Flaxseed gum a versatile natural hydrocolloid for food and non-food applications

Impact of flaxseed gum on the aggregate structure, pasting properties, and rheological behavior of waxy rice starch

This study examines the effects of flaxseed gum (FG) on the aggregate structure, pasting and rheological properties of waxy rice starch (WRS). Results display an increase in the ordered molecular structure (R1047/1024), relative crystallinity (RC), compactness (α), and microphase heterogeneity (ε, density degree of nanoaggregates, from 3.52 to 4.23) for WRS-FG complexes. These suggested FG facilitated the development of more organized molecular and crystalline structures of WRS, accompanied by the formation of ordered nanoaggregates with higher density (i.e., nano-aggregation structure). Also, FG addition resulted in the formation of enhanced gel network structure characterized by thicker layer walls and more uniform pores. These structural transformations contributed to a rise in gelatinization temperature (To, from 56.90 °C to 62.10 °C) and enthalpy (ΔH), as well as alterations in paste viscosities (PV, from 1285.00 mPa·s to 1734.00 mPa·s), and the rigidity of network structure (e.g., decreased loss tangent). These results indicate that FG could effectively regulate the techno-functional properties of WRS by rationally controlling the starch intrinsic structures of starch. And this study may improve the pasting and gelling properties of starch, thus driving the development of high-quality starchy foods and prolonging their shelf life, especially for glutinous rice flour products.

Plant gums in Pickering emulsions: A review of sources, properties, applications, and future perspectives

Recently, there has been an increasing research interest in the development of Pickering emulsions stabilized with naturally derived biopolymeric particles. In this regard, plant gums, obtained as plant exudates or from plant seeds, are considered promising candidates for the development of non-toxic, biocompatible, biodegradable and eco-friendly Pickering stabilizers. The main objective of this review article is to provide a detailed overview and assess the latest advances in the formulation of Pickering emulsions stabilized with plant gum-based particles. The plant gum sources, types and properties are outlined. Besides, the current methodologies used in the production of plant gum particles formed solely of plant gums, or through interactions of plant gums with proteins or other polysaccharides are highlighted and discussed. Furthermore, the work compiles and assesses the innovative applications of plant gum-based Pickering emulsions in areas such as encapsulation and delivery of drugs and active agents, along with the utilization of these Pickering emulsions in the development of active packaging films, plant-based products and low-fat food formulations. The last part of the review presents potential future research trends that are expected to motivate and direct research to areas related to other novel food applications, as well as tissue engineering and environmental applications.

Metabolites of Clostridium leptum fermenting flaxseed polysaccharide alleviate obesity in rats

Obesity is a chronic metabolic disease. Our previous research found flaxseed polysaccharide (FP) has an anti-obesity effect, and its anti-obesity effect possibly depends on Clostridium leptum (C. leptum). However, whether the strain takes the role and how it works is still being determined. Here, FP was fermented in vitro by C. leptum and its metabolites were analyzed. Subsequently, the FP fermentation broth of C. leptum (FPF) was given to the obese pseudo sterile rats. The results showed FPF was rich in various metabolites, among which the top ten in relative expression abundance were 3 beta-hydroxy-5-cholestenoate, 7,8-dihydro-3b,6a-dihydroxy-alpha-ionol 9-glucoside, Valyl-Serine, 2-amino-4-[(2-hydroxy-1-oxopropyl)amino]butanoic acid, Agavoside B, glycylproline, lycopersiconolide, armillaritin, Isoleucyl-Hydroxyproline and norethindrone acetate. After intervention with FPF, the weight, abdominal fat ratio, and total fat ratio of rats were significantly reduced and the lipid metabolism of them has been improved. This effect may be achieved by up regulating glucagon-like peptide-1 and adiponectin and further activating the AMP-activated protein kinase signaling pathway. This is the first experimental proof that FP exerts its anti-obesity effects through metabolites from C. leptum fermenting FP, not FP itself and the bacterial cells (debris) of C. leptum. It is also the first demonstration that FPF has a significant anti-obesity effect.

Natural gums and their derivatives based hydrogels: in biomedical, environment, agriculture, and food industry

The hydrogels based on natural gums and chemically derivatized natural gums have great interest in pharmaceutical, food, cosmetics, and environmental remediation, due to their: economic viability, sustainability, nontoxicity, biodegradability, and biocompatibility. Since these natural gems are from plants, microorganisms, and seaweeds, they offer a great opportunity to chemically derivatize and modify into novel, innovative biomaterials as scaffolds for tissue engineering and drug delivery. Derivatization improves swelling properties, thereby developing interest in agriculture and separating technologies. This review highlights the work done over the past three and a half decades and the possibility of developing novel materials and technologies in a cost-effective and sustainable manner. This review has compiled various natural gums, their source, chemical composition, and chemically derivatized gums, various methods to synthesize hydrogel, and their applications in biomedical, food and agriculture, textile, cosmetics, water purification, remediation, and separation fields.

