Properties of acetylated potato protein preparations

The Functional and Physicochemical Properties of Rice Protein Concentrate Subjected to Acetylation

The aim of the present study was to increase the value of rice protein concentrate (RPC) by improving the functional properties of a preparation subjected to acetylation and analyze the impact of this chemical modification on chemical composition, digestibility, and protein patterning using SDS-PAGE electrophoresis and FT-IR spectroscopy. In the modified samples, the protein content increased (80.90-83.10 g/100 g cf. 74.20 g/100 g in the control). Electrophoresis revealed that the content of the main rice protein fractions (prolamin and glutelin) decreased as the concentration of the modifying reagent increased. Through spectroscopic analysis, wavenumbers, corresponding to the presence of proteins or lipids, aromatic systems, and carbohydrates, were observed. The use of acetic anhydride did not change the digestibility of the modified RPC significantly when compared to that of the control sample. The acetylation of the RPC caused a significant increase in its emulsifying properties at pH 8 (1.83-14.74%) and its water-binding capacity but did not have a statistically significant impact on the oil-absorption capacity. There was a slight increase in protein solubility and a decrease in foaming capacity in the modified RPC.

Physical, Chemical and Biochemical Modification Approaches of Potato (Peel) Constituents for Bio-Based Food Packaging Concepts: A Review

Potatoes are grown in large quantities and are mainly used as food or animal feed. Potato processing generates a large amount of side streams, which are currently low value by-products of the potato processing industry. The utilization of the potato peel side stream and other potato residues is also becoming increasingly important from a sustainability point of view. Individual constituents of potato peel or complete potato tubers can for instance be used for application in other products such as bio-based food packaging. Prior using constituents for specific applications, their properties and characteristics need to be known and understood. This article extensively reviews the scientific literature about physical, chemical, and biochemical modification of potato constituents. Besides short explanations about the modification techniques, extensive summaries of the results from scientific articles are outlined focusing on the main constituents of potatoes, namely potato starch and potato protein. The effects of the different modification techniques are qualitatively interpreted in tables to obtain a condensed overview about the influence of different modification techniques on the potato constituents. Overall, this article provides an up-to-date and comprehensive overview of the possibilities and implications of modifying potato components for potential further valorization in, e.g., bio-based food packaging.

Effects of Electrospun Potato Protein-Maltodextrin Mixtures and Thermal Glycation on Trypsin Inhibitor Activity

Fibers of potato protein and polysaccharides were obtained by needleless electrospinning. Mixtures of maltodextrin DE2 (dextrose equivalent) (0.8 g/mL), DE21 (0.1 g/mL), and different concentrations of potato protein (0.05, 0.1, 0.15, and 0.2 g/mL) were used for fiber production. Glycation was performed via the Maillard reaction after thermal treatment (0/6/12/24/48 h, 65 °C, 75% relative humidity). The effects of electrospinning and heating on trypsin inhibitor activity (IA) were studied. The results of the IA assay showed that electrospinning and glycation caused significant differences in IA among blends, heating times, and the interaction of blend and heating time (p < 0.001). The higher the protein content in the fibers, the higher the IA. The lowest IA was found in the mixture with the lowest protein content after 48 h. In other blends, the minimum IAs were found between 6 and 12 h of heating. The determination of the free lysine groups showed a nonsignificant decrease after heating. However, higher free lysine groups per protein (6.3−9.5 g/100 g) were found in unheated fibers than in the potato protein isolate (6.0 ± 0.5 g/100 g). The amide I and amide II regions, detected by the Fourier transform infrared spectra, showed only a slight shift after heating.

