Enzymic Developments in the Production of Maltose and Glucose

Abstract

Major advances in starch technology and starch processing have taken place in the last two decades as a result of the development of new amylolytic enzymes (Fogarty and Kelly, 1979, 1980; Norman, 1979). As a result, a range of products with specific compositions and physical properties may be produced. The various commercially used enzymes and their applications are summarized in Table 1. Thermostable α-amylases e.g. those from Bacillus amyloliquefaciens (Borgia and Campbell, 1978) and Bacillus licheniformis (Saito, 1973; Madsen et al., 1973; Morgan and Priest, 1981) are used in liquefaction processes which with the aid of heat convert insoluble starch granules into partial hydrolysates with lower viscosities. In these processes the hydrolytic action is concluded when the degree of polymerisation is about 10–12. Due to their thermostabilities and hydrolytic action patterns thermostable α-amylases (E.C. 3.2.1.1, α-1,4 glucan 4-glucanohydrolase, endo-amylase) are particularly suited as thinning agents in liquefaction processes but in order to obtain hydrolysates with low molecular weight carbohydrates suitable for fermentation and additional uses, other microbial amylolytic enzymes must be used.