Several airs were prepared and stability was measured. Results of

backscattering for different positions of the tube can be represented versus

time. Only as some examples, in figures 8-10 backscattering evolution with

time for different systems are shown.

A. Rheological measurements

Emulsions in novel foods: new textures and new formulations for protein allergic groups

Aguilera, Y.1, Gutiérrez, J. M.1, Maestro, A.1, Castells, P.2, Farré, I.2, Biarnés, J.2, and González, C.1

1 Departament d’Enginyeria Química, Universitat de Barcelona; 2 Fundació Alicia

Tlf: 34 93 402 9013 Fax: 34 934021291 e-mail: carme.gonzalez@ub.edu

A quite stable highly concentrated emulsion of olive oil in water, with texture, color and flavor similar to that of

conventional mayonnaise can be obtained without egg nor milk, using edible surfactants as lecithin and monodiglycerid.

Light foams with enough stability and quite homogeneous can be prepared with lecithin or sucroesters as surfactants

and a variety of foods:

AcknowledgmentFinancial support from CYCYT CTQ2005-09063-C03-01/PPQ is

gratefully acknowledged.

Results and discussion

Conclusions

Substitute of mayonnaise Foams

For all the emulsions a clear predominance of storage modulus is observed, indicating that the elastic component

predominates. As an example, the sample with an O/W ratio of 3/1 and 1wt% L+4wt%MDG is shown in Figures 3 and 4.

This sample was the most similar to the conventional mayonnaise. Higher G’ and G” values are found at 4ºC, pointing out

that emulsions are more stable when stored in the fridge. The rheological parameters also increase with the O/W ratio, as

expected for an oil-in-water emulsion. G’ and G” increase with total concentration of surfactants, according to the

formation of more but smaller droplets when this concentration increases.

B.Stability

The stability of emulsions was measured for all the samples. It can be seen that the stability increases when O/W

decreases (Fig.5 and 6), since less dispersed phase is present and coalescence is less favored. However, these samples

are unsalted. If salt is added to that samples, they become quite unstable due to coalescence (Fig.7), at least after the first

hour. Then, salt should be added just some minutes before the serving of the dish.

Introduction.There are some groups of people that are allergic or intolerant to different

foods, like those allergic to proteins (phenylcetonurics), or to other products. It

is important to find some foods similar to the conventional ones in flavor,

aspect and texture, but without including the components that they cannot eat.

On the other hand, it seems to be important to obtain new textures in food that

can be highly appreciated by consumers as products for high gastronomy. For

both purposes, edible surfactants can be useful. In this communication we

present formulations where edible surfactants are included, on the one hand to

obtain a substitute of mayonnaise without egg or milk, where mono-diglyceride

(MDG) and lecithin (L) are used as surfactants, and on the other hand for

obtaining foams, where lecithin and sucroesters (SE) are used instead.

G' vs. . Several %L:%MDG ratios. T=4ºC and 20ºC

1

10

100

1000

10000

0.01 0.1 1 10 100

[rad/s]

G' [P

a]

0.5wt% L:2%MDG, 20ºC 0.5wt% L:2%MDG, 4ºC0.75wt% L:3%MDG, 20ºC 0.75wt% L:3%MDG, 4ºC1wt% L:4%MDG, 20ºC 1wt% L:4%MDG, 20ºC

O/W=3/1

G" vs. . Several %L:%MDG ratios. T=4ºC and T=20ºC

1

10

100

1000

10000

0.01 0.1 1 10 100

[rad/s]

G" [

Pa

]

0.5wt% L:2%MDG, 20ºC 0.5wt% L:2%MDG, 4ºC

0.75wt% L:3%MDG, 20ºC 0.75wt% L:3%MDG, 4ºC

1wt% L:4%MDG, 20ºC 1wt% L:4%MDG, 4ºC

O/W=3/1

Fig. 1. G’ of frequency sweep emulsions several O/W. T=20ºC and 4ºC. 1%wt L+4%wt MDG.

Fig. 3. G’ of frequency sweep emulsions at several %L:%MDG. T=20ºC and 4ºC. O/W=3/1.

