Isolation of Tomato Seed Meal Proteins with Salt Solutions

Salt solutions were used in isolating tomato seed meal proteins. Na₂SO₃ and NaCl solutions at different concentrations, and pH were included in a central composite design to find optimum conditions of protein isolation. The highest total protein yield was achieved with water extraction (no salt present). Salt extraction at pH 7.5 produced isolates with protein content of 93.4% (NaCl 5% w/v) and 77.1% (Na₂SO₃ 0.5% w/v). Observed values were in good agreement with predicted values. Isolates extracted with different salt solutions ranged from less soluble but very resistant to heat and Ca²⁺, to very surface active with functional properties comparable to commercial soy isolates.