Plant seed mucilage as emerging biopolymer in food industry applications

Mucilages: sources, extraction methods, and characteristics for their use as encapsulation agents

The increasing interest in the use of natural ingredients has driven keen research and commercial interest in the use of mucilages for a range of applications. Typically, mucilages are polysaccharide hydrocolloids with distinct physicochemical and structural diversity, possessing characteristic functional and health benefits. Apart from their role as binding, thickening, stabilizing, and humidifying agents, they are valued for their antimicrobial, antihypertensive, antioxidant, antiasthmatic, hypoglycemic, and hypolipidemic activities. The focus of this review is to present the range of mucilages that have been explored as encapsulating agents. Encapsulation of food ingredients, nutraceutical, and pharmaceutical ingredients is an attractive technique to enhance the stability of targeted compounds, apart from providing benefits on delivery characteristics. The most widely adopted conventional and emerging extraction and purification methods are explained and supplemented with information on the key criteria involved in characterizing the physicochemical and functional properties of mucilages. The unique traits and benefits of using mucilages as encapsulation agents are detailed with the different methods used by researchers to encapsulate different food and bioactive compounds.

Gastroprotective effect of mucilage fraction from Solenostemma argel via cytoprotection and attenuation of oxidative stress, inflammation and apoptosis

Introduction: Polysaccharides have numerous therapeutic values including immunity stimulation, angiotensin converting enzyme inhibition, wound healing, anti-diabetic and cytotoxic activities, in addition to their potent anti-oxidant properties. This work examined the gastroprotective and ulcer healing potential of mucilage fraction isolated from Solenostemma argel (Delile) Hayne (MFA) against ethanol-induced gastric ulcer in rats. Methods: Forty Sprague-Dawley rats were divided into five groups (n=8); normal control (I), ethanol control (II), 20 mg/kg Antodine pretreated rats (III), 100 mg/kg, and 200 mg/kg MFA pretreated rats, respectively (IV & V). All rats in groups II-V received single intragastric dose of ethanol (5 mL/kg) to induce gastric ulcer. Gastric mucosal injuries were assessed by stomach gross examination as well as histopathology, and immunohistochemistry of apoptotic markers. Also, several biochemical parameters including oxidative stress, proinflammatory cytokines, cytoprotective and cell proliferative biomarkers were measured. Results: High-performance liquid chromatography (HPLC) analysis of MFA revealed its composition of glucose, D-fucose and N-acetyl glucosamine as monosaccharaides, in addition to glucuronic and galacturonic acids. The data showed that MFA, 200 mg/kg had potent antioxidant, anti-inflammatory, cytoprotective, cell proliferative, and antiapoptotic activities which were better than Antodine. Conclusion: This study revealed that MFA had significant gastroprotective effects against ethanol-induced gastric injuries and could be a promising adjuvant therapy for ulcer treatment.

Mucilage as a functional food hydrocolloid: ongoing and potential applications in prebiotics and nutraceuticals

Mucilage is a soluble dietary fiber used as a food additive to give foods a firmer texture, aside from its many health benefits and pharmacological properties. It is a polysaccharide in nature, composed of large molecules of sugars and uronic acid moieties. The extraction of mucilage is achieved from a wide variety of plant parts, including rhizomes, roots, and seeds, and it has also been reported from microorganisms. In this review, the nutritional and medicinal applications of mucilage are described in the context of the different mucilage types. The current article highlights state-of-the-art valorization practices relating to mucilage and its potential novel usages in the food industry and nutraceuticals, and as a prebiotic, in addition to its nutritional and anti-nutritional values. Analysis of the prebiotic action of mucilage with respect to its structure activity relationship, as well as how it modulates gut bacteria, is presented for the first time and in the context of its known health benefits inside the colon. It is recommended that more investigations are carried out to maximize the health benefits of mucilage and ensure its safety, especially upon long-term usage.

