Ice recrystallization inhibition activity of pulse protein hydrolysates after immobilized metal affinity separation.

Creating molecules capable of inhibiting ice recrystallization is an active research area aiming to improve the freeze-thaw characteristics of foods and biomedical materials. Peptide mixtures have shown promise in preventing freezing-induced damage, but less is known about the relationship between their amino acid compositions and ice recrystallization inhibition (IRI) activities. In this article, we used Ni2+ immobilized metal affinity chromatography (IMAC) to fractionate pulse protein hydrolysates, created by Alcalase and trypsin, into mixtures lacking and enriched in His, and Cys residues. The aim of this study was to fractionate pulse protein hydrolysates based on their amino acid compositions and evaluate their resulting physicochemical and IRI characteristics. Ni2+ IMAC fractionation induced IRI activity in all of the evaluated soy, chickpea, and pea protein hydrolysates regardless of their amino acid composition. Ni2+ IMAC fractionation produced chemically distinct fractions of peptides, differing by their molecular weights, amino acid composition, and IRI activities. The resulting peptide mixtures' molecular weight, amino acid composition, secondary structure, and sodium ion levels were found to have no correlation with their IRI activities. Thus, we demonstrate for the first time the ability of Ni2+ IMAC fractionation to induce IRI activity in hydrolyzed pulse proteins.

A comprehensive review on pulse protein fractionation and extraction: processes, functionality, and food applications.

The increasing world population requires the production of nutrient-rich foods. Protein is an essential macronutrient for healthy individuals. Interest in using plant proteins in foods has increased in recent years due to their sustainability and nutritional benefits. Dry and wet protein fractionation methods have been developed to increase protein yield, purity, and functional and nutritional qualities. This review explores the recent developments in pretreatments and fractionation processes used for producing pulse protein concentrates and isolates. Functionality differences between pulse proteins obtained from different fractionation methods and the use of fractionated pulse proteins in different food applications are also critically reviewed. Pretreatment methods improve the de-hulling efficiency of seeds prior to fractionation. Research on wet fractionation methods focuses on improving sustainability and functionality of proteins while studies on dry methods focus on increasing protein yield and purity. Hybrid methods produced fractionated proteins with higher yield and purity while also improving protein functionality and process sustainability. Dry and hybrid fractionated proteins have comparable or superior functionalities relative to wet fractionated proteins. Pulse protein ingredients are successfully incorporated into various food formulations with notable changes in their sensory properties. Future studies could focus on optimizing the fractionation process, improving protein concentrate palatability, and optimizing formulations using pulse proteins.

Recent advances in pulse protein conjugation and complexation with polyphenols: an emerging approach to improve protein functionality and health benefits.

Pulses have attracted much attention in the food industry due to their low cost, high yield, and high protein content, which promises to be excellent alternative protein sources. Recently, techniques for covalent and noncovalent binding of pulse proteins to polyphenols are expected to solve the problem of their poor protein functional properties. Additionally, these conjugates and complexes also show several health benefits. This review summarizes the formation of conjugates and complexes between pulse proteins and polyphenols through covalent and noncovalent binding and the impact of this structural change on protein functionalities and potential health benefits. Recent studies show that pulse protein functionalities can be influenced by polyphenol dose. This is mainly the case for adverse effects on solubility and enhancement in emulsifying capacity. Also, the conjugates/complexes exhibit antioxidant activity and can alter protein digestibility. The antioxidant activity of polyphenols could be retained after binding to proteins, while the effect on digestibility depends on the type or dosage of polyphenols. Considering the link between polyphenols and their potential health benefits, pulse polyphenols would be a good choice for producing the conjugates/complexes due to their low cost and proven potential benefits. Further studies on the structure-function-health benefits relationship of pulse protein-polyphenol conjugates and complexes are still required, as well as the validation of their application as functional foods in the food industry.

Prospects on emerging eco-friendly and innovative technologies to add value to dry bean proteins.

The world's growing population and evolving food habits have created a need for alternative plant protein sources, with pulses playing a crucial role as healthy staple foods. Dry beans are high-protein pulses rich in essential amino acids like lysine and bioactive peptides. They have gathered attention for their nutritional quality and potential health benefits concerning metabolic syndrome. This review highlights dry bean proteins' nutritional quality, health benefits, and limitations, focusing on recent eco-friendly emerging technologies for their obtaining and functionalization. Antinutritional factors (ANFs) in bean proteins can affect their in vitro protein digestibility (IVPD), and lectins have been identified as potential allergens. Recently, eco-friendly emerging technologies such as ultrasound, microwaves, subcritical fluids, high-hydrostatic pressure, enzyme technology, and dry fractionation methods have been explored for extracting and functionalizing dry bean proteins. These technologies have shown promise in reducing ANFs, improving IVPD, and modifying allergen epitopes. Additionally, they enhance the techno-functional properties of bean proteins, making them more soluble, emulsifying, foaming, and gel-forming, with enhanced water and oil-holding capacities. By utilizing emerging innovative technologies, protein recovery from dry beans and the development of protein isolates can meet the demand for alternative protein sources while being eco-friendly, safe, and efficient.

