Syrup pullulanase

The B-amylase has been used to produce extremely high maltose syrups for confectionery industries and high conversiem syrups used in brewing (77-79). Figure 2 shows the effect of B-amylase and pullulanase on the time course of maltose... 

Pullulanase (EC3.2.1.41) and isoamylase (EC3.2.1.68) are so-called debranching enzymes because they catalyze the hydrolysis of the 1,6 linkages without effect on the 1,4 linkages29 (see Chapter 7). These enzymes are particularly useful in the production of extremely high maltose syrups with maltose levels of 50 to 90%.30 Table 21.3 provides an overview of commercial enzymes used in the com refining process today and typical operating requirements. 

Starch is first liquefied and hydrolyzed to specific dextrose equivalents with hydrochloric acid. After evaporation to 60 percent solids, a saccharifying enzyme (fungal a-amylase) is added to continue hydrolysis to the desired level. By choosing two or more types of enzymes (such as a-amylase, -amylase, glu-coamylase, pullulanase) and adjusting the initial acid hydrolysis, syrups with different ratios of dextrose, maltose, and higher saccharides can be obtained.92... 

By use of a debranching enzyme, isoamylase or pullulanase, the a-D-(l — 6)-linkages in amylopectin are broken, thus opening up to beta-amylase action those parts of the amylopectin molecule that are otherwise resistant.14 In this way, syrups of very high maltose content can be made.19... 

Starch (i. e. high fructose, corn syrup, fuel ethanol, etc.) Amylases, pullulanases, glucose isomerases Acids High temperatures... 

A. Starch industry pullulanase, invertase, glucose isomerase syrups from starch and sucrose... 

Special products similar to maltose syrups are maltooligosaccharides containing 2-7 glucose units linked to each other by a-D-(1 4) bonds. They are obtained by enzymatic hydrolysis of starch with isoamylase or pullulanase and by hydrolysis of the obtained products using a-amylase. Maltooligosaccharides are fully utihsable sugars, which are used similarly to maltose syrups. 

Pullulanase Aerobacter aerogenes Increase of fermentability of starch worts or syrups. 

Enzyme conversions are more specific and controlled compared to acid hydrolysis. This is dne to the specificity of the enzymes for certain substrates or chemical bonds. The final result is that enzyme-based processes yield better-quaUty syrups. The most common and widely used enzymes with their specific activity are a-amylase, P-amylase, pullulanase, amyloglucosidase, cyclodextrin glycosyl-transferase, and glucose isomerase (Guzman Maldonado and Paredes Lopez 1995, Hobbs 2003, Kruger et al. 1987, Teague and Brumm 1992, Woods and Swinton 1995). 

Regular and high-maltose corn syrups are manufactured starting with a low-DE syrup that is further treated with p-amylase or a combination of pullulanase and... 

P-amylase (Figure 13.3). P-Amylase works best at pH 5 and a temperature of 55°C. The utilization of only p-amylase yields syrups with 50%-55% maltose, while the additional use of debranching pullulanase yields syrups with approximately 70%-80% maltose. Regular and high-maltose syrups are widely used as flavorings for breakfast cereals, beverages, and other food products (Table 13.2 Hoobs 2003, Serna-Saldivar 2004). 

When producing maltose syrups, why does the addition of pullulanase or debranching enzyme significantly increase maltose content What are the major food uses of regular and high-maltose syrups ... 

Acting together with either - debranching enzymes (pullulanase, isoamylase) in fixed bed or with soluble amylose of low m.w. as substrate it is possible to produce maltose syrups of 70-90%. For crystallization the syrups are emiched in m. content to 95% by various fractionation techniques, such as carbon column or cation-exchange chromatography, solvent precipitation, membrane separation or combinations of the latter with ultrafiltration. 

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