Is 635 Vegan? Uncovering the Truth About This Ambiguous Flavor Enhancer

January 12, 2026 •

3 min read

Food additive E635 is a powerful flavor enhancer, but its origins are often unclear for consumers. Understanding if a product containing this ingredient, also known as disodium 5'-ribonucleotides, is vegan requires close inspection and, sometimes, direct communication with the manufacturer. This is because while it can be produced from plant sources, it is also frequently derived from meat or fish.

Quick Summary

This article explains what E635 (disodium 5'-ribonucleotides) is and why its vegan status is not guaranteed. It details how to verify the ingredient's origin in processed foods and offers guidance on making informed, plant-based choices.

Key Points

Ambiguous Source: E635 (Disodium 5'-ribonucleotides) can be sourced from either animal products (like fish or meat) or plant-based materials (like yeast), making it an unreliable vegan ingredient.
Made from Two Additives: E635 is a mix of E627 (guanylate) and E631 (inosinate), with E631 being the primary cause for concern regarding animal origin.
Read Labels Carefully: Look for explicit vegan certifications on packaging or check for other hidden non-vegan ingredients like dairy derivatives or gelatin.
Contact the Manufacturer: The most reliable way to determine the source of E635 in a specific product is to contact the company directly and ask about their sourcing.
Common in Processed Foods: E635 is a flavor enhancer commonly found in processed snacks, instant noodles, and seasoned products, so vigilance is required when purchasing these items.
Safer Alternatives Exist: Many vegan-friendly alternatives to umami flavor exist, including nutritional yeast, mushroom powder, and plant-based yeast extracts.

What is 635 (Disodium 5'-Ribonucleotides)?

E635, also labeled as INS 635 or disodium 5'-ribonucleotides, is a food additive used to enhance the savory umami flavor in many processed foods. It is a combination of two other flavor enhancers: disodium guanylate (E627) and disodium inosinate (E631), often in a 1:1 ratio. These ingredients work synergistically with naturally occurring glutamates or added MSG (E621) to significantly boost a product's overall flavor profile.

The Ambiguity: How 635 Can Be Non-Vegan

The reason E635 is a gray area for vegans lies in the sourcing of its components, particularly E631 (disodium inosinate).

Animal-derived sources: Historically and often today, inosinate is extracted from animal products. Common sources include fish, such as sardines and anchovies, or meat extracts. When derived this way, any product containing E635 would not be suitable for a vegan diet. Products like instant noodles, snack foods, gravies, and canned soups frequently use E635 sourced from animals for a rich, umami flavor.
Vegan-friendly sources: E635 can also be commercially produced through the fermentation of sugars or from plant-based materials, such as yeast extract or tapioca starch. When a manufacturer explicitly uses a vegan-friendly source, the product is safe for vegans. However, the label alone does not provide this information, and many companies do not specify the origin of their flavor enhancers.

Where to Find 635 and How to Check

E635 is prevalent in a wide array of processed goods. Here is a list of common foods to check:

Chips and other savory snacks
Instant noodles and pre-packaged soups
Sauces, gravies, and seasoning packets
Frozen dinners and ready-to-eat meals
Certain cheese products and processed meats (for flavoring)

To determine if a product with E635 is vegan, you must take proactive steps:

Look for certified vegan labels: Products with a clear 'Vegan' or 'Certified Vegan' logo are your safest bet, as this guarantees the manufacturer has sourced vegan-friendly ingredients for all components.
Read ingredient lists carefully: While E635 will be listed, also check for other non-vegan indicators like meat extracts, whey, casein, gelatin, or dairy derivatives.
Contact the manufacturer directly: If a product is not explicitly labeled vegan, the only way to know for certain is to contact the company's customer service. Ask specifically about the sourcing of 'disodium 5'-ribonucleotides' (E635) and if they use yeast-based or animal-based derivatives.

Navigating Processed Foods: E635 vs. Vegan Alternatives

For vegans, the safest approach with any processed food containing E635 is to assume it is not vegan unless certified otherwise. Thankfully, many products are formulated with vegan alternatives to achieve a similar umami effect.

Comparison of Flavor Enhancers


Feature	E635 (Disodium 5'-Ribonucleotides)	Vegan-Safe Alternatives (e.g., Yeast Extract)
Source	Can be from animal (meat/fish) or plant (yeast) sources	Typically from yeast, corn, or other plant-based sources
Vegan Status	Not reliably vegan; requires manufacturer confirmation	Reliably vegan if sourced correctly; check for added ingredients
Sourcing Transparency	Low; origin is not disclosed on standard labels	Higher, as these are often used in products specifically marketed as vegan
Labeling	May be listed as E635, INS 635, or Disodium 5'-ribonucleotides	May be labeled as yeast extract, nutritional yeast, or mushroom powder

The Verdict: Check Before You Eat

In conclusion, the simple answer to "is 635 vegan?" is a definitive "it depends." The critical ambiguity of E635's sourcing means vegans cannot blindly assume that a product is plant-based just because it lacks overt animal products. The ingredient could be derived from meat or fish, making it unsuitable for a vegan diet. The responsibility falls on the consumer to investigate the product's origin, either through vegan certification labels or direct contact with the manufacturer. For a worry-free plant-based diet, opting for products that are clearly labeled vegan or made with transparently sourced ingredients like nutritional yeast is the safest course of action. This vigilance ensures your dietary choices remain consistent with your ethical or health-based reasons for being vegan. For more information on navigating hidden animal ingredients, the Vegan Society offers comprehensive resources.

Frequently Asked Questions

E635 is the E-number for disodium 5'-ribonucleotides, a food additive that functions as a flavor enhancer to boost the savory umami taste in processed foods.

E635 is a mixture containing disodium inosinate (E631), which is frequently derived from meat or fish products. Without specific information from the manufacturer, its animal or plant-based origin is unknown.

The most reliable way is to look for a 'Certified Vegan' label on the packaging. If none is present, you must contact the manufacturer to confirm their specific sourcing of E635.

Yes, E635 can be, and often is, derived from fish extracts during its manufacturing process, particularly the inosinate component (E631).

You should check processed foods like instant noodles, savory chips, crackers, snack seasonings, and premade soups or broths.

No, it does not. E635 can be made from vegan sources like yeast or fermented sugars. However, because its origin is not specified on the ingredient list, you cannot assume it's vegan unless certified.

Yes. Many companies use plant-based alternatives to achieve umami flavor, such as nutritional yeast, mushroom powder, or plant-based yeast extracts, especially in products marketed toward vegans.