Real World: Vitamin C Concentration in Orange Juice and Grapefruit

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Transcript Real World: Vitamin C Concentration in Orange Juice and Grapefruit

  Cannot be stored in body, needs to be replenished regularly Promotes healthy cell development, normal tissue growth and repair, and helps in absorption of calcium.

   Vitamin C is lost in foods easily, so it is best to eat fruits and vegetables in raw form Scurvy -disease caused by lack of vitamin C It’s an antioxidant, helps protect body against contaminants

     DCPIP(2,6 – dichlorophenol-indophenol) can be used as an indicator for ascorbic acid. DCPIP turns clear when it is oxidized by the orange juice. When there is excess DCPIP, it no longer turns clear and dyes the sample purple. 1% DCPIP solution added to juice until color change occurred The amount of DCPIP added was recorded Taking into account the amount of vitamin C there should be in the juice based on daily value, the theoretical and actual values of Vitamin C were calculated

 Theoretical › › › › Total volume of container Amount of servings 100% daily value Volume of juice used  Experimental › › › 1% DCPIP solution mL of DCPIP added, gives grams of DCPIP 1:1 mol ratio

Theoretical:

Theoretical grams of Vitamin C X Servings= grams vitamin C per bottle

Fresh Squeezed Orange Juice:

0.124g X 2 servings=0.248g vitamin C per bottle

Experimental:

Total volume in bottle/volume added=theoretical grams vitamin C/grams vitamin C in sample

Fresh Squeezed Orange Juice:

473mL/10.31mL=0.248g/x X=0.0055g

Orange Juice Conc. (10 mL) Orange Juice Freshly Squeezed (10 mL) Grapefruit Juice Conc. (25 mL) Grapefruit Juice Freshly Squeezed (25 mL)

Vitamin C Theoretical (g) Vitamin C Actual (g)

  In all juices, there was almost double the theoretical amount of vitamin C Reason?

› Companies want to make sure that they have at least the amount of vitamin C in their juice that they claim › Too much is not a bad thing

 25mL of juice samples were titrated with an iodine solution until the endpoint was reached. A 1% starch indicator was used as the indicator  The amount of vitamin C was calculated and compared based on daily values for each juice

Total mL iodine added Grams of vitamin C

Fresh Squeezed Orange Juice

Trial One 10.41mL

0.0055g

Trial Two 10.27mL

0.0054g

Total mL iodine added Grams of vitamin C

Orange Juice from Concentrate

Trial One Trial Two 7.11mL

7.19mL

0.00180g

0.00182g

Trial Three 10.24mL

0.00537g

Trial Three 7.34mL

0.00186g

Total mL iodine added Grams of vitamin C

Fresh Squeezed Grapefruit Juice

Trial One 7.14mL

0.00283g

Trial Two 7.24mL

0.00287g

Total mL iodine added Grams of vitamin C

Grapefruit Juice from Concentrate

Trial One 7.38mL

Trial Two 7.11mL

0.00187g

0.00181g

Trial Three 7.33mL

0.00291g

Trial Three 7.24mL

0.00184g

  Fresh squeezed orange juice has the highest Vitamin C concentration Fresh squeezed juices have a higher vitamin C concentration than juice from concentrate

    3 samples of each juice were titrated with standardized NaOH pH level were measured each addition of NaOH Calibration curve were made pH calculated for each juice › Used the curve to estimate equivalence point › Another way: change in volume vs. pH

mL of base added vs. pH Orange Juice (conc.) Trial #1

11,5 10,5 9,5 8,5 7,5 6,5 5,5 4,5 3,5 0 3 6 9 12 15 18 21 24

Amount Added (mL)

27 30 33 36 39

mL of base added vs. pH Orange Juice (Freshly Squeezed) Trial #1

11,5 10,5 9,5 8,5 7,5 6,5 5,5 4,5 3,5 0 3 6 9 12 15 18 21

Amount added (mL)

24 27 30 33 36

10,5 9,5 8,5 7,5 6,5 5,5 4,5 3,5 2,5 0 4

mL of base added vs. pH Grapefruit Juice (conc.) Trial #1

8 12 16 20 24

mL NaOH added

28 32 36 40 44

11,5 10,5 9,5 8,5 7,5 6,5 5,5 4,5 3,5 0 4

mL of base added vs. pH Grapefruit Juice (Freshly Squeezed) Trial #1

8 12 16 20 24 28

mL NaOH added

32 36 40 44 48

Orange Juice (Conc.) Trial 1 Trial 2 Trial 3 Average E.P. (mL)

23.26

23.60

23.40

23.42

pH

8.00

8.40

7.50

7.97

Total Acidity

0.0963M

E.P.

(mL) Grapefruit Juice (Conc.) pH Total Acidity Orange Juice (Fresh Squeezed) E.P. (mL)

23.50

22.50

22.80

22.93

pH

8.25

8.10

7.82

8.06

Total Acidity

0.0943M

E.P.

(mL) Grapefruit Juice (Fresh Squeezed) pH Total Acidity Trial 1 Trial 2 Trial 3 Average

35.50

36.50

37.20

36.40

7.00

7.20

6.90

7.03

0.1497 M 38.00

37.40

37.40

37.60

8.36

8.60

8.50

8.49

0.1546M

 Freshly squeezed juices had a higher pH than the juices from concentrate  Grapefruit juice more exaggerated relationship  Freshly squeezed juices are more acidic

All experiments showed that freshly squeezed juices had more vitamin C

Two of three: orange juice had most

Juice Orange Juice Conc. (10 mL) Orange Juice Freshly Squeezed (10 mL) Grapefruit Juice Conc. (25 mL) Grapefruit Juice Freshly Squeezed (25 mL) Juice Orange Juice Conc.

Orange Juice Freshly Squeezed Grapefruit Juice Conc. Grapefruit Juice Freshly Squeezed Average (mL)

Iodine Titration

Vitamin C Theoretical (g) 7.21

0.00180

10.31

7.24

0.0055

0.00187

7.24

DCPIP

Average (mL) 0.90

3.40

2.33

2.53

Vitamin C Theoretical (g) 0.00283

0.00254

0.01310

0.00630

0.00990

Vitamin C Actual (g) 0.00591

0.02230

0.01530

0.01660

Vitamin C Actual (g) 0.001827

0.00542

0.00184

0.00287

    http://www.fitnesshealthzone.com/vitamins supplements/importance-of-vitamin-c/ http://www.practicalbiology.org/areas/advan ced/health-and-disease/whats-in-our food/measuring-the-vitamin-c-content-of foods-and-fruit-juices,53,EXP.html

http://en.wikipedia.org/wiki/Dichlorophenolind ophenol http://www.google.com/#sclient=psy&hl=en& q=Determination+of+the+Total+Acidity+in+Ora nge+Juice&aq=f&aqi=&aql=&oq=&gs_rfai=&p bx=1&fp=fae64975a117d0cd