A single-ingredient, freeze-dried extract of shijimi (Corbicula japonica), the small brackish-water clam of Japanese home cooking. The powder is 100% shijimi extract with no carrier, and the reference analysis gives 70.5 g of glycogen and 15.1 g of protein per 100 g, with vitamin B12 and riboflavin from the clam itself.
Tell us what you are developing and which documents you need. We reply from Japan within one working day with the product specification, SDS and the CoA of the current lot.
Shijimi (Corbicula japonica) are cleaned of sand, washed and frozen, then boiled in a steam kettle and dried in a vacuum freeze dryer. The dried extract is milled into powder and packed. Nothing is added: the finished powder is 100% shijimi extract, made in Japan from Japanese clams.
Step 1 · Corbicula japonica
Shijimi from northern Japan, fully domestic raw material
Step 2 · visual check
Foreign matter removed by visual inspection
Step 3 · freezer
Clams frozen before cooking
Step 4 · steam kettle
Clams boiled to give the extract
Step 5 · vacuum freeze dryer
Water removed from the frozen extract under vacuum
Step 6 · foreign matter check
Milled to a fine powder
Step 7 · moisture max. 2%
Total plate count max. 10,000/g; coliforms negative
Step 8 · weight and appearance
Packed in 500 g bags
The grade on this page. Other grades, where available, are specified on request.
Example lot values are published in the developer's guide below. They are an example, not a specification; your lot's CoA governs.
A Japanese trading company selling directly to brand owners and contract manufacturers. No distributor layer between you and the documents.
Every shipment travels with the Certificate of Analysis of its own lot, with the measured values and the full safety panel.
A small first order lets you run a pilot batch before committing to bulk. Larger volumes are quoted by volume and delivery terms.
For registered companies developing a product. Tell us the format you plan and we will say honestly what to expect.
After payment is received. Freight quoted on request. Specification and SDS before you order, CoA with the goods.
If you are comparing ingredients for a new SKU, these questions separate one material from another quickly.
Shijimi is a bivalve mollusc. Australia and New Zealand require molluscs to be declared on food labels, and other markets keep their own allergen lists. Settle the label wording before you formulate.
Bivalves take up elements from the water they live in. If your market sets limits for lead, cadmium, arsenic or mercury, tell us before you order and we confirm what data is available for your lot.
This is an ingredient of animal origin. Some markets apply seafood or animal-product rules at import, and supplements for the UAE need halal certification. Ask your import broker and regulatory team early.
Shijimi is often associated with ornithine, but the composition analysis of this grade does not include it. If your formula or label relies on an ornithine value, raise it before sampling.
This grade is 100% shijimi extract with no dextrin or starch carrier, so the label shows one ingredient. If your blend adds a carrier anyway, compare offers on price per gram of extract rather than per kilogram of powder.
What each component is, what the processing changes, and what published research on the raw material has examined. No health claims; references on request.
Shijimi Extract Powder is a freeze-dried extract of shijimi (Corbicula japonica), a small clam of Japanese rivers and brackish waters that is still an everyday miso soup ingredient in Japan. The clams come from northern Japan, and every step from washing to milling takes place in Japan.
The powder is 100% shijimi extract. Some shijimi extract powders are made on a dextrin or corn starch carrier; this one has none, so your label carries a single ingredient and every gram you dose is extract.
Glycogen makes up most of the powder: 70.5 g per 100 g, with 15.1 g of protein, 4.3 g of ash and almost no fat. It is not an ornithine-standardised ingredient: the composition analysis does not include ornithine, and we do not state a figure. The guide below explains why shijimi is linked with ornithine and what research on the clam has found.
The minimum order is one 500 g bag, so you can run a pilot batch before you scale.
For another Japanese shellfish ingredient, see Oyster Extract Powder (Peptide). For an ingredient from a traditional Japanese food, see Nattokinase Extract Powder 40,000 FU/g.
To discuss volume or your application, or to request the specification or a sample, use the request form on this page.
Shijimi is the Japanese name for small clams of the genus Corbicula. This extract is made from Corbicula japonica, a brackish-water clam that lives in rivers and brackish waters throughout Japan (Comparative Biochemistry and Physiology Part B, 2014). Shijimi has been eaten in Japan since prehistoric times, and its shells are found in shell mounds of the Jomon period.