Potato protein: current review of structure, technological properties, and potential application on spray drying microencapsulation

Studies regarding spray drying microencapsulation are aplenty available; especially focusing on processing parameters, microparticle characteristics and encapsulation efficiency. Hence, there is a rising interest in tailoring wall materials aiming to improve the process's effectiveness. Reflecting a market trend in the food industry, plant-based proteins are emerging as alternative protein sources, and their application adaptability is an increasing research of interest related to consumers' demand for healthy food, product innovation, and sustainability. This review presents a perspective on the investigation of potato protein as a technological ingredient, considering it a nonconventional source obtained as by-product from starch industry. Furthermore, this piece emphasizes the potential application of potato protein as wall material in spray drying encapsulation, considering that this purpose is still limited for this ingredient. The literature reports that vegetal-based proteins might present compromised functionality due to processing conditions, impairing its technological application. Structural modification can offer a potential approach to modify potato protein configuration aiming to improve its utilization. Studies reported that modified proteins can perform as better emulsifiers and antioxidant agents compared to intact proteins. Hence, it is expected that their use in microencapsulation would improve process efficiency and protection of the core material, consequently delivering superior encapsulation performance.

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

Recently protein has gained eminence due to awareness and demand for healthy food. Potato proteins are extracted from potato fruit juice and industrial potato waste; its nutritional and functional values have been found more significant than other vegetables and cereal proteins. Potato proteins can be easily extracted by various separation techniques, including an ion exchange (IEX) and expanded bed adsorption (EBA), and their functional properties can be modified for desire purposes. It contains many essential amino acids necessary for the human body, with an amino acid score (AAS) of 65%. Recent research on potato proteins resulted in several descriptions of new technologies to produce food-grade potato protein. It has recently drawn more attention as a protein source for human consumption, especially as an allergy free protein source and selective activity against cancer cells. Growing shreds of evidence have highlighted that potato protein can be used in many upcoming nutraceuticals and allergy-free food products. Therefore it is gaining more attention from nutritionists and food scientists. This review has summarized the recent knowledge on the nutritional and functional aspects of potato proteins, especially its non-allergic properties, enhancement in functional properties, and possible future-based products.

Modification of pulse proteins for improved functionality and flavor profile: A comprehensive review

Consumers' preference to have a healthy eating pattern has led to an increasing demand for more nutrient-dense and healthier plant-based foods. Pulse proteins are exceptional quality ingredients with potential nutritional benefits, and might act as health-promoting agents for addressing the new-generation foods. However, the utilization of pulse protein in foods has been hampered by its relatively poor functionality and unpleasant flavor. Protein structure modification has been proved to be a useful means to improve the functionality and flavor profile of pulse protein. This paper begins with a brief introduction of hierarchical structure of pulse protein materials to better understand the structure characteristics. A comprehensive review is presented on the current techniques including chemical and enzymatic modifications and molecular breeding on pulse protein structure and functionality/flavor. The mechanism and the limitations and the toxicological concerns of these approaches are discussed. We conclude that understanding protein structure-functionality relationship is extremely valuable in tailoring proteins for specific functional outcomes and expanding the availability of pulse proteins. Furthermore, selective protein modification is a valuable in-depth toolkit for generating novel protein constructs with preferable functional attributes and flavor profiles. Innovative structure modification with special focus on the molecular basis for the exquisite protein designs is a pillar of pulse protein access to the desired functionality.

Effect of Acetylation on Physicochemical and Functional Properties of Commercial Pumpkin Protein Concentrate

The purpose of the present study was to determine the effects of acetylation with different doses of acetic anhydride on the chemical composition and chosen functional properties of commercial pumpkin protein concentrate (PPC). The total protein content decreased as compared to unmodified samples. Electrophoretic analysis revealed that in the acetylated pumpkin protein, the content of the heaviest protein (35 kDa) decreased in line with increasing concentrations of modifying reagent. Acetylation of PPC caused a significant increase in water-binding and oil-absorption capacity and for emulsifying properties even at the dose of 0.4 mL/g. Additionally, an increase in foaming capacity was demonstrated for preparations obtained with 2.0 mL/g of acetic anhydride, whereas acetylation with 0.4 and 1.0 mL/g caused a decrease in protein solubility as compared to native PPC.