Dry beans are a source of lysine-rich proteins and high-quality AA for the diet.Physical treatments can reduce the ANFs of beans and increase protein digestibility.Eco-friendly technologies can treat, modify, extract, and separate bean proteins.Conformational changes with protein unfolding improve WHC, EA, and solubility.The combined use of emerging technologies allows for conveying advantages of each one.

Pulse Globulins 11S and 7S: Origins, Purification Methods, and Techno-functional Properties.

A growing interest in pulse proteins in recent years results from their crucial role in the transition toward sustainable food systems. Consequently, current research is mainly focused on the production of protein ingredients and the evaluation of their nutritional and techno-functional properties for the development of animal product analogues. However, the individual impacts of the major proteins 11S legumin and 7S vicilin on pulse techno-functionalities remains unclear. Thus, this review aims to represent current knowledge on pulse 11S and 7S globulin origins, extraction, separation, and purification methods as well as their techno-functionalities. This paper also discusses the principal challenges related to pulse vicilin and legumin purification methods, such as efficiency and environmental concerns, as well as 11S/7S ratio variability. This review highlights the fact that 11S and 7S fractions serve different purposes in pulse functionality and that more efficient and eco-friendly purification techniques are required to properly assess their respective functional attributes. Such research would allow the determination of optimal 11S/7S ratios for the integration of pulse protein ingredients in various food formulations. Hence, food industries would be able to select species/varieties, agronomical methods, and processing methods to produce ingredients with suitable 11S/7S ratios, catering to consumers' ethical, environmental, and nutritional concerns.

Pulse protein processing: The effect of processing choices and enzymatic hydrolysis on ingredient functionality.

Plant-based protein ingredients are an emerging solution to the environmental and health issues associated with animal-based proteins. Pulses have become a promising source of these plant-based ingredients. In order to produce functional proteins from pulse grains, extensive processing must be conducted to extract their proteins. These processing steps have consequential effects on the composition and structure of the resulting proteins which may modify their functional properties. This study reviews the most prominent options for each unit operation of pulse protein processing such as extraction, isolation, and drying. It also emphasizes the benefits and drawbacks of such methods and their effects on the pulse protein functionality. Furthermore, enzymatic hydrolysis is discussed as an optional processing step that is thought to counteract loss of functionality associated with pulse protein isolation. However, review of enzymatic hydrolysis literature reveals methodological issues in which insoluble and nonfunctional fractions of pulse protein hydrolysates are removed before analysis. This literature may draw into question the validity of the conventional wisdom that enzymatic hydrolysis is always beneficial to protein functionality.

Protein composition of pulses and their protein isolates from different sources and in different isolation pH values using a reverse phase high performance liquid chromatography method.

The objective of this study was to compare the composition of pulse proteins isolated from lentils and green and yellow peas at two isolation pH values (9 and 11) and determine the effect of this variability on protein functionality. Chromatogram peaks obtained from reverse-phase high performance liquid chromatography were identified by isolation of albumin-, vicilin- and legumin-rich fractions for the three pulses. Protein composition was obtained for each isolate and compared against that of the originating pulse flour. Lentil flour showed the highest level of vicilin with a vicilin/legumin ratio of âˆ¼ 2.5, while this ratio was 1.3 and 1.2 for green and yellow pea flour, respectively. Albumin content of yellow pea flour was high (∼36.1 %), which reduced to âˆ¼ 15-19 % in isolated proteins showing a loss in albumins during the isolation. Higher extraction pH increased pea protein yield but led to lower protein solubility with no changes in foaming properties and in-vitro digestibility.

Conversion of Pulse Protein Foam-Templated Oleogels into Oleofoams for Improved Baking Application.

The food industry has long been searching for an efficient replacement for saturated-fatty-acid-rich fats for baking applications. Although oleogels have been considered a potential alternative for saturated and trans fats, their success in food application has been poor. The present study explored the use of oleofoams obtained by whipping the pulse protein foam-templated oleogels for cake baking. Oleogels were prepared at room temperature by adding canola oil containing high-melting monoglyceride (MAG) or candelilla wax (CW) to the freeze-dried pea or faba bean protein-stabilized foams. Oleogels were then whipped to create the oleofoams; however, only the oleogels containing MAG could form oleofoams. CW-oleogel could not form any oleofoam. The most stable oleofoams with the highest overrun, stability, and storage modulus were obtained from 3% MAG+pulse protein foam-templated oleogels. The MAG plus protein foam-templated oleogels showed smaller and more packed air bubbles than MAG-only oleofoam, which was ascribed to the protein's ability to stabilize air bubbles and provide a network in the continuous oil phase to restrict air bubble movement. A novel batter preparation method for oleofoam was developed to increase air bubble incorporation. The X-ray microtomography images of the cakes showed a non-homogeneous distribution of larger air bubbles in the oleofoam cake compared to the shortening cake although their total porosity was not much different. The oleofoam cakes made with the new method yielded similar hardness and chewiness compared to the shortening cakes. By improving rheology and increasing air incorporation in the batter, high-quality cakes can be obtained with MAG-containing oleofoams made from pulse protein foam-templated oleogels.

