propylenated fatty acids as emulsifiers

264 Grasas y Aceites Vol. 50. Fase. 4 (1999), 264-268

Propylenated fatty acids as emuisîfiers

By Y. El-Shattory, Saadia M. Aly and M,G. Megahed

Fats and Oils Departnnent, National Research Centre, Dokki, Cairo, Egypt.

RESUMEN

Ácidos grasos propilenados como emulsionantes.

Se prepararon estearato, palmitato, laurato, oleato y linoleato de hidroxipropilenilos mediante reacción de oxido de propileno con ácido graso a 160 °C durante cinco horas de agitación en presencia de hidróxido potásico como catalizador. Se determinaron las propiedades físico-químicas de los cinco productos, en cuanto a su uso como emulsionantes.

PALABRAS-CLAVE: Acido graso propilenado - Emulsionante alimentario - Propiedades físicas - Propiedades químicas.

SUIVI IVIARY

Propylenated fatty acids as emulsifiers.

Hydroxy propylenyl stéarate, palmitate, laurate, oléate and linoleate were prepared by reaction of propylene oxide with fatty acrd at 160 °C for five hours stirring in presence of potassium hydroxide as a catalyst. Physico-chemical properties of the five products, regarding their use as emulsifiers, were determined.

KEY-WORDS: Chemical properties - Food emulsifier - Physical properties - Propylenated fatty acid.

1. INTRODUCTION

In general, for a surfactant to act as an emulsifier, it must show good surface activity and produce a low interfacial tension in the particular system in which it is to be used. This means that it must have a tendency to migrate to the interface, rather than to remain dissolved in either one of the bulk phases (1 ). The emulsifiers were used to improve bread volume and texture, to extend shelf-life, and to control cookers spread factor (2). Various food products, such as butter, low fat spreads, shortening, chocolate, and margarine are water- in - oil (W/0) emulsions and require emulsifiers to prevent separation (3-5). The degree of solubility of surfactants in water often suggests approximate hydrophilic lipophilic balance (HLB) values are indicators of behavioral characteristics and do not indicate emulsifying efficiency. The selection of a suitable emulsifier for an 0/W or a W/0 emulsion must be determined by experimentation. However a

low HLB value (3-6) will promote or stabilize W/0 emulsion, an intermediate HLB value (8-13) will stabilize 0/W emulsion, and a high HLB value (15-18) will act as a solubilizer (6).

2. MATERIAL AND METHOD

— Hydroxy propylenyl fatty acids were prepared by adding propylene oxide slowly to fatty acid at 160 °C while stirring for five hours.

— pH was measured with a pH meter (Corlan model SA 520).

— Surface tension was measured in distilled water at room temperature (15 °C) with a (Sc-Du Nouy Interfacial Tensiometer Model 70545) (7).

— HLB was determined as described in (9). — Viscosity and shear stress were determined

with Bohlin Visco 88 B v according to (10). — Solubility was determined in different solvents,

as water, ether, petroleum ether (40/60), n-Hexane, oil and ethanol.

— Emulsifying power was determined according to Titus (11).

— Infrared (IR) spectra were determined with Backman according to (12).

3. RESULTS AND DISCUSSION

The solubility of the mentioned emulsifiers in different solvents are recorded in table I where it can be seen that all emulsifiers are soluble in both oil and ethanol at 75 °C. Generally, hydroxy propenyl stéarate and palmitate are insoluble with different degrees in all solvents at 25 °C while they are soluble in oil and ethanol only at 75 °C and insoluble in the rest of solvents at this temperature.

