Disodium inosinate is the disodium

Sodium

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

 salt

Salt

In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

 of inosinic acid

Inosinic acid

Inosinic acid or inosine monophosphate is a nucleotide monophosphate. Inosinic acid is important in metabolism. It is the ribonucleotide of hypoxanthine and the first nucleotide formed during the synthesis of purine. It is formed by the deamination of adenosine monophosphate, and is hydrolysed...

 with the chemical formula C₁₀H₁₁N₄Na₂O₈P. It is used as a food additive

Food additive

Food additives are substances added to food to preserve flavor or enhance its taste and appearance.Some additives have been used for centuries; for example, preserving food by pickling , salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines...

 and often found in instant noodles, potato chips, and a variety of other snacks.
Disodium inosinate is used as a flavor enhancer, in synergy with monosodium glutamate

Monosodium glutamate

Monosodium glutamate, also known as sodium glutamate or MSG, is the sodium salt of glutamic acid, one of the most abundant naturally occurring non-essential amino acids....

 (MSG) to provide the umami

Umami

Umami , popularly referred to as savoriness, is one of the five basic tastes together with sweet, sour, bitter, and salty.-Etymology:Umami is a loanword from the Japanese meaning "pleasant savory taste". This particular writing was chosen by Professor Kikunae Ikeda from umai "delicious" and mi ...

 taste. It is often added to foods in conjunction with disodium guanylate

Disodium guanylate

Disodium guanylate, also known as sodium 5'-guanylate and disodium 5'-guanylate, is a natural disodium salt of the flavor enhancer guanosine monophosphate . Disodium guanylate is a food additive with the E number E627...

; the combination is known as disodium 5'-ribonucleotides.

As a relatively expensive product, disodium inosinate is usually not used independently of glutamic acid; if disodium inosinate is present in a list of ingredients, but MSG does not appear to be, it is possible that glutamic acid is provided as part of another ingredient or is naturally occurring in another ingredient like tomatoes, Parmesan cheese or yeast extract

Yeast extract

Yeast extract is the common name for various forms of processed yeast products made by extracting the cell contents ; they are used as food additives or flavourings, or as nutrients for bacterial culture media. They are often used to create savory flavors and umami taste sensations. Monosodium...

.
Disodium inosinate is generally produced from meat or from fish.