Unravelling the functionality of anionic and non-ionic plant seed gums on milk protein cryogels conveying Lacticaseibacillus rhamnosus GG

Cryogels offer a promising macroporous platform that can be employed as either a functional ingredient in food composites or a colloidal template for incorporating bioactives, including probiotic living cells. The aim of the present work is to explore the functionality of two plant seed polysaccharides, flaxseed gum (FG) and alfalfa galactomannan (AAG), in individual and combined (1:1 ratio) milk protein-based cryogels, namely sodium caseinate (NaCas) and whey protein isolate (WPI). These cryogels were created by freeze-drying hydrogels formed via L.rhamnosus GG - a human gut-relevant probiotic strain - fermentation. Our findings showed that including gum in the composition limited volume contraction during lyophilisation, reduced macropore size and thickened cryogel skeleton vessels. Furthermore, gum-containing cryogels displayed improved thermal stability and slower water disintegration rates. The AAG-stabilised cryogels specifically showed a notable reduction in monolayer water content compared to FG. From a mechanistic viewpoint, AAG influenced the physicochemical and microstructural properties of the cryogels, most probably via its self-association during cryogenic processing, promoting the development of intertwined protein-gum networks. FG, on the other hand, enhanced these properties through electrostatic complexation with proteins. Cryogels made from protein-polysaccharide blends exhibited promising techno-functional properties for enhancing and diversifying food product innovation.

Synthesis of flaxseed gum/melanin-based scaffold: A novel approach for nano-encapsulation of doxorubicin with enhanced anticancer activity

Doxorubicin is a powerful chemotherapy medicine that is frequently used to treat cancer, but because of its extremely destructive side effects on other healthy cells, its applications have been severely constrained. With the aim of using lower therapeutic doses of doxorubicin while maintaining the same anti-cancerous activity as those of higher doses, the present study designs nano-encapsulation of doxorubicin by acrylamide grafted melanin as core and acrylic acid grafted flax seed gum as shell (DOX@AAM-g-ML/AA-g-FSG-NPs) for studies in-vivo and in-vitro anticancer activity. For biological studies, the cytotoxicity of DOX@AAM-g-ML/AA-g-FSG-NPs was examined on a cancerous human cell line (HCT-15) and it was observed that DOX@AAM-g-ML/AA-g-FSG-NPs exhibited very high toxicity towards HCT-15. In-vivo investigation in colon cancer-inflicted rat model also showed that DOX@AAM-g-ML/AA-g-FSG-NPs showed better anticancer activity against cancerous cells as compared to free doxorubicin. The drug release behavior of DOX@GML-GFS-NPs was studied at several pH and maximum drug release (95 %) was recorded at pH -7.2, and kinetic data of drug release was follows the Higuchi (R2 = 0.9706) kinetic model. Our study is focussed on reducing the side effects of doxorubicin by its nano-encapsulation in acrylamide grafted melanin as core and acrylic acid grafted flax seed gum that will also enhance its efficiency.

A low-fat synbiotic cream cheese containing herbal gums, Bifidobacterium adolescentis and Lactobacillus rhamnosus: Physicochemical, rheological, sensory, and microstructural characterization during storage

This study aimed to use natural herbal gums, as fat replacers, for preparing a low-fat synbiotic cream cheese; for this purpose, the effects of Lepidium perfoliatum seed gum (LPSG) (1% w/w) and flaxseed gum (FG) (1% w/w) on physicochemical, rheological, organoleptic, and microstructural properties of low-fat cream cheese containing B. adolescentis and L. rhamnosus were analyzed over a 45-day storage period. The results indicated that adding LPSG and FG had no significant effects on acidity and pH (p > .05). The results also showed that full-fat (FF) cheese samples had the highest textural (hardness (1.099-0.88), cohesiveness (0.72-0.67), springiness (1.95-1.64), adhesiveness (1.01-0.69), and spreadability (1.53-1.17)), viscosity and sensory scores (color (4.22-4.18), odor (4.13-4.09), taste (4.19-3.89), texture (4.08-3.81), and overall acceptability (4.01-3.72)) during 45-day storage. Based on the probiotic count test, only the treated samples with LPSG + FG had a probiotic count in the standard range (6.23 cfu/g) at the end of the storage time. The outcomes of the present study indicated that the incorporation of LPSG and FG into the formulation of low-fat synbiotic cream cheese could be an effective strategy to overcome the problems associated with fat reduction.

Influence of roasted flaxseed marc flour on rheological, structural, fermentation, water distribution, and migration properties of wheat dough

Roasted flaxseed (RF) marc, which is a by-product obtained from RF oil extraction, has high nutritional value. This study evaluated the impact of RF marc flour on rheological, structural, fermentation, water distribution, and migration properties of the wheat dough. Results showed that adding RF into wheat flour (WF) could effectively increase the water absorption in the dough and retard the retrogradation of starch. The fermentation results revealed that adding RF could improve the gas retention coefficient of dough. Compared to the dough prepared with WF, the doughs enriched with RF had higher tan δ values (ratio of loss modulus G″ to storage modulus G'), indicating a more liquid-like property. The mobility of tightly bound and free water in dough was decreased by adding RF, whereas the distribution of free water was increased. On the one hand, adding RF would dilute the gluten content in dough, resulting in a weaker protein network. On the other hand, the dietary fiber and proteins in RF could offset the gluten dilution effect to some extent. Overall, the results suggested that the substitution level of RF in WF should be below 25% to avoid serious dough quality deterioration, and the RF-WF blended flour could be a potential ingredient to produce wheat products with moist taste. These findings could be useful for guiding the future usage of RF marc in wheat-based products.

