Step 1: Analyze option (A).
Invert sugar is a mixture of glucose and fructose obtained by hydrolysis of sucrose.
Fructose alone is not invert sugar.
So, (A) is incorrect.
Step 2: Analyze option (B).
Leucine and Tryptophan are essential amino acids.
They cannot be synthesized by the human body and must be obtained from diet.
So, (B) is correct.
Step 3: Analyze option (C).
Curdling of milk involves denaturation of proteins (casein).
So, statement (C) is incorrect.
Step 4: Analyze option (D).
Amylose is a linear polymer of \( \alpha \)-D-glucose units.
Branched structure is found in amylopectin, not amylose.
So, (D) is incorrect.
Step 5: Final conclusion.
Only option (B) is correct.
\[
\boxed{\text{Leucine and Tryptophan are essential amino acids}}
\]