Water seems not to be the suitable solvent for solubility of these mentioned emulsifiers. The insolubility of these emulsifiers in water suggests a non polar nature, while the solubility of some emulsifiers in oil indicate that these emulsifiers can be blended with lipids during formation of food system without employing organic solvents (13). Figure 1 shows that pH values of the five emulsifiers are alkaline in character which agree with those of

(c) Consejo Superior de Investigaciones Científicas Licencia Creative Commons 3.0 España (by-nc)

http://grasasyaceites.revistas.csic.es

Vol. 50. Fase. 4(1999) 265

sorbitol fatty acids reported by (14). Melting point, as shown in Figure 2, indicates that the value concerning hydroxy propylenyl stéarate is more or less double of those of laurate and palmitate, while oléate and linoleate are liquid emulsifiers. Surface tension of the five emulsifiers are drawn in Figure 3. Those of stéarate, linoleate and laurate are more or less the same as the value of hydroxy propylenyl palmitate while hydroxy propylenyl oléate shows the lowest value. Those results are in close agreement with sorbitol fatty acids reported by (14).

Table I Solubility of some synthetic emulsifiers

Solvent

Water

Ether

P. ether (40/60)

n-Hexane

Cotton seed oil

Ethanol

Temp. ("C)

25

75

25

75

25

75

25

75

25

75

25

75

(1)

1

ss

ss PS

SS

PS

ss PS

1

s

PS

s

(2)

so c

ss PS

PS

s

ss PS

1

s

PS

S

Compounds

(3)

SO

G

S

S

S

S

S

S

S

S

S

S

(4)

SS

PS

S

S

S

S

S

S

S

S

s s

(5)

ss PS

s s

s s

s s

s s

s s

(1) Hydroxy propylenyl stéarate (2) Hydroxy propylenyl palmitate (3) Hydroxy propylenyl laureate (4) Hydroxy propylenyl oléate (5) Hydroxy propylenyl linoleate

I = Insoluble PS = Partialy soluble s s = Springly soluble s = Soluble

PH 6-M

Emulsifier type

1 Hydroxy propylenyl stéarate 2 Hydroxy propylenyl palmitate 3 Hydroxy propylenyl laureate 4 Hydroxy propylenyl oléate 5 Hydroxy propylenyl linoleate

Emulsifier type

Figure 2 Melting points (°C) of ennulsifiers

(See Figure 1 for emulsifier types)

Figure 1 pH values of ennulsifiers

1 ^ M l

Emulsifier type

Figure 3 Surface tension (dyn/cm^) of emulsifiers


Viscosity of hydroxy propylenyl stéarate is more or less double the value of those of linoleate and oléate. Hydroxy propylenyl laurate has the lowest viscosity value and that of palmitate is much higher than that of laurate (Figure 4). Shear stress of hydroxy propylenyl stéarate is about three times of that of linoleate and oléate and about four times of that of laurate and palmitate as refere in Figure 5. Emulsifying power values are given in Figure 6, which shows that all emulsifiers tested have more or less the same value. On the other side the HLB range from 3.4 HLB to 6.2 HLB (Figure 7) so these emulsifiers promote or stabilize W/0 emulsions (15,16). The relation between both shear stress to viscosity and emulsifying power to HLB are more or less parallel to each other as shown in Figures 8 and 9. From Figures (10-14), concerning the infrared spectra, it can be stated that:

— Broad band appears for streching vibration of 0-H group absorbed near 3600-3400 cm^-1.

— Forked band for streching vibration band for C-H group absorbed near 3000-2800 cm^-1 for methylene and methyl groups. The symmetrical bending vibration for (CH3) occures near 1373 cm^-1 and assymmetrical bending vibration near MSOcm'^-l.



266 Grasas y Aceites

0-H bending vibration in region of 1420-1300 cm^-1 in primary and secondary alcohol. H bending couple with C-H wegging vibration to produce band near 1420 and secondary 1330 cm^-1. C-0 streching vibration in alcohols

produces strong band in 1260-1000 CITT^-I. C-0 streching coupled with the adjacent C-C streching vibration. This in primary alcohol gives better vibration. Streching vibration of C = O of acid and ester absorbed near 1715 cm^ l .

