The potential of dry fractionation processes for sustainable plant protein production

Plant Protein-Based Delivery Systems: An Emerging Approach for Increasing the Efficacy of Lipophilic Bioactive Compounds

The development of plant protein-based delivery systems to protect and control lipophilic bioactive compound delivery (such as vitamins, polyphenols, carotenoids, polyunsaturated fatty acids) has increased interest in food, nutraceutical, and pharmaceutical fields. The quite significant ascension of plant proteins from legumes, oil/edible seeds, nuts, tuber, and cereals is motivated by their eco-friendly, sustainable, and healthy profile compared with other sources. However, many challenges need to be overcome before their widespread use as raw material for carriers. Thus, modification approaches have been used to improve their techno-functionality and address their limitations, aiming to produce a new generation of plant-based carriers (hydrogels, emulsions, self-assembled structures, films). This paper addresses the advantages and challenges of using plant proteins and the effects of modification methods on their nutritional quality, bioactivity, and techno-functionalities. Furthermore, we review the recent progress in designing plant protein-based delivery systems, their main applications as carriers for lipophilic bioactive compounds, and the contribution of protein-bioactive compound interactions to the dynamics and structure of delivery systems. Expressive advances have been made in the plant protein area; however, new extraction/purification technologies and protein sources need to be found Their functional properties must also be deeply studied for the rational development of effective delivery platforms.

Chickpea protein ingredients: A review of composition, functionality, and applications

Chickpea (Cicer arietinum L.) is a pulse consumed all over the world, representing a good source of protein, as well as fat, fiber, and other carbohydrates. As a result of the growing global population the demand for the protein component of this pulse is increasing and various approaches have been proposed and developed to extract same. In this review the composition, functionality, and applications of chickpea protein ingredients are described. Moreover, methods to enhance protein quality have been identified, as well as applications of the coproducts resulting from protein extraction and processing. The principal dry and wet protein enrichment approaches, resulting in protein concentrates and isolates, include air classification, alkaline/acid extraction, salt extraction, isoelectric precipitation, and membrane filtration. Chickpea proteins exhibit good functional properties such as solubility, water and oil absorption capacity, emulsifying, foaming, and gelling. During protein enrichment, the functionality of protein can be enhanced in addition to primary processing (e.g., germination and dehulling, fermentation, enzymatic treatments). Different applications of chickpea protein ingredients, and their coproducts, have been identified in research, highlighting the potential of these ingredients for novel product development and improvement of the nutritional profile of existing food products. Formulations to meet consumer needs in terms of healthy and sustainable foods have been investigated in the literature and can be further explored. Future research may be useful to improve applications of the specific coproducts that result from the extraction of chickpea proteins, thereby leading to more sustainable processes.

Grains - a major source of sustainable protein for health

Cereal grains are the main dietary source of energy, carbohydrates, and plant proteins world-wide. Currently, only 41% of grains are used for human consumption, and up to 35% are used for animal feed. Cereals have been overlooked as a source of environmentally sustainable and healthy plant proteins and could play a major role in transitioning towards a more sustainable food system for healthy diets. Cereal plant proteins are of good nutritional quality, but lysine is often the limiting amino acid. When consumed as whole grains, cereals provide health-protecting components such as dietary fiber and phytochemicals. Shifting grain use from feed to traditional foods and conceptually new foods and ingredients could improve protein security and alleviate climate change. Rapid development of new grain-based food ingredients and use of grains in new food contexts, such as dairy replacements and meat analogues, could accelerate the transition. This review discusses recent developments and outlines future perspectives for cereal grain use.

