1. Determine the amount of fat from the food sample. Use this value to calculate

Question

1. Determine the amount of fat from the food sample. Use this value to calculate:

a) The amount of fat per serving of the food sample. Be sure to compare this value to the fat per serving stated on the food package label.

b)The percent recovery of fat based on the amount of fat per serving on the package.

2. Utilizing the H NMR spectrum of the extracted fat and the equations provide calculate:

a. The percent of saturated fat

b. The percent of unsaturated fat

c. The percent of monosaturated fat

d. The percent of polyunsaturated fat

Experimental NMR

http://postimg.org/image/wl2o0tmy7/full/

Fat Equations

http://postimg.org/image/4md3npapb/

Food Package label

http://postimg.org/image/b2m2dsj8v/

Given NMR

http://postimg.org/image/k94d12ohb/

Explanation / Answer

1.a) Manufacturers usually round the numbers on the Nutrition Facts label to the nearest whole number. For example, a food with 0.6 g of fat per serving and another one with 1.4 g of fat per serving will both list 1 g of fat per serving on the label. So the true fat percentage of our turkey could be anywhere from 2% to 5%.

b) Esterification Procedure :

Dissolve the fat contained in the vials by adding 3 mL chloroform followed by 3 mL diethyl ether and transfer this solution to a pressure tube. Wash the vial a second time with chloroform and ether to ensure complete transfer of the hydrolyzed fat to the pressure tube. Evaporate the chloroform/ether mixture to dryness. Once dry, add 2 mL 12% BF3 in methanol and 1 mL toluene to the pressure tube. Seal the tube and place in an oven set to 100 °C for 55 min, shaking gently every 10 minutes. Allow the tube to cool to room temperature. Add 5 mL H2 O, 2 mL hexane, and 1 g Na2 SO4 to each tube. Shake or vortex for 1 minute. Allow the two layers to separate, decant the top (hexane) layer and transfer it to a 40 mL vial containing 1 g Na2 SO4 . Add a second 2 mL portion of hexane to the pressure tube. Shake or vortex for 1 minute. Again, allow the layers to separate, decant the top layer and transfer to the vial containing 1 g Na2 SO4 and the first hexane portion. Accurately measure a final volume of the hexane/ toluene mixture before analysis by GC/MS. This value will be used to calculate the amount of fat found in the samples.

2.

a) Fat:

a. Multiply the grams of fat by 9* = (x) the number of fat calories.

b. Divide (x) the number of fat calories by the total number of calories in the food item = % fat content. * 1 gram of fat contains 9 calories (kcal)

Fat – 3 x 9 = 27 fat calories 27/90 = 30% total fat.

b) Saturated Fat:

a. Multiply the grams of saturated fat by 9 = (xx) the number of saturated fat calories in the food item. b. Divide (xx) the number of saturated fat calories in the food item by the total number of calories in the food item = % of saturated fat.

Saturated Fat – 0 x 9 = 0 0/90 = 0% saturated fat.

c) 10 to 15% of your daily calories from monounsaturated fat

d) no more than 10% of your daily calories from polyunsaturated fat

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.