Polysaccharide-addition order regulates sonicated egg white peptide stabilized nanoemulsions and β-carotene digestion in vitro

In this paper, the effects of the polysaccharide-addition order (before and after homogenisation) on the stability of nanoemulsion stabilised by sonicated egg white peptides and the in vitro digestive behaviour of loaded β-carotene were investigated. The pyrene fluorescence results showed that the concentration of micelles formed by flaxseed gum (FG) in complex with peptides was significantly higher than that of peach gum (PG). The order of polysaccharide-addition affected the emulsion properties and stability; adding polysaccharides before homogenisation led to protein bridging flocculation, low polysaccharide coverage and a higher interfacial adsorbed protein content of the emulsion. PG enhanced potential spatial resistance and electrostatic repulsion, effectively prevented emulsion flocculation and improved electrostatic stability. After homogenisation, FG was added to emulsions to improve environmental stability, including ionic, temperature and storage stability. Due to the viscosity of polysaccharides and the formed polysaccharide-protein-lipid aggregates, the increasing degree of bridging flocculation promoted the prominent of apparent viscosity, and the G' and G'' exhibited a frequency-dependent increase. The polysaccharide type and mode changed the surface loading charge and droplet interface thickness, delayed the destruction of the droplet structure by protease, and slowed the release of β-carotene to form micelles. In this study, a stable emulsion system and an efficient emulsion transport system for bioactive substances were obtained by regulating polysaccharides adding order, which is significant for constructing an efficient food emulsion delivery system.

Selected plants producing mucilage: Overview, composition, and their potential as functional ingredients in the development of plant-based foods

The increase in the preference for vegan and vegetarian diets is directly related to changing eating habits and the need for plant-based alternatives to animal-based products, which are better for health, due to the high content of essential amino acids and lipid profile rich in polyunsaturated fatty acids, and have lower environmental impacts. In this scenario, there is a growing demand for plant-based foods, making it necessary to find new plant-based ingredients for application in foods and beverages. Flaxseed, chia seed, and Barbados gooseberry contain mucilage, a component with potential application in plant-based products. These hydrocolloids can be used as gelling agents, texture modifiers, stabilizers, and emulsifiers in solid and semi-solid foods. This review presents the extraction, characterization, and application of flaxseed, chia seed, and Barbados gooseberry mucilage for use in plant-based foods. It was found that mucilage composition varies due to the extraction method used, extraction conditions, and geographic location of the seed or leaf. However, applications in plant-based foods are currently limited, mainly focused on applying chia mucilage in bakery products and packaging. Research on applying flaxseed and Barbados gooseberry mucilage to plant-based products is limited, though it has been shown to have potential applications in packaging. Mucilage may also increase the nutritional profile of the product and provide better technological, functional, and sensory characteristics. Therefore, because of mucilage's excellent functional and technological properties, it is a promising candidate to act as an ingredient in plant-based food products.

Double network hydrogel based on curdlan and flaxseed gum with photothermal antibacterial properties for accelerating infectious wound healing

The healing of infected wounds has always been a clinical challenge. With the increasing threat of drug resistance due to antibiotic overuse, it is imperative to improve antibacterial wound dressings. In this study, we designed a double network (DN) hydrogel via a "one pot method" with antibacterial activity, and natural polysaccharides with the potential to promote skin wound healing were used. That is, a DN hydrogel matrix was formed by the hydrogen bond crosslinking of curdlan and the covalent crosslinking of flaxseed gum under the action of borax. We added ε-polylysine (ε-PL) as a bactericide. Tannic acid/ferric ion (TA/Fe³⁺) complex was also introduced into the hydrogel network as a photothermal agent to induce photothermal antibacterial properties. The hydrogel had fast self-healing, tissue adhesion, mechanical stability, good cell compatibility and photothermal antibacterial activity. In vitro studies of hydrogel showed its ability to inhibit S. aureus and E. coli. In vivo experiments also demonstrated the significant healing effect of hydrogel when used to treat wounds infected by S. aureus by promoting collagen deposition and accelerating the formation of skin appendage. This work provides a new design for the preparation of safe antibacterial hydrogel wound dressings and demonstrates great potential for promoting wound healing of bacterial infections.

Water Stress and Seed Color Interacting to Impact Seed and Oil Yield, Protein, Mucilage, and Secoisolariciresinol Diglucoside Content in Cultivated Flax (Linum usitatissimum L.)

