Batch and continuous production of high fructose syrup from Jerusalem artichoke tubers has been studied using yeast cells immobilized in open pore gelatin matrix. In a batch reactor, the hydrolysis was 93% ( d-fructose/ d-glucose = 90/10 ) and 42 mg d-fructose per ml was produced from the artichoke tuber extract by immobilized cells in 3 h. The same immobilized cells were recycled and used repeatedly for 10 batch cycles starting with fresh juice at the beginning of each cycle. It was found that immobilized cells were extremely stable and the percent hydrolysis was almost constant for all 10 batch cycles. In a continuous reactor using an immobilized cell concentration of 65.7 g (dry wt) l −1 of total working bioreactor volume, the percent hydrolysis was found to remain constant at ∼100% at dilution rates <1.26 h −1, but beyond that it decreased. Volumetric productivity attained its maximum value at D = 2.08 h −1 and was found to be 100 g l −1 h −1. This was achieved at a feed sugar conversion of 80%. At 90% conversion and D = 1.66 h −1, the productivity was found to be 90 g l −1 h −1. Continuous operation of the immobilized cell bioreactor at a constant dilution rate of 1.65 h −1 for 240 h resulted in only 2% loss of original activity.