Characterization of Amaranthus species: ability in nanoparticles fabrication and the antimicrobial activity against human pathogenic bacteria.

The present work aimed at differentiating five Amaranthus species from Saudi Arabia according to their morphology and the ability in nanoparticle formulation. Biogenic silver nanoparticles (AgNPs) were synthesized from leaf extracts of the five Amaranthus species and characterized by different techniques. Fourier-transform infrared spectroscopy (FT-IR) was used to identify the phyto-constituents of Amaranthus species. The nanoparticles (NPs) were characterized by UV-visible spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). The antibacterial activity of the synthesized NPs was tested against Staphylococcus aureus, E. coli, Klebsiella pneumoniae and Pseudomonas aeruginosa using the agar well diffusion method. Spherical NPs varying in size and functional groups from the five plant species were demonstrated by TEM, DLS and FTIR analysis, respectively. Variations in NPs characteristics could be related to the phytochemical composition of each Amaranthus species since they play a significant role in the reduction process. EDX confirmed the presence of Ag in plant fabricated AgNPs. Antibacterial activity varied among the species, possibly related to the NPs characteristics. Varied characteristics for the obtained AgNPs may reflect variations in the phytochemical composition type and concentration among Amaranthus species used for their fabrication.

Dynamic digestion of a high protein beverage based on amaranth: Structural changes and antihypertensive activity.

An amaranth beverage (AB) was subjected to a simulated process of dynamic gastrointestinal digestion DIDGI®, a simple two-compartment in vitro dynamic gastrointestinal digestion system. The structural changes caused to the proteins during digestion and the digesta inhibitory capacity of the angiotensin converting enzyme (ACE) were investigated. In gastric compartment the degree of hydrolysis (DH) was 14.7 ± 1.5 % and in the intestinal compartment, proteins were digests in a greater extent (DH = 60.6 ± 8.4 %). Protein aggregation was detected during the gastric phase. The final digesta obtained both at the gastric and intestinal level, showed ACE inhibitory capacity (IC50 80 ± 10 and 140 ± 20 µg/mL, respectively). Purified fractions from these digesta showed even greater inhibitory capacity, being eluted 2 (E2) the most active fraction (IC50 60 ± 10 µg/mL). Twenty-six peptide sequences were identified. Six of them, with potential antihypertensive capacity, belong to A. hypochondriacus, 3 agglutinins and 3 encrypted sequences in the 11S globulin. Results obtained provide new and useful information on peptides released from the digestion of an amaranth based beverage and its ACE bioactivity.

HPLC-Based Metabolomic Analysis and Characterization of Amaranthus cruentus Leaf and Inflorescence Extracts for Their Antidiabetic and Antihypertensive Potential.

The aim of this study was to investigate the potential of Amaranthus cruentus flavonoids (quercetin, kaempferol, catechin, hesperetin, naringenin, hesperidin, and naringin), cinnamic acid derivatives (p-coumaric acid, ferulic acid, and caffeic acid), and benzoic acids (vanillic acid and 4-hydroxybenzoic acid) as antioxidants, antidiabetic, and antihypertensive agents. An analytical method for simultaneous quantification of flavonoids, cinnamic acid derivatives, and benzoic acids for metabolomic analysis of leaves and inflorescences from A. cruentus was developed with HPLC-UV-DAD. Evaluation of linearity, limit of detection, limit of quantitation, precision, and recovery was used to validate the analytical method developed. Maximum total flavonoids contents (5.2 mg/g of lyophilized material) and cinnamic acid derivatives contents (0.6 mg/g of lyophilized material) were found in leaves. Using UV-Vis spectrophotometry, the maximum total betacyanin contents (74.4 mg/g of lyophilized material) and betaxanthin contents (31 mg/g of lyophilized material) were found in inflorescences. The leaf extract showed the highest activity in removing DPPH radicals. In vitro antidiabetic activity of extracts was performed with pancreatic α-glucosidase and intestinal α-amylase, and compared to acarbose. Both extracts exhibited a reduction in enzyme activity from 57 to 74%. Furthermore, the in vivo tests on normoglycemic murine models showed improved glucose homeostasis after sucrose load, which was significantly different from the control. In vitro antihypertensive activity of extracts was performed with angiotensin-converting enzyme and contrasted to captopril; both extracts exhibited a reduction of enzyme activity from 53 to 58%. The leaf extract induced a 45% relaxation in an ex vivo aorta model. In the molecular docking analysis, isoamaranthin and isogomphrenin-I showed predictive binding affinity for α-glucosidases (human maltase-glucoamylase and human sucrase-isomaltase), while catechin displayed binding affinity for human angiotensin-converting enzyme. The data from this study highlights the potential of A. cruentus as a functional food.