Enzymatic Hydrolysis of Pulse Proteins as a Tool to Improve Techno-Functional Properties.

Pulse proteins are being increasingly investigated as nutritious and functional ingredients which could provide alternatives to animal proteins; however, pulse protein ingredients do not always meet the functionality requirements necessary for various applications. Consequently, enzymatic hydrolysis can be employed as a means of improving functional properties such as solubility, emulsifying, foaming, and gelling properties. This review aims to examine the current literature regarding modification of these properties with enzymatic hydrolysis. The effects of enzymatic hydrolysis on the functionality of pulse proteins generally varies considerably based on the enzyme, substrate, processing steps such as heat treatment, degree of hydrolysis, and pH. Differences in protease specificity as well as protein structure allow for a wide variety of peptide mixtures to be generated, with varying hydrophobic and electrostatic properties. Typically, the most significant improvements are seen when the original protein ingredient has poor initial functionality. Solubility is usually improved in the mildly acidic range, which may also correspond with improved foaming and emulsifying properties. More work should be carried out on the potential of enzymatic hydrolysis to modify gelation properties of pulse proteins, as the literature is currently lacking. Overall, careful selection of proteases and control of hydrolysis will be necessary to maximize the potential of enzymatic hydrolysis as a tool to improve pulse protein functionality and broaden the range of potential applications.

Functional Performance of Plant Proteins.

Increasingly, consumers are moving towards a more plant-based diet. However, some consumers are avoiding common plant proteins such as soy and gluten due to their potential allergenicity. Therefore, alternative protein sources are being explored as functional ingredients in foods, including pea, chickpea, and other legume proteins. The factors affecting the functional performance of plant proteins are outlined, including cultivars, genotypes, extraction and drying methods, protein level, and preparation methods (commercial versus laboratory). Current methods to characterize protein functionality are highlighted, including water and oil holding capacity, protein solubility, emulsifying, foaming, and gelling properties. We propose a series of analytical tests to better predict plant protein performance in foods. Representative applications are discussed to demonstrate how the functional attributes of plant proteins affect the physicochemical properties of plant-based foods. Increasing the protein content of plant protein ingredients enhances their water and oil holding capacity and foaming stability. Industrially produced plant proteins often have lower solubility and worse functionality than laboratory-produced ones due to protein denaturation and aggregation during commercial isolation processes. To better predict the functional performance of plant proteins, it would be useful to use computer modeling approaches, such as quantitative structural activity relationships (QSAR).

Advanced and feasible pulses processing technologies for Ethiopia to achieve better economic and nutritional goals: A review.

BACKGROUND: Pulses are the dried seeds of the Leguminosae family that serve as cheaper proteins, particularly in developing countries. They contain proteins ranging 20-25%. Pulses play important roles in the farming systems and in the diets of poor people. They are ideal crops for simultaneously achieving three key developmental goals: reducing poverty, improving human health, and enhancing ecosystem sustainability. The year 2016 was declared as the year of pulses by the United Nations. These growing global attentions given to legumes has resulted in increasing their nutritional and economic desirability. OBJECTIVES: This review presents the potential of pulses processing in Ethiopia for enhanced nutritional and economic outcomes. Pulses are important foods and export commodity in Ethiopia, which are exported in unprocessed form, fetching low returns. DATA AND DISCUSSIONS: There are advanced but simple pulses processing technologies that include concentrating or isolation of proteins for nutritional and other uses. Pin milling of legumes and air classification of the flour helps to obtain protein concentrate of 60-75% purity. Protein isolation by alkaline extraction and isoelectric precipitation results in proteins of 90-95% purity. Legume proteins are mainly globulins and albumins that are nutritionally of great quality. The protein products are being texturized by thermal and mechanical means to make meat analogues, substitutes and extenders. SUMMARY AND CONCLUSION: Ethiopia being one of the significant legume producers, can benefit from this growing market by adopting the processing technologies and exporting premium quality plant proteins. This help Ethiopia satisfy domestic protein needs for child nutrition. This review summarizes the potentials for developing pulses processing technologies in Ethiopia for better economic and nutritional benefits.

