Early researchers cracked open root vegetables and seaweed, curious about the sticky, starchy textures inside. Chemists in the nineteenth century grew fascinated by strange white powders like starch, cellulose, and gums. They saw people thicken stews with flour and noticed that animal nutrition depended on plant fibers. By the time H. Schützenberger produced cellulose nitrate in the 1800s and the food industry turned to agar and pectin during the world wars, polysaccharides had moved from kitchen curiosity to industrial demand. In my own lab experience, the shift from using natural thickeners in cooking to understanding them under a microscope happened both by patient trial and a few failed experiments. What really marks polysaccharides’ development: nobody engineered this knowledge in a vacuum. Farmers, millers, and laboratory workers learned through real use, driven by food shortages, textile demand, and a hunger for better shelf life.
Polysaccharides cover a spread of substances: starch, cellulose, chitosan, pectin, alginate, guar gum, dextran, xanthan gum, carrageenan, and pullulan, among others. These materials show up in bread, jams, ice cream, even in wound dressings and pharmaceuticals. Extracted from plants, algae, fungi, and even crustaceans, each one has its own quirks. For example, pectin lifts jam to just the right spreadable level without overpowering the fruit flavor. Chitosan from crustacean shells turns up in water filters. The versatility built into their complex chains gives polysaccharides a unique role in nearly every sector. From the food shelf to the pharmacy, you’ll find their fingerprints.
Physical appearance runs a spectrum—powdery, gelatinous, stringy, sometimes nearly invisible in solution. Chemical structures range from linear chains like cellulose to branching forms like amylopectin, both holding glucose at their core but behaving drastically differently. Some dissolve easily in water; others resist most solvents aside from strong acids. The way chains form hydrogen bonds or tangle together under different temperatures and pH makes a world of difference for both texture and digestibility. My time stirring beakers of starch or trying to dissolve cellulose taught me that even a small pH change can mean the difference between a sticky mess and a clear solution. I realized that the kitchen’s sauce thickener, when misunderstood, can slow down an entire production line.
Industry and science focus on source, purity, viscosity, particle size, solubility, and residual protein or ash. Food grade and pharmaceutical grade require different purity levels. Thickening and gelling powers often get measured by bloom strength for gelatin or millipascal-seconds for viscosity. On consumer labels, ingredients appear with plain names—starch, cellulose gum, guar, and the like—or with food code numbers, such as E1400 for modified starch. Regulatory agencies, FDA and EFSA among them, demand clear labeling for allergy risks with crustacean-derived items like chitosan or possible gluten carryover in wheat-based starches. Any operation not paying attention to specs can get a rude awakening from a failed batch or a regulatory recall.
Producers pull polysaccharides from roots, grains, seeds, shells, or algae by milling, cooking, and chemical washing. For cellulose, the process involves pulping wood, separating lignin, then further bleaching and filtering. Starch comes from crushing potatoes or corn, steeping, and separating out the protein and fiber. More technical modifications mean extra steps—acid or alkali treatment for crosslinking or hydrolysis, sometimes the use of specific enzymes for precision. Extraction isn’t sterile or glamorous. Workers in processing plants sweat over proper temperature settings, pH control, and timing. Miss a single wash cycle or rush a filter, and end up with a failed extraction or unsafe residues.
Unmodified polysaccharides rarely fit all applications. Markets want phosphate-modified starch for freeze-thaw stability in frozen meals, or hydroxypropyl cellulose to dissolve in cold water. Chemical cross-linking toughens starch granules. Acetylation or carboxymethylation changes cellulose for better water dispersibility or even film coating for pills. I’ve watched technicians debate over the right degree of substitution, knowing that too much modification throws off flavor or causes regulatory headaches. A little creativity in the chemistry lab can turn a simple thickener into a plastic alternative or a medical adhesive. Each tweak answers a real-world problem: spoilage, inconsistent texture, sensitivity to temperature shifts, and packaging challenges.
Market shelves use a mix of technical names, common names, and proprietary labels. Starch ester may go out as pregelatinized starch, hydroxypropyl cellulose as Klucel, or sodium alginate as Algogel. Carrageenan may show up as E407 or simply as seaweed extract, and dextran sometimes arrives with a pharmaceutical trade mark depending on the degree of polymerization. Marketing departments often reshape names to highlight natural origins or reinforce clean-label trends. Chemists, meanwhile, need to keep track of nomenclature changes to spot incompatibilities between suppliers or products.
