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Agar

Agar, also known as agar-agar, is a gelatinous polysaccharide extracted from the cell walls of certain red algae species within the class Rhodophyceae, primarily from genera such as Gelidium and Gracilaria.^[1] It consists mainly of agarose, a neutral linear polymer of agarobiose units (alternating D-galactose and 3,6-anhydro-L-galactose), and agaropectin, a sulfated and branched fraction that contributes to its charged properties.^[2] Chemically, agar is a hydrophilic colloid with low sulfate content (typically 1.5–2.5% by weight) and a molecular formula approximated as C₁₄H₂₄O₉ for its repeating units, rendering it odorless, tasteless, and white to pale yellow in powder or flake form.^[3] Originating from East Asia where production was industrialized in the 18th century, agar was introduced to Europe and the United States in the 19th century.^[1] A key feature of agar is its unique thermoreversible gelling behavior: it dissolves in boiling water but forms a firm, transparent gel upon cooling at 32–43°C, with a melting point exceeding 85°C—hysteresis that distinguishes it from most other gelling agents.^[2] This high gel strength, often measured at 600–1,100 g/cm² using the Nikan-Sui method, along with its clarity, thermal stability, and resistance to bacterial degradation, makes agar ideal for applications requiring durable solid matrices.^[1] Agar is generally recognized as safe (GRAS) by the U.S. Food and Drug Administration, with permitted use levels up to 2.0% in confections and 0.8% in baked goods, and it exhibits low toxicity, though excessive consumption can act as a bulk laxative due to its indigestibility.^[3] In the food industry, agar functions as a vegan gelatin substitute for thickening, stabilizing, and gelling in products like jellies, marshmallows, dairy desserts, and canned meats, leveraging its neutral flavor and ability to withstand high temperatures during processing.^[4] Microbiologically, it is indispensable for solid culture media, such as nutrient agar, enabling the isolation and growth of bacteria and fungi by providing a supportive, non-nutritive matrix.^[2] Beyond these, agar supports biochemical techniques like immunodiffusion and electrophoresis, serves in pharmaceuticals for capsule shells and wound dressings, and aids biotechnology in tissue engineering and plant cell culture.^[1] Global production is approximately 21,000 tonnes as of 2024, centered in Asia and South America, sourced from both wild-harvested and cultivated algae to meet demands across these diverse sectors.^[5]

Etymology and History

Etymology

The term "agar" originates from the Malay word agar-agar, which refers to a jelly-like or gelatinous substance derived from certain red seaweeds.^[6]^[7] In Malay and Indonesian contexts, agar-agar specifically denotes the product extracted from algae such as those in the genera Gelidium and Gracilaria, emphasizing its gelling properties.^[7] The word entered European languages in the 19th century through colonial trade routes, particularly via Dutch traders in the East Indies who encountered the substance in Indonesia and introduced it to Europe for culinary uses like fruit jellies.^[8]^[7] Portuguese explorers and colonists, active in Southeast Asia, also adopted the term as agar-agar, retaining the doubled form in Portuguese-speaking regions, while it was shortened to "agar" in English scientific nomenclature by the late 1800s, with the first recorded use in English dated to 1885.^[6]^[1] Across cultures, variations reflect local adaptations and sources: in Japan, it is known as kanten (meaning "cold sky" or related to its winter preparation), while early Western texts often referred to it as "Chinese gelatin" or "China grass" due to its prominence in Chinese cuisine and trade.^[7]^[9] In China, it is called dongfen ("frozen powder"), highlighting its cooling and solidifying qualities.^[7] The scientific names of key agar-producing algae include Gelidium (from Latin gelidus, meaning "icy" or "frozen," alluding to the algae's cold-water habitat) and Gracilaria (from Latin gracilis, meaning "slender," describing the plant's form). These names were established in botanical classification during the 18th and 19th centuries.^[7]^[10]^[9]

