Identification of Food Constituents Essay

Method ( proving for cut downing sugars ) 1. Add 3cm? of whole milk. by utilizing a pipette or syringe to the trial tubing. 2. Add 5cm? of Benedict’s reagent and topographic point it in the boiling H2O bath for 8 proceedingss. Do the same for semi-skimmed milk and skimmed milk. 3. Once all 3 of the trial tubing are left to chill in the air. detect the colors. It will be a good thought to put up a scope of coloring material criterions from glucose concentrations of 1 % . 2 % . 3 % . 4 % and 5 % so that you can associate the colorss observed to these concentrations. 4. A positive consequence would be from green to yellow to brick-red coloring material.

Method ( proving for non-reducing sugars ) 5. Make up the same solution as measure 1 but this clip. adding 3cm? of dilute hydrochloric acid to interrupt the glycosidic bonds between the monosaccharoses. 6. Then add 3cm? of Na hydrated oxide solution to neutralize it. 7. Add 5cm? of Benedict’s reagent and topographic point it in the H2O bath for 8 proceedingss. 8. Once it’s left to chill. it should now turn brick-red coloring material. 9. The concentration of a non-reducing sugar can be estimated by first adding a bead of 10 % saccharase ( invertase ) dressed ore to 2cm?

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

of the solution to be tested and go forthing for 30 proceedingss at room temperature. The solution is tested for the presence of a reduction sugar. This method is preferred to acid hydrolysis. Method ( proving for amylum ) 10. On each of the three types of milk. merely add a few beads of I which is dissolved in K iodide solution. 11. The sample should alter from browny-orange. to a dark. bluish black coloring material. Method ( proving for proteins ) 12. Topographic point 2cm? of the three different types of milks on each tubing. 13. Then add 2cm? of Biuret reagent and you should see a purple-violet coloring material development.

The strength of it is relative to the protein content. Method ( proving for fats ) 14. Add 3cm? of the three different types of milk on each trial tubing and 3cm? of H2O. 15. Topographic point 1 bead of Sudan III to each trial tubing and agitate gently to blend. 16. Using a microscope. a slide and a screen faux pas. place any emulsion of ruddy fat droplets. 17. Alternatively. you could add a bead of each of the milk on a filter paper and see if there is a semitransparent discoloration for a positive consequence. Consequences table Solution ( Milk ) TestObservationsConclusion

SkimmedBenedict’sLime green ( lightest ) A little sum of monosaccharoses or cut downing sugars present Semi-skimmedBenedict’sLime viridity ( igniter ) A little sum of monosaccharoses or cut downing sugars present WholeBenedict’sLime greenA slight sum of monosaccharoses or cut downing sugars present SkimmedInvertaseYellowish-greenHardly any monosaccharoses or cut downing sugars present Semi-skimmedInvertaseYellowish-greenHardly any monosaccharoses or cut downing sugars present WholeInvertaseYellowish-greenHardly any monosaccharoses or cut downing sugars present SkimmedBiuretViolet purpleProtein nowadays.

Semi-skimmedBiuretPurpleLot’s of protein present WholeBiuretLight purpleProtein present Conclusion If there were to be a just sum of monosaccharoses to be present all 3 different types of milk. so we would certainly see a brick-red precipitate formed when adding the Benedict’s reagent. But harmonizing to my scope of coloring material criterions from glucose ( monosaccharose ) concentrations. the lime-green coloring material given out from each of the 3 milks shows us that it does incorporate a minor sum of monosaccharoses ( cut downing sugars ) .

Adding a bead of saccharase usually should interrupt the glycosidic bonds that are keeping the disaccharides together to organize monosaccharoses. But my consequences show that it’s a yellowish-green coloring material alternatively of a brick-red coloring material after adding Benedict’s reagent. This shows us that there is barely any disaccharides present which I thought there would be as lactose. a disaccharide. is largely present in milks. But this consequence may hold a different position on that. The fact that all 3 milks turned violet after adding Biuret reagent assures us that there is protein present.

If there is protein present. that means there is starch present excessively because amylum and proteins are polyoses. Evaluation It is noticeable that I haven’t done the trial for amylum and fats. This is merely due to the fact that I run out of clip. Using a 5cm? micro syringe would be more accurate than a pipette. When a precipitate is settled. I could hold used a swayer to mensurate it out ( in millimeter ) alternatively of merely utilizing my eyes. Even better. utilizing tintometer would hold provide accurate measurings on the sum of color nowadays and hence. give us an indicant of how much of the nutrient components were present.