A metabolome study of Corbicula japonica identified more than 200 metabolites in its tissues, including free amino acids, peptides and organic acids, and found that the amounts of several of them shift with the salinity of the water the clams live in (same source).
Glycogen is the form in which animals store glucose: a large, branched chain of glucose units. In this extract it is the main component, at 70.5 g per 100 g in the reference analysis, measured as the carbohydrate that is extracted with trichloroacetic acid and does not dissolve in ethanol (modified Somogyi method).
Total carbohydrate is 79.3 g per 100 g by difference, so glycogen accounts for most of it. Protein (15.1 g), ash (4.3 g), moisture (1.2 g) and fat (0.1 g) make up the rest.
The reference analysis lists 18 amino acids after acid hydrolysis. All nine essential amino acids are present: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. The most abundant are glutamic acid (1.75%), alanine (1.11%) and aspartic acid (1.00%). Glutamic acid is best known as the amino acid of umami taste; the figure here is total glutamic acid after hydrolysis, not free glutamate.
Clams are a well-known food source of vitamin B12: the NIH Office of Dietary Supplements lists 17 µg in 3 ounces of cooked clams, 708% of the Daily Value. The adult RDA and the US Daily Value are both 2.4 µg per day (NIH ODS vitamin B12 fact sheet, updated July 2025).
In the reference analysis, this extract carries 0.27 mg (270 µg) of vitamin B12 per 100 g, about 2.7 µg per gram, so 1 g of powder corresponds to roughly 110% of the US Daily Value. Riboflavin (vitamin B2) is 2.22 mg and niacin 16.3 mg per 100 g; vitamin E (tocopherols) was not detected. Minerals per 100 g: potassium 765 mg, sodium 752 mg, calcium 342 mg, phosphorus 234 mg, magnesium 79.1 mg and iron 3.34 mg. Which nutrient statements a finished product may make depends on your market and on the data for your lot.
In Japan, shijimi is closely associated with ornithine. Ornithine is an amino acid of the urea cycle that the body does not build into proteins, and it is not among the 18 amino acids reported in the analysis of this grade. We therefore do not state an ornithine content for this powder.
Research on Corbicula japonica explains part of the association. One study found that freezing the clams increased the ornithine content of their extract, an effect it did not see in scallop, littleneck clam or hard clam (Bioscience, Biotechnology, and Biochemistry, 2004). A follow-up study isolated an ornithine-containing tripeptide from the clam, named acorbine (beta-alanyl-ornithyl-ornithine), and proposed it as the source of the free ornithine released on freezing (Biochimica et Biophysica Acta, 2007).
The process for this powder includes a freezing step before the clams are boiled. The studies describe the chemistry of the clam; they did not test this product, and without a measurement we make no statement about its ornithine level. If your formula depends on an ornithine value, raise it before sampling.
The figures on this page describe composition and quality. We make no health claims for this ingredient.
Start at the minimum order. Free sample. Specification, SDS and lot CoA on request.
Request a sample or quotationShijimi Extract Powder is a freeze-dried extract of shijimi (Corbicula japonica), a small clam of Japanese rivers and brackish waters that is still an everyday miso soup ingredient in Japan. The clams come from northern Japan, and every step from washing to milling takes place in Japan.
The powder is 100% shijimi extract. Some shijimi extract powders are made on a dextrin or corn starch carrier; this one has none, so your label carries a single ingredient and every gram you dose is extract.
Glycogen makes up most of the powder: 70.5 g per 100 g, with 15.1 g of protein, 4.3 g of ash and almost no fat. It is not an ornithine-standardised ingredient: the composition analysis does not include ornithine, and we do not state a figure. The guide below explains why shijimi is linked with ornithine and what research on the clam has found.
The minimum order is one 500 g bag, so you can run a pilot batch before you scale.
For another Japanese shellfish ingredient, see Oyster Extract Powder (Peptide). For an ingredient from a traditional Japanese food, see Nattokinase Extract Powder 40,000 FU/g.
To discuss volume or your application, or to request the specification or a sample, use the request form on this page.
Shijimi is the Japanese name for small clams of the genus Corbicula. This extract is made from Corbicula japonica, a brackish-water clam that lives in rivers and brackish waters throughout Japan (Comparative Biochemistry and Physiology Part B, 2014). Shijimi has been eaten in Japan since prehistoric times, and its shells are found in shell mounds of the Jomon period.
