Modeling and Formulation Optimization of (Saurida tumbil) Greater Lizardfish Sausage Produced by Ohmic heating via response surface methodology (RSM)

Nowadays, by converting the cheap and commercial low-valued fish into value-added products such as fish sausages, as well as the application of novel ohmic heating method to cook more uniform, faster compared to other thermal severe methods and with minimal processing can play an important role in producing a safe and nutritious product. Therefore, the purpose of this study is to investigate some microbial and chemical characteristics of (Saurida tumbil) greater lizardfish sausage heated by emerging ohmic heating method and formulation optimization was performed by response surface methodology -central composite design (RSM-CCD) by considering KCl (0.7- 2.3 %), Soy Oil ( 4-14 %) and Isolated Soy Protein (0.2-1.8%). Optimization of 20 fish sausage formulation produced by ohmic heating was done by response surface methodology using Design Expert software version 11 and the relationship between the independent variables and the five responses was investigated. KCl has been shown an inhibitory effect on samples total plate count level. The interaction effect of soybean oil and soy protein isolate had a significant effect on pH changes. Increasing soybean oil percentage caused a little increase and subsequently reduction of pH and increasing soy protein isolate led to a significant decrease in pH. Furthermore, higher amount of KCl and soy protein isolate reduced the amount of cooking loss. In addition increase of soy bean oil percentage caused reduction and increase of soy protein isolate lead to increase of water holding capacity. Based on the results of formulation optimization in fish sausages with formulations containing 2% potassium chloride, 6% soybean oil and 1.5% soy protein isolate can increase water holding capacity, the lowest microbial load and the lowest peroxide value, cooking loss and optimized pH.