Maltose A -

Wort. Wort is the Hquid drained off the mash tun containing maltose, a grain sugar derived from the conversion of starch during the mashing process by the action of the organic enzyme, maltase, found in badey malt. 

Maltose, a decomposition product of starch, is a dimer of two glucose molecules. These are combined head-to-tail carbon atom 1 of one molecule is joined through an oxygen atom to carbon atom 4 of the second molecule. To form maltose, the two OH groups on these carbon atoms react, condensing out H20 and leaving the O atom bridge. 

Saliva begins the process of chemical digestion with salivary amylase. This enzyme splits starch molecules into fragments. Specifically, polysaccharides, or starches, are broken down into maltose, a disaccharide consisting of two glucose molecules. Salivary amylase may account for up to 75% of starch digestion before it is denatured by gastric acid in the stomach. 

If starch is mixed with saliva and left to stand for a few minutes, it will break down to maltose, a disaccharide (that is two joined monosaccharides). The enzyme present in the saliva, called amylase, catalyses this hydrolysis reaction. 

Although the findings presented in Table 13.2 and Figure 13.6 indicate excellent selectivity, a more rigorous analysis of selectivity is warranted given the chemical similarity and extreme spectral overlap between glucose, sucrose, and maltose. A pure component selectivity analysis (PCSA) can be used to further characterize the selectivity of the PLS calibration model.31,37... 

Figure 5.2 Optical-density variation at 575 nm as a function of maltose (a) and glucose (b) concentration.

Figure 9.7 Structures of some sugars. (A) L-Fucose (pyranose form). Note that the -CH3 group points downward this indicates l series in the Haworth structural convention. (B) Maltose (a-D-glucopyranosyl-l,4-D-glucopyranose) (C) cellobiose (/3-D-glucopyranosyl-1,4-D-glycopyranose) and (D) sucrose (a-D-glucopyranosyl-l,2-/3-D-fructofuranoside). (Reproduced by permission from Diem K, Lentner C. Scientific Tables. Basel Ciba-Geigy, 1971.)...

The maltose molecule is too small to be fitted conveniently into the molecular barrier hypothesis, but the receptor for this substance functions well with maltodextrins which do have higher molecular weights. The receptor is induced with maltose, a substrate which is doubtless commonly encountered in the diet of enteric bacteria. Biologically the receptor serves for transport of maltose and for chemotaxis to this substrate (72). The data presented in Table IV, especially that pertaining to the ferrichrome receptor, demonstrate convincingly that phage receptors were designed for nutritious substances. 

Maltose, a disaccharide formed by the hydrolysis of starch, is found in germinated grains such as barley. Maltose contains two glucose units joined together by an a-1.4 -glycosidebond. 

Figure 11.10. Maltose, a Disaccharide. Two molecules of glucose are linked by an a -1,4-glycosidic bond to form the disaccharide maltose.

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