Every production facility conforms to strict food safety and pharmaceutical GMPs. Air and water filtration, contamination controls, and careful handling of chemicals during modification keep both workers and consumers safe. Food-grade citations follow CODEX or USP standards, and professionals monitor for heavy metals, pesticides, and microbial risk. Any slip-up in safety means recalling entire product lots, fines, shut-downs, and eroded consumer trust. Companies handle potential allergens and animal-derived starting materials under separate lines to avoid cross-contamination. Experience in facility management taught me that no checklist or protocol ever replaces mindful handling of raw and finished goods. Mistakes hurt people and destroy years of reputation.
Food industry stands out for its use of polysaccharides in thickeners, stabilizers, and gelling agents for dairy, bakery, desserts, and sauces. Nutraceuticals use resistant starches and fiber-rich components for prebiotic supplements. In pharmaceuticals, excipients such as MCC (microcrystalline cellulose) ensure pills stay stable and disintegrate at the right moment. Medical materials’ world taps chitosan for wound dressing and biofilm, while textile chemistry uses derivatives for finishing and sizing. Even agriculture sees polysaccharides used for slow-release fertilizers and seed coatings. Each industry brings its own set of demands, often forcing scientists and engineers to rethink how to tweak the same base material for very different ends.
Today’s research pivots around finding new sources, extraction methods with lower energy use, and more precise chemical modification. Efforts push for greener, safer processing—enzymes over acids, water-based separations over harsh solvents. R&D teams also work on unlocking hidden functions, like antioxidant potential in certain hemicelluloses or nano-scale cellulose crystals for high-strength composites. Start-up labs experiment with polysaccharides as sugar replacers, biodegradable packaging, medical encapsulants, and tissue scaffolding. More than just a trend, this drive begins with community and environmental concerns, demanding both cost-effective scalability and clear evidence of benefit.
The majority of common polysaccharides, especially those sourced from edibles, have long safety records. Some modified versions raise questions—highly cationic or chemically substituted derivatives sometimes affect digestibility or gut flora. Heavy metals left from poor extraction steps can also create toxicity risk. Scientists test digestibility, allergenicity, and metabolic impacts during development. I worked on a project years ago that found a rare immune response to certain yeast-derived glucans. The takeaway: even age-old materials can cause trouble if modified or sourced poorly. Toxicity research never stops, especially as new derivatives or sources reach the market.
Polysaccharide science stands at a powerful crossroads. New bio-based economies rely on finding replacements for fossil-fuel plastics with renewable, compostable packaging materials. Polysaccharide blends and nanofibers promise lighter, stronger materials for industrial and medical uses. As prebiotics, they help gut health and possibly mental wellness through the microbiome. Research into plant cell wall enzymes pushes the door open for engineering crops with custom polysaccharide content for better yields or more climate resilience. As I talk to colleagues in food and pharma, the key challenge lies in bridging tradition and technology—honoring safe, familiar materials while daring to innovate. That edge keeps the field real, lively, and relevant for labs, farmers, and everyday consumers.
Walk through the health food aisle or scroll across supplement websites, and you’ll see the word “polysaccharide” pop up everywhere. Chaga extracts, mushroom blends, aloe vera gels—almost every bottle claims to support immunity or digestion because it contains some type of polysaccharide. But buzzwords aside, what real benefits do these complex carbs bring to the table?
Polysaccharides occur naturally in plants, fungi, and even seaweed. These large carbohydrate molecules, like beta-glucans from oats and mushrooms, work hard behind the scenes. Several medical studies confirm that certain polysaccharides actually help regulate immune responses. For example, beta-glucans in shiitake mushrooms activate white blood cells, kicking your body’s protective system into a higher gear. Some athletes and people I know who work in crowded offices swear by these mushroom supplements during flu season, and some research backs up what they’ve experienced.
Beyond the immune-boosting angle, some polysaccharides such as inulin, found in root vegetables like chicory, feed good gut bacteria. Our bodies can’t digest these fibers directly, but our gut microbes love them. People who eat more prebiotic-rich foods notice smoother digestion and have fewer problems with bloating or irregularity. Studies from research universities show a clear link between prebiotic intake and a diverse gut microbiome—which leads to stronger digestion and, according to some evidence, even a better mood.