Flaxseed (Linum usitatissimum L.) is a plant with a wide range of medicinal, health, nutritional, and industrial uses. This study assessed the genetic potential of yellow and brown seeds in thirty F4 families under different water conditions concerning seed yield, oil, protein, fiber, mucilage, and lignans content. Water stress negatively affected seed and oil yield, while it positively affected mucilage, protein, lignans, and fiber content. The total mean comparison showed that under normal moisture conditions, seed yield (209.87 g/m²) and most quality traits, including oil (30.97%), secoisolariciresinol diglucoside (13.89 mg/g), amino acids such as arginine (1.17%) and histidine (1.95%), and mucilage (9.57 g/100 g) were higher in yellow-seeded genotypes than the brown ones ((188.78 g/m²), (30.10%), (11.66 mg/g), (0.62%), (1.87%), and (9.35 g/100 g), respectively). Under water stress conditions, brown-seeded genotypes had a higher amount of fiber (16.74%), seed yield (140.04 g/m²), protein (239.02 mg. g^-1), methionine (5.04%), and secondary metabolites such as secoisolariciresinol diglucoside (17.09 mg/g), while their amounts in families with yellow seeds were 14.79%, 117.33 g/m², 217.12 mg. g^-1, 4.34%, and 13.98 mg/g, respectively. Based on the intended food goals, different seed color genotypes may be appropriate for cultivation under different moisture environments.

Particle characteristics and tribo-rheological properties of soy protein isolate (SPI) dispersions: Effect of heating and incorporation of flaxseed gum

To understand the heat treatment and flaxseed gum (FG) on the properties of commercial spray dried soy protein isolate (SPI), SPI dispersions were prepared with mass ratio of 6 %, 9 %, and 12 % in water and the corresponding protein concentrations of 2.2 %, 3.61 % and 5.23 % were reached after centrifugation. The solutions were treated at different temperatures (25, 75 and 100 °C) and the particle characteristics and physical properties of the resulted samples were determined. The influence of different concentrations (0.05 % to 0.3 %) of FG addition was evaluated in the SPI solution at 5 % protein concentration. The results showed that heating caused decrease of particle size of the SPI proteins and 100 °C heat treatment caused decrease of hydrophobicity and viscosity of the protein dispersions, and increase of their physical stability, and the effect was more marked at high protein concentration; while heat treatment at 75 °C caused substantial increase in protein hydrophobicity and viscosity, and decrease of stability. Addition of FG resulted in increase of particle size, absolute value of zeta potential and hydrophobicity of the protein solutions. The viscosity of the solution was decreased with addition of FG, but higher FG concentration could lead to higher viscosity. The physical stability of the mixed system was improved at low FG concentrations, but decreased at concentration higher than 0.2 %, which was more significant after 100 °C heat treatment. FG incorporation could improve the boundary lubrication of the protein solutions.

Protein Fractions from Flaxseed: The Effect of Subsequent Extractions on Composition and Antioxidant Capacity

Flaxseed proteins exhibit functionalities interesting for the food industry, including antioxidant capacity. Antioxidant activity depends on the protein composition and the presence of phenolic compounds extracted with them from the matrix. The research focused on the effect of subsequent protein extractions (water, salt and alkaline) of flaxseed meals (of three cultivars) on the protein fraction composition and its relations to antioxidant capacity. The protein and phenolic profiles and antioxidant functionalities (in antiradical ORAC and emulsion assays) were analysed. Spectroscopic characteristics of the fractions (fluorometric and FT-IR analysis) were also included. Our study has shown the effect of fractionation on the share of proteins at MW from 56–38 kDa (globulin-like) and <15 kDa (albumin-like) in the protein profiles. The highest globulin share was in the alkaline-extracted fractions (AEF) and albumin in the salt-extracted (SEF) ones. SDG (secoisolariciresinol diglucosides) and phenolic acids (p-coumaric and ferulic) were extracted with flaxseed proteins. Their contents were fraction-dependent and the highest in AEF. The concentration of phenolics in AEF corresponded with the highest antiradical capacity (ORAC) compared with the other fractions. However, the SEF showed a higher ability to inhibit oxidation in emulsions than AEF, which could be associated with the higher content of the low MW proteins.

The properties of potato gluten-free doughs: comparative and combined effects of propylene glycol alginate and hydroxypropyl methyl cellulose or flaxseed gum

Different methods are often used to make gluten-free (GF) bread to get better bread characteristics. To explore the effects of emulsifiers and hydrocolloids on the characteristics of GF dough, different esterification levels of propylene glycol alginate (PGA), hydroxypropyl methyl cellulose (HPMC), flaxseed gum with (FG) different molecular weight, and the binary blends of HPMC/PGA and FG/PGA were added to GF dough, made with potato starch and potato protein in a ratio of 6:4. The results showed that the potato GF dough with FG and FG/PGA obtained a higher viscoelasticity than the other doughs. HPMC and FG promoted to the formation of network structure, but the network structure formed by PGA and their combination was more developed. It was found that all PGA, HPMC, FG and their combination could improve the softness of GF breads. The results provided a basis for optimizing the quality of potato GF bread.

