Proteins from land plants – Potential resources for human nutrition and food security

Composition, Protein Profile and Rheological Properties of Pseudocereal-Based Protein-Rich Ingredients

The objectives of this study were to investigate the nutrient composition, protein profile, morphology, and pasting properties of protein-rich pseudocereal ingredients (quinoa, amaranth, and buckwheat) and compare them to the more common rice and maize flours. Literature concerning protein-rich pseudocereal ingredients is very limited, mainly to protein profiling. The concentrations of macronutrients (i.e., ash, fat, and protein, as well as soluble, insoluble and total dietary fibre) were significantly higher for the protein-rich variants of pseudocereal-based flours than their regular protein content variants and the rice and maize flours. On profiling the protein component using sodium dodecyl sulfate⁻polyacrylamide gel electrophoresis (SDS-PAGE), all samples showed common bands at ~50 kDa and low molecular weight bands corresponding to the globulin fraction (~50 kDa) and albumin fraction (~10 kDa), respectively; except rice, in which the main protein was glutelin. The morphology of the starch granules was studied using scanning electron microscopy with quinoa and amaranth showing the smallest sized granules, while buckwheat, rice, and maize had the largest starch granules. The pasting properties of the ingredients were generally similar, except for buckwheat and amaranth, which showed the highest and lowest final viscosity, respectively. The results obtained in this study can be used to better understand the functionality and food applications of protein-rich pseudocereal ingredients.

Development of a Sono-Assembled, Bifunctional Soy Peptide Nanoparticle for Cellular Delivery of Hydrophobic Active Cargoes

Soy proteins are prone to aggregate upon proteolysis, hindering their sustainable development in food processing. Here, a continuous work on the large insoluble peptide aggregates was carried out, aiming to develop a new type of soy peptide-based nanoparticle (SPN) for active cargo delivery. Sono-assembled SPN in spherical appearance and core-shell structure maintained by noncovalent interactions was successfully fabricated, exhibiting small particle size (103.95 nm) in a homogeneous distribution state (PDI = 0.18). Curcumin as a model cargo was efficiently encapsulated into SPN upon sonication, showing high water dispersity (129.6 mg/L, 10⁴ higher than its water solubility) and storage stability. Additionally, the pepsin-resistant SPN contributed to the controlled release of curcumin at the intestinal phase and thus significantly improved the bioaccessibility. Encapsulated curcumin was effective in protecting glutamate-induced toxicity in PC12 cells, where the matrix SPN can simultaneously reduce lipid peroxidation and elevate antioxidant enzymes levels, innovatively demonstrating its bifunctionality during cellular delivery.

Vegan-mycoprotein concentrate from pea-processing industry byproduct using edible filamentous fungi

Background

Currently around one billion people in the world do not have access to a diet which provides enough protein and energy. However, the production of one of the main sources of protein, animal meat, causes severe impacts on the environment. The present study investigates the production of a vegan-mycoprotein concentrate from pea-industry byproduct (PpB), using edible filamentous fungi, with potential application in human nutrition. Edible fungal strains of Ascomycota (Aspergillus oryzae, Fusarium venenatum, Monascus purpureus, Neurospora intermedia) and Zygomycota (Rhizopus oryzae) phyla were screened and selected for their protein production yield.

Results

A. oryzae had the best performance among the tested fungi, with a protein yield of 0.26 g per g of pea-processing byproduct from the bench scale airlift bioreactor cultivation. It is estimated that by integrating the novel fungal process at an existing pea-processing industry, about 680 kg of fungal biomass attributing to about 38% of extra protein could be produced for each 1 metric ton of pea-processing byproduct. This study is the first of its kind to demonstrate the potential of the pea-processing byproduct to be used by filamentous fungi to produce vegan-mycoprotein for human food applications.

Conclusion

The pea-processing byproduct (PpB) was proved to be an efficient medium for the growth of filamentous fungi to produce a vegan-protein concentrate. Moreover, an industrial scenario for the production of vegan-mycoprotein concentrate for human nutrition is proposed as an integrated process to the existing PPI production facilities.

