Formulation Optimization of Cryoprotectant for Crisp Grass Carp by Response Surface Methodology

Abstract

The composite cryoprotectants was created using trehalose, polydextrose and sodium lactate. Response surface methodology based on the single-factor investigation was applied to explore optimal cryoprotectant solution formulation on salt soluble protein content of crisp grass carp, and compared to the traditional commercial cryoprotectants, then studied the optimal immersion time and effect of freeze-thaw treatment on crisp grass carp. The results indicate that the optimal formula of composite cryoprotectants is 4% trehalose, 6% polydextrose and 5% sodium lactate. Salt soluble protein content of the optimal cryoprotectants is higher than that traditional commercial cryoprotectants (4% sucrose +4% sorbitol) in crisp grass carp, and the optimal immersion time is 30min. The optimal composite cryoprotectants with low sweetness and low heat can prevent effectively protein from frozen denaturation. Thus the composite cryoprotectants of trehalose, polydextrose and sodium lactate can replace sucrose and sorbitol.