Effect of partial replacement of porcine fat with pre-emulsified soybean oil using fish protein isolate as emulsifier on characteristic of sausage.

Partial replacement of animal fats with n-3 rich oils is a promising way to improve nutritive value of meat products. In the present work, the effects of porcine fat substitution with soybean oil (SBO) on characteristics of sausages were studied at the oil substitution levels of 25, 35, and 45% by weight of porcine fat. SBO was introduced to the sausages alternatively in native or pre-emulsified forms, the latter with fish protein isolate (FPI) or Na-caseinate (Nc) as emulsifier. Characteristics of the sausages, including cooking loss, water holding capacity, texture attributes, microstructure, and color, were then determined. The sausages added with pre-emulsified SBO stabilized by FPI showed better stability than the control (without added SBO), as indicated by lower cooking loss and higher hardness. Microstructure with better homogeneity was also evident in the sausages added with pre-emulsified SBO stabilized by FPI. However, the sausages added with pre-emulsified SBO stabilized by Nc showed poorer stability than the control, and possessed sponge-like microstructure. Generally, increased oil substitution level led to inferior stability of the product, especially in the sausages formulated with pre-emulsified SBO stabilized by Nc. The results suggested that FPI might be used in comminuted meat products with desirable effects, in the pre-emulsification, on replacement level up to 35% of porcine fat.