Identification of Proteins and Complex Carbohydrates in Some Commercial Low-Fat Dairy Products by Means of Immunolocalization Techniques

Macromolecular assemblies of proteins and hydrocolloids in low-fat dairy products contribute to the structure and texture of these foods. Immunolocalization techniques were used to identify B-lactoglobulin, casein, bovine whey proteins, and egg albumin in low-fat frozen desserts, reduced fat process cheese, and salad dressings. SimpJesse18 I 00 protein particles were examined and characterized by these methods and compared to naturally occurring protein structures in the low-fat foods. Hydrocolloid identification in low-fat salad dressing was accomplished by complexing cellulase and hemicellulase with colloidal gold and applying the probe as a pre-embedding step, on sections of embedded specimens or on material dried on grids. This enzyme-gold method may be generally applied for identification of cellulose and hemicellulose in complex food systems. Immunolocalization techniques employed in this study should prove useful in probing the fundamental structure-texture relationship in foods