Protein recovery as a resource from waste specifically via membrane technology-from waste to wonder

Economic growth and the rapid increase in the world population has led to a greater need for natural resources, which in turn, has put pressure on said resources along with the environment. Water, food, and energy, among other resources, pose a huge challenge. Numerous essential resources, including organic substances and valuable nutrients, can be found in wastewater, and these could be recovered with efficient technologies. Protein recovery from waste streams can provide an alternative resource that could be utilized as animal feed. Membrane separation, adsorption, and microbe-assisted protein recovery have been proposed as technologies that could be used for the aforementioned protein recovery. This present study focuses on the applicability of different technologies for protein recovery from different wastewaters. Membrane technology has been proven to be efficient for the effective concentration of proteins from waste sources. The main emphasis of the present short communication is to explore the possible strategies that could be utilized to recover or restore proteins from different wastewater sources. The presented study emphasizes the applicability of the recovery of proteins from various waste sources using membranes and the combination of the membrane process. Future research should focus on novel technologies that can help in the efficient extraction of these high-value compounds from wastes. Lastly, this short communication will evaluate the possibility of integrating membrane technology. This study will discuss the important proteins present in different industrial waste streams, such as those of potatoes, poultry, dairy, seafood and alfalfa, and the possible state of the art technologies for the recovery of these valuable proteins from the wastewater.

Physicochemical and Antioxidative Characteristics of Potato Protein Isolate Hydrolysate

This study investigated the physicochemical characteristics of potato protein isolate hydrolysate (PPIH) and its antioxidant activity. Potato protein isolate (PPI) was hydrolyzed into PPIH by the proteases bromelain, Neutrase, and Flavourzyme. Compared with PPI, the resulting PPIH had a lower molecular weight (MW, from 103.5 to 422.7 Da) and smaller particle size (<50 nm), as well as a higher solubility rate (>70%) under acidic conditions (pH 3–6). PPIH presented good solubility (73%) across the tested pH range of 3–6. As the pH was increased, the zeta potential of PPIH decreased from −7.4 to −21.6. Using the 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical-scavenging assay, we determined that the half-maximal effective concentration (EC₅₀) values of ascorbic acid, PPIH, and PPI were 0.01, 0.89, and >2.33 mg/mL, respectively. Furthermore, PPIH (50 μg/mL) protected C2C12 cells from H₂O₂ oxidation significantly better than PPI (10.5% higher viability rate; p < 0.01). These findings demonstrated the possible use of PPIH as an antioxidant in medical applications.

Laccase-catalyzed conjugation of potato protein (PPT) with selected pectic polysaccharides (PPS): Conjugation efficiency and emulsification properties

The current study focused on the investigation of laccase-catalyzed conjugation of potato protein (PPT) with selected pectic polysaccharides (PPS) and modulation of the conjugation in order to obtain desired functional ingredients. PPS, including sugar beet pectin/arabinan, apple/citrus pectin and potato galactan, were evaluated as substrates in the conjugation reaction-catalyzed by laccases (Trametes versicolor-LacTv, Coriolus hirsutus-LacCh). LacCh exhibited a higher catalytic efficiency than LacTv. The reactivity of PPT/PPS and their ratio were determinants for their heteroconjugation. Both laccases exhibited the highest specificity towards the conjugation of PPT/sugar beet pectin. Predictive models were developed for conjugation efficiency and emulsification performance. The conjugation extent was negatively affected by the protein proportion and the protein proportion/enzyme concentration interaction; while the emulsification performance was positively correlated with the protein proportion and the protein proportion/reaction time interaction. This study contributed to the understanding of laccase-catalyzed conjugation reaction for the controlled synthesis of conjugated-PTT as functional ingredients.