A metabolome study of Corbicula japonica identified more than 200 metabolites in its tissues, including free amino acids, peptides and organic acids, and found that the amounts of several of them shift with the salinity of the water the clams live in (same source).
Glycogen is the form in which animals store glucose: a large, branched chain of glucose units. In this extract it is the main component, at 70.5 g per 100 g in the reference analysis, measured as the carbohydrate that is extracted with trichloroacetic acid and does not dissolve in ethanol (modified Somogyi method).
Total carbohydrate is 79.3 g per 100 g by difference, so glycogen accounts for most of it. Protein (15.1 g), ash (4.3 g), moisture (1.2 g) and fat (0.1 g) make up the rest.
The reference analysis lists 18 amino acids after acid hydrolysis. All nine essential amino acids are present: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. The most abundant are glutamic acid (1.75%), alanine (1.11%) and aspartic acid (1.00%). Glutamic acid is best known as the amino acid of umami taste; the figure here is total glutamic acid after hydrolysis, not free glutamate.
Clams are a well-known food source of vitamin B12: the NIH Office of Dietary Supplements lists 17 µg in 3 ounces of cooked clams, 708% of the Daily Value. The adult RDA and the US Daily Value are both 2.4 µg per day (NIH ODS vitamin B12 fact sheet, updated July 2025).
In the reference analysis, this extract carries 0.27 mg (270 µg) of vitamin B12 per 100 g, about 2.7 µg per gram, so 1 g of powder corresponds to roughly 110% of the US Daily Value. Riboflavin (vitamin B2) is 2.22 mg and niacin 16.3 mg per 100 g; vitamin E (tocopherols) was not detected. Minerals per 100 g: potassium 765 mg, sodium 752 mg, calcium 342 mg, phosphorus 234 mg, magnesium 79.1 mg and iron 3.34 mg. Which nutrient statements a finished product may make depends on your market and on the data for your lot.
In Japan, shijimi is closely associated with ornithine. Ornithine is an amino acid of the urea cycle that the body does not build into proteins, and it is not among the 18 amino acids reported in the analysis of this grade. We therefore do not state an ornithine content for this powder.
Research on Corbicula japonica explains part of the association. One study found that freezing the clams increased the ornithine content of their extract, an effect it did not see in scallop, littleneck clam or hard clam (Bioscience, Biotechnology, and Biochemistry, 2004). A follow-up study isolated an ornithine-containing tripeptide from the clam, named acorbine (beta-alanyl-ornithyl-ornithine), and proposed it as the source of the free ornithine released on freezing (Biochimica et Biophysica Acta, 2007).
The process for this powder includes a freezing step before the clams are boiled. The studies describe the chemistry of the clam; they did not test this product, and without a measurement we make no statement about its ornithine level. If your formula depends on an ornithine value, raise it before sampling.
The figures on this page describe composition and quality. We make no health claims for this ingredient.
It is 100% shijimi extract, made from Corbicula japonica clams from northern Japan, with no carrier or other ingredient. The clams are washed, frozen, boiled in a steam kettle, vacuum freeze-dried and milled. Per 100 g, the reference analysis gives glycogen 70.5 g, protein 15.1 g, ash 4.3 g, fat 0.1 g and moisture 1.2 g; your lot's CoA governs.
We do not state an ornithine figure, because the composition analysis of this grade does not include ornithine. Research on Corbicula japonica reports that freezing the clams increases free ornithine in the extract, and this process includes a freezing step, but the effect has not been measured on this grade. If your formula or label depends on an ornithine value, tell us before sampling.
Per 100 g in the reference analysis: vitamin B12 0.27 mg, riboflavin 2.22 mg, niacin 16.3 mg, potassium 765 mg, sodium 752 mg, calcium 342 mg, phosphorus 234 mg, magnesium 79.1 mg and iron 3.34 mg; vitamin E was not detected. One gram carries about 2.7 µg of vitamin B12, against a US Daily Value of 2.4 µg. Label statements depend on your market's rules and your lot data.
Shijimi is a bivalve mollusc, so check allergen labelling: Australia and New Zealand, for example, require molluscs to be declared. As an ingredient of shellfish origin it may fall under animal-product or seafood rules at import, and supplements for the UAE need halal certification. If your market sets heavy-metal limits, tell us before you order and we confirm the data available for your lot.
