Question

Which of the following compound gives sweet and meaty flavour to fish?

• A. Inosine monophosphate
• B. Inosine
• C. Adenosine diphosphate
• D. Hypoxanthine

Hint:

Remember the ATP degradation pathway: IMP is the flavor enhancer (freshness), while Hypoxanthine (Hx) is the bitter compound that indicates spoilage. This is a common topic in fish processing exams.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
After harvest, fish muscle undergoes biochemical changes known as post-mortem autolysis.
During this process, high-energy phosphate compounds like adenosine triphosphate (ATP) break down through a predictable enzymatic pathway.
The concentration of these ATP degradation products directly affects the flavor, freshness, and quality of the fish tissue.

Step 2: Detailed Explanation:
The post-mortem breakdown of ATP in fish muscle follows this sequence:
\[ \text{ATP} \rightarrow \text{ADP} \rightarrow \text{AMP} \rightarrow \text{IMP} \rightarrow \text{HxR (Inosine)} \rightarrow \text{Hx (Hypoxanthine)} \]
Inosine monophosphate (IMP) accumulates in the muscle tissue during the early stages of storage.
IMP is a key flavor-enhancing nucleotide that contributes to the fresh, sweet, and meaty umami taste of fresh seafood.
It works synergistically with glutamic acid to create the characteristic flavor profile of high-quality fish.
As storage continues, autolytic enzymes convert IMP into inosine (HxR) and eventually into hypoxanthine (Hx).
Hypoxanthine has a bitter taste and is a primary indicator of spoilage and quality loss in fish.
Therefore, inosine monophosphate is the compound responsible for the desirable sweet and meaty flavor of fresh fish.

Step 3: Final Answer:
Inosine monophosphate (IMP) is the nucleotide that provides the sweet and meaty umami flavor to fresh fish.
Thus, the correct option is (A).