Emulsifying properties of lentil protein preparations obtained by dry fractionation

Dry fractionated legume protein ingredients are gaining attention as alternatives to conventional solvent extracted legume proteins, being more resource efficient and often exhibiting novel functional properties. However, lack of knowledge about the relationship between composition and functionality limit a more wide-spread use of dry-fractionated legume protein in applications. In this study, lentil fractions of different degrees of refinement were prepared using air classification having protein and starch contents of 16–59% and 4–64%, respectively. The dry fractionated lentil fractions could emulsify and stabilize 10 wt% oil-in-water emulsions, while a conventional lentil protein isolate used for comparison was not able to form stable emulsions. The latter had significantly larger mean droplet diameters (around 20 µm) due to droplet flocculation than emulsions made with the different lentil fractions ranging between 0.3 and 5.5 µm. Similar surface charges (between −22 and −31 mV) indicated that the discrepancy could be ascribed to differences in steric repulsion and mechanical strength of the interfacial layers between conventionally and dry fractionated lentil. Storage stability tests of emulsions stabilized with dry fractionated samples resulted in separation into a low and higher density phase with the individual droplets being stable against coalescence in both phases. The phase separation was attributed to gravimetrical sedimentation of larger insoluble components accumulating in the denser phase, which was impacted by the degree of refinement by air classification. The results highlight the potential of dry fractionation for the production of sustainable ingredients with unique composition and functionality.

Non-animal proteins as cutting-edge ingredients to reformulate animal-free foodstuffs: Present status and future perspectives

Consumer interest in protein rich diets is increasing, with more attention being paid to the protein source. Despite the occurrence of animal proteins in the human diet, non-animal proteins are gaining popularity around the world due to their health benefits, environmental sustainability, and ethical merit. These sources of protein qualify for vegan, vegetarian, and flexitarian diets. Non-animal proteins are versatile, derived mainly from cereals, vegetables, pulses, algae (seaweed and microalgae), fungi, and bacteria. This review's intent is to analyze the current and future direction of research and innovation in non-animal proteins, and to elucidate the extent (limitations and opportunities) of their applications in food and beverage industries. Prior knowledge provided relevant information on protein features (processing, structure, and techno-functionality) with particular focus on those derived from soy and wheat. In the current food landscape, beyond conventionally used plant sources, other plant proteins are gaining traction as alternative ingredients to formulate animal-free foodstuffs (e.g., meat alternatives, beverages, baked products, snack foods, and others). Microbial proteins derived from fungi and algae are also food ingredients of interest due to their high protein quantity and quality, however there is no commercial food application for bacterial protein yet. In the future, key points to consider are the importance of strain/variety selection, advances in extraction technologies, toxicity assessment, and how this source can be used to create food products for personalized nutrition.

Alternative Protein Sources as Technofunctional Food Ingredients

Proteins obtained from alternative sources such as plants, microorganisms, and insects have attracted considerable interest in the formulation of new food products that have a lower environmental footprint and offer means to feed a growing world population. In contrast to many established proteins, and protein fractions for which a substantial amount of knowledge has accumulated over the years, much less information is available on these emerging proteins. This article reviews the current state of knowledge on alternative proteins and their sources, highlighting gaps that currently pose obstacles to their more widespread application in the food industry. The compositional, structural, and functional properties of alternative proteins from various sources, including plants, algae, fungi, and insects, are critically reviewed. In particular, we focus on the factors associated with the creation of protein-rich functional ingredients from alternative sources. The various protein fractions in these sources are described as well as their behavior under different environmental conditions (e.g., pH, ionic strength, and temperature). The extraction approaches available to produce functional protein ingredients from these alternative sources are introduced as well as challenges associated with designing large-scale commercial processes. The key technofunctional properties of alternative proteins, such as solubility, interfacial activity, emulsification, foaming, and gelation properties, are introduced. In particular, we focus on the formation of isotropic and anisotropic structures suitablefor creating meat and dairy product analogs using various structuring techniques. Finally, selected studies on consumer acceptance and sustainability of alternative protein products are considered.

Impact of ultra-fine milling and air classification on biochemical and techno-functional characteristics of wheat and rye bran

