ASH- MINERAL CONTENT

EQUIPMENT

CRUICABLE

PIPE CLAY TRIANGLE

TRIPOD

BUNSEN BURNER

FOOD SAMPLE

HEAT PROOF MAT

TONGS

AIM

The aim of this experiment is to obtain the ASH/Mineral content of food samples

ASH

Experiment / Method

Obtain equipment and

PPE

Weight crucible and record

weight

Add food sample to

crucible and weigh again, record new

weight

Light bunsen burner and

place crucible on top of pipe clay triangle

Burn till only ASH remains

Remove crucible and weigh

Weighting the crucible twice is necessary as once the sample has burned only ASH will remain and it will be too difficult to remove from the crucible at this stage. So subtracting the individual crucible weight form the combined weight will give the weight on just the food sample.

Repeat for each sample

Experiment/ Method

Use only small food sample as this will burn quicker

Burn times will differ depending on the sample used due to its content

Same scales used Same oven is used – same

temperature Individual weights of each crucible

taken to allow for differences

Calculations

1, Combined weight of crucible and food sample - Original weight of crucible = Original Food sample weight

2, Combined weight of crucible and food before burning - combined weight of both after burning = Weight of food sample after burning

C = CRUCIBLE FS = FOOD SAMPLECWB = COMBINED WEIGHT BEFORECWA = COMBINED WEIGHT AFTERFSB = FOOD SAMPLE BEFOREFSA = FOOD SAMPLE AFTER

Ash content is the difference between the food sample end weight (obtained from calculation 2 on previous slide) and original food weight.

RESULTS

Sample Crucible

Food sample

CWB CWA DIFFERENCE(CWB/CWA)

DIFFERENCE(FSB/ FSA)

Bakers Puppy

16.5G 2.4G 18.54G

16.21G

2.33G 0.07G

Royal Canin

19.9G 1.8G 21.7G 20.05G

1.73G 0.07GAsh content as a percentage = Difference between FSB & FSA divided by the Original food sample multiplied by 100Combined Weight before – dish weightCombined weight after - Dish weight x 100

Bakers puppy = 0.07 / 2.4 x 100 = 2.92 %Royal Canin = 0.07 / 1.8 x 100 = 3.89 5

There is 2.92 % ASH or mineral content in Bakers puppy and 3.89% in royal canin.

Conclusion/ Evaluation

This is obviously a very basic method, to achieve more Accurate results professionals would use a furnace that would burn at extremely high temperatures for a longer period of time to ensure absolutely everything that could burn away had. It may have been beneficial to burn the same amount of food sample and possibly to even use the same crucible as these all had some slight differences in weight. To check how accurate the results where they could be compared to those on the back of the food labels.