Impact of Flaxseed Gums on the Colloidal Changes and In Vitro Digestibility of Milk Proteins

Flaxseed (Linum usitatissimum L.) mucilage is one of the most studied plant seed gums in terms of its techno-functional and health-promoting properties. Nonetheless, the interplay of flaxseed gum (FG) with other food biopolymers, such as milk proteins, under in vitro digestion conditions remains underexplored. The aim of the present work was to investigate the colloidal interplay between flaxseed gum (golden or brown) and milk proteins (sodium caseinate or whey protein isolate) under simulated in vitro digestion conditions and its relationship with the attained in vitro protein digestibility. The presence of flaxseed gum in the milk protein food models and in the oral food boluses obtained was associated with the occurrence of segregative microphase separation. Flaxseed gum exhibited a prominent role in controlling the acid-mediated protein aggregation phenomena, particularly in the sodium caseinate gastric chymes. The addition of FG in the food models was associated with a higher amount of intact total caseins and β-lactoglobulin at the end of the gastric processing step. Monitoring of the intestinal processing step revealed a very advanced cleavage of the whey proteins (>98%) and caseins (>90%). The degree of the milk protein hydrolysis achieved at the end of the intestinal processing was significantly higher in the systems containing flaxseed gum (i.e., 59−62%) than their gum-free protein counterparts (i.e., 46−47%). It was postulated that the electrostatic milk protein complexation capacity and, to a lesser extent, the thickening effect of flaxseed gum influenced the in vitro digestibility of the milk proteins.

A review of flaxseed lignan and the extraction and refinement of secoisolariciresinol diglucoside

Lignan is a class of diphenolic compounds that arise from the condensation of two phenylpropanoid moieties. Oilseed and cereal crops (e.g., flaxseed, sesame seed, wheat, barley, oats, rye, etc.) are major sources of plant lignan. Methods for commercial isolation of the lignan secoisolariciresinol diglucoside (SDG) are not well reported, as most publications describing the detection, extraction, and enrichment of SDG use methods that have not been optimized for commercial scale lignan recovery. Simply scaling up laboratory methods would require expensive infrastructure to achieve a marketable yield and reproducible product quality. Therefore, establishing standard protocols to produce SDG and its derivatives on an industrial scale is critical to decrease lignan cost and increase market opportunities. This review summarizes the human health benefits of flaxseed lignan consumption, lignan physicochemical properties, and mammalian lignan metabolism, and describes methods for detecting, extracting, and enriching flaxseed lignan. Refining and optimization of these methods could lead to the development of inexpensive lignan sources for application as an ingredient in medicines, dietary supplements, and other healthy ingredients.

Flaxseed Bioactive Compounds: Chemical Composition, Functional Properties, Food Applications and Health Benefits-Related Gut Microbes

Flaxseed (Linum usitatissimum L.) has gained worldwide recognition as a health food because of its abundance in diverse nutrients and bioactive compounds such as oil, fatty acids, proteins, peptides, fiber, lignans, carbohydrates, mucilage, and micronutrients. These constituents attribute a multitude of beneficial properties to flaxseed that makes its use possible in various applications, such as nutraceuticals, food products, cosmetics, and biomaterials. The importance of these flaxseed components has also increased in modern times because of the newer trend among consumers of greater reliance on a plant-based diet for fulfilling their nutritional requirements, which is perceived to be hypoallergenic, more environmentally friendly, sustainable, and humane. The role of flaxseed substances in the maintenance of a healthy composition of the gut microbiome, prevention, and management of multiple diseases has recently been elucidated in various studies, which have highlighted its importance further as a powerful nutritional remedy. Many articles previously reported the nutritive and health benefits of flaxseed, but no review paper has been published reporting the use of individual flaxseed components in a manner to improve the techno-functional properties of foods. This review summarizes almost all possible applications of flaxseed ingredients in food products from an extensive online literature survey; moreover, it also outlines the way forward to make this utilization even better.

Health benefits of flaxseed and its peptides (linusorbs)

Flaxseed (Linum usitatissimum L.) has been associated with numerous health benefits. The flax plant synthesizes an array of biologically active compounds including peptides or linusorbs (LOs, a.k.a., cyclolinopeptides), lignans, soluble dietary fiber and omega-3 fatty acids. The LOs arise from post-translational modification of four or more ribosome-derived precursors. These compounds exhibit an array of biological activities, including suppression of T-cell proliferation, excessive inflammation, and osteoclast replication as well as induction of apoptosis in some cancer cell lines. The mechanisms of LO action are only now being elucidated but these compounds might interact with other active compounds in flaxseed and contribute to biological activity attributed to other flax compounds. This review focuses on both the biological interaction of LOs with proteins and other molecules and comprehensive knowledge of LO pharmacological and biological properties. The physicochemical and nutraceutical properties of LOs, as well as the biological effects of certain LOs, and their underlying mechanisms of action, are reviewed. Finally, strategies for producing LOs by either peptide synthesis or recombinant organisms are presented. This review will be the first to describe LOs as a versatile scaffold for the action of compounds to deliver physiochemically/biologically active molecules for developing novel nutraceuticals and pharmaceuticals.

Structural Characterization and Functional Properties of Flaxseed Hydrocolloids and Their Application

Flaxseed is an excellent source of valuable nutrients and is also considered a functional food. There are two types of hydrocolloids in flaxseed: flaxseed gum and proteins. Flaxseed gum exhibits emulsifying and foaming activities or can be used as a thickening and gelling agent. Due to its form of soluble fiber, flaxseed gum is related to many health benefits. Flaxseed proteins have various functional properties based on their physicochemical properties. While albumins possess the emulsion-forming ability, globulins better serve as foaming agents. Flaxseed proteins may also serve as a source of functional peptides with interesting biological and health-related activities. Functional properties and health-related benefits predetermine the application of these hydrocolloids, mainly in the food industry or medicine. Although these properties of flaxseed hydrocolloids have been recently and extensively studied, they are still not widely used on the industrial scale compared to other popular plant gums and proteins. The aim of this review was to present, discuss and highlight the recent discoveries in the structural characteristics and functional and biological properties of these versatile hydrocolloids with respect to factors affecting their characteristics and offer new insights into their potential applications as comparable alternatives to the other natural hydrocolloids or as the sources of novel functional products.