Seed mucilage evolution: Diverse molecular mechanisms generate versatile ecological functions for particular environments

Plant myxodiasporous species have the ability to release a polysaccharidic mucilage upon imbibition of the seed (myxospermy) or the fruit (myxocarpy). This is a widespread capacity in angiosperms providing multiple ecological functions including higher germination efficiency under environmental stresses. It is unclear whether myxodiaspory has one or multiple evolutionary origins and why it was supposedly lost in several species. Here, we summarize recent advances on three main aspects of myxodiaspory. (a) It represents a combination of highly diverse traits at different levels of observation, ranging from the dual tissular origin of mucilage secretory cells to diverse mucilage polysaccharidic composition and ultrastructural organization. (b) An asymmetrical selection pressure is exerted on myxospermy-related genes that were first identified in Arabidopsis thaliana. The A. thaliana and the flax intra-species mucilage variants show that myxospermy is a fast-evolving trait due to high polymorphism in a few genes directly acting on mucilage establishment. In A. thaliana, these actors are downstream of a master regulatory complex and an original phylogenetic overview provided here illustrates that this complex has sequentially evolved after the common ancestor of seed plants and was fully established in the common ancestor of the rosid clade. (c) Newly identified myxodiaspory ecological functions indicate new perspectives such as soil microorganism control and plant establishment support.

Arabinoxylan and rhamnogalacturonan mucilage: Outgoing and potential trends of pharmaceutical, environmental, and medicinal merits

Demand for safe, environmentally friendly and minimally processed food additives with intrinsic technological (stabilizing, texturizing, structuring) and functional potential is already on the rise. There are actually several natural excipients eligible for pharmaceutical formulation. Mucilage, as a class constitutes arabinoxylan and rhamnogalacturonan-based biomolecules used in the pharmaceutical, environmental as well as phytoremediation industries owing to its particular structure and properties. These compounds are widely used in pharmaceutical, food and cosmetics, as well as, in agriculture, paper industries. This review emphasizes mucilage valuable applications in the pharmaceutical and industrial fields. In this context, much focus has recently been given to the valorization of mucilage as an ingredient for food or nutraceutical applications. Furthermore, different optimization and extraction techniques are presented to develop better utilization and/or enhanced yield of mucilage. The highlighted mucilage extraction methods warrant assessing up-scale processes to encourage for its industrial applications. The current article capitalizes on cutting-edge characteristics of mucilage and posing for other possible innovative applications in non-food industries. Here, the first holistic overview of mucilage with regards to its physicochemical properties and potential novel usages is presented.

Draft Genome Sequences of Pantoea agglomerans, Paenibacillus polymyxa, and Pseudomonas sp. Strains, Seed Biogel-Associated Endophytes of Cucumis sativus L. (Cucumber) and Cucumis melo L. (Cantaloupe)

We report here the draft genome sequences of strains of Pantoea agglomerans (EKM10T, EKM20T, EKM21T, and EKM22T), Paenibacillus polymyxa (EKM10P and EKM11P), and Pseudomonas sp. strain EKM23D. These microbes were cultured from fresh seed biogels of Cucumis sativus L. (cucumber) and Cucumis melo L. (cantaloupe). The strains suppress the growth of soilborne fungal/oomycete phytopathogens in vitro.

We report here the draft genome sequences of strains of Pantoea agglomerans (EKM10T, EKM20T, EKM21T, and EKM22T), Paenibacillus polymyxa (EKM10P and EKM11P), and Pseudomonas sp. strain EKM23D. These microbes were cultured from fresh seed biogels of Cucumis sativus L. (cucumber) and Cucumis melo L. (cantaloupe). The strains suppress the growth of soilborne fungal/oomycete phytopathogens in vitro.

Functionalizing and bio-preserving processed food products via probiotic and synbiotic edible films and coatings

Edible films and coatings constitute an appealing concept of innovative, cost-effective, sustainable and eco-friendly packaging solution for food industry applications. Edible packaging needs to comply with several technological pre-requisites such as mechanical durability, low permeability to water vapor and gases, good optical properties, low susceptibility to chemical or microbiological alterations and neutral sensory profile. Over the past few years, functionalization of edible films and coatings via the inclusion of bioactive compounds (antioxidants, micronutrients, antimicrobials, natural coloring and pigmentation agents) and beneficial living microorganisms has received much attention. As for living microorganisms, probiotic bacterial cells, primarily belonging to the Lactobacilli or Bifidobacteria genera, have been exploited to impart bespoke health and biopreservation benefits to processed food. Given that the health benefit conferring and biopreservation potential of probiotics is dependent on several extrinsic and intrinsic parameters, the development of probiotic and synbiotic edible packaging concepts is a quite challenging task. In the present chapter, we aimed at a timely overview of the technological advances in the field of probiotic, symbiotic and synbiotic edible films and coatings. The individual or combined effects of intrinsic (matrix composition and physical state, pH, dissolved oxygen, water activity, presence of growth stimulants or inhibitors) and extrinsic (film forming method, food processing, storage time and conditions, exposure to gastrointestinal conditions) factors on maintaining the biological activity of probiotic cells were addressed. Moreover, the impact of living cells inclusion on the mechanical, physicochemical and barrier properties of the edible packaging material as well as on the shelf-life and quality of the coated or wrapped food products, were duly discussed.