Historical Development

Agar's origins trace back to 17th-century Japan, where it was developed as a gelling agent derived from red seaweed for culinary purposes, particularly in the preparation of tokoroten, a popular summertime jelly dish consumed in the form of cold noodle-like strips.^[11] This innovation is attributed to an innkeeper named Minoya Tarozaemon around 1658, who reportedly discovered the gelling property accidentally when seaweed broth froze overnight during a cold winter, leading to its refinement into kanten, a dried form used in Edo-period cuisine.^[12] Records from the Edo period (1603–1868) document its widespread use among common townspeople in urban centers like Edo (modern Tokyo), where it served as a refreshing, low-calorie treat amid feudal Japan's dietary customs.^[9] The substance reached Europe in the late 19th century, primarily through informal channels rather than formal expositions, as Japanese immigrants and traders shared knowledge of kanten with Western households, sparking initial curiosity for its culinary and potential scientific applications.^[13] Scientific interest surged in the 1880s, catalyzed by German microbiologist Robert Koch's laboratory, where agar was adopted as a superior alternative to gelatin for bacterial cultivation due to its stability at incubation temperatures.^[14] A pivotal milestone occurred in 1881 when Fanny Angelina Hesse, an American-born assistant in Koch's lab and wife of his collaborator Walther Hesse, suggested using agar—familiar to her from Japanese friends in New Jersey—for solidifying nutrient media, addressing gelatin's limitations like melting and contamination by molds.^[14] Koch implemented this in his 1882 isolation of Mycobacterium tuberculosis, crediting the Hesses briefly in the publication and establishing agar as a cornerstone of microbiology.^[13] Commercialization accelerated in the early 20th century, with Japan maintaining its lead through established drying and export practices refined since the 17th century, supplying agar primarily for food and emerging lab uses.^[12] Industrial production began in Spain during World War II in the 1940s, leveraging abundant Gelidium seaweed stocks along the Catalan coast to meet growing European demand, with factories adopting alkaline extraction methods to scale output for both culinary and pharmaceutical markets.^[7] By the 1950s, Spanish firms like Hispanagar had become key exporters, complementing Japan's focus on high-quality kanten while introducing mechanized processing that boosted global availability.^[15] Following World War II, agar production expanded dramatically to support surging needs in microbiology labs and the postwar food industry, driven by economic recovery and scientific advancements in antibiotics and tissue culture.^[16] Wartime shortages of Japanese Gelidium supplies prompted a shift to more abundant Gracilaria species, particularly in Chile and Indonesia, where cultivation techniques enabled higher yields and diversified sourcing to prevent depletion of wild stocks.^[17] This transition, initiated during the war but accelerated in the 1950s–1960s, increased global output from approximately 2,500 tons annually around the time of World War II to about 10,000 tons by the mid-1970s, fueling applications in desserts, pharmaceuticals, and research. In recent decades up to 2025, modern developments have emphasized sustainable sourcing amid concerns over Gelidium overharvesting, with initiatives promoting farmed Gracilaria and eco-certification to balance demand from expanding biotech and vegan food sectors. As of 2025, global agar production is estimated at approximately 25,000 tons annually, driven by demand in food, biotech, and pharmaceutical sectors.^[18] European Union-funded projects since 2020 have advanced algae aquaculture hubs, integrating circular economy principles to reduce environmental impact while ensuring supply chain traceability.^[19] Industry leaders have adopted practices like regenerative seaweed farming, cutting extraction inefficiencies by up to 30% and addressing biodiversity risks through monitored wild harvests.^[20]

Sources and Production

Natural Sources

Agar is primarily derived from certain species of red algae within the phylum Rhodophyta, particularly those belonging to the genera Gelidium, Gracilaria, and Pterocladia, which synthesize agar as a key component of their cell walls.^[21] These algae produce agar as a sulfated galactan polysaccharide that provides structural support, enabling the organisms to withstand mechanical stresses from ocean currents and waves.^[21] Among these, Gelidium cartilagineum stands out as a principal species for extracting high-quality agar due to its superior gelling properties and purity.^[22] The agar content in these algae exhibits seasonal variations, typically reaching higher levels during summer months when environmental conditions favor polysaccharide accumulation.^[23] These agar-producing red algae are distributed across temperate and tropical marine environments worldwide, thriving in intertidal and subtidal zones of oceans. Major natural habitats include coastal regions of Asia—such as Japan, China, and Indonesia—along with Morocco in North Africa and Chile in South America, where suitable water temperatures and nutrient availability support robust growth.^[24] By the 2020s, over 80% of global agar supply originated from cultivated Gracilaria species, reflecting a significant reliance on farmed sources in these areas.^[25] Historically, agar extraction depended heavily on wild harvesting of Gelidium and Pterocladia, but since the 1970s, there has been a marked shift toward aquaculture, particularly for Gracilaria, to meet rising industrial demand and mitigate overexploitation of natural stocks.^[26] As of 2024, global agar production reached approximately 24,650 tons annually, with aquaculture systems in ponds and offshore farms enhancing yield predictability.^[18] However, climate change poses emerging challenges, as rising sea temperatures and ocean acidification disrupt algal growth cycles, potentially reducing yields in warming waters and altering agar composition in vulnerable habitats.^[27]

Production Methods

Agar production begins with the harvesting of red algae, primarily species such as Gelidium and Gracilaria, followed by thorough cleaning to remove sand, salt, and epiphytes, and subsequent drying to preserve the biomass for processing.^[28] An essential initial step is alkaline pretreatment, often using a dilute solution of sodium hydroxide (NaOH) at 1-2% concentration for several hours, which removes impurities like proteins and lipids, and desulfates the agaropectin fraction to enhance gelling properties and extraction efficiency of the agar.^[29] The core extraction process involves boiling the pretreated algal material in water or dilute alkali at temperatures around 85-100°C for 1-4 hours to solubilize the polysaccharides, forming a viscous extract that is then filtered to separate insoluble residues.^[28] The filtrate undergoes gelation by cooling to form a solid gel, which is purified through repeated freeze-thaw cycles—freezing at -10°C or below and thawing at room temperature—to eliminate water-soluble impurities and concentrate the agar.^[30] Finally, the purified gel is dried, typically via hot air or vacuum drying, and ground into powder or flakes for commercial use.^[28] Traditional production of Japanese kanten employs a labor-intensive method where cleaned and boiled algal mixtures are spread thinly for sun-drying, followed by natural freezing in winter to induce gelation and purification without chemical additives.^[1] In contrast, modern industrial methods utilize hot-water extraction at 85-100°C, sometimes with alkaline pretreatment and optional bleaching for higher purity and whiteness, enabling large-scale production with automated filtration and drying systems.^[30] Agar yields typically range from 10-30% of the dry algal weight, influenced by species, pretreatment conditions, and extraction duration, with higher yields achieved through optimized alkaline treatments.^[31] For bacteriological-grade agar, quality standards demand greater than 95% clarity in a 1.5% gel solution and low mineral content, often with ash levels below 6.5%, to ensure minimal interference in microbial growth media.^[32] By 2025, emerging enzymatic and ultrasound-assisted extraction methods have improved sustainability, operating at temperatures around 100°C with enzymes to hydrolyze algal cell walls, reducing processing time and energy compared to traditional methods while minimizing chemical waste, with ongoing research aimed at further yield improvements.^[33] Biotech enhancements, such as ultrasound-assisted enzymatic protocols, further boost efficiency by disrupting cell structures non-thermally, addressing environmental concerns over traditional alkali-heavy processes.^[33]