Invited review: Resource inputs and land, water and carbon footprints from the production of edible protein of animal origin

Abstract. The objective of this review is to analyze crucial factors in the output from the production of proteins in food of animal origin, such as milk, meat and eggs. We then consider inputs such as land, water, fuel, minerals and feed, as well as characterize emissions. Finally, we estimate footprints for land (land footprint, LF), water (water footprint, WF) and greenhouse gas emissions (i.e., carbon footprint, CF) during the production process. The wide range of different land and water inputs per unit feed between various studies largely influences the results. Further influencing factors are species and categories of animals that produce edible protein, their yields and the feeding of animals. Coproducts with no or low humanly edible fractions and grassland as feed contribute to a lower need for arable land and lower LF, WF and CF. The most efficient land use or the lowest LF per kilogram of edible protein was estimated for higher milk and egg yields; the highest LF values were calculated for beef, followed by pork. The lowest WF and CF were calculated for edible protein of chicken meat and eggs. Edible protein from ruminants is mostly characterized by a higher CF because of the high greenhouse gas potential of methane produced in the rumen. A key prerequisite for further progress in this field is the harmonization of data collection and calculation methods. Alternatives to partial or complete replacement of protein of terrestrial animals, such as marine animals, insects, cell cultures, single-cell proteins or “simulated animal products” from plants, as well as changing eating patterns and reducing food losses are mentioned as further potential ways for more efficient feed production. For all those dealing with plant or animal breeding and cultivation and all those who are working along the whole food production chain, it is a major challenge to enhance the production of more food for more people with, at the same time, less, limited resources and lower emissions.

Characterization of Linkage Disequilibrium and Population Structure in a Mungbean Diversity Panel

Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] is an important grain legume globally, providing a high-quality plant protein source largely produced and consumed in South and East Asia. This study aimed to characterize a mungbean diversity panel consisting of 466 cultivated accessions and demonstrate its utility by conducting a pilot genome-wide association study of seed coat color. In addition 16 wild accessions were genotyped for comparison and in total over 22,000 polymorphic genome-wide SNPs were identified and used to analyze the genetic diversity, population structure, linkage disequilibrium (LD) of mungbean. Polymorphism was lower in the cultivated accessions in comparison to the wild accessions, with average polymorphism information content values 0.174, versus 0.305 in wild mungbean. LD decayed in ∼100 kb in cultivated lines, a distance higher than the linkage decay of ∼60 kb estimated in wild mungbean. Four distinct subgroups were identified within the cultivated lines, which broadly corresponded to geographic origin and seed characteristics. In a pilot genome-wide association mapping study of seed coat color, five genomic regions associated were identified, two of which were close to seed coat color genes in other species. This mungbean diversity panel constitutes a valuable resource for genetic dissection of important agronomical traits to accelerate mungbean breeding.

Development of novel quinoa-based yoghurt fermented with dextran producer Weissella cibaria MG1

The aim of this study was to develop a novel beverage fermented with Weissella cibaria MG1 based on aqueous extracts of wholemeal quinoa flour. The protein digestibility of quinoa based-milk was improved by applying complex proteolytic enzymes able to increase protein solubility by 54.58%. The growth and fermentation characteristics of Weissella cibaria MG1, including EPS production at the end of fermentation, were investigated. Fermented wholemeal quinoa milk using MG1 showed high viable cell counts (>10⁹cfu/ml), a pH of 5.16, and significantly higher water holding capacity (WHC, 100%), viscosity (0.57mPas) and exopolysaccharide (EPS) amount (40mg/l) than the chemical acidified control. High EPS (dextran) concentration in quinoa milk caused earlier aggregation because more EPS occupy more space, and the chenopodin were forced to interact with each other. Microstructure observation indicated that the network structures of EPS-protein improve the texture of fermented quinoa milk. Overall, Weissella cibaria MG1 showed satisfactory technology properties and great potential for further possible application in the development of high viscosity fermented quinoa milk.

Impact of protease and amylase treatment on proteins and the product quality of a quinoa-based milk substitute

Plant proteins are often characterized by low solubilities and impaired functionalities e.g. emulsifying properties.

Protein efficiency in intensive dairy production: a Swedish example

BACKGROUND

Animal agriculture has been criticised in terms of its sustainability from several perspectives. Ruminants such as dairy cows can transform inedible, low-quality protein in roughage and by-products from the food industry into the high-quality protein found in milk and meat. Evaluation of the protein conversion efficiency of dairy production from a sustainability and resource perspective must be based on the proportion of the animal feed edible to humans. A relevant metric is thus edible feed protein conversion ratio (eFPCR), i.e. human-edible protein output in cow's milk per unit human-edible protein input in feed. In this study, eFPCR was calculated for five regionally adapted and realistic feed rations fed to Swedish dairy cows producing different annual milk yields typical for high-yielding, intensive dairy production.

RESULTS

All scenarios except one showed a protein efficiency ratio of >1 for human-edible protein. Thus, depending on the composition of their diet, most Swedish dairy cows can convert human-inedible protein into edible, high-value protein. However, higher milk yield led to a decrease in eFPCR, regardless of diet.

CONCLUSION

Dairy cows in high-yielding, intensive production systems such as those used in Sweden have the capacity to convert low-value inedible protein into high-value edible protein. However, a minor part of the dairy cow diet is edible for humans and this fraction must be minimised to justify dairy production. These results are in line with previous findings on protein conversion efficiency and add scientific input to the debate on sustainable food systems and sustainable diets. © 2017 Society of Chemical Industry.

