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ARS Home » Research » Publications at this Location » Publication #92265
Title: CONVERSION OF CYCLODEXTRIN INTO HIGH-AMYLOSE STARCH OF LOW MOLECULAR WEIGHT BY MEANS OF CYCLODEXTRIN GLUCANOTRASFERASE

Author
item Rendleman Jr, Jacob
item Knutson Jr, Clarence

Submitted to: Biotech and Applied Biochemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/9/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Starch in the U.S., particularly starch from corn, is produced in large quantity. New and expanded markets are needed to utilize this renewable resource. Cyclodextrins, which can be made from starch by means of certain enzymes, are products with numerous commercial applications and are being used increasingly by the agricultural, pharmaceutical, cosmetic, and food industries. In this study, a process to further convert cyclodextrins was discovered. The process is enzyme-based and the product is a highly insoluble, amylose (straight-chained starch) of low molecular weight. Yields are high (78%). The reaction is unique and has potential as a means for producing an insoluble form of starch that can be incorporated into foods as non-digestible, "low-calorie" components. This information should be useful not only to starch and cyclodextrin manufacturers, but also to scientists who use or plan to use cyclodextrins or amylose in their research. Creating new products and/or lowering the cost of production will ultimately create greater demand for corn products in the marketplace and provide the consumer with better quality, lower cost goods.

Technical Abstract: Over a wide range of temperature (25-70 deg C), alpha-cyclodextrin (alpha-CD) was converted by Bacillus macerans cyclodextrin glucanotransferase into highly insoluble high-amylose starch of low average degree of polymerization (dp 56-73) in yields as high as 78%. Ability to undergo this conversion was highly concentration dependent. Gamma-CD was also convertible in good yield; however, beta-CD was relatively resistant. Degrees of polymerization and the percentages of amylose in the high-amylose products were estimated from spectrophotometric measurements on their iodine complexes. A plausible mechanism for conversion of cyclodextrin into starch is proposed.