Cereal Chem. 73 (2):199-207 |
Physicochemical Properties of Small- and Large-Granule Starches of Waxy, Regular, and High-Amylose Barleys.
T. Vasanthan (1) and R. S. Bhatty (2). (1) Department of Applied Microbiology and Food Science, 51 Campus Drive, University of Saskatchewan, Saskatoon, Canada, S7N SA8. Phone: 306/966-8766. Fax: 306/966-5015. (2) Crop Development Centre, University of Saskatchewan, 51 Campus Drive, Saskatoon, Canada, S7N SA8. Author to whom requests for reprints should be sent. Phone: 306/966-4970. Fax: 306/966-5015. E-mail: <bhattyrs@duke,usask.ca> Accepted December 5, 1995. Copyright 1996 by the American Association of Cereal Chemists, Inc.
Small- and large-granule starches were isolated from pin-milled and air-classified fractions of waxy (SB 89528), regular (Condor), and high-amylose (Glacier) barleys, and their physicochemical properties were investigated. The isolations contained 95-97% starch, 0.1-0.3% protein, and 0.1-0.2% ash. Scanning electron microscopy showed that the starch granules were oval to round in shape with diameter ranges of 2-10 µm for small and 12-26 µm for large granules. The starches had A-type X-ray diffraction patterns, typical of cereal starches. The differences in the physicochemical properties such as X-ray diffraction relative intensities, swelling factor, amylose leaching, Brabender pasting, differential scanning calorimetry thermal characteristics, and resistance to acid and alpha-amylase hydrolysis were greater among the three genotypes than between the small- and large-granule starches from the same genotype. The large-granule barley starches may be substituted for corn starches because their physicochemical properties are generally similar.