Effects of thermal processing on the nutritional and functional properties of defatted conophor nut (Tetracarpidium conophorum) flour and protein isolates

Conophor nut (Tetracarpidium conophorum) was processed using different heat treatments to explore its full potential as food ingredients. The raw, boiled, and toasted nuts were defatted and the proteins isolated by alkaline solubilization and isoelectric precipitation. The variously processed nuts were analyzed for the proximate and amino acid compositions, and functional properties. The protein contents of the isolate ranges between 86.86 g/100g and 87.74 g/100 g, about 1.5-fold higher than those of the defatted flour samples. The essential amino acids of the isolates ranged between 40.57%-41.55%. Glutamic acid, aspartic acid, and arginine were the most predominant amino acids, while methionine and lysine were the first and second limiting amino acids, respectively. The protein efficiency ratio, biological values as well as the functional properties of the proteins were improved with processing. These properties may enhance the potential use of conophor nut protein isolates as high-quality protein ingredient in food systems.

Beef, Chicken, and Soy Proteins in Diets Induce Different Gut Microbiota and Metabolites in Rats

Previous studies have paid much attention to the associations between high intake of meat and host health. Our previous study showed that the intake of meat proteins can maintain a more balanced composition of gut bacteria as compared to soy protein diet. However, the associations between dietary protein source, gut bacteria, and host health were still unclear. In this study, we collected colonic contents from the growing rats fed with casein, beef, chicken or soy proteins for 90 days, and analyzed the compositions of gut microbiota and metabolites. Compared to the casein group (control), the chicken protein group showed the highest relative abundance of Lactobacillus and the highest levels of organic acids, including lactate, which can in turn promote the growth of Lactobacillus. The soy protein group had the highest relative abundance of Ruminococcus but the lowest relative abundance of Lactobacillus. Long-term intake of soy protein led to the up-regulation of transcription factor CD14 receptor and lipopolysaccharide-binding protein (LBP) in liver, an indicator for elevated bacterial endotoxins. In addition, the intake of soy protein also increased the levels of glutathione S-transferases in liver, which implicates elevated defense and stress responses. These results confirmed that meat protein intake may maintain a more balanced composition of gut bacteria and reduce the antigen load and inflammatory response from gut bacteria to the host.

Application of Response Surface Methodology to Study the Effects of Brisket Fat, Soy Protein Isolate, and Cornstarch on Nutritional and Textural Properties of Rabbit Sausages

The effects of brisket fat, soy protein isolate, and cornstarch on chemical and textural properties of rabbit sausages were studied using surface response methodology. Sausage samples were prepared using a five-level three-variable Central Composite Rotatable Design with 16 combinations, including two replicates of the center point, carried out in random order. The level of brisket fat (BF), soy protein isolate (SPI), and cornstarch (CS) in the sausage formulation ranged within 8.3–16.7%, 0.7–2.3%, and 1.3–4.7%, respectively. Increasing BF decreased moisture and ash contents but increased protein and fat contents of the sausages (p < 0.05). Increasing SPI increased moisture content but decreased ash and carbohydrate contents of the sausages (p < 0.05). Increasing CS increased carbohydrate content (p < 0.05). Increasing BF increased hardness, adhesiveness, cohesiveness, and chewiness but decreased springiness (p < 0.05). SPI addition increased springiness but decreased adhesiveness, cohesiveness, and chewiness (p < 0.05). In conclusion, varying the levels of BF and SPI had a more significant effect on chemical and textural properties of rabbit sausages than CS.

Past, present and future: The strength of plant-based dairy substitutes based on gluten-free raw materials

Plant-based foods are gaining popularity and the market is developing fast. This trend is based on several factors, like the change of lifestyle, interest in alternative diets, and the increasing awareness about sustainable production of food and especially proteins. Plant-based dairy substitutes can serve as an option to traditional food products, meeting many of these interests. However, the market is in its infancy and needs to progress. Trends show, that the market will change from being focused on mainly soya, almond and rice-based products, due to their unsustainable farming, and nutritional concerns, like genetic modification and low protein content. The market is likely to shift towards alternative plants to meet consumers' needs and desire for healthy, flavourful and intriguing products. In this regard, the aspect of allergy-free, like gluten-free products gain in importance. Research studies are approaching the nutritional quality of plant-based dairy substitutes, such as improving the protein quality and glycaemic properties. Furthermore, the application of these products or plant proteins as functional ingredients or substitutes for cow's milk in dairy products like cheese and yoghurt are disseminated. However, there is still a need for much more diversified studies in order to overcome stability, textural, nutritional and sensory problems.

