Determination of the maximum water solubility of eight native starches and the solubility of their acidic-methanol and -ethanol modified analogues.
The maximum water solubilities of eight native starches from potato, shoti, tapioca, maize, waxy maize, amylomaize-7, wheat, and rice and their acid-methanol and acid-ethanol modified analogues have been determined. Maximum solubilities of 18.7 and 17.4 mg/mL were obtained for waxy maize and tapioca and 12.4 mg/mL for potato and maize starches by autoclaving 220 mg/10 mL at 121 degrees C; 8.7 mg/mL was obtained for shoti starch by stirring in 85:15 (v/v) Me(2)SO-H(2)O at 20 degrees C; and 7.0 and 5.2mg/mL for rice and amylomaize-7 starches by stirring in 1M NaOH at 20 degrees C. The acid-alcohol treated starches were 4-9 times more soluble than their native starches. The compositions of the solubilized starches had, in general, much higher ratios of amylose to amylopectin than the ratios in their native granules. A major exception to this was the acid-methanol treated potato, shoti, and rice starches that had much lower ratios of amylose to amylopectin than the ratios in their granules.
Mukerjea
Rupendra
R
Laboratory of Carbohydrate Chemistry and Enzymology, Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA.
Slocum
Giles
G
Robyt
John F
JF
D000687:Amylopectin / Q000378:metabolism; D000688:Amylose / Q000378:metabolism; D000431:Ethanol / Q000737:chemistry*; D006851:Hydrochloric Acid / Q000737:chemistry*; D002365:Manihot / Q000737:chemistry; D000432:Methanol / Q000737:chemistry*; D012275:Oryza / Q000737:chemistry; D011198:Solanum tuberosum / Q000737:chemistry; D012995:Solubility; D013213:Starch / Q000737:chemistry*; D014908:Triticum / Q000737:chemistry; D003313:Zea mays / Q000737:chemistry
D000431:Ethanol; D013213:Starch; D000688:Amylose; D000687:Amylopectin; D006851:Hydrochloric Acid; D000432:Methanol