Crude extract of proteins

Before selecting a method to measure a specific aspect of protein functionality, one must decide on the complexity of the testing matrix. Researchers have used a single purified protein, a crude extract of proteins, a prototype food product, or an actual product to study protein functionality. For meat studies, formulated meat systems, ground muscle, myofibrillar proteins, salt-soluble proteins, actomyosin,... 

Once a crude extract of protein has been made, it is common to separate this mixture into different fractions by a precipitation step. The solubility of a protein reflects a delicate balance between different energetic interactions—both internally within the protein and between the protein and the surrounding solvent. Consequently, the choice of solvent can affect both the solubility and the structure of a protein. 

Figure 1. Crude extract of proteins from M202 seed callus. 12.5% SDS-PAGE stained with Coomassie blue. Lanes A and B contain proteins from callus homogenates treated without and with 2.5 iM GA3. Lanes C and D contain proteins secreted from callus treated without and with 2.5 iM GA3. Alpha-amylase is the predominant protein with Mr 43-44 kDa.

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