Physicochemical changes in Amaranthus spp grains, flour, isolated starch, and nanocrystals during germination and malting.

Amaranth is a pseudocereal that contains between 50 and 60% starch, gluten-free protein, and essential amino acids. This study investigates the physicochemical changes in Amaranthus spp. grains, flour, isolated starch and nanocrystals during germination and malting. The moisture content increased from 8.9% to 41% over 2 h of soaking. The percentage of germination increased rapidly, reaching 96% after 60 h, a remarkable advantage over other cereals. The nutrient composition varied, including protein synthesis and lipid degradation. Lipid concentration decreased during malting, except for soaking, which increased by 62%. Scanning electron microscopy shows that germination does not cause morphological changes on the outer surface of the grains, while transmission electron microscopy indicates the presence of isolated nanocrystals with orthorhombic crystal structure confirmed by X-ray diffraction. The viscosity profile shows a decrease in peak viscosity. Therefore, amaranth is a potential pseudocereal that can be used as an additive in the production of fermented beverages.

Design, Synthesis, and Herbicidal Evaluation of Pyrrolidinone-Containing 2-Phenylpyridine Derivatives as Novel Protoporphyrinogen Oxidase Inhibitors.

In this work, a series of pyrrolidinone-containing 2-phenylpyridine derivatives were synthesized and evaluated as novel protoporphyrinogen IX oxidase (PPO, EC 1.3.3.4) inhibitors for herbicide development. At 150 g ai/ha, compounds 4d, 4f, and 4l can inhibit the grassy weeds of Echinochloa crus-galli (EC), Digitaria sanguinalis (DS), and Lolium perenne (LP) with a range of 60 to 90%. Remarkably, at 9.375 g ai/ha, these compounds showed 100% inhibition effects against broadleaf weeds of Amaranthus retroflexus (AR) and Abutilon theophrasti (AT), which were comparable to the performance of the commercial herbicides flumioxazin (FLU) and saflufenacil (SAF) and better than that of acifluorfen (ACI). Molecular docking analyses revealed significant hydrogen bonding and π-π stacking interactions between compounds 4d and 4l with Arg98, Asn67, and Phe392, respectively. Additionally, representative compounds were chosen for in vivo assessment of PPO inhibitory activity, with compounds 4d, 4f, and 4l demonstrating excellent inhibitory effects. Notably, compounds 4d and 4l induced the accumulation of reactive oxygen species (ROS) and a reduction in the chlorophyll (Chl) content. Consequently, compounds 4d, 4f, and 4l are promising lead candidates for the development of novel PPO herbicides.

RNA Isolation Method in Marginal Crops with High Agronomic Potential.

Ribonucleic Acid (RNA) isolation is a basic technique in the field of molecular biology. The purpose of RNA isolation is to acquire pure and complete RNA that can be used to evaluate gene expression. Many methods can be used to perform RNA isolation, all of them based on the chemical properties of nucleic acids. However, some of them do not achieve high RNA yields and purity levels when used in a number of marginally studied crops of agronomic importance, such as grain and vegetable amaranth plants. In the method described here, the use of guanidinium thiocyanate and two additional precipitation steps with different reagents designed to obtain high yields and RNA purity levels from diverse plant species employed for plant functional genomics studies is described.

