1. Introduction
Soybean seeds have a protein content of 35–40% on a
dry weight basis, which makes them a relatively inexpensive
source of protein for human consumption Soybeans have been transformed
into various forms of soy foods, tofu being the one most
widely accepted throughout the world.
In Asia, for example, about 90% of soybean protein is
consumed in the form of tofu. However, because of its high
moisture content and rich nutrients, tofu is prone to spoilage.
Some tofu purchased in the ‘‘fresh’’ form at an Asian
Market or health-food store may have a shelf-life of only