Emulsifier type

Figure 4 Viscosity (mp) of emulsifiers


values

Emulsifier type

Figure 5 Shear stress (Pa) of emulsifiers

{See Figure 1 for emulsifier types)

Emulsifier type

Figure 7 Hydrophile - linophile balance (HLB) of emulsifiers


~S—Sluear s t res^

Emulsifier type

Figure 8 The relationship between the Shear Stress and Viscosity

Emulsifier type

Figure 6 Emulsifying power (%) of emulsifiers (See Figure 1 for emulsifier types)

60 -T

50 -

40 -

Values 30

20-

10

0

-w-

-

-E.P.%

"HLB

•

«-— 1

• — _ _

«

— _

H 1

. ^

a

Emulsifier type

Figure 9 The relationship between Emulsifying Power Percentages and

Hydrophilic Lipophilic Balance



Vol. 50. Fase. 4(1999) 267

4000 3S00 3600 340D 3200 3300 2300 2800 2400 2200 2000 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 '

Wavenumberj;cm-1]

Figure 10 Infra red spectrum of hydroxy propylenyl stéarate

500 400 300 203

1 L. 1 ! 1

1 _' i_,_

r i 1 1 1 1

n

-^

^

, :

1

/ y

_i„ i

"

1 1

L 1

"

-

-

'

L 1

- • 1

- p ^

^

,

,

' 1

i

--

1

1 ~ -

""r 1 1

1

1

'

' 1

V \î

,.y;

I Í

r 1'

v^

—

1

\

1/

i

1

—

' •

,1 1

.r V J

. , n

'

'i I

, ' 1

1 )

!'i

L ^'\ h !

-—

1

'

1'

"

P J

\u\

--

--

f

^

' Mi',

"i 1

. ' ',/ A/ A II

II 1

•

-A

h 4\ V

,

1 1 i _ 1 ' '"

..L

.L 1 J

zJ 7

1

1

1 ( i |

'

1

1 1

' i

1

/

—

—

'

¡ ;

1 ¡

.,,,

w Ly,

I|

l H i 1

' 1 ' ' " •

''111 1

' ' i 1

!H 1

i'il 1 n Il i l l

4030 3800 3600 3400 3200 3000 2800 2300 2400 2200 200D 1900 1800 1700 1600 1500 1400 1300 1ZX) 1100 1000 9 0 0 8 0 0 7 0 0 e O O g 0 0 4 D 0 3 D 0 2 D O

Wavenumber[cm-1]

Figure 11 Infra red spectrum of hydroxy propylenyl palmitate

1 1 1 1 1 I'M 'Ml'!''hhJiMr' M ' i t ' ' r 1 i n '

LL ri 1 :'' i' i • h 11 ] ¡"[pjUii^j 111 Ml / i M '1' 1 '

Tr t t r f rh Hi l7nT i / i l ! ; 1 i ! ifh 1 n th Í1 irhrri lr

1 i\xL ij 11 imu 11 t H t n V ! rn p I F 1 ! M • 1 1 ' Í i n

-|rr|-W-i-hM-|l|"Nf

^ 1 1 1 1 'i

1 1 ' '

1 ñ^

Úf\' y I

' 1' 1 1 1 1 1 ' ' 1 1 i ' 1 I I ' ! 1 ''i 1 I 1 I 1

i l

nJKl '\m-\M Mïitfl M i l l

1 M LTMpïï iiffl 4000 3800 3600 3400 3203 3300 2600 2600 2400 2200 2000 1900 1800 17130 1600 1500 1400 1300 1200 1100 1030 9 0 0 6 0 0 7 0 0 6 0 0 5 0 0 4 0 0 3 0 0 2 0 0

Wave number [cm"^]

Figure 12 Infra red spectrum of hydroxy propylenyl laureate



268 E U---\-

Tï ï l

M \ ' W

_:;.,.

