Measuring Proteolysis in Cheddar Cheese Slurries: Comparison of Hull and Trinitrobenzene Sulfonic Acid Procedures

Abstract
A modified trinitrobenzene sulfonic acid procedure was compared to the Hull method to determine the more sensitive procedure for detecting proteolysis in Cheddar cheese slurries. Slurries prepared from milled Cheddar cheese curd were sampled daily for 4 days. Each sample was assayed for trichloroacetic acid soluble tryptophan and tyrosine (Hull method) and for trichloroacetic acid soluble amino N (trinitrobenzene sulfonic acid procedure). A linear increase of soluble amino N over the 4 days was detected by the trinitrobenzene sulfonic acid method. The Hull procedure only detected a significant increase of soluble tryptophan and tryosine on the 3rd day. The trinitrobenzene sulfonic acid procedure is more suitable than the Hull procedure for detecting proteolysis in cheese slurry systems.
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