Ultrastructure of acid- and enzyme-modified cross-linked potato starch

✍ Scribed by G. Hollinger; R. H. Marchessault

• Publisher: Wiley (John Wiley & Sons)
• Year: 1975
• Tongue: English
• Weight: 781 KB
• Volume: 14
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1975.360140203

✦ Synopsis

Abstract

Purified potato starch, cross‐linked with epichlorohydrin (65–5.4 anhydroglucose units per cross‐link) by an iterative method that preserved the native crystalline structure of the starch granule, was exposed to enzymic (B. subtilis α‐amylase at 50°C) and acidic (3 N HCl at 40°C) hydrolysis. The stability of the granules to digestion by enzymes, as measured by their weight loss after incubation with the enzyme solution, increased with the degree of cross‐linking; by contrast, the stability to acid attack decreased as a function of the degree of cross‐linking. The morphology of these samples was studied by scanning electron microscopy. A lamellar structure, which was most evident after enzyme treatment, was observed in samples that had a weight loss of greater than 50%. The results reflect differences in accessibility, which are interpreted in terms of a statistical model of the ultrastructure with correlated fluctuations in density in the radial direction.