Question

The sweet taste in fish is caused by

• A. Inosine monophosphate
• B. Hypoxanthine
• C. Lysine
• D. Glutamic acid

Hint:

- IMP (Inosine Monophosphate) = Sweet/Fresh taste.
- Hx (Hypoxanthine) = Bitter/Spoiled taste.
The ratio of these metabolites is used to calculate the \(K\)-value, an objective index of fish freshness.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Flavor and taste in fresh seafood are governed by non-protein nitrogenous compounds, free amino acids, and nucleotides that accumulate or degrade post-mortem.

Step 2: Detailed Explanation:
In very fresh fish, the degradation of adenosine triphosphate (ATP) proceeds as:
\[ \text{ATP} \rightarrow \text{ADP} \rightarrow \text{AMP} \rightarrow \text{IMP (Inosine monophosphate)} \rightarrow \text{HxR (Inosine)} \rightarrow \text{Hx (Hypoxanthine)} \]
- Inosine monophosphate (IMP) is a highly desirable nucleotide that accumulates shortly after harvest and imparts a pleasant, sweetish, and savory (umami) flavor characteristic of fresh fish.
- As spoilage occurs, IMP degrades into Hypoxanthine (Hx), which is responsible for the bitter taste of spoiled fish.
- Glutamic acid is responsible for the distinct savory/umami taste.

Step 3: Final Answer:
The sweet/pleasant fresh fish taste is associated with Inosine monophosphate, which corresponds to option (A).