Therapeutic Effects of Amaranth: Analysis of the Antidiabetic Potential of the Plant.

Amaranth is a pseudocereal rich in macronutrients and micronutrients, with about 60 species cultivated worldwide. It is a high nutritional value food because of its many essential amino acids. Recent investigations demonstrate that the phytochemicals and extracts of amaranth have beneficial effects on health, including antidiabetic potential, a decrease in plasmatic cholesterol and blood pressure, and protection from oxidative stress and inflammation. Nowadays, type 2 diabetes has increased worldwide, becoming a problem of public health that makes it necessary to look for alternative strategies for its prevention and treatment. This review aims to summarize the antidiabetic potential of diverse species of the Amaranth genus. A bibliographical review was updated on the plant's therapeutic potential, including stem, leaves, and seeds, to know the benefits and potential as an adjuvant in treating and managing diabetes and associated pathologies (hypertension, dyslipidemia, and heart disease). This analysis contributes to the generation of knowledge about the therapeutic effects of amaranth, promoting the creation of new products, and the opportunity to conduct clinical trials to assess their safety and efficacy.

Protein extracts from amaranth and quinoa as novel fining agents for red wines.

Due to allergenic concerns, only pea, potato, and wheat proteins have been approved as alternatives for replacing animal-based fining agents in wines. In pursuit of other substitutes, this work aimed to determine the fining ability of amaranth (Amaranthus caudatus L.) proteins (AP) in red wine, compared to quinoa (Chenopodium quinoa Willd.) (QP) and a commercial pea protein. Phenolic and volatile composition, as well as color characteristics, were analyzed. AP was as effective as QP at decreasing condensed tannins, with AP at 50 g/hL being the most effective treatment (25.6% reduction). QP and AP produced a minor or no statistical change in the total anthocyanins and wine color intensity. They reduced the total ester concentration, but the total alcohols remained unchanged. The outcomes of AP and QP were similar, and sometimes better than the pea proteins, thus suggesting that they could be promising options for the development of novel fining agents.

Isolation and characterization of natural nano starch from amaranth starch.

Nano starch exhibits many advantages for application in diverse fields. Amaranth starch consisted of starch particle aggregates, isolated amaranth starch, and few natural nano starch (NNS), while NNS (0.92 ± 0.12 µm) was successfully isolated for the first time. Compared with the isolated amaranth starch, NNS showed smaller particle size but larger molecular weight, suggesting that the molecules arranged densely. NNS had a weak A-type crystal structure because of its more content of short starch chains, but higher amylose content resulted in the increase of its gelatinization temperature. The special NNS, owning several different physicochemical properties from amaranth starch, can open new ways for the production and application of nano biomass materials.

Chemical and cell antioxidant activity of amaranth flour and beverage after simulated gastrointestinal digestion. Role of peptides.

The potential of peptides generated by simulated gastrointestinal digestion (SGID) of two products derived from Amaranthus manteggazianus seeds, flour (F) and beverage (B), to exert peroxyl scavenging activity (ORAC) and antioxidant action on intestinal cells was studied. B was prepared by solubilisation of seed proteins, with the addition of gums and the application of a pasteurization treatment. The gastrointestinal digests FD and BD showed some differences in the peptide/polypeptide composition. The SGID produced increased ORAC activity for both samples, with some differences in the ORAC of the whole digests BD and FD and of some gel filtration fractions. Bioaccessible fractions (FDdbs and BDdbs) were obtained after treatment with cholestyramine resin to remove bile salts due to their cytotoxicity and oxidative effect. BDdbs presented a greater ORAC potency (IC50: 0.05 ± 0.01 and 0.008 ± 0.004 mg protein/ml for FDdbs and BDdbs, respectively). These fractions showed low cytotoxicity values (measured by LDH release) and produced high intracellular ROS inhibition (around 80 %), increased the SOD activity and the GSH content, with no effect on GPx activity in Caco2-TC7 cells exposed to H2O2. Several fractions with MM < 2.2 kDa presented also these cellular actions; fractions from FD induced higher increases in GSH concentration. Amaranth flour and a processed matrix like the beverage are shown as sources of bioactive peptides with potential cell antioxidant activity.