Complex carbs like those found in barley, oats, and certain seaweeds slow down how quickly sugar travels into your blood. Instead of a big sugar spike after a meal, you get a steady release of energy. There’s a reason many nutritionists, including ones I’ve worked with on nutrition programs, tell people to focus on foods rich in these fibers. Clinical trials on beta-glucan from oats and barley show lower cholesterol and steadier insulin responses, which is especially good news for people at risk for diabetes or heart conditions.
Ginseng, reishi mushrooms, and aloe vera have been used for generations across Asia and beyond. Some of this wisdom gets lost in translation, but recent evidence confirms that the polysaccharides in these plants help lower inflammation and support recovery after illness. During times of stress or recovery, I’ve turned to herbal blends that include these non-digestible carbs as a supportive piece of my wellness routine. Nurses and doctors familiar with Traditional Chinese Medicine sometimes recommend these formulas to patients looking for ways to support general well-being.
Not all polysaccharide products work the same way. Some supplements use concentrated extracts while others lean on whole foods. The most important factor: variety. Diets built around whole, plant-based foods naturally include many different forms of fiber and polysaccharides, which support both immunity and digestion without adding unnecessary pills or powders. For those curious about supplements, look for brands that show third-party testing and explain the kind of polysaccharide used. If you already eat vegetables, whole grains, mushrooms, and legumes, you’re giving your body steady access to these helpful compounds.
Polysaccharide products offer more than marketing spin. They deliver proven help for immune function, digestion, and energy balance—when you choose wisely and include them as part of a balanced, real-world diet. That’s not magic, just solid nutrition backed up by lived experience and real science.
Polysaccharides are carbohydrates with long chains of sugar molecules. Starch, cellulose, and glycogen all fall into this group. Common foods like oats, beans, grains, and certain vegetables all provide them. From years of checking food labels and trying to manage blood sugar, it’s clear that not all carbs act the same in the body.
Carbohydrate choices matter a lot for people with diabetes. Short-chain sugars such as glucose or sucrose can spike blood sugar pretty quickly. Polysaccharides in their natural form tend to break down slower. For example, eating an apple (rich in fiber and polysaccharides) has a very different effect than sipping a soda. Fiber, a non-digestible polysaccharide, doesn’t raise blood sugar at all. In fact, eating more fiber helps slow the absorption of other sugars and keeps blood sugar steadier.
Starch is digested into glucose, but the time this takes often stretches out over a few hours—especially when surrounded by fiber. Beans, lentils, and whole grains provide starch along with loads of fiber and nutrients. These foods have what experts call a low glycemic index, meaning they lead to smaller rises in blood sugar. Dietitians with years on the job often suggest swapping white bread for whole grain, or white rice for brown, to get more of these slow-release carbs.
It’s easy to lump all polysaccharides together, but they show up in different forms. Processed starches like those found in white flour or pastries may hit the bloodstream almost as fast as table sugar. On the other hand, foods like barley or chickpeas digest much slower. People with diabetes benefit from skipping highly refined polysaccharide sources and choosing options rich in natural fiber.
Long-term studies support this approach. Diets rich in whole, fiber-filled foods tend to help with blood sugar management, cholesterol levels, and even weight. The American Diabetes Association recommends beans, lentils, oatmeal, quinoa, and whole grains for these reasons. Some polysaccharides, like those in seaweed or certain mushrooms, even seem to offer added health benefits by feeding gut bacteria or supporting immune health. Nutrition research grows more confident each year that whole-food polysaccharides help people with diabetes lead fuller, healthier lives.
Nobody manages diabetes exactly the same way. Some folks find they can handle whole grains just fine, while others notice blood sugar creeping up even from foods generally considered healthy. Tracking meals with a glucose monitor and noting how different foods affect blood sugar gives solid, personal insight. If numbers keep bouncing around, a dietitian can help spot hidden sugars and swap in better choices.
Think simple swaps. Add beans to salads, cook steel-cut oats instead of instant, roast sweet potatoes instead of baking with processed flours. Reading labels helps, but cooking from scratch with real ingredients works even better. Treat processed foods—those that strip away the natural fiber—with caution. Focusing on variety, plenty of greens, and naturally fiber-rich foods pays off every time.
