reducing sugars

• What reagent can be used to test for the presence of reducing sugars?

  benedict's reagent
• what are some reducing sugars?

  all monosaccharides and some disaccharides (eg maltose)

  • these are therefore sugars that can DONATE AN ELECTRON to the Benedict's reagent
• what is Benedict's reagent?

  an alkaline solution of Copper (II) Sulphate
• What happens when a reducing sugar is added to Benedict's solution and heated?

  it forms an insoluble red precipitate - copper (I) oxide.
• summarise the Benedict's test?

  1. add 2cm^3 of the food sample to be tested (needs to be in LIQUID FORM to begin with)
  2. add 2cm^3 of benedict's reagent
  3. heat mixture gently in a water bath for 5 minutes.
  4. positive result- mixture turns brick red - reducing sugar present