Angiotensin-I-Converting Enzyme (ACE)-Inhibitory Peptides from Plants

Hypertension is an important factor in cardiovascular diseases. Angiotensin-I-converting enzyme (ACE) inhibitors like synthetic drugs are widely used to control hypertension. ACE-inhibitory peptides from food origins could be a good alternative to synthetic drugs. A number of plant-based peptides have been investigated for their potential ACE inhibitor activities by using in vitro and in vivo assays. These plant-based peptides can be obtained by solvent extraction, enzymatic hydrolysis with or without novel food processing methods, and fermentation. ACE-inhibitory activities of peptides can be affected by their structural characteristics such as chain length, composition and sequence. ACE-inhibitory peptides should have gastrointestinal stability and reach the cardiovascular system to show their bioactivity. This paper reviews the current literature on plant-derived ACE-inhibitory peptides including their sources, production and structure, as well as their activity by in vitro and in vivo studies and their bioavailability.

Transcriptomic analysis reveals the flooding tolerant mechanism in flooding tolerant line and abscisic acid treated soybean

Soybean is highly sensitive to flooding stress and exhibits markedly reduced plant growth and grain yield under flooding conditions. To explore the mechanisms underlying initial flooding tolerance in soybean, RNA sequencing-based transcriptomic analysis was performed using a flooding-tolerant line and ABA-treated soybean. A total of 31 genes included 12 genes that exhibited similar temporal patterns were commonly changed in these plant groups in response to flooding and they were mainly involved in RNA regulation and protein metabolism. The mRNA expression of matrix metalloproteinase, glucose-6-phosphate isomerase, ATPase family AAA domain-containing protein 1, and cytochrome P450 77A1 was up-regulated in wild-type soybean under flooding conditions; however, no changes were detected in the flooding-tolerant line or ABA-treated soybean. The mRNA expression of cytochrome P450 77A1 was specifically up-regulated in root tips by flooding stress, but returned to the level found in control plants following treatment with the P450 inhibitor uniconazole. The survival ratio and root fresh weight of plants were markedly improved by 3-h uniconazole treatment under flooding stress. Taken together, these results suggest that cytochrome P450 77A1 is suppressed by uniconazole treatment and that this inhibition may enhance soybean tolerance to flooding stress.

Recent Advances in the Utilization of Natural Emulsifiers to Form and Stabilize Emulsions

Consumer concern about human and environmental health is encouraging food manufacturers to use more natural and sustainable food ingredients. In particular, there is interest in replacing synthetic ingredients with natural ones, and in replacing animal-based ingredients with plant-based ones. This article provides a review of the various types of natural emulsifiers with potential application in the food industry, including phospholipids, biosurfactants, proteins, polysaccharides, and natural colloidal particles. Increased utilization of natural emulsifiers in food products may lead to a healthier and more sustainable food supply. However, more research is needed to identify, isolate, and characterize new sources of commercially viable natural emulsifiers suitable for food use.

Antioxidant and Biological Activities of Proteinaceous Extract from Algerian Glycine max Plant

OBJECTIVE

Glycine max is commonly used in Algeria for treatment of anemia deficiency and osteoporosis, it ranks first in terms of vegetal proteins. The experiment was aimed at characterizing the proteinaceous Glycine max extract and evaluating its antioxidant, biological and hematological potential.

METHODOLOGY

Extraction of proteinaceous materials from Glycine max plant was undertaken using water and n-hexane as extracting media. The isolation of proteins from the crude materials was done, providing the use of ammonium sulfate. The Glycine max proteins were characterized by UV-visible and FT-IR spectroscopy and analyzed by SEM micrograph and x-ray diffraction (XRD). Rheological parameters G' and G'' were assessed. The isolated proteins were tested for their antioxidant, antimicrobial and hemagglutination activities.

RESULTS

There was a gelling effect of the protein extract which can be used as an alternative in principally made vaccines with its microbiological and antifungal activities.

CONCLUSION

The proteinaceous extract from Algerian Glycine max would have a potential use in biomedical application.

Continuous method to determine the trypsin inhibitor activity in soybean flour

The determination of trypsin inhibitor (TI) activity is of importance to evaluate the nutritional value of soybean flours. An analytical method, which involves a continuous spectrophotometric rate determination for trypsin activity against the substrate N-benzoyl-DL-arginine p-nitroanilide, is proposed as an alternative to the standard discontinuous assay. Stopping the reaction with acetic acid and a centrifugation/filtration step to decrease turbidity are not required, thus reducing costs and sample preparation time. The TI activity of different flour samples, determined by both assays, demonstrated to be statistically comparable, irrespective of the TI concentration level. The coefficients of variation of the novel method did not exceed 8% at any concentration level. The curves of progress reaction showed a non-linear behavior in samples without TI. A reduction of incubation time from 10min to 2min increased the method sensitivity and extended its linear range. A more economical, faster and simpler assay was developed.