• Enzymatic Protein Cross-Linking via Microbial Transglutaminase:
• Biochemical Action of MTGase:
• Transglutaminase (EC 2.3.2.13, derived from Streptomyces mobaraensis) catalyzes acyl transfer between the $\gamma$-carboxamide group of peptide-bound glutamine and primary $\epsilon$-amino groups of lysine.
• Forms covalent $\epsilon$-($\gamma$-glutamyl)lysine isopeptide bonds, reinforcing the protein gel network in yogurt, fermented dairy foods, and surimi.
• Conclusion: Transglutaminase (Option 2).

Correct option: (2) Transglutaminase

Evaluating the Assertion and Reason concerning Other convenience foods from fruits and vegetables:

The correct answer is Option 4: (A) is false but (R) is true..

• Protein Solubilization and Gelation in Surimi Manufacturing:
• Functional Muscle Fractions:
• Surimi is refined mechanically deboned fish meat washed to remove water-soluble sarcoplasmic proteins and lipids.
• The functional matrix is composed of salt-soluble myofibrillar proteins (actin and myosin), which form a strong, elastic, cohesive heat-set gel upon adding $2 - 3\%\ \text{NaCl}$ and thermal cooking.
• Conclusion: Myofibrillar proteins (Option 1).

Correct option: (1) Myofibrillar proteins