[In vivo study of the biological value of amaranth protein concentrate and its module with chicken egg protein].

Amaranth (Amaranthus L.), like other pseudocereals as quinoa (Chenopodium quinoa Willd.), chia (Salvia hispanica L.) and buckwheat (Fagopyrum sp.), is a promising source of dietary protein. Depending on the subspecies and breeds of amaranth, the protein content in its grain is estimated from 13.1 to 21.5%, and its amino acid score varies over a significant range and can be limited. The aim of this study was to obtain a protein concentrate from amaranth (Amaranthus L.) grain of the Voronezh breed, enrich it with chicken egg protein, determine the amino acid score of the obtained protein module, and experimentally evaluate in vivo its true digestibility and biological value. Material and methods. The amaranth protein concentrate was obtained from grain according to the technological scheme, including its enzymatic treatment, alkaline extraction, acid precipitation of proteins, microfiltration and lyophilization. The amino acid composition and amino acid score of the concentrate were determined. The protein module was obtained by mixing amaranth protein concentrate and chicken egg protein in a weight ratio of 58:42. The true digestibility and biological value of the protein module has been determined in vivo. The experiment was carried out on 32 Wistar male rats divided into 2 groups (n=16 rats): control group 1 with a body weight of 118.7±3.1 g and experimental group 2 with a body weight of 119.5±3.0 g. Animals of groups 1 and 2 received diets in which egg protein and a protein module were used as a protein source, respectively. Within 15 days of the experiment, individual indicators of food intake and body weight gain of each animal were determined. From the 14th to the 15th day food intake was determined and feces were collected. The amount of nitrogen in the food and feces was determined for each rat using the Kjeldahl method. The true digestibility of the protein was determined according to obtained data. Results. The resulting amaranth protein concentrate contained 70.4±0.6% of protein, 17.0±1.0% fat, 9.8±0.8% carbohydrates, 1.8±0.2% ash, its moisture content was 1.4±0.1%. There were no significant differences in food intake and body weight gain between animals of both groups. The calculated value of the true digestibility of chicken egg protein was 98.8±0.1% for the control group 1, of the protein module was 99.0±0.1% for the experimental group 2, the differences between the groups were not significant. Conclusion. The results of amino acid analysis and the in vivo study of the true digestibility of the protein module (composition amaranth protein/chicken egg protein) indicate the absence of limitation relative to the amino acid scale of the "ideal" protein (FAO/WHO, 2007) and high true digestibility. The biological value of the protein module, calculated according to PDCAAS, is 99.0±0.1%, which confirms the prospects for its inclusion in specialized foods.

Betacyanins obtained from alternative novel sources as natural food colorant additives: incorporated in savory and sweet food products.

The aim of this study was to assess the performance and stability of betacyanin compounds present in enriched extracts of red-fleshed pitaya peels (Hylocereus costaricensis) and the flowers of Amaranthus caudatus; they were evaluated as natural food colorants in tagliatelle pasta and meringue cookies. The recovered natural extracts showed promising stability, maintaining a deep pink color over a storage time of 14 days, without deeply changing the chemical composition. A number of factors were assessed, including the microbial load, texture, color, nutritional value, and contents of organic acids, fatty acids, and even free sugars of the products. Some significant interactions between the type of colorant and storage time contributed to the changes in some analyzed parameters, as can be observed from the results for organic and fatty acids in the tagliatelle pasta and meringue cookies. Another significant achievement was the reduction in the microbial load during the storage time, which strengthens the antibacterial power of these natural extracts.

