**1. Introduction**

A diversity of bioactive biomolecules present in soybean is covered in this chapter such as e-Phe-Leu and Trp-Leu, and Val-Leu-Ile-Val-Pro derived from glycinin; Bowman-Birk inhibitor, Kunitz trypsin inhibitor, hemagglutinin, isoflavone-deprived soy peptide, neu‐ tral PR-5 protein, SbPRP protein, ferritin, peroxisomal proteins, defense proteins such as calmodulin, disease resistance protein, beta-glucan-binding protein, l unasin, and glysoja‐ nin; enzymes such as phenylalanine ammonia-lyase and tyrosine ammonia-lyase, de‐ fense-related enzymes, cysteine proteinase, isoflavone synthase, isocitrate lyase, vestitone reductase and chalcone reductase, UDP-glucose: flavonoid 3-O-glucosyltransferase, betaglucosidase, isoflavone conjugate-hydrolyzing beta-glucosidase, genes related to 2-oxo‐ glutarate-dependent dioxygenases, 5'-adenylylsulfate reductase, and ATP sulfurylase, anticarcinogenic daidzein-rich fraction, polysaccharides, glyceollins, and isoflavones. The aforementioned soybean constituents manifest many uses and consumption of soybean promotes health.

Soybean represents a rich and yet relatively inexpensive source of proteins. Hence it is a common dietary component in many countries. It is well known that some of its constitu‐ ents like isoflavones are beneficial to health, and regular consumption of soybean has been associated with a reduced incidence of diseases such as osteoporosis, cancer and cardiovas‐ cular disease. A wealth of information pertaining to the various bioactive constituents of soybean has been accumulated. The aim of this article is to review the information that is available.

© 2013 Ng et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2013 Ng et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
