FS&T 101BEmulsions

LAB REPORT

TITLE Michael Manning02/26/15Lab section (Group F)

DATA

Figure 1. Commercial Mayonnaise. This picture represents the fat emulsion that is created in commercial mayonnaise.

Figure 2. Group B’s Mayonnaise. This pictures represents the fat emulsion created in the production of mayonnaise in class.

Figure 3. Commercial Salad Dressing. This picture shows the emulsion of fat in commercial salad dressing.

Figure 4. Group F’s salad dressing. This picture shows the large bubbles of fat emulsion created in their salad dressing.

Table 1. Observation of three different emulsions of oil in water during an hour long duration.

Emuls Immediate 2 min 5 min 10 min 30 min 60 minA Blended

emulsion, w/ a lot of foam on top

No change Small amount of oil precipitate

More oil precipitate

Increased oil precipitate

Increased oil precipitate

Oil Phase:(zero) mL

Oil Phase:(zero) mL

Oil Phase:0.5 mL

Oil Phase:9 mL

Oil Phase:14 mL

Oil Phase:19 mL

Interphase:91 mL

Interphase:91 mL

Interphase:90.5 mL

Interphase:82 mL

Interphase:77 mL

Interphase:72 mL

B Blended emulsion w/ some foam on top

No change Small amount of oil precipitate

No change Water precipitate

More water precipitate

Oil Phase:(zero) mL

Oil Phase:(zero) mL

Oil Phase:0.5 mL

Oil Phase:0.5 mL

Oil Phase:0.5

Oil Phase:0.5 mL

Interphase:92 mL

Interphase:92 mL

Interphase:91.5 mL

Interphase:91.5 mL

Interphase:72.5 mL

Interphase:56.5 mL

C Blended emulsion w/ no foam on top

No change No change No change Small amount of water precipitate

More water precipitate

Oil Phase:(zero) mL

Oil Phase:(zero) mL

Oil Phase:(zero) mL

Oil Phase:(zero) mL

Oil Phase:(zero) mL

Oil Phase:(zero) mL

Interphase:100 mL

Interphase:100 mL

Interphase:100 mL

Interphase:100 mL

Interphase:98 mL

Interphase: 94 mL

CALCULATIONS

Calculate the percentage of fat in your mayonnaise and salad dressing. Assume that only the egg yolk and vegetable oil contain fat. Assume that egg yolk is 32% fat and vegetable oil is 100% fat. Assume also that the density of vinegar is 1g/mL.

Mayonnaise158.00g of Mayo (assuming 15g for 15mL of vinegar)Egg yolk = 14g14g * 0.32 = 4.48g of fat from egg yolkVegetable oil = 126g126g * 1.00 = 126g

4.48g + 126.00g = 130.48g of fat from Mayo

(130.48/158.00g) * 100 = 82.58% fat in Mayo

Salad Dressing177.91g (WEIGHED in class)0.5 cups of olive oil ~107.81g

(107.81g/177.91) * 100 = 60.60%

QUESTIONS (10pts each, 40 total)

1. Discuss the difference between three water/oil emulsions, in terms of the change of volume in water phase, oil phase and interphase over time. Do the emulsifiers function as expected?

The first emulsion we did was just oil and water. After blending together we got a large amount of foam formation at the top past the measurement markers of the 100 mL graduated cylinder. The emulsion stayed in matrix until minute five where we began to see a small amount of oil at the top layer between the foam and mixture. The oil made a dramatic increase from 5 minutes to 10 minutes going from 0.5 mL of oil to 9 mL of oil. This process of decreasing foam and increasing oil precipitation layer went on throughout the remainder of the experiment until one hour in where the final volume was 19 mL.

The second emulsion included oil and water but we added an egg yolk as well. After blending there was again foam at the top but much less. We experienced no oil in the beginning until 5 min in (similarly to the first experiment (experiement A); however, instead of increasing oil precipitation, we saw water precipitate. The oil was again on top of the mixture but the oil stayed consistent at 0.5 mL the entire hour while the water increased in volume. At 5 minutes and 10 minutes we still saw no sign of water but at 30 minutes, at the bottom of the mixture was a layer of water, 19 mL. The next

measurement at one hour the water precipitation at the bottom of the mixture emulsion had increased to 35 mL.

The third experiment included the same ingredients with added Critical Micelle Concentration (CMC). This emulsion had no foam and no oil formation. Our emulsion stayed at 100 mL until our measurement at minute 30 where 2 mL of water formed at the bottom and then at 60 minute another 4 mL of water had formed leaving the volumes of emulsion and water precipitate at 94 mL and 6 mL respectively.

Yes, emulsifiers work how we would expect since they contain molecules that act as decrease the activity of surfactants and allowed molecules to increase repulsive tension.

2. Could the mayonnaise and salad dressing be labeled as such in the USA? Explain why or why not. (Please refer to the “Code of regulation” on Smartsite)

No, mayonnaise and salad dressing could not be labeled as such in the USA since the regulations state that:1) Mayonnaise is not to exceed 65% vegetable oil by weight and our mixture is

79.75% vegetable by weight.2) Salad dressing is not to exceed 30% by weight of vegetable oil by weight and out

mixture is 60.60% by weight. If the regulation of specific food items does not meet the specific requirements of the FDA’s CFR Title 21 food regulations, than the food item cannot be called by certain labeled names. This is similar to the argument for companies wanting to call a product chocolate when there is no cocoa butter in it. If it does not contain chocolate, or any of the other ingredients necessary it cannot be called chocolate.

3. From observing your microscope pictures, compare the oil droplet size and oil droplet packing density: (why differences?)

If we take a look at the commercial mayo, the packing density of the dispersed phase is much greater and the oil droplet size is much smaller and uniform than in group B’s where the oil droplets are much more spread out and the oil droplet sizes are much different in size (some larger than others).

For salad dressing we see a similar pattern where the commercial salad dressing is more uniform in size and although from the slides the packing density may be different and increased in the salad dressing from group F, that may be because it was recently mixed or the slide was just a better slide in one of the other.

Either way, mayo has, and should have, a higher packing density and smaller oil droplet size. This is because more energy goes into the emulsion process which breaks down the oil droplet sizes and with the emulsifying agents, leaves the oil in the dispersed phase around the continuous phase.

4. The principle formulation difference between caramel and fudge is the ratio of sucrose to corn syrup. a. What is a doctor in a candy formulation? In our formulations what was the doctor.

A doctor is an invert sugar and in our formulations the doctor was corn syrup. b. How did the ratio of doctor to sucrose influence the final structures of the two

candies?The increase in corn syrup to sugar ratio increases the corn syrup molecules getting tangled up with each other and decreasing sucrose’s crystallization so there is not a grainy texture.