Nutritional aspects of non-conventional edible plants from Brazil: Caruru (Amaranthus spinosus L) and trapoeraba (Commelina benghalensis).

Caruru (Amaranthus spinosus L) and trapoeraba (Commelina benghalensis) are NCEPs introduced into Brazil and are widely used by certain communities. Given the lack of information on carotenoids, vitamins, and minerals present in A. spinosus and C. benghalensis grown in Brazil, this study aimed to determine the proximate composition and the micronutrient profile of these two NCEPs obtained from family farming in the Middle Doce River (Médio Rio Doce) region in the state of Minas Gerais, Brazil. The proximate composition was evaluated using AOAC methods, vitamin E by HPLC with fluorescence detection, vitamin C and carotenoids by HPLC-DAD, and minerals by atomic emission spectrometry with inductively coupled plasma. In summary, the leaves of A. spinosus exhibited a high content of dietary fiber (10.20 g.100 g-1), potassium (708.8 mg·100 g-1), iron (4.0 mg·100 g-1) and ß-carotene (6.94 mg·100 g-1), while the leaves of C. benghalensis were sources of potassium (1399.31 mg·100 g-1), iron (5.7 mg·100 g-1), calcium (163 mg·100 g-1), zinc (1.3 mg·100 g-1), ascorbic acid (23.61 mg·100 g-1), and ß-carotene (31.33 mg·100 g-1). It was therefore concluded that C. benghalensis and A. spinosus, especially, presented excellent potential as important nutritional sources for human consumption, highlighting the gap existing between the available technical and scientific material, thus making them an important and necessary axis of research.

Antioxidant and Antimicrobial Effects of Baby Leaves of Amaranthus tricolor L. Harvested as Vegetable in Correlation with Their Phytochemical Composition.

Amaranth is used as a spinach replacement; therefore, it is sometimes called Chinese Spinach. So far, the activity of the plant has not been associated with the presence of specific compounds. Three cultivars of Amaranthus tricolor L. were investigated for their antioxidant and antimicrobial activities. The correlation between the bioactivity and metabolite profiles was investigated in order to indicate active compounds in A. tricolor. The phytochemical profile of a total of nine extracts was studied by HPLC-DAD-ESI/HRMS, revealing the presence of 52 compounds. The highest antioxidant activity was noticed in the Red cultivar (0.06 mmol TE/g DE (Trolox Equivalent/Dry Extract Weight) and was related to the presence of amino acids, flavonoids and phenolic acids, as well as individual compounds such as tuberonic acid hexoside. All studied extracts revealed antimicrobial activity. Gram-positive bacteria were more susceptible to N-(carboxyacetyl) phenylalanine, phenylalanine, tuberonic acid and succinic acid and Gram-negative bacteria to dopa, tryptophan, norleucine, tuberonic acid hexoside, quercetin-O-hexoside, luteolin-O-rhamnosylhexoside, luteolin-6-C-hexoside succinic acid, gallic acid-O-hexoside, dihydroxybenzoic acid and hydroxybenzoic acid. Maleic acid showed promising antifungal activity. In summary, A. tricolor is a good source of antioxidant and antimicrobial compounds.

Amaranth proteins and peptides: Biological properties and food uses.

Amaranthus grains have attracted great attention due to its attractive health benefits. The grains have processing properties (e.g., starch related properties) similar to those of common cereals. Amaranth grains are gluten free and protein is a significant component of these grains. Proteins of the grains have been used in various food applications such as formulations of edible films and emulsions for controlled release of bioactive compounds. The proteins have been hydrolyzed using different enzymes to produce peptides and hydrolysates, which showed a range of biological functions including anti-hypertensive and antioxidant activities among others. They have been formulated into staple foods including breads and pastas for improved nutritional quality. This review summarizes the recent advances of the last 5 years in understanding the biological functions and food applications of proteins, protein hydrolysates and peptides from the grains of different Amaranthus species. Limitations in the studies summarized are critically discussed with an aim to improve the efficiency in amaranth grain protein and peptide research.

