The multiple functional properties of soy proteins make soy the preferred vegetable protein for food applications — a cost-effective and high-quality protein ingredient.

The functional properties of soy proteins depend on factors related to their physical and chemical properties. Understanding these properties requires detailed knowledge of the nature and structure of soy protein itself.

For example, functionality is affected by intrinsic factors (e.g. basic composition of the soybean), environmental factors (e.g. pH, salts, carbohydrates, lipids), and different processing treatments.

Protein Dispersability Index (PDI)*

This guide to functionality in soy protein products measures the level of protein that is soluble or suspended in water. Cargill Texturizing Solutions offer soy flour in four PDI designations:

• 90 PDI** – Minimal heat treatment, enzyme active. Functions: crumb whitening, dough conditioning in bakery applications.
• 50 & 70 PDI** – Light heat treatment. Functions: water absorption/retention; fat repulsion; protein enhancement; improved cell structure for baked goods, breads, pancakes, donuts, tortillas, bagels.
• 20 PDI** – Full heat treatment. Functions: water absorption/retention; flavor and protein enhancement.

(*) standard AOCS method for measuring heat treatment in soy processing

(**) Produced in the U.S.