Properties

Chemical Composition

Agar is a sulfated polysaccharide primarily composed of two fractions: agarose, which constitutes 70-80% of the total, and agaropectin, accounting for the remaining 20-30%.^[34] Agarose is a neutral, linear polymer formed by repeating units of D-galactose and 3,6-anhydro-L-galactose, linked alternately through β-1,4 glycosidic bonds between the D-galactose and the anhydro sugar, and α-1,3 glycosidic bonds connecting the anhydro-L-galactose to the next D-galactose unit.^[1] The repeating disaccharide unit of agarose has the chemical formula (C_{12}H_{18}O_{9})_n.^[35] In contrast, agaropectin is a branched polysaccharide with a similar backbone of alternating D-galactose and L-galactose units but incorporates charged groups, including sulfate esters and small amounts of pyruvic acid, which contribute to its anionic nature and lower gelling capacity compared to agarose.^[1] These structural differences arise from the extraction source, with variations in sulfate content influencing the overall properties; for instance, bacteriological-grade agar is processed to achieve lower sulfate levels (typically under 1-2%) to enhance purity and performance in gel formation.^[21] Food-grade agar often contains trace impurities such as minerals (e.g., calcium, magnesium) and proteins from the algal source, whereas laboratory-grade agar undergoes additional purification to minimize these contaminants for precise applications.^[36] The molecular structure of agar was first elucidated through classical methods, including methylation analysis and periodate oxidation, as detailed in Araki's foundational work separating and characterizing agarose in 1937 and 1956.^[1] Confirmation of the composition comes from acid hydrolysis, which breaks down agar into its monomeric units, primarily D-galactose, verifying the galactan nature of both agarose and agaropectin fractions.^[1] Modern structural analysis relies on nuclear magnetic resonance (NMR) spectroscopy, which provides detailed insights into glycosidic linkages, anhydro configurations, and substituent positions without degradation; for example, ^{13}C-NMR distinguishes agar's characteristic signals for the C-6 anhydro ring and sulfate-bearing carbons, enabling precise compositional profiling.^[37]

Physical Properties

Agar is insoluble in cold water but becomes soluble in hot water, typically requiring temperatures above 85–95°C for complete dissolution to form a clear solution.^[1] Upon cooling, this solution forms a thermoreversible gel at temperatures between 32–40°C, exhibiting significant hysteresis where the melting point is approximately 50–60°C higher than the gelling point, often exceeding 85°C for remelting.^[21] The gelling properties of agar result in firm, brittle, and elastic gels with high gel strength, commonly measured at 600–1200 g/cm² for food-grade varieties using the Nikan-Sui method on a 1.5% solution.^[1] These gels demonstrate excellent water-holding capacity, retaining up to 99% water content, though they are prone to syneresis—exuding liquid under pressure or mechanical stress—which intensifies at lower concentrations.^[38] Agar possesses a neutral taste and is odorless, contributing no flavor or aroma to formulations.^[21] It maintains stability across a pH range of 4–8, is non-toxic with GRAS status from the FDA, and is biodegradable as a natural polysaccharide.^[1] Key factors influencing agar's physical properties include concentration, typically 1–2% for standard gels where higher levels increase strength and rigidity, and variations in grade arising from seaweed sources and processing methods, which affect overall gelling power and syneresis.^[1] While agar gelation relies primarily on hydrogen bonding and is largely independent of ions, certain divalent cations like calcium can subtly modulate viscosity and stability in specific contexts.^[39]