Intake of soluble fibre from chia seed reduces bioaccessibility of lipids, cholesterol and glucose in the dynamic gastrointestinal model simgi®

The role of soluble fibres on hypoglycemic and hypocholesterolemic effects has been widely documented, but the effect on glucose and cholesterol binding capacity of soluble fibre extracted from chia seed mucilage has not been studied until now. In the present research, dynamic gastrointestinal model simgi® combined with absorption static techniques have been used to explore the effect of chia seed mucilage at 0.75 and 0.95% w/w on the bioaccessibility of glucose, dietary lipids and cholesterol along the gastrointestinal tract. Glucose bioaccessibility was reduced when 0.95% of chia mucilage was present in sugar food models. The total reduction of glucose bioaccessibility reached a maximum of 66.7% while glucose dialysis retardation index presented its maximum of 53.4% at the end of small intestine digestion. The in vitro studies with lipid food models, showed that the presence of both, 0.75 and 0.95% of chia seed mucilage caused substantial reductions on the bioaccessibility of free fatty acids (16.8 and 56.1%), cholesterol (18.2 and 37.2% respectively) and bile salts (4.8 and 64.6%), revealing a clear dependence on fibre concentration. These innovative results highlight the potential functionality of the soluble fibre extracted from chia seeds to improve lipid and glycemic profiles and suggest the dietary health benefits of this new soluble fibre source as an ingredient in functional foods designed to reduce the risk of certain non-communicable diseases.

Encapsulated Limonene: A Pleasant Lemon-Like Aroma with Promising Application in the Agri-Food Industry. A Review

Limonene, mainly found as a major component in Citrus spp., has been proven to possess a valuable potential as sustainable replacement to synthetic pesticides and food preservatives. This review intends to give a clear overview of the principal emerging applications of limonene in the agri-food industry as antimicrobial, herbicidal and antioxidant agent. To successfully use limonene in a greener agri-food industry, its preservation had become a top concern for manufacturers. In order to elucidate the most efficient and sustainable manner to encapsulate limonene, the different techniques and materials tested up to the present are also reviewed. In general, encapsulation conserves and protects limonene from outside aggressions, but also allows its controlled release as well as enhances its low water solubility, which can be critical for the discussed applications. Other parameters such as scalability, low cost and availability of equipment will need to be taken into account. Further efforts would likely be oriented to the elucidation of encapsulating sustainable systems obtained by cost-efficient elaboration processes, which can deliver effective concentrations of limonene without affecting crops and food products.

Bioengineered three-dimensional physical constructs from quince seed mucilage for human adipose-derived mesenchymal stem cells

In this study, we aimed at fabricating a novel porous physical construct from quince seed mucilage for translational medicine applications. To achieve this goal, quince seed mucilage was extracted, molded, and freeze-dried. After being freeze-dried, the molded constructs were chemically crosslinked with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide to maintain the mechanical integrity of the structure. The fabricated scaffolds were characterized in-depth by scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller analysis, thermogravimetric analysis, and dynamic mechanical analysis in addition to the swelling, liquid uptake, and porosity tests. The extraction yield of mucilage was calculated to be 6.28% ± 0.40% (n = 3). The swelling ratio of crosslinked quince seed mucilage–derived scaffolds was found to be 12,677.50% ± 388.82% (n = 3), whereas the porosity of crosslinked quince seed mucilage–derived scaffolds was 83.43% ± 2.84% (n = 3). The analyses confirmed the crosslinked quince seed mucilage–derived scaffolds to be possessed interconnected, highly porous structure. Afterward, human adipose-derived mesenchymal stem cells were seeded on the crosslinked quince seed mucilage–derived scaffolds, and the cell viability on the scaffolds was assessed with 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. The MTT results revealed the scaffolds not to be possessed any cytotoxic effect on seeded cells. Human adipose-derived mesenchymal stem cells adhesion and migration on the crosslinked quince seed mucilage–derived scaffolds were also evaluated histologically using hematoxylin and eosin staining in addition to scanning electron microscopy analysis. In conclusion, we believe that crosslinked quince seed mucilage–derived scaffolds have the potential to be an alternative to routinely used polysaccharides in regenerative medicine applications.

