What Happens During The Benedict Test For Reducing Sugars?

During the benedict test for reducing sugars, positive colour changes resulted in the contents of the test tube changing to a yellow-green or orange-brown colour indicating the presence of a reducing sugar. Test tubes 1,3,4,6 and 10 respectively, 1% glucose, maltose solution, honey solution, lactose solution and beer reacted positively to this colour change.
Sugars that comprise of aldehyde groups that can experience oxidation to wind up carboxylic acids are categorized as reducing sugars (Shankara, 2008). All monosaccharide's and disaccharides can be oxidized (Shankara, 2008). When the cyclic structure is opened, the aldehyde group is accessible for oxidation (Shankara, 2008). The Benedict's reagent comprises of Cu2+ particles that are lessened (Shankara, 2008). Ketoses likewise go about as reducing sugars because the ketone bunch on carbon 2 isomerizes to give an aldehyde group on carbon 1 (Shankara, 2008). At the point when oxidation of a sugar happens, the Cu2+ is lessened to Cu+, which creates a red cuprous oxide precipitate, Cu2o as seen in test tubes 1 and 3 (Shankara, 2008).

Although sucrose is a disaccharide it cannot return to an open chain structure in its cyclic structure that would give the aldehyde group required to reduce the cupric ion, and therefore is not a reducing sugar (Shankara, 2008). Test tubes 1,3,4,6 and 10 all brought about a positive change for the Benedict test, however demonstrated a slight range in colour. Test tubes 1, 3, and 10, containing 1% glucose result, 1% maltose result and beer respectively showcased a more yellow colour, showing that there were low traces of reducing sugars. Test tubes, 4 and 6 containing honey solution and lactose solution respectively showcased a more brown shade, indicating that there was a moderate amount of reducing sugars