Uses

Culinary Uses

Agar serves as a popular vegetarian and vegan substitute for animal-derived gelatin in culinary applications, particularly in desserts, jellies, and custards, where it is typically used at concentrations of 0.5–2% to achieve a firm, sliceable gel that sets at room temperature and remains stable under heat.^[40] Unlike gelatin, agar produces a firmer texture that does not melt easily, making it ideal for molded preparations.^[41] In Asian cuisines, agar has been a traditional gelling agent since the 17th century, when it was reportedly discovered in Japan through an accidental process of extracting and drying seaweed broth.^[9] It features prominently in Japanese desserts such as anmitsu, a layered sweet with agar jelly, red bean paste, fruits, and syrup, and mizu shingen mochi, a translucent "raindrop" cake made primarily from water and agar for a delicate, wobbly consistency.^[42]^[43] In Chinese cuisine, agar is used to create agar-agar pudding, a simple yet elegant chilled dessert often flavored with fruits or nuts, reflecting its long-standing role in regional sweet preparations.^[44] Western adaptations have incorporated agar into vegan versions of classic desserts like panna cotta, where it provides a creamy set without dairy, and fruit gels that maintain clarity and structure.^[45] It also serves as a stabilizer in bakery glazes and icings at lower concentrations of 0.2–0.5%, preventing sugar adhesion and enhancing shelf life.^[44] In molecular gastronomy, agar is employed for spherification techniques, creating burst-in-the-mouth liquid spheres coated in a thin gel layer, as seen in innovative presentations of juices or cocktails.^[46] Nutritionally, agar contributes soluble fiber to dishes, promoting digestive health and satiety, while being virtually calorie-free at typical usage levels.^[47] Additionally, its gelling mechanism is unaffected by proteolytic enzymes in tropical fruits like pineapple or kiwi, allowing it to set successfully in fruit-based recipes where gelatin would fail.^[46] By 2025, the surge in plant-based eating has expanded agar's role beyond desserts into meat analogs and dairy alternatives, where it forms emulsion gels to mimic fatty textures in products like vegan burgers or yogurts, with the global plant-based food market reaching approximately USD 50 billion.^[48]

Uses in Microbiology

Agar serves as a primary solidifying agent in microbiology, typically incorporated at concentrations of 1.5% to 2% (w/v) into nutrient broths to form solid or semi-solid media that support the growth and isolation of bacteria and other microorganisms.^[49] This gelling property allows for the creation of a stable matrix where microbial colonies can develop distinctly, facilitating isolation techniques such as streaking or spreading. Unlike liquid broths, these solidified media enable the enumeration and purification of individual strains by promoting visible colony formation on the surface.^[50] The preparation of agar plates involves dissolving the agar along with essential nutrients—such as peptones, salts, and carbon sources—in water, followed by autoclaving at 121°C for 15-20 minutes to ensure sterility.^[51] The mixture is then cooled to approximately 50°C, supplemented with selective agents if needed, and poured into sterile Petri dishes where it solidifies into a thin layer (about 4 mm deep) suitable for inoculation. For example, Luria-Bertani (LB) agar, a common nutrient-rich medium, uses this method to culture a wide range of bacteria, allowing for the observation of colony morphology for identification purposes.^[52] Similarly, nutrient agar provides a general-purpose medium for non-fastidious organisms, while MacConkey agar incorporates bile salts, lactose, and indicators like neutral red to selectively isolate and differentiate Gram-negative enteric bacteria based on lactose fermentation, producing pink colonies for fermenters and colorless for non-fermenters.^[53]^[54] In motility assays, lower concentrations of agar (0.3% to 0.7%) create soft, semi-solid media that permit bacterial swarming or swimming, essential for studying flagella-driven movement or chemotaxis.^[55] A notable application is the Kirby-Bauer disk diffusion method, where bacteria are inoculated onto Mueller-Hinton agar (1.5% agar), and antibiotic-impregnated disks are placed to measure zones of inhibition, assessing antimicrobial susceptibility through diffusion in the semi-solid environment.^[56] Agar's advantages in these contexts include its chemical inertness, as it is not metabolized by most microbes, ensuring that growth reflects the added nutrients rather than the gelling agent itself; its ability to withstand high-temperature sterilization at 121°C without degradation; and its transparency, which allows clear microscopic or macroscopic observation of colony development and subsurface growth.^[57]^[58] This shift to agar occurred in the 1880s when Angelina Hesse proposed it as a superior alternative to gelatin, which liquefied at incubation temperatures, revolutionizing bacterial culturing by enabling reliable solid media for Koch's laboratory.^[59]

Uses in Biotechnology and Plant Science

In plant tissue culture, agar serves as a gelling agent in media such as the Murashige-Skoog (MS) formulation, typically at concentrations of 0.6-1% (6-10 g/L), to provide a solid matrix for rooting, callus induction, and the sterile propagation of explants from various species. This setup enables controlled environmental conditions that mimic soil support while preventing contamination, allowing explants to develop roots and shoots in a nutrient-rich, aseptic environment.^[60]^[61] For animal cell culture, low-melting-point (LMP) agarose is employed due to its biocompatibility and mild gelling temperature (around 35-40°C), facilitating gentle encapsulation of mammalian cells without thermal stress and enabling the formation of 3D scaffolds for tissue engineering applications. These scaffolds support cell proliferation, spreading, and extracellular matrix deposition, as demonstrated in human dermal fibroblast cultures where LMP agarose microgels promoted significant cell growth in a three-dimensional architecture.^[62]^[63] In broader biotechnology, agarose gels at 1-2% concentrations are standard for DNA electrophoresis, where the porous matrix separates nucleic acid fragments by size under an electric field, with higher percentages resolving smaller fragments (e.g., 100-1,000 bp) more effectively. Additionally, agar overlays, often at 0.5-1%, are used in viral plaque assays to quantify infectious virus particles by restricting diffusion and forming visible lysis zones (plaques) on infected cell monolayers.^[64]^[65] Agar's advantages in plant science include its provision of mechanical support without introducing toxicity or reacting with media components, while its semi-solid structure permits adequate gas exchange for aerobic respiration in cultured tissues. Unlike alternatives such as gellan gum, which forms clearer gels for better root observation and retains moisture to reduce desiccation but requires lower concentrations (2-3 g/L) and may alter water potential, agar remains widely adopted for its stability across a broad pH range and enzyme inertness.^[66]^[60]^[67] By 2025, agar derivatives like LMP agarose have expanded into synthetic biology for organoid cultures, where microgel suspensions encapsulate stem cells to promote lumen formation and three-dimensional morphogenesis in naive and primed pluripotent states. In CRISPR applications, agarose gels continue to validate editing efficiency through assays like T7 endonuclease I digestion, where 1-2% gels detect indels by heteroduplex cleavage patterns, supporting high-throughput screening in genome engineering workflows.^[68]^[69]