Polysaccharides found in mushrooms, seaweed, oats, and plant extracts often show up in capsules or powders at health stores. The supplement world markets them for everything from boosting immunity to gut health. Truth is, effects depend on what you take, how much, and what your body needs.
A few brands suggest taking polysaccharides on an empty stomach, thinking this helps with absorption. Some digestion experts say it’s better to eat them with food, especially if you get mild nausea from standalone supplements. I’ve tried both ways. A glass of water and food in my stomach definitely reduced that queasy feeling with my reishi powder. Consider your own digestion; what settles best for you will probably win out.
Labels on these supplements range from 200 mg to two grams per serving. Some clinical trials use even higher doses, though they usually involve short timeframes or close supervision. Too much may cause stomach issues.
No one-size-fits-all here. Adults usually start low, around 500 mg per day, and pay close attention to how they feel. A registered dietitian or healthcare provider can help match the right dose for your weak immune system, allergies, or gut troubles. Kids, pregnant women, and anyone with chronic conditions really need that medical opinion first—many brands overstate benefits, and safety profiles aren’t always clear.
Supplements often come with lots of promises and flashy names. Not all products contain what they claim: ConsumerLab and USP testings have shown that many “polysaccharide” mushroom supplements barely contain active compounds. Look for certified third-party testing on the bottle. Translated: trust but verify.
Ingredients lists shouldn’t read like a chemistry textbook. If you spot artificial colors, sugars, or mystery fillers, it’s better to move on. Pure extracts typically have fewer additives. I stick with companies that not only show a polysaccharide percentage but also explain the extraction process—hot water extraction often yields higher levels of the good stuff.
Side effects don’t pop up for everyone, but some deal with bloating, loose stools, or stomachache after starting a new supplement. Others with mushroom or seaweed allergies can get breakouts or rashes. Anyone with diabetes must pay particular attention, as some polysaccharides influence blood sugar. Bring this up at your next appointment if you have concerns.
Mixing supplements with prescription medicine raises a risk of interactions. Certain polysaccharides, especially in high amounts, might thin blood or impact the way the body processes certain drugs. Keep your doctor in the loop before adding anything new.
Don’t fall into the “more is better” trap. Meals with beans, oats, and broccoli already boost your fiber and polysaccharide intake in natural ways. Supplements can help, but whole foods give more vitamins, minerals, and gut benefits.
In my experience, small and consistent doses seem to offer the most benefit. No immediate miracles—just a gentle nudge to the system. When unsure, listening to your body and favoring transparency in sourcing always help steer toward better health choices.
Polysaccharides show up in almost everything these days, from supplements at the pharmacy to thickeners in your favorite salad dressing. A lot of people reach for them because of their “natural” image and the claims about benefits for digestion, immunity, or cholesterol. Coming from things like mushrooms, seaweed, oats, and even shrimp shells, polysaccharide products seem safe on the surface. But plenty of things labeled “natural” can still cause trouble, and it pays to look at what downsides pop up with widespread use.
People love fiber, but ramping up certain polysaccharides can lead to gas, bloating, or diarrhea. Suddenly stirring extra inulin or guar gum into a diet leaves the gut scrambling to adjust. Some folks with sensitive stomachs or inflammatory bowel conditions feel the impact even at small doses. High intake sometimes blocks absorption of minerals like calcium, zinc, or iron. Nutrition isn’t just about what you eat; it’s also about what your body can actually use.
Mushroom-based beta-glucans have gained fans, especially with the wellness trend, but allergies remain a real risk. Reactions can range from itchy skin to life-threatening problems for some. Chitosan, made from the shells of crustaceans, isn’t an option for someone with a shellfish allergy. Not every package spells out the exact source. Contamination with heavy metals or pesticides, especially with seaweed or imported plant products, worries people too. A study from China flagged arsenic and mercury in some seaweed-derived supplements, and the World Health Organization tracks these risks closely.
It’s tempting to pile on supplements without telling a doctor, but some polysaccharides can interact with prescriptions. For example, soluble fibers may slow down how fast other drugs get absorbed, leading to less reliable results for things like diabetes meds or heart pills. Chitosan products sometimes interfere with blood thinners, which puts patients at risk. Simple changes add up fast.