In search of better snacks: ohmic-heating nixtamalized flour and amaranth addition increase the nutraceutical and nutritional potential of vegetable-enriched tortilla chips.

BACKGROUND: Nixtamalized flour snacks such as tortilla chips are widely consumed across the world, but they are nutritionally poor and contribute to obesity and other non-communicable diseases. The production of healthy versions of such snacks, by incorporating vegetables and improving the quality of the flours used in their formulation, could help address these nutritional challenges. This study compared the fortification of baked tortilla chips with vegetable leaf powders (kale and wild amaranth at 0%, 4%, 8%, and 16% w/w) and using two types of nixtamalized flour: traditional (TNF) and with ohmic heating (OHF). RESULTS: Overall, the use of OHF increased 1.88 times the fibre in enriched and non-enriched snacks with respect to TNF, but the latter had 1.85 times more protein. Addition of 16% of vegetable powders increased protein (kale = 1.4-fold; amaranth = 1.3-fold) and dietary fibre (kale = 1.52-fold; amaranth = 1.7-fold). Amaranth enrichment improved total phenolic content (TPC) and total flavonoid content (TFC) of chips at least 1.2 and 1.63 times, respectively. OHF chips also had higher bound TPC than TNF ones, regardless of vegetable addition. Combinations of OHF with 16% amaranth produced chips 1.74-fold higher in antioxidant capacity than non-enriched ones, due to increased content of phenolics such as ferulic acid. CONCLUSION: This work showed that tortilla chips made using nixtamalized flour produced with assisted ohmic heating, alone or in combination with wild amaranth leaf powder, could be used in the production of healthy maize snacks to enhance their prospective antioxidant activity and nutritional value. © 2023 Society of Chemical Industry.

Development of a Functional Cookie Formulated with Chaya (Cnidoscolus aconitifolius (Mill.) I.M. Johnst) and Amaranth (Amaranthus cruentus).

Chaya and amaranth are Mexican traditional foods with a high nutritional value. Many studies have demonstrated the individual beneficial effect of each. However, there is no evidence of the use of these foods on the formulation of functional foods. This study evaluated the effect of replacing 5-20% of wheat flour with chaya and amaranth flours to generate four different formulations of cookies. Proximal analysis, total polyphenols and oxalate content, antioxidant activity, fatty acid profile, and sensory analysis were performed on the cookies. The results of the chemical composition showed that all cookies have a high protein content (9.21-10.10%), an adequate amount of fiber (5.34-6.63%), and a balanced ratio of unsaturated-saturated fatty acids (70:20), and they contain PUFAs (50.4-53.2 g/100 g of fatty acids), especially α-linolenic and oleic acids. All formulations presented antioxidant activity (2540 ± 65.9 to 4867 ± 61.7 Trolox equivalents (µmoles/100 g)) and polyphenols (328-790 mg/100 g); in particular, quercetin was identified in their composition. Results of the sensory analysis indicated that incorporation of chaya and amaranth flour in cookies does not affect the acceptability of the products. The inclusion of traditional foods, such as chaya and amaranth, in cookies enhances their nutritional value and increases the content of bioactive compounds associated with health effects.

Kiwicha (Amaranthus caudatus L.) protein hydrolysates reduce intestinal inflammation by modulating the NLRP3 inflammasome pathway.