Other Uses

Agar serves as a thickener and stabilizer in cosmetics, such as lotions and creams, due to its ability to form stable gels that enhance texture and moisture retention.^[70] In pharmaceuticals, it functions as a bulk laxative in fiber supplements, providing gentle relief from constipation when consumed with adequate water, and is used in pill coatings to enable controlled drug release.^[2]^[23] Industrially, agar acts as an adhesive in paper sizing to improve surface smoothness and printability.^[71] It is a key component in reversible hydrocolloid materials for dental impressions, offering precise molding that can be softened with heat and reset in water.^[72] Additionally, agar has been employed in photography emulsions as a supporting medium for light-sensitive layers.^[73] In miscellaneous applications, agar is incorporated into artist's gels as a natural binder and thickener for painting mediums, providing a translucent, flexible matrix that dries to a stable film.^[74] It also gels pet foods, particularly canned varieties, to maintain structure and prevent separation while contributing dietary fiber.^[75] In biofuel research, agar aids in stabilizing algal biomass during cultivation and harvesting processes for biodiesel production, leveraging its gel transition properties to improve efficiency.^[76] Agar holds Generally Recognized as Safe (GRAS) status from the FDA for use as a direct food additive, with no numerical acceptable daily intake (ADI) established by regulatory bodies like EFSA and JECFA; it is safe for use in foods at authorized levels and as a laxative up to about 15 g per day when taken with sufficient water to avoid gastrointestinal discomfort.^[77]^[40] Allergies to agar are rare but can manifest as itching or hives in sensitive individuals.^[47] Environmentally, agar biopolymers enhance soil stability by increasing water retention and reducing permeability, thereby mitigating erosion in vulnerable areas.^[78] Emerging applications by 2025 include agar-based biodegradable plastics for packaging, which degrade naturally and offer a sustainable alternative to petroleum-derived materials through blending with plasticizers like glycerol.^[79] In wound care, agar hydrogels and aerogels promote healing in dressings by providing antimicrobial properties, moisture control, and biocompatibility for chronic wounds such as diabetic ulcers.^[80]^[81]

