Topics in Dietary Fiber Research

Abstract

Pectic substances originate primarily in the cell walls and fibrous portions of fruit, vegetable, and other land plant tissues. They are complex colloidal carbohydrate derivatives containing as their major structural feature acid polysaccharides composed primarily of galaturonic acid units. Neutral sugars such as arabinose, galactose, rhamnose, and xylose have been identified as associated with the pectin molecule (1). Aspinall’s work indicates that the rhamnose may be a part of the main chain structure of the pectin molecule. The association of arabinose and galactose may be either a sidechain attachment or an incidental part of the main chain. By this it is meant that the entire sugar molecule is not involved in the chain structure.