--

JL

-[-

i "

1;;

^ • \ \

"--1

..|;:!' : :

MM

i / 1 ' 1

sFrl

: | -4™: i

::| yjj^ MillÏÏÎÎ M- hi ; :

- - • : : T -

•"i f n l '

ill j t •' M

::rl "•r

' " : ]

¿Mi

Tin

- - •

:;n

ilii

;;:!

!i;i

§ •tW

rr-

Iffr

;TT

HI:

^ ^

•Í-Í-:

iT|T

¡ni'

à n - | l

r[4H

!H|:'

\\:Ú:\

H'm'

r r - j -

'H ¡ 1 ^ ; : M h i i l M r

-pd^:-' 1 -A' is j l j ^ #

1/ ' 'H '^

"k|-|-H

il ; i h ! : : 1 M -híhn^

i ,;¡Mj. M' ii Hi

i l ' . i iM;.

in'iiM' n H h h i

: : : n l : i

|lm-.

tt^ ff fn iU

; : ' J Î Ï ^

Itt

i": •V

JH-i

Q i l :n hi

w

-r-

i 1

lui

;-|j

m 3

"ÏÏ

t i ;

r:f : 1;

Ll.

i-T-

iiïiTiïïï"

Hiihin i i i !

4 ini

i ; , ;

1iï;

--

:::1

t r

r-

-r--

_4

n :

§1-. ,.._

^ri-"-

lí i

rf-T

•-: : [ :- : :

--r-r

-.:-|..-i

; : 1 1 !

Grasas y Aceites

« œ 3800 3600 3400 3200 3CXX) 28C0 2600 2400 2200 2000 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900

Wavenumber[cm-1]

700 600 500 400 300 200

Figure 13 Infra red spectrum of hydroxy propylenyi oléate

lp h-

hr

¡¡-r

oülLi-.

>v):

f r j - r r

inl i

IvM

hM Ni

niil i i

^•rUT||---JTr- i-- :4

:JM i::Jnnn:|j i N|;;:í|:|nj:!ii]lllm :J jnMiiMMipliiJ i ; M [ ; : 1 U ; i ! ; ' jn : M 1 •

iî Í I M Í M |i i:|!l:- -M-

nm!:lHî i!M IH; ;|n

li H/:Mi niijiihmin (iMiinlliiliiliimIi 1 irpjll iiiilij Ijiim|: ii iiiimliiii lili iiin ji Ni! iíjip ||nmn jmin|lij;|!i j!|!mm nuh I¡Í;Wmi'mm jjlljjimjilil jllinljijil,

--•k-[--r-j-:-r-j-:4---|--4-

i- m Hm ii imm-HnNpHm i: |Mi'|im|rh|iinimi|nmN;iJïï 1: H Mmt|:n|::,/^Hnji: ih: ii miminmi mil ini l^Jl imh n i n - m i i i n i i i i l / i l l Un Inn ;i r n - m i ! mml l l i n l m ^ i i -mimH; mui i l i l n m i i n im N Mi i j imiini li iiHiihnmj 11 n'- im Imli ii ¡iii iim n Ijiml: ii l i ! i l : | ; 1! i ! i : l ! ! i | ni i! 'mH' n i l M i 1 Jljimmn jipl^h ü; IH llihi i liÜ ili i f ihnl: i! iil i p i i i l i i l l i l nn imn l iiJi I I I l i l i iHi iim^ i ' i illHiiil i;il iifi liiIniH lili ni

^:|n:r[nn'j:n'in"'j^ :|n^'pT" ú n i M i ^ h i n h - n; ;

; |n : I n h p n j i ; . |.n-|n 1 n ;| ;M|"|ïï|nmH: I n i l n t n

jm [ [mmn:JnnL ;^ flmíímmllml-'nim Imiimli lin nm^m^ : Mjimilmim!/minii mi iniii i|ii illi ii/i i i l i i l f ii\. iml imi imnj l^miH i lU i i j ^