Dry milling and air classification were applied to produce three different ingredients from wheat and rye brans. Dried and pin disc-milled brans having particle size medians of 89-131 µm were air classified to produce protein- and soluble dietary fibre-enriched hybrid ingredients (median particle size 7-9 µm) and additionally brans were ultra-finely milled (median particle size 17-19 µm). The samples were characterised in regard to their composition and techno-functional properties. In air classification, protein content increased from 16.4 and 14.7% to 30.9 and 30.7% for wheat and rye brans, which corresponded to protein separation efficiencies of 18.0 and 26.9%, respectively. Concurrently, the ratio between soluble and insoluble dietary fibre increased from 0.22 to 0.85 for wheat and from 0.56 to 1.75 for rye bran. The protein- and soluble dietary fibre-enriched wheat bran fraction showed improved protein solubility at alkaline pH when compared to pin disc- and ultra-finely-milled wheat bran, whereas less difference between the wheat ingredients was observed at native and acidic pH. The protein- and soluble dietary fibre-enriched rye bran fraction exhibited lower solubility than the pin disc- or ultra-finely-milled rye brans at all the studied pH-values. Ultra-fine milling alone decreased protein solubility and increased damaged starch content when compared to the pin disc-milled brans. Both protein enrichment and ultra-fine milling improved colloidal stability in comparison to the pin disc-milled raw materials. The lowest water and oil binding capacities were obtained for the protein-enriched fractions. Ultrasound-assisted emulsification of the protein- and soluble dietary fibre-enriched fractions and the ultra-finely-milled brans revealed no major differences in the visual quality or stability of the emulsions. The results suggest that modification of the techno-functional properties of cereal brans may be acquired via both air classification and ultra-fine milling.

Fava bean (Vicia faba L.) for food applications: From seed to ingredient processing and its effect on functional properties, antinutritional factors, flavor, and color

The food industry, along with the consumers, is interested in plant-based diet because of its health benefits and environmental sustainability. Vicia faba L. (V. faba) is a promising source of pulse proteins for the human diet and can yield potential nutritional and functional ingredients, namely, flours, concentrates, and isolates, which are relevant for industrial food applications. Different processes produce and functionalize V. faba ingredients relevant for industrial food applications, along with various alternatives within each unit operation used in their production. Processing modifies functional properties of the ingredients, which can occur by (i) changing in overall nutritional composition after processing steps and/or (ii) modifying the structure and conformation of protein and of other components present in the ingredients. Furthermore, V. faba limitations due to off-flavor, color, and antinutritional factors are influenced by ingredient production and processing that play a significant role in their consumer acceptability in foods. This review attempts to elucidate the influence of different ways of processing on the functional, sensory, and safety aspects of V. faba L. ingredients, highlighting the need for further research to better understand how the food industry could improve their utilization in the market.

State-of-the-Art Production Chains for Peas, Beans and Chickpeas-Valorization of Agro-Industrial Residues and Applications of Derived Extracts

The world is confronted with the depletion of natural resources due to their unsustainable use and the increasing size of populations. In this context, the efficient use of by-products, residues and wastes generated from agro-industrial and food processing opens the perspective for a wide range of benefits. In particular, legume residues are produced yearly in very large amounts and may represent an interesting source of plant proteins that contribute to satisfying the steadily increasing global protein demand. Innovative biorefinery extraction cascades may also enable the recovery of further bioactive molecules and fibers from these insufficiently tapped biomass streams. This review article gives a summary of the potential for the valorization of legume residual streams resulting from agro-industrial processing and more particularly for pea, green bean and chickpea by-products/wastes. Valuable information on the annual production volumes, geographical origin and state-of-the-art technologies for the extraction of proteins, fibers and other bioactive molecules from this source of biomass, is exhaustively listed and discussed. Finally, promising applications, already using the recovered fractions from pea, bean and chickpea residues for the formulation of feed, food, cosmetic and packaging products, are listed and discussed.

Comparison of Faba Bean Protein Ingredients Produced Using Dry Fractionation and Isoelectric Precipitation: Techno-Functional, Nutritional and Environmental Performance