Pectin-Based Films Loaded with Hydroponic Nopal Mucilages: Development and Physicochemical Characterization

Nopal is a potential source of mucilage that can be used in different food applications. One of its potential use is the development of films and coatings where it can act as a packaging material but also as a source of bioactive compounds. Therefore, this work aimed to develop and characterize pectin-based films loaded with mucilage extracted from two species of nopal, Copena F1 (Cop) and Villanueva (Vi). The obtained mucilages were denominated as materials without fibre (Copwtf and Viwtf) and with fibre (Copwf and Viwf), according to the fibre’s size. Films were produced with pectin (2% w/v), mucilage (2.5% w/v) and glycerol (0.5% w/v) by the casting method. The addition of mucilages was shown to influence the visual appearance, optical properties and morphology of the films. The presence of mucilage also changed the moisture content, water contact angle and water vapour permeability of the films. The pectin-based films without mucilage presented the best mechanical properties. Fourier-transform infrared (FTIR) spectroscopy showed similar signals in terms of frequency and intensity, for all the films, not showing any chemical modification. Results show that the mucilage obtained from different nopal fractions can be used in pectin-based films foreseeing their use as films or coatings in food applications.

Synthesis and characterization of magnetite/Alyssum homolocarpum seed gum/Ag nanocomposite and determination of its antibacterial activity

Due to applications of silver nanoparticles (Ag NPs) especially in advanced science fields, it is important to produce Ag antibacterial nanocomposites with enhanced antibacterial activity and reusability. Over the past decade researches about natural polymers have emphasized the use of them as nanoparticles coating. In this work, a novel core-shell antibacterial agent was synthesized through a three-step procedure. Fe₃O₄ nanoparticles (Fe₃O₄ NPs) were synthesized and coated with a natural polymer called Alyssum homolocarpum seed gum (AHSG). Ag NPs were immobilized on the AHSG resulting in formation of the new nanocomposite with improved antimicrobial properties. The immobilization of Ag NPs prevents the release of toxic Ag⁺ ions. The Fe₃O₄@AHSG@Ag nanocomposite could easily be separated from medium using an external magnetic field due to presence of the Fe₃O₄ superparamagnetic nanoparticles. The as-synthesized nanocomposite was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, vibrating sample magnetometer and dynamic light scattering. The results showed that the magnetic nanocomposite was synthesized and coated successfully. Finally, results of disk diffusion method demonstrated that the nanocomposite exhibits excellent antibacterial activity against gram-positive and gram-negative bacteria.

Polysaccharides at fluid interfaces of food systems

Fabrication of next generation polysaccharides with interfacial properties is driven by the need to create high performance surfactants that operate at extreme environments, as for example in complex food formulations or in the gastrointestinal tract. The present review examines the behaviour of polysaccharides at fluid food interfaces focusing on their performance in the absence of any other intentionally added interfacially active components. Relevant theoretical principles of colloidal stabilisation using concepts that have been developed for synthetic polymers at interfaces are firstly introduced. The role of protein that in most cases is present in polysaccharide preparations either as contaminant or as integral part of the structure is also discussed. Critical assessment of the literature reveals that although protein may contribute to emulsion formation mostly as an anchor for polysaccharides to attach, it is not the determinant factor for the long-term emulsion stability, irrespectively of polysaccharide structure. Interfacial performance of key polysaccharides is also assessed revealing shared characteristics in their modes of adsorption. Conformation of polysaccharides, as affected by the composition of the aqueous solvent needs to be closely controlled, as it seems to be the underlying fundamental cause of stabilisation events and appears to be more important than the constituent polysaccharide sugar-monomers. Finally, polysaccharide adsorption is better understood by regarding them as copolymers, as this approach may assist to better control their properties with the aim to create the next generation biosurfactants.