Bio-Refinery of Oilseeds: Oil Extraction, Secondary Metabolites Separation towards Protein Meal Valorisation—A Review

Edible oil extraction is a large and well-developed sector based on solvent assisted extraction using volatile organic compounds such as hexane. The extraction of oil from oilseeds generates large volumes of oilseed by-products rich in proteins, fibres, minerals and secondary metabolites that can be valued. This work reviews the current status and the bio-macro-composition of oilseeds, namely soybean, rapeseed, sunflower and flaxseed, and the refining process, comprising the extraction of oil, the valorisation and separation of valuable secondary metabolites such as phenolic compounds, and the removal of anti-nutritional factors such as glucosinolates, while retaining the protein in the oilseed meal. It also provides an overview of alternative solvents and some of the unconventional processes used as a replacement to the conventional extraction of edible oil, as well as the solvents used for the extraction of secondary metabolites and anti-nutritional factors. These biologically active compounds, including oils, are primordial raw materials for several industries such as food, pharmaceutical or cosmetics.

Comparative structural and techno-functional elucidation of full-fat and defatted flaxseed extracts: implication of atmospheric pressure plasma jet

BACKGROUND

The relatively inferior techno-functionality of flaxseed protein/polysaccharide complexes, especially regarding emulsifying and antioxidant activities, has partially limited their implication in the health food system. The present study aimed to investigate the effects of an atmospheric pressure plasma jet (APPJ) on the physicochemical, structural and selected techno-functional properties of flaxseed extracts.

RESULTS

The results obtained showed that the full-fat and defatted flaxseed extract solutions (5 mg mL^-1 ) displayed a sustainable decline in pH (-54.06%, -48.80%, P < 0.05) and zeta potential values (-29.42%, -44.28%, P < 0.05), but a gradual increase in particle sizes, as visualised by an optical microscope, during 0-120 s of APPJ treatment. Moreover, the APPJ led to initial decrease but subsequent increase in protein carbonyls and secondary lipid oxidation products, and concurrently changed the spatial conformation and microstructure of flaxseed extracts, as indicated by endogenous fluorescence properties and scanning electron microscopy (SEM). Additionally, the protein subunit remodeling and gum polysaccharides depolymerization were different for full-fat and defatted flaxseed extracts after 30 s of APPJ exposure. Importantly, the emulsifying and antioxidant activities of defatted flaxseed extract were particularly improved, as assessed by cyro-SEM and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity following 15-30 s of APPJ treatment, as a result of the changing interactions between protein and gum polysaccharides, as well as the release of specific phenolic compounds.

CONCLUSION

APPJ could serve as a promising strategy for tailoring the specific techno-functionality of flaxseed extracts based on mild structural modification. © 2021 Society of Chemical Industry.

Effect of flaxseed gum on the brittleness of oleogels based on candelilla wax

The present study aimed to decrease the brittleness of flaxseed oleogels based on candelilla wax (CLW) in combination with flaxseed gum (FG). Effects of flaxseed gum concentrations (0–0.4%) on the characteristics of flaxseed oleogels including oil binding capacity, textural, thermal, and rheological properties, and crystal polymorphisms were investigated. Higher concentrations (≥0.2%) of FG significantly decreased the textural parameters (e.g., hardness, fracturability) of oleogels (p < 0.05), suggesting that FG could decrease brittleness. Rheological results indicated that all flaxseed oleogels exhibited solid-like characteristics because the elastic modulus was larger than the viscous modulus. The elastic modulus of flaxseed oleogels presented a maximum value at 0.1% gum concentration. Any increase in gum concentration beyond this concentration decreased the elastic modulus. Increasing FG concentration up to 0.4% decreased the enthalpy of flaxseed oleogels during the melting process. The β′-polymorphic form is an orthorhombic perpendicular (O_⊥) subcell structure. Similar β′ crystal forms were observed among flaxseed oleogels, indicating that FG did not affect them negatively. The study showed that the physical properties of flaxseed oleogels based on CLW could be significantly changed by FG addition. These results provided a deeper comprehension of the novel system, which should be considered a new way to obtain healthy fats with better plasticity for food applications.

Oleogels using candelilla wax as a gelling agent and flaxseed gum as a structural modifier: preparation and characterization.