Dry fractionated faba bean protein-rich flour (FPR) produced by milling/air classification, and faba bean protein isolate (FPI) produced by acid extraction/isoelectric precipitation were compared in terms of composition, techno-functional properties, nutritional properties and environmental impacts. FPR had a lower protein content (64.1%, dry matter (DM)) compared to FPI (90.1%, DM), due to the inherent limitations of air classification. Of the two ingredients, FPR demonstrated superior functionality, including higher protein solubility (85%), compared to FPI (32%) at pH 7. Foaming capacity was higher for FPR, although foam stability was similar for both ingredients. FPR had greater gelling ability compared to FPI. The higher carbohydrate content of FPR may have contributed to this difference. An amino acid (AA) analysis revealed that both ingredients were low in sulfur-containing AAs, with FPR having a slightly higher level than FPI. The potential nutritional benefits of the aqueous process compared to the dry process used in this study were apparent in the higher in vitro protein digestibility (IVPD) and lower trypsin inhibitor activity (TIA) in FPI compared to FPR. Additionally, vicine/convicine were detected in FPR, but not in FPI. Furthermore, much lower levels of fermentable oligo-, di- and monosaccharides, and polyols (FODMAPs) were found in FPI compared to FPR. The life cycle assessment (LCA) revealed a lower environmental impact for FPR, partly due to the extra water and energy required for aqueous processing. However, in a comparison with cow's milk protein, both FPR and FPI were shown to have considerably lower environmental impacts.

Proteomic Analysis of Irradiation with Millimeter Waves on Soybean Growth under Flooding Conditions

Improving soybean growth and tolerance under environmental stress is crucial for sustainable development. Millimeter waves are a radio-frequency band with a wavelength range of 1-10 mm that has dynamic effects on organisms. To investigate the potential effects of millimeter-waves irradiation on soybean seedlings, morphological and proteomic analyses were performed. Millimeter-waves irradiation improved the growth of roots/hypocotyl and the tolerance of soybean to flooding stress. Proteomic analysis indicated that the irradiated soybean seedlings recovered under oxidative stress during growth, whereas proteins related to glycolysis and ascorbate/glutathione metabolism were not affected. Immunoblot analysis confirmed the promotive effect of millimeter waves to glycolysis- and redox-related pathways under flooding conditions. Sugar metabolism was suppressed under flooding in unirradiated soybean seedlings, whereas it was activated in the irradiated ones, especially trehalose synthesis. These results suggest that millimeter-waves irradiation on soybean seeds promotes the recovery of soybean seedlings under oxidative stress, which positively regulates soybean growth through the regulation of glycolysis and redox related pathways.

Use of Sieving As a Valuable Technology to Produce Enriched Buckwheat Flours: A Preliminary Study

Fractionation processes based on physical separation are a good strategy to produce enriched cereal flours. Therefore, the aim of this work is to evaluate the suitability of sieving of buckwheat flours to produce protein and phenolic (especially rutin) enriched fractions. Because of that, dehulled whole buckwheat flour (GSTQ) was sieved obtaining fractions with a particle size of 215 µm, 160 µm, 85 µm, and 45 µm (GS215, GS160, GS85, and GS45). For that purpose, the determination of protein, ash, and total starch content and free and bound phenolic compounds was carried out. The highest content of total phenolic compounds was obtained in GS215 (3118.84 mg Kg-1 d.w.), followed by GS160 (2499.11 mg Kg-1 d.w.), GS85 (989.46 mg Kg-1 d.w.), GSTQ (983.15 mg Kg-1 d.w.), and GS45 (481.31 mg Kg-1 d.w.). Therefore, the phenolic content decreased with the particle size decrease from 215 µm to 45 µm. Besides, there were no significant differences between the total phenolic content in GS85 and GSTQ. The fraction with 215 µm reported the highest protein and mineral salt content and presented rutin amounts four times higher than GSTQ.

Food processing for the improvement of plant proteins digestibility

Proteins are essential macronutrients for the human diet. They are the primary source of nitrogen and are fundamental for body structure and functions. The plant protein quality (PPQ) refers to the bioavailability, digestibility, and amino acid composition. The digestibility specifies the protein quantity absorbed by an organism relative to the consumed amount and depends on the protein structure, previous processing, and the presence of compounds limiting the digestion. The latter are so-called antinutritional factors (ANF), exemplified by phytates, tannins, trypsin inhibitors, and lectins. Animal proteins are known to have better digestibility than plant proteins due to the presence of ANF in plants. Thus, the inactivation of ANF throughout food processing may increase the PPQ. New food processing, aiming to increase the digestibility of plant proteins, and new sources of proteins are being studied for the animal protein substitution. Here, it is presented the impact of processing on the protein digestibility and reduction of ANF. Several techniques, such as cooking, autoclaving, germination, microwave, irradiation, spray- and freeze-drying, fermentation, and extrusion enhanced the PPQ. The emerging non-thermal technologies impact on protein functionalities but require studies on the protein digestibility. How to accurately determine and how to improve the protein digestibility of a plant source remains a scientific and technological challenge that may be addressed by novel or combining existing processing techniques, as well as by exploring protein-enriched by-products of the food industry.