References

[1]
CHAPTER 1 - PRODUCTION, PROPERTIES AND USES OF AGAR
Agar can be defined as a hydrophilic colloid extracted from certain seaweeds of the Rhodophyceae class. It is insoluble in cold water but soluble in boiling ...
[2]
Agar | C14H24O9 | CID 71571511 - PubChem - NIH
It is used as a gel in the preparation of solid culture media for microorganisms, as a bulk laxative, in making emulsions, and as a supporting medium for ...
[3]
None
### Summary of Introduction and Key Sections on Agar-Agar
[4]
[PDF] Agar-Agar Extraction, Structure, Properties And Applications: A Review
Agar, a gelatinous polysaccharide in the cell walls of many red algal species, is widely used as a gelling, thickening, and stabilizing agent. Agars with the ...
[5]
AGAR Definition & Meaning - Merriam-Webster
Etymology. short for Malay agar-agar, name for the red alga from which it is extracted ; First Known Use. 1885, in the meaning defined at sense 1 ; Time Traveler.<|control11|><|separator|>
[6]
1) agar -- a red seaweed polysaccharide
It is known in Japan as “Kanten” meaning “cold weather,” in China it is “Dongfen” or “frozen powder.” The word “agar” is Malayan and is used in the double form ...
[7]
What is the origin of the word 'agar-agar'? - Quora
Dec 27, 2020 · The word "agar" comes from agar-agar, the Malay name for red algae (Gigartina, Gracilaria) from which the jelly is produced. It is also known as ...Is 'jelly' derived from a sea plant known as 'agar'?Why is 'Agar-Agar' written two times? Why is it not only “Agar”?More results from www.quora.com
[8]
Agar | SpringerLink
Agar and its ability to produce fruit and vegetable jellies were introduced to Europe by Dutch people living in Indonesia. In 1882, Robert Koch introduced agar ...
[9]
A Brief History Of Agar - Asian Scientist Magazine
Jan 26, 2016 · Despite its Japanese origin, agar takes its name from the Malay word for Gelidium, agar-agar. It's possible that this came about because the ...
[10]
Agar Definition and Examples - Biology Online Dictionary
Aug 2, 2023 · It is derived from the Malay word 'agar-agar' meaning 'jelly'. This seaweed product has been traditionally used as an integral ingredient for ...What Is Agar? · History · Chemical Composition · Uses
[11]
Agar | Research - The Tokyo Foundation
The History of Kanten in Japan. Tokoroten was popular as a summertime snack in the city of Edo, now Tokyo. Typically served cold in noodle-like strips, it is ...
[12]
PRODUCTION, TRADE AND UTILIZATION OF SEAWEEDS AND ...
Using these techniques, commercial production of agar was established in Japan in the late seventeenth century and remained a uniquely Japanese activity for ...
[13]
The Introduction of Agar-agar into Bacteriology - ASM Journals
Agar-agar was introduced into bacteriology by Frau Hesse, who helped her bacteriologist husband in his studies. She was born Fannie Eilsheus in 1850.
[14]
Meet the Forgotten Woman Who Revolutionized Microbiology With a ...
Jun 25, 2024 · Fanny Angelina Hesse introduced agar, a kitchen jelly, as a replacement for gelatin, which was easily consumed by microbes, in 1881.
[15]
How and when was agar discovered - Hispanagar
Nov 5, 2020 · Agar's use dates to 17th-century Japan, discovered by an innkeeper in a legend. It was later used in Europe and in 1881 for microorganism ...Missing: commercialization 20th<|separator|>
[16]
Gelidium - an overview | ScienceDirect Topics
Gelidium species were the original materials used in Japan, but shortages during World War II led to the employment of Gracilaria species, to counteract the ...
[17]
Global shortage of technical agars: back to basics (resource ...
May 1, 2018 · Agar production appears to have followed the seaweed harvest pattern, maintaining high production values of about 800 t year−1, during the 1960s ...
[18]
Sustainable Sourcing of Agar Environmental Benefits and Challenges
Jan 15, 2025 · This blog post will provide an overview on the environmental benefits of eco-friendly agar production and challenges in supply chain.Missing: initiatives 2020-2025
[19]
Four new projects launched to advance sustainable algae farming ...
Oct 13, 2025 · The European Union launches four new projects to advance sustainable algae farming and blue innovation hubs.Missing: agar 2020-2025
[20]
Agar 6.7 CAGR Growth Outlook 2025-2033 - Archive Market Research
Rating 4.8 (1,980) Mar 21, 2025 · Growing interest in sustainable agar sourcing: Companies are focusing on ensuring eco-friendly practices throughout the entire production and ...
[21]
Agar - an overview | ScienceDirect Topics
Agar, also known as agar agar, is defined as a gelatinous substance extracted from seaweed, commonly used as a flavorless vegan substitute for gelatin.Missing: review | Show results with:review
[22]
[PDF] Agar - Colony Gums
Agar or Agar-Agar is a dried hydrophilic, colloidal polygalactoside extracted from Gelidium Cartilagineum, Gracilaria Confervoides and related red algae ...
[23]
Red Seaweed (Rhodophyta) Phycocolloids: A Road from the ...
Seasonal changes of environmental conditions influence agar content in seaweeds [8]. Most papers on the subject observe a higher agar content in summer than ...
[24]
2. SEAWEEDS USED AS A SOURCE OF AGAR
Most agar is extracted from species of Gelidium (Figure 1) and Gracilaria (Figure 2). Closely related to Gelidium are species of Pterocladia.
[25]
Gracilaria as the Major Source of Agar for Food, Health and ...
Agar production from Gracilaria species is widely used in many industries, accounting for 80% of the world's total production [3] .
[26]
Gracilaria seaweeds - Cultured Aquatic Species
In the past the emphasis was to produce Gracilaria biomass for agar production. Now it is more profitable for the pond operators to supply their Gracilaria as ...
[27]