•H-nimi 'mrm- 'mím'm'm l l É y m n ili ili HH i á^Jip i lÉ! Iil ii|i

! i l i im i i i l i i l i im i lm i lm i l * ' Jlillí illj|jj!jlii!jm!jlijmi!i;i

~ í |T Í r rn ]—

TiÉ-ífmir

i n m . i m n n-J •mn i :n;|n • Iil- M'liLuliin ! M H N [lím n : 1 nii i nmlmli njl |:i:mji i | | iiii iimiijlni 1 niiml; ¡H! I l l Ji|i Mmli! i' 1 \iilmlilii|lmi

vmr f limlilmiilmii iJi|tnilîSli!ÏÏl

4000 3800 3600 3400 3200 3000 2800 2600 2400 2200 2000 1900 1800 1700 1600 1500 140O 1300 12D0 1103 1000 9 0 0 8 0 0 7 0 0 6 0 0 * 0 0 4 0 0 3 0 0 2 0 0

Wavenumber[cm-13

Figure 14 Infra red spectrum of hydroxy propylenyi linoleate

REFERENCES 10

1. Akoh, C.C. and Chigozie, V.N. (1992).—«Enfiulsif¡cation properties of polyesters and sucrose ester blends II: Alky I glycoside polyesters».—Journal of the American Oil Chemists'Society 69 (1), 14-19.

2. Akoh, C.C. (1992).—«Emulsif¡cation properties of polyesters and sucrose ester blends I: Carbohydrate fatty acid polyesters».—Journal of the Anrierican Oil Chemists'Society 69 (1)9-13.

3. Breyer, L.M. and Walker, C.E. (1983).—«Comparative effects of various sucrose-fatty acid esters upon bread and cookies».—Journal of Food Science 48, 955-958.

4. Ebeler, S.E. and Walker, C.E. (1983).—«Cereal Chem».— 60, 270.

5. Pomeranz, Y. (1981).—«Ibid».—58, 190. 6. Akoh, C.C. and Swanson, B.G. (1989).—«Synthesis

and properties of alkyl glycoside and stachyose fatty acid polyesters».—Journal of the American Oil Chemists'Society 66, 1295-1301.

7. Alexander, A.E. and Haytex, J.B.—«Physical Methods of Chemistry».—John Wiley and Sons, New York, 1971, pp. 501-655.

8. Lutton, E.S. (1950).—«Review of the polymorphism of saturated even glycerides».—Journal of the American Oil Chemists'Society 27, 276-281.

9. Othmer, K. (1965).—« Encyclopedia of Chemical Technol».

11

12

Tobias, J. and Tracy, P.H. (1950).—«Basic viscosity of ice cream mixes ice cream».—^Tr. J. 46, 183. Titus, T.C., Wiancko, N.N., Barbour, H.F. and Mickle, J.B. (1968).—«Emulsifier efficiency in model systems of milk fat or soybean oil and water».—Food Technology 22, 115-117. Akoh, C.C. and Swanson, B.G. (1987).—«One-stage synthesis of raffinose fatty acid polyesters».—Journal of Food Science 52 (6) 1570-1576.

13. Feuge, R.O., Zehngue, H.J., Weiss, T.J. and Brown, M. (1970).—«Preparation of sucrose esters by interesterification».—Journal of the American Oil Chemists' Society 47, 56-60.

14. El-Shattory, Y, Saadia, M. Aly and Megahed, M.G. (1995).—«Performance characteristics of some syntheticemulsifiers».—SOFW Journal 121 (10) 762.

15. Nawar, W.W. (1985).—«Food Chemistry».—Edited by O.R. Fennema, Marcel Dekker, Inc., New York, pp. 139-244. Gupta, R.K., James, K.A. and Smith, F.J. (1983).— «Sucrose esters and sucrose ester/glyceride blends as emulsifiers».—Journal of the American Oil Chemists'Society 60, 862-869.

Recibido: Mayo 1998 Aceptado: Diciembre 1998

16



propylenated fatty acids as emulsifiers

Documents