Soy proteins
Functionality
Functional properties of vegetable proteins and soy proteins in particular, are dependent on factors related to their physical and chemical properties. Understanding of the functional properties of soy proteins requires a detailed knowledge of soy protein’s nature and structural properties.
Intrinsic factors (e.g. basic composition of the soy bean) environmental factors (e.g. pH, salts, carbohydrates, lipids), as well as the different processing treatments also affect functionality.
Soy proteins are able to create a matrix between carbohydrates, other proteins, fat and water due to their hydrophilic and lipophilic properties. Among others, soy protein has the following functionalities: fat and water binding, texture and structure improvement, viscosity building, gelling properties and shelf-life extension.
It is the multiple functional properties of soy proteins that make soy the preferred vegetable protein for food applications, used as a cost effective and high quality protein ingredient.
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: crumb whitening, dough conditioning in bakery applications.
50 & 70 PDI** – Light heat treatment: water absorption/retention; fat repulsion; protein enhancement; improved cell structure for baked goods, breads, pancakes, donuts, tortillas, bagels.
20 PDI** – Full heat treatment: water absorption/retention; flavor and protein enhancement.
(*) standard AOCS method for measuring heat treatment in soy processing
(**) Produced in the U.S.