically during the early stages of gastric digestion and again after 90 min of intestine digestion, and LC-MS/MS identified the last digestive products of the stomach and intestine as essential seed storage proteins. Oxidation causes walnut proteins to form aggregates, which are then re-oxidized during digestion, and proper oxidative modification may benefit intestinal digestion. Full article
Show Figures

Figure 1

Article
Ultrasound-Assisted Extraction of Protein from Pumpkin Seed Press Cake: Impact on Protein Yield and Techno-Functionality
Foods 2022, 11(24), 4029; https://doi.org/10.3390/foods11244029 - 13 Dec 2022
Cited by 4 | Viewed by 1589
Abstract
Conventional solvent-based methods widely used for isolating plant proteins may deliver an unsatisfactory protein yield and/or result in protein degradation. The present study started with the optimization of pumpkin seed protein from press cake by alkaline extraction and subsequent isoelectric precipitation. Subsequently, extraction [...] Read more.
Conventional solvent-based methods widely used for isolating plant proteins may deliver an unsatisfactory protein yield and/or result in protein degradation. The present study started with the optimization of pumpkin seed protein from press cake by alkaline extraction and subsequent isoelectric precipitation. Subsequently, extraction was supported by ultrasound under three conditions: ultrasonic treatment followed by alkaline extraction (US+AE), concomitant ultrasonic treatment and alkaline extraction (UAE), and alkaline extraction followed by ultrasonic treatment (AE+US). Compared to the control group, an increase in protein yield was achieved after ultrasonic treatment, while the highest protein yield was obtained with AE+US (57.8 ± 2.0%). Isolates with a protein content of 94.04 ± 0.77 g/100 g and a yield of 43.6 ± 0.97% were obtained under optimized conditions. Following ultrasonic treatment applied during extraction, solubility, foaming capacity, foam stability, and denaturation enthalpy of the isolated protein increased, and water binding capacity decreased as compared to non-sonicated samples. The d90 particle size percentile of the extracted suspensions was 376.68 ± 38.32 µm for the control experiments, and particle size was significantly reduced in ultrasound-assisted treatments down to d90 = 179.93 ± 13.24 µm for the AE+US treatment). Generally, ultrasonication resulted in a significant increase in protein yield and improved techno-functional properties of the isolates. Full article
Show Figures

Figure 1

Article
Structure-Function Guided Extraction and Scale-Up of Pea Protein Isolate Production
Foods 2022, 11(23), 3773; https://doi.org/10.3390/foods11233773 - 23 Nov 2022
Cited by 5 | Viewed by 1611
Abstract
The lack of adequate guidance and control of the extraction conditions as well as the gap between bench- and industrial-scale production, contributes to the poor functionality of commercial pea protein isolate (cPPI). Therefore, pea protein extraction conditions were evaluated and scaled up to [...] Read more.
The lack of adequate guidance and control of the extraction conditions as well as the gap between bench- and industrial-scale production, contributes to the poor functionality of commercial pea protein isolate (cPPI). Therefore, pea protein extraction conditions were evaluated and scaled up to maximize protein purity and yield, while maintaining structural integrity, following mild alkaline solubilization with isoelectric precipitation and salt solubilization coupled with membrane filtration. Both extraction methods resulted in high protein yield (>64%) and purity (>87%). Structure-function characterization illustrated the preserved structural integrity of PPI samples and their superior solubility, gelation, and emulsification properties compared to cPPI. Results confirmed, for the first time, that double solubilization at mild pH (7.5) can replace single solubilization at high alkalinity and achieve a similar yield while preserving structural integrity. Additionally, this study demonstrated, the scalability of the benchtop salt extraction coupled with ultrafiltration/diafiltration. Scaling up the production eliminated some structural and functional differences between the salt-extracted PPI and pH-extracted PPI. Scaling-up under mild and controlled conditions resulted in partial denaturation and a low degree of polymerization, coupled with the superior functionality of the produced isolates compared to cPPI. Results of this work can be used as a benchmark to guide the industrial production of functional pea protein ingredients. Full article
Show Figures

Figure 1

Review

Jump to: Research

Review
Protein-Based Fat Replacers: A Focus on Fabrication Methods and Fat-Mimic Mechanisms
Foods 2023, 12(5), 957; https://doi.org/10.3390/foods12050957 - 23 Feb 2023
Cited by 5 | Viewed by 3048
Abstract
The increasing occurrence of obesity and other non-communicable diseases has shifted the human diet towards reduced calorie intake. This drives the market to develop low-fat/non-fat food products with limited deterioration of textural properties. Thus, developing high-quality fat replacers which can replicate the role [...] Read more.
The increasing occurrence of obesity and other non-communicable diseases has shifted the human diet towards reduced calorie intake. This drives the market to develop low-fat/non-fat food products with limited deterioration of textural properties. Thus, developing high-quality fat replacers which can replicate the role of fat in the food matrix is essential. Among all the established types of fat replacers, protein-based ones have shown a higher compatibility with a wide range of foods with limited contribution to the total calories, including protein isolate/concentrate, microparticles, and microgels. The approach to fabricating fat replacers varies with their types, such as thermal–mechanical treatment, anti-solvent precipitation, enzymatic hydrolysis, complexation, and emulsification. Their detailed process is summarized in the present review with a focus on the latest findings. The fat-mimic mechanisms of fat replacers have received little attention compared to the fabricating methods; attempts are also made to explain the underlying principles of fat replacers from the physicochemical prospect. Finally, a future direction on the development of desirable fat replacers in a more sustainable way was also pointed out. Full article
Show Figures

Graphical abstract

Back to TopTop