Question

How do you measure the concentration of reducing sugars?

Answer 1

Hint: We know that this is made naturally by green plants and some photosynthetic forms of algae and is considered to be the most abundant form of a monosaccharide sugar. Similarly, sucrose may be a disaccharide during which the aldehyde radical of glucose is employed up in forming a bond between glucose and fructose.

Complete step by step solution:
Any sugar is said to be a reducing sugar if it is capable of acting as a reducing agent because it has a free aldehyde group or a free ketone group. Along with some disaccharides, some oligosaccharides, and some polysaccharides, all monosaccharides are reducing sugars. Glucose has a free aldehyde group which can be oxidized to the acidic groups. Hence, glucose is a reducing sugar. The glucose in starch and cellulose doesn't contain a free aldehyde radical and hence, starch and cellulose don't act as reducing sugars.
Reducing sugar is any sugar that's capable of acting as a reducer because it's a free aldehyde radical or a free group. All monosaccharaides are reducing sugars, alongside some disaccharides, some oligosaccharides, and a few polysaccharides. The monosaccharides are often divided into two groups: the aldoses, which have an aldehyde radical, and therefore the ketoses, which have a group.
Benedict's solution is a deep-blue alkaline solution of stabilized \[C{{u}^{2+~}}\] ions. It oxidizes aldehyde groups to carboxylate ions, and the \[C{{u}^{2+~}}\]ions are reduced to a brick red precipitate of \[C{{u}_{2}}O.\]
\[RCH{{O}_{\left( aq \right)}}+\underset{deep\text{ }blue}{\mathop{\left[ Cu_{(aq)}^{2+} \right]}}\,+OH_{(aq)}^{-}\xrightarrow{{}}RCOO_{(aq)}^{-}+\underset{brick\text{ }red}{\mathop{\left[ C{{u}_{2}}{{O}_{(s)}} \right]}}\,+3{{H}_{2}}O\]
Heating the unknown to about \[95{}^\circ C\] with Benedict's solution leads to the formation of a brick-red precipitate that indicates the presence of a reducing sugar. We treat your unknown and a standard set of solutions containing known concentrations of glucose with standard Benedict's solution. We remove the precipitate and measure the intensity of absorption in a colorimeter. A calibration graph prepared from the glucose solutions enables you to determine the concentration of your unknown.

Note:
Remember that the aldehyde functional group allows the sugar to act as a reducer, for instance, within the Tollens' test or Benedict's test. The cyclic hemiacetal sorts of aldoses can hospitably reveal an aldehyde, and certain ketoses can undergo tautomerization to become aldoses. However, the acetals, including those found in the polysaccharide linkages, cannot easily become free aldehydes. Reducing sugars react with amino acids within the Maillard reaction, a series of reactions that happens while cooking food at high temperatures which is vital in determining the flavor of food.