Physicochemical and functional properties of red lentil protein isolates from three origins at different pH.

Red lentils (Lens culinaris) present an attractive raw material for meat mimics due to its red-coloured proteins, abundance, high protein and low cost. However, data on its functional properties at various pH remain scarce. In this study, the physicochemical and functional properties of red lentil proteins (RLP) from three origins (USA, Nepal and Turkey), isolated by isoelectric precipitation, were evaluated. Amino acid profiles, water holding (ranging from 3.1 to 3.5 g/g) and oil absorption (ranging from 5.8 to 7.3 g/g) capacities of RLP samples were significantly different (p < 0.05). RLP consisted of legumin and vicilin, and comprised predominantly glutamine/glutamic acid (ranging from 8.72 to 10.55 g/100 g). Surface charge, protein solubility, foaming and emulsifying properties were the lowest and poorest at pH 5.2 (isoelectric point). Overall, good functional properties of RLP under high acidity and alkalinity conditions make it a promising protein for mimicking a wide range of meats.

Heat induced gelation of pulse protein networks.

This study examines the effect of salts (0.5 M NaCl or 0.25 M CaCl2) and protein concentration (7.5-15%) on the gel-forming abilities of lentil (LPC), yellow pea (YPC), and faba bean (FPC) protein concentrates formed at pH 7.0. The surface hydrophobicity of YPC (84.8 arbitrary units, a.u.) was found to be lower than LPC (147.2 a.u.) and FPC (135.0 a.u.). In contrast, the surface charge for LPC, YPC, and FPC was -37.8, -28.4, and -29.3 mV, respectively. The Lg/Vn ratio of YPCs was determined as 0.65 followed by LPC (0.57) and FPC (0.41). The presence of salts reduced the least gelling concentration. LPC and FPC also appeared to have a more ordered structure than YPC as evident by CLSM. The network appeared more ordered as the protein concentration increased or in the presence of NaCl or CaCl2 according to CLSM and synchrotron based micro computed tomography (µCT).

Comparison of legume and dairy proteins for the impact of Maillard conjugation on nanoemulsion formation, stability, and lutein color retention.

While dairy proteins have traditionally been used to stabilize nanoemulsions, there is a trend towards plant-based formulations. Additionally, both types of protein are poorly soluble near their isoelectric point. The main goals of this research were to develop and characterize Maillard conjugates from pea protein (PPI) or caseinate and dextran, and to evaluate the physical stability of nanoemulsions made with such emulsifiers at various ionic strengths, pH = 4.6, and temperatures during storage, as well as lutein color retention over storage. Protein conjugates formed nanoemulsions with diameters of 125 ± 12 nm (PDI = 0.13 ± 0.00) and 269 ± 36 nm (PDI = 0.76 ± 0.42) (pH = 7) for caseinate and PPI, respectively. Conjugation improved the physical stability (droplet size) of emulsions at the isoelectric point, during storage at 4-55 °C, and in ionic solutions. Lutein color degradation was better associated with particle size than conjugation and was lowest for PPI-stabilized emulsions. This study suggests that Maillard conjugation could improve PPI emulsification properties.

Physicochemical properties and gelling behaviour of Bambara groundnut protein isolates and protein-enriched fractions.

Plant proteins, and specifically those from legume crops, are increasingly recognised as sustainable and functional food ingredients. In this study, we expand on the knowledge of Bambara groundnut (Vigna subterranea (L.) Verdc.) [BGN] proteins, by characterising the composition, microstructure and rheological properties of BGN protein isolates obtained via wet extraction and protein-enriched fractions obtained via dry fractionation. The BGN protein isolates were compared in the context of the major storage protein, vicilin, as previously identified. Molecular weight analysis performed with gel electrophoresis and size-exclusion chromatography coupled to light-scattering, revealed some major bands (190 kDa) and elution patterns with molecular weights (205.6-274.1 kDa) corresponding to that of BGN vicilin, whilst the thermal denaturation temperature (Tp 91.1 °C, pH 7) of BGN protein isolates also coincided to that of the vicilin fraction. Furthermore, the concentration dependence of the elastic modulus G' of the BGN protein isolates, closely resembled that of BGN vicilin (both upon NaCl addition); suggesting that vicilin is the main component responsible for gelation. Confocal laser scanning and scanning electron micrographs revealed inhomogeneous aggregate structures, which implies that fractal scaling were better suited for description of the BGN protein isolate gel networks. Concerning the BGN protein-enriched fractions, both rotor and impact milling with air jet sieving and air classification, respectively, were successfully applied to separate these fractions from those high in starch; as evident from compositional analysis, particle size distributions and microscopic imaging. When considering sustainability aspects, dry fractionation could thus be a viable alternative for producing BGN protein-enriched fractions.