Just the tonic! Legume biorefining for alcohol has the potential to reduce Europe's protein deficit and mitigate climate change

Industrialised agriculture is heavily reliant upon synthetic nitrogen fertilisers and imported protein feeds, posing environmental and food security challenges. Increasing the cultivation of leguminous crops that biologically fix nitrogen and provide high protein feed and food could help to address these challenges. We report on the innovative use of an important leguminous crop, pea (Pisum sativum L.), as a source of starch for alcohol (gin) production, yielding protein-rich animal feed as a co-product. We undertook life cycle assessment (LCA) to compare the environmental footprint of 1 L of packaged gin produced from either 1.43 kg of wheat grain or 2.42 kg of peas via fermentation and distillation into neutral spirit. Allocated environmental footprints for pea-gin were smaller than for wheat-gin across 12 of 14 environmental impact categories considered. Global warming, resource depletion, human toxicity, acidification and terrestrial eutrophication footprints were, respectively, 12%, 15%, 15%, 48% and 68% smaller, but direct land occupation was 112% greater, for pea-gin versus wheat-gin. Expansion of LCA boundaries indicated that co-products arising from the production of 1 L of wheat- or pea-gin could substitute up to 0.33 or 0.66 kg soybean animal feed, respectively, mitigating considerable greenhouse gas emissions associated with land clearing, cultivation, processing and transport of such feed. For pea-gin, this mitigation effect exceeds emissions from gin production and packaging, so that each L of bottled pea gin avoids 2.2 kg CO2 eq. There is great potential to scale the use of legume starches in production of alcoholic beverages and biofuels, reducing dependence on Latin American soybean associated with deforestation and offering considerable global mitigation potential in terms of climate change and nutrient leakage - estimated at circa 439 Tg CO2 eq. and 8.45 Tg N eq. annually.

Protein extraction from agri-food residues for integration in biorefinery: Potential techniques and current status

The biorefinery concept is attracting scientific and policy attention as a promising option for enhancing the benefits of agri-food biomass along with a reduction of the environmental impact. Obtaining bioproducts based on proteins from agri-food residues could help to diversify the revenue stream in a biorefinery. In fact, the extracted proteins can be applied as such or in the form of hydrolyzates due to their nutritional, bioactive and techno-functional properties. In this context, the present review summarizes, exemplifies and discusses conventional extraction methods and current trends to extract proteins from residues of the harvesting, post-harvesting and/or processing of important crops worldwide. Moreover, those extraction methods just integrated in a biorefinery scheme are also described. In conclusion, a plethora of methods exits but only some of them have been applied in biorefinery designs, mostly at laboratory scale. Their economic and technical feasibility at large scale requires further study.

Fractionation and grain hardness effect on protein profiling, pasting and rheological properties of flours from medium-hard and extraordinarily soft wheat varieties

In the present study coarse fraction (CF), medium fine fraction (MFF) and fine fraction (FF) were separated from flours milled from medium-hard and extraordinarily soft wheat varieties and were evaluated for various quality characteristics. Grain hardness of medium-hard and extraordinarily soft wheat varieties varied from 77 to 80 and 17 to 18, respectively. Ash and protein content was the highest for FF and the lowest for CF. Varieties with greater hardness produced higher CF and lower of FF. FF showed higher unextractable polymeric protein (UnEx-PP) and dough stability as compared to MFF and CF. FF showed lower damage starch content as related by lower Sodium SRC (NaSRC) as compared to MFF and FF. CF showed higher paste viscosities than FF and difference were greater amongst fractions from varieties with lower grain hardness. FF with greater proportion of small size particles showed greater accumulation of 98 kDa and 85 kDa PPs than CF. This study demonstrated that fractionation of flours can be employed to produce fractions with varied gluten strength required for production of various products.