A review of the berberine natural polysaccharide nanostructures as potential anticancer and antibacterial agents

Despite the promising medicinal properties, berberine (BBR), due to its relatively poor solubility in plasma, low bio-stability and limited bioavailability is not used broadly in clinical stages. Due to these drawbacks, drug delivery systems (DDSs) based on nanoscale natural polysaccharides, are applied to address these concerns. Natural polymers are biodegradable, non-immunogenic, biocompatible, and non-toxic agents that are capable of trapping large amounts of hydrophobic compounds in relatively small volumes. The use of nanoscale natural polysaccharide improves the stability and pharmacokinetics of the small molecules and, consequently, increases the therapeutic effects and reduces the side effects of the small molecules. Therefore, this paper presents an overview of the different methods used for increasing the BBR solubility and bioavailability. Afterwards, the pharmacodynamic and pharmacokinetic of BBR nanostructures were discussed followed by the introduction of natural polysaccharides of plant (cyclodextrines, glucomannan), the shells of crustaceans (chitosan), and the cell wall of brown marine algae (alginate)-based origins used to improve the dissolution rate of poorly soluble BBR and their anticancer and antibacterial properties. Finally, the anticancer and antibacterial mechanisms of free BBR and BBR nanostructures were surveyed. In conclusion, this review may pave the way for providing some useful data in the development of BBR-based platforms for clinical applications.

Structure conformation, physicochemical and rheological properties of flaxseed gums extracted under alkaline and acidic conditions

The present work aimed at investigating an extraction protocol based on consecutive steps of isoelectric point (pH ~ 4.25) mediated gum swelling and deproteinisation as an alternative method to produce flaxseed gum extracts of enhanced techno-functional characteristics. The osidic and proximate composition, structure conformation, flow behaviour, dynamic rheological and thermal properties of gums isolated from brown and golden flaxseeds were assessed. Gum extraction under near-to-isoelectric point conditions did not impair the extraction yield, residual protein and ash content, whilst it resulted in minor changes in the sugar composition of the flaxseed gum extracts. The deconvolution of the GPC/SEC chromatographs revealed the presence of four major polysaccharidic populations corresponding to arabinoxylans, rhamnogalacturonan-I and two AX-RG-I composite fractions. The latter appeared to minimise the intra- and interchain polymer non-covalent interactions (hydrogen bonding) leading to a better solvation affinity in water and lyotropic solvents. Golden flaxseed gums exerted higher molecular weight (M_w = 1.34-1.15 × 10⁶ Da) and intrinsic viscosities (6.63-5.13 dL g^-1) as well as better thickening and viscoelastic performance than the brown flaxseed gum exemplars. Golden flaxseed gums exhibited a better thermal stability compared to the brown flaxseed counterparts and therefore, they are suitable for product applications involving severe heat treatments.

The Application of Spray-Dried and Reconstituted Flaxseed Oil Cake Extract as Encapsulating Material and Carrier for Probiotic Lacticaseibacillus rhamnosus GG

Agro-industrial by-products are promising source of biopolymers, including proteins and polysaccharides. This study was designed to evaluate the flaxseed oil cake extract (FOCE) as natural encapsulating material and carrier for probiotic Lacticaseibacillus rhamnous GG (LGG). The powders were obtained using three spray drying inlet temperatures (110 °C, 140 °C, 170 °C), and reconstituted. The influence of temperature on water activity, morphology, chemical composition, flowability and cohesiveness of the powders was estimated. For all variants, the survival of bacteria during spray drying, and simulated passage through the gastrointestinal tract was evaluated. The preservation of LGG probiotic features such as cholesterol reduction, hydrophobicity and adhesion to mucin were examined. Results revealed that all physicochemical and functional characteristics of the powders were affected by the inlet temperature. This study demonstrated that FOCE is an appropriate matrix for spray drying (due to flaxseed proteins and polysaccharides) providing high survivability of bacteria (89.41-96.32%), that passed meaningfully through the simulated gastrointestinal tract (4.39-5.97 log reduction), largely maintaining their probiotic properties, being a promising environmentally-friendly carrier for probiotic LGG.

The Role of Ultrasound in the Preparation of Zein Nanoparticles/Flaxseed Gum Complexes for the Stabilization of Pickering Emulsion

Ultrasound is one of the most commonly used methods to prepare Pickering emulsions. In the study, zein nanoparticles-flaxseed gum (ZNP-FSG) complexes were fabricated through various preparation routes. Firstly, the ZNP-FSG complexes were prepared either through direct homogenization/ultrasonication of the zein and flaxseed gum mixture or through pretreatment of zein and/or flaxseed gum solutions by ultrasonication before homogenization. The Pickering emulsions were then produced with the various ZNP-FSG complexes prepared. ZNP-FSG complexes and the final emulsions were then characterized. We found that the complex prepared by ultrasonication of zein as pretreatment followed by homogenization of the ZNP with FSG ((ZNP_U-FSG)H) exhibited the smallest turbidity, highest absolute potential value, relatively small particle size, and formed the most stable complex particles. Meanwhile, complex prepared through direct ultrasonication plus homogenization on the mixture ((ZNP-FSG)HU) showed significantly decreased emulsifying properties and stability. Compared with the complex without ultrasonic treatment, the complex and emulsion, which prepared by ultrasonicated FSG were extremely unstable, and the phase separation phenomenon of the emulsion was observed 30 min after preparation. The above conclusions are also in line with the findings obtained from the properties of the corresponding emulsions, such as the droplets size, microstructure, freeze-thaw stability, and storage stability. It is, therefore, clear that to produce stable Pickering emulsion, ultrasonication should be avoided to apply together at the end of ZNP-FGS complex preparation. It is worth noticing that the emulsions prepared by complex with ultrasonicated zein (ZNP_U-FSG)H are smaller, distributed more uniformly, and are able to encapsulate oil droplets well. It was found that the emulsions prepared with ZNP_U-FSG remained stable without serum phase for 14 days and exhibited improved stability at low-temperature storage. The current study will provide guidance for the preparation of protein–polysaccharide complexes and Pickering emulsions for future work.

