An efficient purification process for sweet potato beta-amylase by affinity precipitation with alginate

β-amylases are used in production of maltose syrup. It is shown that sweet potato β-amylase can be purified by affinity precipitation with alginate with 80% activity yield and 44 fold purification. SDS-PAGE of the purified protein showed a single band and a subunit weight of 50 kDa. Preliminary data with soybean and barley enzymes indicate that this may be a general method for purification of β-amylases.