Technological and antioxidant properties of proteins obtained from waste potato juice

The article presents the technological and antioxidant properties of potato juice (PJ) protein concentrate obtained by the novel ultrafiltration method. Commercial products, obtained from waste PJ by the traditional method of acid coagulation of proteins, were studied for comparison. Functional properties such as water or oil absorption, foaming capacity, and foam stability (FS) as well as solubility at various pH were assessed. Moreover, the total phenolic compound content, antioxidant activity, and mineral composition were determined. The results showed that PJ protein concentrate obtained by ultrafiltration has good oil absorption properties (6.30 mL/g), which is more than two times higher than the commercial proteins used in the comparison (P2 = 2.33 mL/g and P3 = 2.67 mL/g). Moreover, the ability to create and stabilize foam was also higher (FS ranging from 20.0% at pH = 10 to 11.3% at pH = 2 after 60 min of testing). It had higher content of macro- and microelements and antioxidant activity compared to other samples. Therefore, it is possible to obtain interesting potato protein concentrate from the waste product of the starch production process, which may be an interesting raw material for enriching food.

The influence of thermal hydrolysis process on emulsifying properties of potato protein isolate

The article considers the influence of the thermal hydrolysis process on emulsifying properties and viscosity of potato protein isolates. During the study, there was demonstrated a significant improvement in emulsifying properties of the protein isolates as a result of denaturation. Thermal hydrolysis process includes high temperature and pressure. The improvement in emulsion stability maintained in some variants up to a week has been observed. Significant correlations were found between emulsification activity and emulsion stability after 1 week (p > 0.05). The rheological measurement showed an increase in viscosity after HPP. As the proposed method of the protein isolate modification does not affect the chemical composition of the protein solution, but only its molecular structure, it enables to increase the emulsifying properties in a simple and cost-effective way.

The Nutritional Value and Biological Activity of Concentrated Protein Fraction of Potato Juice

Potato protein is recognized as one of the most valuable nonanimal proteins due to the high content of essential amino acids. So far, it has not been used in human nutrition on a large scale due to technological limitations regarding its acquisition. In this study, the protein fraction of potato juice was concentrated with the use of membrane separation. The obtained potato juice protein concentrate (PJPC) was characterized in terms of nutritional value and biological activity, and the amino acid composition, mineral content, and antioxidant properties were determined. Moreover, in vitro cytotoxic activity against cancer cells of the gastrointestinal tract was investigated. The results of the present study indicate that PJPC is an excellent source of lysine and threonine, while leucine is its limiting amino acid, with an amino acid score (AAS) of 65%. Moreover, PJPC contains substantial amounts of Fe, Mn, K, and Cu. As demonstrated experimentally, PJPC is also characterized by higher antioxidant potential than potato itself. Biological activity, however, is not limited to antioxidant activity alone. Cytotoxicity studies using a gastric cancer cell line (Hs 746T), a colon cancer cell line (HT-29), and human colon normal cells (CCD 841 CoN) proved that PJPC is characterized by selective activity against cancer cells. It can thus be concluded that the developed method of producing protein concentrate from potato juice affords a product with moderate nutritional value and interesting biological activity.

Structural Assessment and Catalytic Oxidation Activity of Hydrophobized Whey Proteins

Chemical modification of whey proteins allows manipulation of their characteristics, such as surface charge and hydrophobicity. Herein, we report the influence of hydrophobization accomplished by a preacetylation stage and a subsequent combined acetylation-heating process on some characteristics of whey proteins. Hydrophobization extensively (≥90%) acetylated the available free amino groups of whey proteins. The produced protein particles were nanoscaled (75 nm) and had a significantly low isoelectric point (3.70). Hydrophobization increased the β-sheet content of whey proteins and significantly decreased the solvent exposure of tyrosine residues. It also conferred a less compact tertiary structure to the proteins and decreased the extent of disulfide-bond formation by heating. The mobility of α-lactalbumin in nonreducing electrophoresis gel increased as a consequence of hydrophobization. Then, the ability of whey proteins to catalyze hydroquinone autoxidation was examined, and it was found that the activity decreased as a result of hydrophobization. The catalytic activity of the proteins was associated with the free-amino-group content, which determined the extent of cation-π attractive interactions; ζ-potential, which determined the extent of anion-π repulsive interactions; and π-stacking between hydrophobic residues and the electron cloud of the quinone ring.