Digestive and Absorptive Enzymes in Rats Fed Phytic Acid Extract from Sweet Potato (ipomoea Batatas)

Phytic acid is a storage form of phosphorus which is found in plant seeds and in many roots and tubers (1). Phytic acid has long been recognized as an antinutrient for its ability to bind to, precipitate and decrease the availability of diand trivalent cationic minerals (2). The reduced availability of minerals will prove disadvantageous, as minerals play a major role in many enzyme systems and metabolic pathways in animals. Apart from binding to minerals, phytic acid is also thought to regulate the process of digestion by binding to some digestion products, thereby delaying the onset of diabetes and hyperlipidemia (3). Phytic acid may also prove beneficial as it is thought to impair starch digestion and thus help in blood glucose control (4). It has also been suggested that phytic acid may directly bind to some metabolic by-products and even some enzymes, thereby directly affecting the activities of those enzymes. Both phytic acid and polyphenols have been shown to play a role in reducing the in vitro rate of starch digestibility and possibly blood glucose response (5). Studies carried out by Yoon et al. (6) also show that phytic acid may affect starch digestibility through interaction with amylase, protein and/or binding with salivary minerals such as calcium.