Dextrose equivalency starch hydrolyzate

Currently, only hydrolases (amylases) are used to modify starch. The use of amylases to produce products derived from hydrolysis of starch is described in Chapters 7,20, 21 and 22. Starch hydrolyzates with good adhesion property that can be applied at high solids to minimize the energy required to remove moisture after application are very desirable for coating food items with seasonings, flavors and colorants. This property can be achieved by treating starch with an amylase or amylases to a dextrose equivalency (DE) (see Chapter 21) of 2-40.228 Waxy maize is the preferred starch. 

Both processes use starch (com, potato, rice, wheat, etc.) as the substrate. Com and potato starches are most commonly used. In both processes, the starch is hydrolyzed to a dextrose equivalent (DE) of 3 to 8 (see Chapter 21) prior to use.25 If liqui-faction/hydrolysis is not sufficient, retrogradation occurs. This limits the availability of substrate, resulting in low yields of cyclodextrins, and interferes with later recovery steps. If the starch is over-hydrolyzed, the disproportionation reaction dominates and yields of cyclodextrins are low. If an a-amylase is used to hydrolyze the starch, it must be inactivated by acidification, raising the temperature, otherwise, the yield will be greatly reduced. 

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... 

The properties and subsequently the applications of the resulting corn syrup products, were dependent upon the extent of hydrolysis. The extent of hydrolysis in corn syrup is expressed in dextrose equivalents (DE) which is the percentage of glucosidic bonds hydrolyzed with native starch being 0 and pure glucose being 100. The DE of acid-catalyzed corn syrups depend only upon the time of reaction. All acid-catalyzed syrup at any single DE level will always have the same dextrin profile. 

Chemical Properties. From the food standpoint, probably the most important chemical property of the starch hydrolyzates is fermentability. Dextrose, of course, is well known to be readily fermentable by most organisms. Maltose, likewise, is generally readily fermentable. Thus the total of these two sugars roughly defines the fermentability of a hydrolyzate. Physical conditions permitting, the higher the dextrose equivalent, the higher the fermentability. 

Commercial g. are produced in various degrees of hydrolysis (- dextrose equivalent, DE), ranging from >20% DE to <80% DE the latter is termed starch hydrolyzate and consists largely of - dextrose. G. of DE <30% are available as spray-dried, hygroscopic, white powders dried glucose syrup or - solid glucose. 

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