The increase in the world population along with new policies aimed at a more sustainable world has led to the need of searching for new food sources, which are environmentally friendly, implying healthy and nutritious diets. This study explored the biological activity of two kiwicha (Amaranthus caudatus L.) protein hydrolysates obtained with the aid of Bioprotease LA-660 regarding their anti-inflammatory response at the intestinal level, employing the CACO-2 cell line. The results obtained showed that the in vitro administration of these hydrolysates decreased the expression of proinflammatory cytokines, increased the expression of anti-inflammatory cytokines, and decreased the gene expression of the major components of inflammasomes in the intestinal CACO-2 cell model. To the best of our knowledge, this is the first study involving the evaluation of the anti-inflammatory activity of kiwicha hydrolysates at the intestinal level, employing the CACO-2 cell model and its ultrastructural characterization using scanning electron microscopy. We conclude that the Amaranthus caudatus hydrolysates are a valuable source of active peptides that take part as functional ingredients in food and nutraceutical preparations.

[Amaranth grain proteins: prospects for use in specialized food products].

Amaranth is a widespread genus of predominantly annual herbaceous plants belonging to the Amaranthaceae family, which is one of the most widely used pseudocereals along with quinoa and buckwheat in nutrition. The aim of the research was to review and analyze the results of the studies on the characteristics of amaranth grain proteins, the effect of various food processing methods on their quality, and the prospects for using amaranth protein hydrolysates in therapeutic nutrition. Material and methods. For the main search for the literature, the PubMed bibliographic database was used, which covers about 75% of the world's medical publications. In addition, Scopus and Web of Science databases and non-commercial search engine Google Scholar were used. The depth of the search was 15 years. Results. The paper presents a brief review of modern approaches for obtaining amaranth protein isolates and concentrates, including the use of a complex of physicochemical methods: grinding, sifting, extraction at high pH values, defatting, ultrafiltration, centrifugation, isoelectric precipitation, and drying of the protein product. A comparative characteristic of amino acid content of protein fractions of pseudocereals is presented. Basically, leucine, isoleucine, and valine are limiting amino acids for the grain protein of various varieties of amaranth. When substantiating and developing modern effective food technologies for processing amaranth grain, the studies dedicated to the evaluation of their impact on the biological value of amaranth protein deserve special attention. Methods of grain fermentation, sprouting, steaming, malting, boiling can be used to increase the bioavailability and digestibility of its ingredients. The results of in vitro and in vivo studies indicate the presence of hypotensive, hypolipidemic and antioxidant activity of the amaranth protein and its hydrolysates what determines the prospects for their use as part of foods for special dietary uses and therapeutic nutrition. An analysis of the scientific publications presented in the review indicates an increase in demand for high-quality gluten-free products and an increase in the range of mass-consumption foods, such as bakery, pasta, flour confectionery, with pseudo-cereals in their composition, including amaranth. Conclusion. The high biological value and technological properties of amaranth protein concentrates/isolates determine the prospects for their use to create a wide range of specialized foods for various purposes.

Foaming and Structural Studies on the Acidic Subunit of Amaranth 11S Globulin Modified with Antihypertensive Peptides as a Function of pH and Ionic Strength.

Some studies aimed at revealing the relationship between protein structure and their functional properties. However, the majority of these reports have been carried out using protein isolates. There are limited reports on the possible relationship between the functional properties and the structure of a purified protein. In this work the amaranth 11S globulin acidic subunit (AAC) and five mutations of the same protein that were modified in their variable regions with antihypertensive peptides (VYVYVYVY and RIPP), were analyzed at two ionic strength (2.9 and 17.6 g/L NaCl) and pH (3.0-7.0). Results revealed better solubility for the proteins mutated at the terminal ends (AACM.1 and AACM.4) and lower solubility for the protein inserted with RIPP peptide. Spectroscopy studies revealed an increase of ß-sheet structure at high salt concentration for all proteins. It was also observed that salt concentration acted as a modulator, which allowed a better foam features for all modified proteins limiting movement of side chains and reducing red-shifted displacement of λmax. All proteins showed foam capacity ranging from 76 to 93% although foam stability was twofold better for modified proteins than for AAC at high salt concentration. This study allowed better understanding about the structural changes that influence the foaming properties of engineered proteins.