beta-Cyclodextrin production by simultaneous fermentation and cyclization.

Abstract

Production of beta-cyclodextrin (CD) with high-dextrose equivalent (DE) starch hydrolysates by simultaneous fermentation and cyclization (SFC) gives higher yields than using only the enzyme CGTase, because fermentation eliminates glucose and maltose that inhibit CD production, while at the same time, produces ethanol that increases yield. A 10% (w/v) solution of cassava starch, liquefied with alpha-amylase, was incubated with CGTase using: only the enzyme, added ethanol (from 1 to 5%), and added yeast S. cerevisiae (12% w/v), plus nutrients, the latter being the SFC process. Reaction conditions were: 38 degrees C, pH 6.0, DE from 2 to 25, and 3.3 mL of CGTase/L. The yield of beta-CD has decreased with an increase in DE, and maximum reaction yields were found for DE equal to 3.54, reaching 5.6, 14.7, and 11.5 mM beta-CD, respectively. For an increase of DE, of approx 6 times (from 3.54 to 23.79), beta-CD yield decreased 6 times for the first, and second reaction media with 3% (v/v) ethanol, and only approx 3 times for SFC (from 11.5 to 3.73 mM), showing that this process is less sensitive to variations in the DE.