STUDY OF THE INFLUENCE OF BUCKWHEAT FLOUR AND FLAX SEEDS ON CONSUMPTION PROPERTIES OF LONG-STORED BAKERY PRODUCTS

Rusk and ring-shaped bakery products relate to the group of long-stored ones. For today it is urgent to use ingredients that give products functional properties in food technologies. The important source of food fibers, full-value protein, unsaturated fatty acids, mineral substances and vitamins are grain and oil-bearing crops. Buckwheat and flax seeds are separated among them due to the valuable chemical composition and positive effect on the human organism. The aim of the work was to establish the influence of buckwheat flour and flax seeds on the technological process course and quality of long-stored bakery products. Buckwheat flour of green and dark buckwheat of TM “Organic-Eco-Product” (Ukraine) is used in the rusk technology. For producing ring-shaped products (ring-shaped crackers), gold flax seeds were used. Research results testify that good quality parameters of bread for producing rusks from it, were achieved at dosing green buckwheat seeds as 20 % and dark ones as 15 % instead of the flour mass. It has been established, that rusks with adding green buckwheat flour have quality parameters, corresponding to requirements of normative documents. It has been proven, that it is not expedient to use dark buckwheat flour in the rusk technology, because ready products have the increased water share and soaking index. It is connected with the influence of the operation of hydrothermal processing of grains that dark buckwheat flour is produced of, its high water-absorbing and water-retaining capacities. For the technology of ring-shaped crackers, enriched with flax seeds, it is recommended to dose flax seeds as 15 % of the flour mass. At such dosage bakery products got the highest number of points by the complex quality parameter and corresponded to requirements of normative documents.

Obtaining a novel mucilage from mutamba seeds exploring different high-intensity ultrasound process conditions

We evaluated the effect of ultrasonic power (200-600 W) and process time (1-7 min) on the recovery of a novel polysaccharide from mutamba (Guazuma ulmifolia Lam.) seeds applying high-intensity ultrasound. Ultrasound process conditions intensification gradually was removing the mucilage layer around the hydrated seeds. Then, the scanning electron micrographs showed that the mucilage was removed completely at the highest applied energy density (10,080 J/mL). Although the colour of mutamba seed mucilage (MSM) have been changed due to increase of energy density, it not affects its practical use because the MSM can be purified to remove impurities. The results obtained in this study demonstrated that the ultrasound process conditions intensification did not affect the primary structure of MSM according to ζ-potential, FTIR spectrum, and monosaccharide residues data. In conclusion, ultrasound process conditions intensification allows the full recovery of the MSM at a short process time (7 min) without altering its quality and the primary structure.

Making glue from seeds and gums: Working with plant-based polymers to introduce students to plant biochemistry

Plants and plant products are key to the survival of life on earth. Despite this fact, the significance of plant biochemistry is often underrepresented in science curricula. We designed an innovative laboratory activity to engage students in learning about the biochemical properties of natural polymers produced by plants. The focus of the hands-on activity is on mucilages and gums, which contain complex polysaccharides that have applications in industry. The 1.5-h activity is organized into three laboratory exercises. It begins with a demonstration of the water absorption property of seed coat mucilage upon hydration of seeds from psyllium, a plant that is grown commercially for mucilage production. The second exercise involves microscopy of a variety of plant seeds stained with ruthenium red dye to visualize pectin polysaccharides of the seed mucilage. Students learn about phenotypic variation among plant species and how the seed coat mucilage is beneficial to keep seeds hydrated during germination. The third exercise highlights an industrial application of plant gums as adhesives. The students prepare edible glue made with gum arabic, a type of plant polymer from the dried exudate of the Acacia plant. This three-part activity has been implemented in conjunction with a Girls Researching Our World (GROW) summer workshop for sixth to eighth graders over a 4-year period. It may be adapted as a laboratory activity for students of all ages, for example, to enhance biochemistry education for high-school students or undergraduate non-majors. © 2019 International Union of Biochemistry and Molecular Biology, 47(4):468-475, 2019.