Beta-glucans and other immune-modulating polysaccharides draw praise for “boosting” defenses, but that’s a two-edged sword. For people dealing with autoimmune diseases, kicking the immune system into higher gear can make symptoms worse. Without careful research, what helps one person can harm another.
Buyers need clear labeling that spells out sources and potential allergens. Companies must show results from purity and contamination tests, so customers know what’s inside. Talking with a doctor or pharmacist before using these products, especially with ongoing health issues or prescriptions, avoids a lot of trouble. Anyone adding more fiber or specialized supplements should do it slowly. That gives the gut time to adapt.
Companies and regulators can keep watch using independent quality checks. People want new options, but that doesn’t excuse slippery standards or vague claims. A little transparency, careful sourcing, and customer education go a long way toward making polysaccharide products safer for everyone. Smart choices protect both health and trust.
People check ingredients for lots of reasons. Sometimes allergies push them to read deeper. Sometimes it’s a hope to find something closer to nature instead of a long chemical list. Polysaccharides, which turn up in everything from food packaging to pills, rarely catch much attention unless a label makes it clear where they come from. Yet, the origin tells a story about sustainability, safety, and, quite simply, what we're really getting.
Polysaccharides come from plants, seaweed, bacteria, even fungi. Major food and supplement companies rely on a handful of usual suspects. Corn, wheat, and potatoes supply most of what you find in the grocery aisle. Cornstarch is top of the heap in North America; potato starch takes the lead in some European products. Sugarcane bagasse has also found its place as a source, especially when companies aim to repurpose agricultural waste. Seaweed, especially red and brown types, gives us agar, carrageenan, and alginate, which thicken and stabilize foods. Bread made softer by guar or xanthan gum owes its texture to beans or fermented glucose by bacteria.
Not every extract fits every diet. Wheat-based fillers cause trouble for people with celiac disease. Even something as simple as plant vs. animal origin becomes a big deal for folks following vegan or vegetarian diets. In my own house, we watch for corn because of a specific allergy. It doesn't feel like overkill to read labels closely in that case. Beyond health, the source tells us something about environmental impact. Seaweed farming, for example, supports healthy coastlines and absorbs carbon, but it can also disrupt habitats when not managed well. Corn production in the US has been tied to heavy pesticide and water use.
Not every company wants to print "corn-derived" or "seaweed extract" so consumers know what's inside the capsule or film. That’s changing as people demand cleaner supply chains and more honesty in branding. Certifications like Non-GMO Project Verified and Certified Organic help, but they don’t automatically spell out all sources. Some polysaccharides get heavily processed, stripping away most traces of origin. Processed doesn’t always mean unsafe, but less transparency can make it hard to spot a potential allergen.
One way forward? Companies could list the original plant or organism—corn, potato, or seaweed—directly on the packaging. This small step offers big returns for consumers, especially for families juggling health concerns or looking for sustainable options. Sourcing ingredients responsibly, taking care to avoid major allergens and supporting sustainable agriculture, also builds trust. It’s not just a matter of catching up to stricter regions like the EU, but meeting the real concerns families and individuals have about what they bring home.
Every trip to the store or pharmacy brings us face to face with products full of hidden complexity. Knowing the origin of polysaccharides isn't just for scientists—it shapes our choices, affects our health, and speaks to wider questions of how products get made. Transparency and careful sourcing let us make those choices with more confidence. That matters, not just for now, but for what kind of world we hand over next.