Understanding the Global Agar-Agar Supply Chain - ChemAnalyst
Oct 9, 2025 · Understanding the agar-agar supply chain is strategically critical in today's increasingly demand-sensitive and sustainability-driven economy.
[28]
Can Seaweed Farming Play a Role in Climate Change Mitigation ...
Whereas, the effects of climate change on macroalgal cultivation are not yet clear (Callaway et al., 2012), ocean warming may reduce fucoid canopies through ...
[29]
3. AGAR
A short and simplified description of the extraction of agar from seaweeds is that the seaweed is washed to remove foreign matter and then heated with water for ...
[30]
Agar Extraction By-Products from Gelidium sesquipedale as a ... - NIH
Dec 19, 2018 · Alkaline treatment is a common step largely used in the industrial extraction of agar, a phycocolloid obtained from red algae such as Gelidium sesquipedale.
[31]
Exploring alternative red seaweed species for the production of agar ...
The industrial-scale extraction of agar involves alkaline pre-treatments, high-temperature and pressure extraction, filtration processes, and freeze-thaw cycles ...
[32]
Factors that affect yield and quality of agar - ResearchGate
A maximum agar yield (34.33 ± 0.58%) was recorded during the 35-day growth period, while the highest gel strength (1606.33 ± 19.65 g cm−2) was noted during the ...
[33]
Agar and Its Use in Chemistry and Science
Specifications for bacteriological grade agar include good clarity, controlled gelation temperature, controlled melting temperature, good diffusion ...
[34]
Optimization of Ultrasound-Assisted Enzymatic Extraction ...
Aug 6, 2025 · Agar yield was higher at lower temperature, stronger alkali solution and shorter treatment duration. Higher 3,6-ahydrogalactose content and ...
[35]
Chemical structure of agarose (C 12 H 18 O 9 ) [14]. - ResearchGate
... is a polysaccharide with the chemical formula C 12 H 18 O 9 ( figure 10) that is obtained from agar. Agar itself is a mixture of agarose and agaropectin ...
[36]
https://www.sigmaaldrich.com/US/en/product/sial/56763
[37]
13C-N.m.r. spectroscopic analysis of agar, k-carrageenan and t ...
This observation made it possible to recommend the 13C-NMR spectroscopy as the simplest tool for distinguishing the polysaccharides of the agar and carrageenan ...
[38]
Physics of agarose fluid gels: Rheological properties and ...
Agarose gels are known for their tendency to release water and are susceptible to syneresis, which increases with decreasing of agarose concentration meaning ...
[39]
Analysis of Influencing Factors on Viscosity of Agar Solution for ...
The results showed that the order of the influence on the viscosity of agar solution was agar concentration > water hardness > solution temperature > pH.
[40]
Re‐evaluation of agar (E 406) as a food additive - EFSA Journal
Dec 21, 2016 · Agar forms gels at very low concentrations, with a concentration threshold for gelation around 0.2% (Imeson, 2010). According to Armisen and ...
[41]
https://www.capecrystalbrands.com/blogs/cape-crystal-brands/agar-agar-vs-gelatin-for-vegan-classic-cooking
[42]
https://sakura.co/blog/anmitsu-the-fantastic-story-behind-this-dessert
[43]
Mizu Shingen Mochi: Try the Viral Raindrop Cake in Japan - byFood
Jul 18, 2025 · This round-shaped gelatin dessert was originally served with kinako (roasted soybean powder) and kuromitsu (black sugar syrup) on a takeaway boat plate.Missing: anmitsu 17th century
[44]
3. agar and agarose applications
For icings the concentration of agar ranges from 0.2 to 0.5%. Agar stabilizes the icing and prevents the adhesion of the sugar coating to the wrapper. An ...
[45]
Panna cotta with agar-agar: the recipe - Edible Molecules
Jul 7, 2019 · The recipe uses 500mL cream, 100g sugar, 2g agar-agar, and 1 tsp vanilla. Boil cream, sugar, vanilla, add agar-agar, pour into strawberry sauce ...
[46]
Everything You Should Know About Agar-Agar—& How to Cook With It
Jul 1, 2021 · Agar is not a 1:1 substitute for gelatin. I had the most success substituting agar-agar for between a third and half the amount of gelatin ...
[47]
Agar Agar Benefits and How to Use - Dr. Axe
Oct 21, 2024 · It's low in calories but high in fiber, manganese, magnesium, folate and iron. It may also help improve digestive health, aid in weight loss and ...
[48]
Top trends shaping plant-based meat and dairy in 2025
Jul 1, 2025 · We're now noticing a marked shift in plant-based product development, and that's just one of the trends shaping the future of alt meat and dairy.
[49]
A Plant-Based Animal Fat Analog Produced by an Emulsion Gel of ...
May 9, 2023 · In this study, we propose an approach by developing a gelled emulsion based on sodium alginate, soybean oil (SO), and pea protein isolate.Missing: dairy | Show results with:dairy
[50]
https://teach.genetics.utah.edu/content/microbiology/plates/
[51]
Making Agar Plates - Genetic Science Learning Center
Agar plates are made by choosing a recipe, preparing media, sterilizing it, and pouring the cooled media into plates.
[52]
Pouring LB Agar Plates - Addgene
LB agar plates are made by mixing LB powder with water, autoclaving, then adding antibiotic to the molten agar and pouring into plates.
[53]
How to Make the Perfect Agar Plate Every Time - Bitesize Bio
Aug 23, 2024 · 1. Use a Recipe. Make up the medium according to the recipe, then add the desired amount of agar powder (normally about 1% w/v) and stir. · 2.
[54]
Nutrient Agar: Composition, Preparation and Uses - Microbiology Info
Aug 10, 2022 · Nutrient agar is a general purpose, nutrient medium used for the cultivation of microbes supporting growth of a wide range of non-fastidious organisms.
[55]
MacConkey Agar- Composition, Principle, Uses, Preparation and ...
