Carbohydrates Flashcards
General test for Carbohydrates
Molisch’s Test
Reagent and positive result for Molisch’s Test
Reagent: [5% α-naphthol + 95% ethanol] + conc. H2SO4 Sulfuric Acid
+ result: violet ring
Test for reducing sugars
Benedict’s Test
Reagent and positive result Benedict’s Test
Reagent: CuSO4 + Na2CO3 + Na citrate
+ result: brick red ppt. ( - suc, fruc)
Test to detect monosaccharides
Barfoed’s Test
Reagent and positive result for Barfoed’s Test
Reagent: CuSO4 + acetic acid
+ result: red/brown ppt (5mins for mono) (Fru, Gal, Arab, Glu)
Test to distinguish ketose from aldose
Seliwanoff’s Test
Reagent and positive result for Seliwanoff’s Test
Reagent: conc. HCl + 1, 3 - dihydroxybenzene (resorcinol)
+ result: cherry-red sol ketose (suc, fruc)
Test to distinguish pentose from hexose
Bial’s (Orcinol) Test
Reagent and positive result for Bial’s (Orcinol) Test
Reagent: Orcinol (5-methyl-1, 3-dihyroxybenzene)
+ result: blue to green sol. (Pentose; Arab); brown (hexose)
Test to detect galactose
Galactaric (Mucic) Acid Test
Reagent and positive result for Mucic Acid Test
Reagent: conc. Nitric Acid
+ result: white ppt.
Test for starch
Iodine Test
Reagent and positive result for Iodine Test
Reagent: I2/Kl
+ result: blue color
Test for presence of α-linked disaccharide
Fermentation Test