Fig. 4. G” of frequency sweep emulsions at several %L:%MDG. T=20ºC and 4ºC. O/W=3/1.

Fig. 5. Back scattering of emulsions with O/W=4/1 and 1/L:4%MDG. T=20ºC.

Fig. 6. Back scattering of emulsions with O/W=3/1 and 1/L:4%MDG. T=20ºC.

Fig. 7. Back scattering of emulsions with O/W=3/1 and 1/L:4%MDG. T=20ºC. Salted.

ExperimentalMayonnaise substitute: A systematic study with several oil/water (O/W) ratios and several concentrations of surfactants (L and MDG) was done. The emulsions were characterized

from the point of view of their rheological behavior and stability. Rheological measurements were performed in a HAAKE RS300 rheometer, using a serrated plate-plate to avoid

slippage of the samples. Stability was assessed by measuring backscattering vs. time using TURBISCAN equipment MA2000.

Food airs (light foams): Airs were obtained by holding a hand mixer on the surface of the liquid. Stability of foams was measured by means of Turbiscan. The surfactants (L and SE)

concentration in water and the preparation methods were studied in order to determine the best conditions to obtain foams in aqueous systems for each recipe. For the optimum

concentration, the influence of common salt, calcium ion, sugar and acidity on the properties and stability of foam was analized. Formation and stability of foams were investigated

for fruit juices, vegetable juices, dairy foods, alcohol beverages and other the different kinds of foods.

Fig. 8. Backscattering evolution with time for water-sucroester foam.

Fig. 9. Backscattering evolution with time for milk-lecithin foam.

Examples of recipesHighly concentrated emulsion as a substitute of mayonnaise(asparagus with foam of mayonnaise alicia and mustard)Asparagus: Cut the fibrous stem of the asparagus. Peel them, and boil for 3 min.

Cool in water with ice.

Mayonnaise: Warm 75 ml of oil with 4g of monodiglyceride. Dissolve 1g of lecithin

in 25ml of water. Add little by little the oil (with monodiglyceride) to the water (with

lecithin).

Put the mayonnaise in the siphon with cartridge of CO2.

Serve: Foam the mayonnaise on the plate and put the asparagus and touches of

mustard.

Fig.1.

Fig.2.

Frozen chocolate and milk airMilk air: 1L milk, 5g of soy lecithin. Hold the hand mixer in the surface of milk, to

facilitate the incorporation of air bubbles. This will give a foaming and stable

texture.

Chocolate air: 1L water, 400g noir chocolate, 50g hazelnut praliné and 5g of soy

lecithin. Heat the water up to 90ºC and mix with the rest of ingredients using a

hand mixer. Let cool to 45ºC and follow the same procedure as in the milk air.

AimsThe goals of this work were to optimize the

formulations of mayonnaise substitute and several

airs to obtain the desirable texture and taste with

enough stability and a tolerable amount of edible

surfactants.

Backscattering evolution with time

0

10

20

30

0 10 20 30 40

Time (minutes)

Backscatt

eri

ng

(%

)

15 mm bottom

25 mm botton

35 mm botton

45 mm bottom

Backscattering evolution with time

0

10

20

30

40

50

60

0 5 10 15 20

Time (minutes)

Ba

ck

sc

att

eri

ng

(%

)

15 mm bottom

25 mm botton

35 mm botton

40 mm bottom

Backscattering evolution with time

0

10

20

30

40

50

60

0 2 4 6 8 10

Time (minutes)

Ba

ck

sc

att

eri

ng

(%

)

30 mm bottom

35 mm botton

40 mm botton

45 mm bottom

Fig. 10. Backscattering evolution with time for gin-water-sucroester foam. Sodium Chloride facilitates foaming with lecithin, but it has a negative effect with sucroester at ambient

temperatures, and it has no effect at higher temperatures.

Sugar has a negative effect with lecithin, and it has no effect with sucroester.

Acidity does not affect lecithin and sucroester foaming.

For clear fruit juices and L or SE, the presence of pulp avoid the foam formation.

Milk foams at ambient temperature are difficultly obtained. Higher temperatures facilitate the preparation of foam.

Alcoholic beverage foams can be prepared, but the less amount of alcohol, the more stability.