tA simplified procedure for the preparation of immobilized beta-amylase using non-purified extract fromfresh sweet potato tubers is established in this paper, using differently activated agarose supports.Beta-amylase glutaraldehyde derivative was the preparation with best features, presenting improvedtemperature and pH stability and activity. The possibility of reusing the amylase was also shown, whenthis immobilized enzyme was fully active for five cycles of use. However, immobilization decreasedenzyme activity to around 15%. This seems to be mainly due to diffusion limitations of the starch insidethe pores of the biocatalyst particles. A fifteen-fold increase in the Km was noticed, while the decrease ofVmax was only 30% (10.1 U mg−1protein and 7.03 U mg−1protein for free and immobilized preparations,respectively).