| Names | |
| Preferred IUPAC name | polymeric carbohydrate |
| Other names |
Glycans Complex carbohydrates Polymeric carbohydrates |
| Pronunciation | /ˌpɒliˈsæk.ə.raɪdz/ |
| Preferred IUPAC name | Poly(1→4-α-D-glucopyranose) |
| Other names |
Gums Hydrocolloids Plant polysaccharides Complex carbohydrates |
| Pronunciation | /ˌpɒl.iˈsæk.ə.raɪdz/ |
| Identifiers | |
| CAS Number | 9050-36-6 |
| Beilstein Reference | 55467 |
| ChEBI | CHEBI:18154 |
| ChEMBL | CHEMBL1201639 |
| ChemSpider | 21476704 |
| DrugBank | DB11097 |
| ECHA InfoCard | 20259 |
| EC Number | 232-911-6 |
| Gmelin Reference | 8789 |
| KEGG | ko00500 |
| MeSH | D011100 |
| PubChem CID | 24877218 |
| RTECS number | UF8225000 |
| UNII | Z377H96A4F |
| UN number | UN 3316 |
| CAS Number | 37286-64-9 |
| Beilstein Reference | 1367498 |
| ChEBI | CHEBI:18154 |
| ChEMBL | CHEBI:29699 |
| ChemSpider | 2157 |
| DrugBank | DB11110 |
| ECHA InfoCard | 03bab346-ef2e-4da6-b2dc-bd5c0d79eaf8 |
| EC Number | 232-945-1 |
| Gmelin Reference | 58840 |
| KEGG | map00500 |
| MeSH | D020123 |
| PubChem CID | 11966311 |
| RTECS number | SLU509000 |
| UNII | F80PF8V0AP |
| UN number | UN 2811 |
| Properties | |
| Chemical formula | (C6H10O5)n |
| Molar mass | Variable |
| Appearance | White or off-white powder |
| Odor | Odorless |
| Density | 0.5-1.6 g/cm³ |
| Solubility in water | Insoluble to soluble |
| log P | -3.0 |
| Vapor pressure | Negligible |
| Acidity (pKa) | ~12-14 |
| Basicity (pKb) | 13.9 |
| Magnetic susceptibility (χ) | -8.0 × 10⁻⁶ |
| Refractive index (nD) | 1.333–1.335 |
| Viscosity | High |
| Dipole moment | 1.70 D |
| Chemical formula | (C6H10O5)n |
| Molar mass | Variable |
| Appearance | White or off-white powder |
| Odor | Odorless |
| Density | 0.8–1.6 g/cm³ |
| Solubility in water | slightly soluble |
| Acidity (pKa) | 12.1 |
| Basicity (pKb) | 13.8 |
| Magnetic susceptibility (χ) | Diamagnetic |
| Refractive index (nD) | 1.333–2.0 |
| Viscosity | Not less than 20 mPa.s |
| Dipole moment | 2.56 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 410 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -1273.3 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | −16.5 kJ/g |
| Std molar entropy (S⦵298) | 675 J·mol⁻¹·K⁻¹ |
| Std enthalpy of formation (ΔfH⦵298) | -1273.3 kJ/mol |
| Std enthalpy of combustion (ΔcH⦵298) | –16.8 kJ g⁻¹ |
| Pharmacology | |
| ATC code | A16AX10 |
| ATC code | A16AX10 |
| Hazards | |
| Main hazards | No significant hazards. |
| GHS labelling | GHS labelling for polysaccharides: "Not classified as hazardous according to GHS. |
| Pictograms | GHS07 |
| Signal word | Warning |
| Hazard statements | Not a hazardous substance or mixture according to Regulation (EC) No. 1272/2008. |
| NFPA 704 (fire diamond) | Health: 1, Flammability: 1, Instability: 0, Special: - |
| Autoignition temperature | 220°C |
| LD50 (median dose) | 18 g/kg (rat, oral) |
| NIOSH | SL167 |
| PEL (Permissible) | 10 mg/m³ |
| REL (Recommended) | 30-50 g |
| Main hazards | Not hazardous. |
| GHS labelling | Not classified as hazardous under GHS |
| Pictograms | GHS07, GHS08 |
| Signal word | Warning |
| Hazard statements | Non-hazardous according to GHS criteria. |
| NFPA 704 (fire diamond) | Health: 1, Flammability: 1, Instability: 0, Special: - |
| Autoignition temperature | 220–240 °C |
| Explosive limits | Not explosive |
| LD50 (median dose) | LD50 (median dose): >5,000 mg/kg (rat, oral) |
| NIOSH | SL2930000 |
| REL (Recommended) | 1500 mg |
| IDLH (Immediate danger) | Not established |
| Related compounds | |
| Related compounds |
Oligosaccharide Monosaccharide Disaccharide Glycoprotein Proteoglycan Cellulose Starch Chitin Glycogen |
| Related compounds |
Polysaccharide-glycosides Cyclodextrins Glycogen Cellulose Dextran Starch Agar Chitin Heparin |