Fish products and Byproducts Technology

Unit 8 - Fish Protein Hydrolysate

8.2.2. Alkali Hydrolysis
This process involves hydrolyzing the protein at alkaline pH (12.5) and high temperature (95^oC).
Rapid cleavage of large water soluble protein and further degradation at slow rate
Alkali hydrolysis primarily use the fish protein concentrate as the substrate.
Sodium hydroxide is commonly used as an alkaline reactant.
Advantage

• Used to recover and solubulize a broad range of protein
• Aid in modifying properties of insoluble FPC
• Solubilize collagen

Disadavantages

• Resultant product is Poor in functionality and process affect the nutritive value adversely.
• Recovery is low
• Racemization of L-amino acids produces D-amino acids which are not absorbed by human.
• Disulphide bonds are split with loss of Cysteine, serine and threonine via β-elimination reactions and formation of lysinoalanine, ornithinoalanine, lanthionone, and β-amino alanine can also occur
• May produce toxic substances like lysine alanine
• Alkaline hydrolysis reaction products have an inhibiting effect on proteolytic enzymes