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Enhanced production of gamma-cyclodextrin from corn syrup solids by means of cyclododecanone as selective complexant

Rendleman, J.A. Jr.
Carbohydrate research 1993 v.247 pp. 223
corn syrup, dextrins, ketones, maltose, glucose
In the presence of cyclododecanone as complexant, corn syrup solids (dextrose equivalent, d.e., 25; dp 4.5) were converted into cyclomaltooctaose (gamma-cyclodextrin, gamma-CD) in 28% yield by incremental addition of cyclodextrin glucanotransferase (CGTase) at 60 degrees C and pH 7.2. Cyclotridecanone was less effective in enhancing gamma-CD yield (14%); cyclic complexants with fewer than 12 ring atoms or more than 13 ring atoms were ineffective. In systems containing cyclododecanone, D-glucose strongly inhibited the conversion of both maltodextrin (starch hydrolyzate of dp 22) and corn syrup solids (dp 5). Maltose, when present in large proportion, also decreased yields of gamma-CD from corn syrup solids, but not from maltodextrin. Maltotriose had no inhibiting effect on either substrate. The nature of the high-molecular-weight fraction (dp > 10) of starch hydrolyzates was found to influence gamma-CD production and was the predominant factor causing yields from corn syrup solids to be lower than those from maltodextrin. Maltose itself did not undergo conversion: however, other low-molecular-weight maltooligosaccharides were converted into gamma-CD in good yield when treated incrementally with CGTase in the presence of cyclododecanone: 20.1% from maltotriose, 36.5% from maltotetraose, 44.1% from maltopentaose, 41.0% from maltohexaose, and 34.7% from maltoheptaose. Yields from maltooligosaccharides were adversely affected by the presence of both D-glucose and maltose.