Potential of carrot concentrated protein as a natural cryoprotectant in fish surimi during frozen storage

Surimi has become the intermediate material for variety of sea food analogues, which have a growing consumer demand in India. Surimi is stabilized myofibrillar proteins obtained from mechanically deboned fish flesh that is water-washed for removal of sarcoplasmic proteins, blood, inorganic salt, and some lipid and other undesirable materials like pigments so as to enhance the gel forming ability of the washed proteins. Usually, surimi is blended with chemical cryoprotectants like sucrose 4%, sorbitol 4%, phosphate 0.3% etc. before storing at -18 to -20 °C to extend self-life of frozen surimi by preventing deleterious changes in myofibrillar proteins caused by freezing, frozen storage and thawing and then used in the production of fabricated fish food products. Although cryoprotectants such as sucrose, sorbitol and phosphates have been used in surimi industry since long time but the problem of sweetness and high calorific content are of growing concern as these could raise blood glucose level leading to the problems especially for those suffering from defective glucose metabolism, such as person with hypoglycemia or diabetes mellitus. Many studies showed that sorbitol and phosphate have adverse effect on human health like celiac disease, gastrointestinal diseases and diabetes, etc. which made various researchers to search for alternative natural cryoprotectants. Carrot (Daucas carota) is a main vegetable crop grown throughout India. It is reported that carrot roots have anti-freeze protein and natural source of antioxidant and carotenes, mainly beta-carotene and sufficient phenolic compounds. It is proved that the carrot concentrated protein (CCP) contains 18% carrot antifreeze protein which is a leucine-rich repeat protein with the molecular weight of 36.8 k Da and possess strong anti-crystallization ability, provide a softer texture and thermal hysteresis and simultaneously prevent oxidation. Furthermore, supplementation of CCP to food product did not show any adverse effect on food quality