Replacement of animal proteins in food: How to take advantage of nutritional and gelling properties of alternative protein sources

Given the growing world population, there is a need to balance animal and vegetable sources of dietary protein and to limit overall protein resources, and food formulation has to consider alternative protein sources as a way to meet human requirements. The protein concentration, essential amino acids (EAA) of all protein sources were analyzed with respect to human needs along with additional macronutrients of nutritional and energy interest (i.e. carbohydrates and lipids). New indexes are proposed to classify the alternative protein sources considering their EAA balance and how it may change during food processing. A global overview of all protein sources is provided including the quantity of food and associated caloric intakes required to fulfill our daily protein needs. As texture is a key parameter in food formulation, and is often influenced by protein gelation, we conducted an exhaustive review of the literature in a large scientific database on the ability of proteins from all sources to go through the sol-gel transition with the corresponding physical-chemical conditions. Traditional and innovative recipes are discussed and some improvement are proposed in terms of their ability to fulfill human needs for EAA and food and caloric intakes.

Formulation and Evaluation of Linum usitatissimum Mucilage-Based Nanoparticles for Effective Delivery of Ezetimibe

Introduction

The aim of current study was to prepare Linum usitatissimum mucilage (LUM) based nanoparticles, capable of encapsulating hydrophobic drug ezetimibe as nanocarriers.

Methods

Solvent evaporation and nanoprecipitation techniques were used to develop nanoparticles by encapsulating ezetimibe in the articulated matrix of polysaccharide fractions. Developed nanoparticles were characterized to determine the particle size, zeta potential, polydispersibility index (PDI), and entrapment efficiency (EE). Morphology and physicochemical characterization were carried out through SEM, FTIR, PXRD and thermal analysis. Saturation solubility and in vitro release studies were also performed. Safety assessment of ezetimibe loaded nanoparticles was evaluated via oral acute toxicity study.

Results

The mean particle size, zeta potential, PDI and EE for emulsion solvent evaporation were 683.6 nm, -28.3 mV, 0.39, 63.7% and for nanoprecipitation were 637.7 nm, 0.07, -27.1 mV and 80%, respectively. Thermal analysis confirmed enhanced thermal stability, whereas PXRD confirmed amorphous nature of drug. Saturation solubility (p-value <0.05) demonstrated improved solubility of drug when enclosed in linseed nanoparticles. Nanoprecipitation surpasses emulsion solvent evaporation in dissolution test by possessing smaller size. Acute oral toxicity study indicated no significant changes in behavioral, clinical or histopathological parameters of control and experimental groups.

Conclusion

The in vitro release of ezetimibe was augmented by enhancing aqueous solubility through devised nanoparticles. Thus, linseed mucilage could act as biopolymer in the fabrication of nanoparticle formulation. The acute oral toxicological investigations provided evidence that LUMNs were safe after oral administration.

Hydrogels based on low-methoxyl amidated citrus pectin and flaxseed gum formulated with tripeptide glycyl-l-histidyl-l-lysine improve the healing of experimental cutting wounds in rats

Hydrogels based on natural and modified polysaccharides represent growing group of suitable matrices for the construction of effective wound healing materials. Bioactive tripeptide glycyl-l-histidyl-l-lysine and amino acid α-l-arginine are known to accelerate wound healing and skin repair. In this study, hydrogels based on low-methoxyl amidated citrus pectin or flaxseed gum were prepared and used for the transport of these healing agents to the experimental cutting wounds affected by extensive skin damage. Fourier-transform infrared spectroscopy, rheology, differential scanning calorimetry, scanning electron microscopy, swelling and release tests confirmed that these hydrogels differed in structure and physical properties. The cationic tripeptide was found to bind to carboxylic groups in LMA pectin, and the C3OH hydroxyl and ring oxygen O5 are involved in this interaction. The pectin hydrogel showed high viscosity and strong elastic properties, while the flaxseed gum hydrogel was characterised as a viscoelastic system of much lower viscosity. The former hydrogel released the drugs very slowly, while the latter hydrogel demonstrated zero order releasing kinetics optimal for drug delivery. In the in vivo wound healing testing on rats, both polysaccharide hydrogels improved the healing process mediated by the mentioned biomolecules. The tripeptide applied in the hydrogels showed significantly higher healing degree and lower healing time than in the control animals without treatment and when it was applied in an aqueous solution. Despite the absence of a synergistic effect, the mixture of the tripeptide and α-l-arginine in the hydrogels was also quite effective in wound healing. According to histological analysis, complete healing was achieved only when using the tripeptide in the flaxseed gum hydrogel. These observations might have an important prospect in clinical application of polysaccharide hydrogels.