Aug 10, 2022 · MacConkey agar is used for the isolation of gram-negative enteric bacteria. It is used in the differentiation of lactose fermenting from lactose ...
[56]
7.7: Testing for Bacterial Motility - Biology LibreTexts
Jan 2, 2024 · The agar concentration (0.3%) is sufficient to form a soft gel without hindering motility. When a non-motile organism is stabbed into ...
[57]
Kirby-Bauer Disk Diffusion Susceptibility Test Protocol | ASM.org
Dec 8, 2009 · The Kirby-Bauer disk diffusion susceptibility test determines the sensitivity or resistance of pathogenic bacteria to various antimicrobial compounds.
[58]
What Is Agar and Why Is It Used in Microbiology? - Gino Biotech
Oct 23, 2024 · Agar serves as a primary solidifying agent in microbiological culture media. Here's why it's so valuable: Non-Nutritional Substance: Agar itself ...
[59]
Versatile Solidified Nanofibrous Cellulose-Containing Media ... - NIH
For solid cultures of mesophilic microorganisms, agar is an ideal solidifying agent and has been used essentially unchanged since it was first introduced in ...
[60]
Progress in the development of gelling agents for improved ... - NIH
Jul 23, 2015 · The use of agar as an alternative to gelatin was first proposed by Angelina Hesse the wife of Walther Hesse, an associate of Koch in 1882 to ...
[61]
Murashige and Skoog Medium - an overview | ScienceDirect Topics
Agar (8–10 g/l) and the gellan gum known as Phytagel® or Gelrite® (2–3 g/l) are two of the most common gelling agents used for plant tissue culture media. The ...
[62]
http://kumarlab.berkeley.edu/wp-content/uploads/2017/05/Ulrich2010.pdf
[63]
[PDF] agarose matrices - Kumar Lab
Nov 18, 2009 · Agarose also has a number of attractive properties for biomaterial applica- tions, in that it is inexpensive, non-toxic, inert to mammalian cell.
[64]
Development of Three-Dimensional Cell Culture Scaffolds Using ...
Sep 14, 2020 · HDFs cultured in a 3D environment of the A99-agarose microgel scaffold exhibited cell spreading morphology and proliferated significantly. These ...Missing: low- melting animal encapsulation
[65]
Protocol - How to Run an Agarose Gel - Addgene
Feb 20, 2018 · Agarose gels are commonly used in concentrations of 0.7% to 2% depending on the size of bands needed to be separated - see FAQs below. Simply ...
[66]
Viral Concentration Determination Through Plaque Assays - NIH
Nov 4, 2014 · In our study, agarose overlays demonstrated clearer plaques at higher titers than either CMC or liquid overlays for both RVFV and Influenza B ...
[67]
Support Substances | Theories Behind Plant Tissue Culture - passel
Agar melts at about 100oC and solidifies at about 45oC. Agar does not react with medium components nor is it digested by plant enzymes. Agar does not gel well ...
[68]
https://www.cell.com/stem-cell-reports/pdf/S2213-6711%2821%2900204-6.pdf
[69]
Agarose microgel culture delineates lumenogenesis in naive and ...
May 11, 2021 · Cells were resuspended and diluted to 1.5 3 106 cells/100 mL. The cell suspension was mixed 1:1 with a low- melting-point agarose solution ...Missing: animal | Show results with:animal
[70]
https://pmc.ncbi.nlm.nih.gov/articles/PMC8539943/
[71]
Applying Seaweed Compounds in Cosmetics, Cosmeceuticals ... - NIH
Agar has pharmaceutical and industrial cosmetic applications, including its use as a thickener and as an ingredient for tablets or capsules to carry and ...
[72]
[PDF] FISH ERY INDUSTRIAL RESEARCH - Scientific Publications Office
It is used as a glue, for making silk and paper transparent, as a substitute for such products as gelatin and isinglass, for sizing silks and paper, for dying ...
[73]
Alginate Materials and Dental Impression Technique - NIH
Dec 29, 2018 · Elastic impression materials include reversible (agar-agar), irreversible (alginate) hydrocolloids and synthetic elastomers (polysulfides, ...Missing: sizing | Show results with:sizing
[74]
Economic Uses of Algae
It is used in photographic film, shoe polish, dental impression molds, shaving soaps, hand lotions, and in the tanning industry. In food, agar is used as a ...
[75]
Agar Agar Mediums, Binders & Glues | Kremer Pigmente Online Shop
In stock 14-day returnsAgar Agar is a natural thickener, insoluble in cold water, but forms a solid gel in hot water at 1% solution. It is sold in 100g bags for 15.23€.
[76]
Safety and efficacy of a feed additive consisting of agar for pets ... - NIH
Apr 25, 2022 · The panel cannot conclude on agar's safety for pets, but it is effective as a gelling agent, thickener, and for stabilizing canned pet feed.
[77]
Application of Agar liquid-gel transition in cultivation and harvesting ...
Algal biomass was utilized for biofuel production, in biotreatment to treatwastewaterandasbiofertilizertoenhancecropproduction.Hence,Microalgae have 3B role ...
[78]
21 CFR 184.1115 -- Agar-agar. - eCFR
Agar-agar (CAS Reg. No. PM 9002-18-0) is a dried, hydrophyllic, colloidal polysaccharide extracted from one of a number of related species of red algae.
[79]
Agar Biopolymer as a Sustainable Alternative Binder to Enhance the ...
May 5, 2025 · Sustainable materials such as agar biopolymers can be an alternative to cement to improve the strength of fine-grained soils.
[80]
Agar-Based Biodegradable Plastic: A Sustainable Alternative to ...
Aug 7, 2025 · This research emphasizes the promise of agar bioplastic with ethanol as a plasticizer for uses such as packaging and single-use products. Later ...
[81]
Agar/collagen membrane as skin dressing for wounds - PubMed
Nov 25, 2008 · The agar/type I collagen composites are promising biomaterials as wound dressings for healing burns or ulcers.
[82]
In vivo tests of a novel wound dressing based on agar aerogel
In this study, agar aerogel was prepared and evaluated as novel wound dressing material in an in vivo rat study.