Palm Oil Applications - Margerines

Margarines were originally developed in 1869 as an alternative to butter, which was in short supply and expensive. The first margarines were made from animal fats, but today most margarine is formulated with vegetable oils. The product range now includes table margarines, bakery margarines, specialized puff pastry margarine, and has recently been extended to various "low calorie" spreads, which essentially contain much higher levels of water and lower levels of fat than those legally required in margarine.

Table margarines fall into two main types, packet margarines which are designed to be spreadable at ambient temperature, and tub margarines which are spreadable on removal from the refrigerator, at a temperature of 5-10°C. Typically solid fat content curves for the two types are illustrated in chart 2, which shows the much lower solid fat content required in the tub margarine.

When packet margarines are intended for use in a tropical climate, with ambient temperatures around 30°C, higher solids contents than those indicated in Chart 2 are required to avoid melting.

With the availability of hydrogenated oils of various grades, there is a large choice of ingredients for blends with the desired solids content profiles. Individual manufacturers will usually base their choice on local availability and on price, as well as the technical consideration of a fine crystal structure to give the required spreadable character.

Palm oil and palm kernel oil are highly suitable components of margarines of the various types described, and numerous formulas have been published in the technical literature.

The following advantages can be listed for palm oil:

1. It provides the required solid fat content with little or no hydrogenation.
2. It ensures the stable beta prime crystalline form necessary for a fine structure.
3. It is readily available worldwide at very competitive prices.

Palm kernel oil contains short and medium chain length glycerides similar to those present in butterfat, and therefore helps to give the right mouth feel and melting characteristics. This effect is particularly marked when it is used in combination with palm oil, because a lower melting eutectic is formed.

The behavior of palm oil in processing has one disadvantage in margarine manufacture. Palm oil tends to crystallize rather slowly, and consequently presents some difficulty in the packing process.

Type				Tub	Low Fat Spread
		blend for interesterification		blend	blend
	A	B( 1 )	C ( 2 )	D
Hardened Palm Oilm. pt. 42 °C	35	-	-	-	20
Palm Kernel Oil	30	-	30	10	-
Liquid Oil	35	-	-	70	50
Palm Stearin ( I. V. 41 )	-	70	-	20	-
Palm Kernel Olein	-	30	-	-	-
Palm Oil	-	-	70	-	30

Table 3: Margarine Formulations

Notes :

(1) After interesterification 60 parts of the blend are mixed with 40 parts of rapeseed oil before processing into margarine
(2) After interesterification 83 parts of the blend are mixed with 17 parts soya bean oil beore processing into margarine

This problem only become apparent when more than 20% is used in a blend. The problem is an inherent property of the particular glycerides present. Partial hydrogenation of palm oil results in a significant improvement in the rate of crystallization, which is further improved when the process of interesterification is used. This has the added advantage that relatively high proportions of palm stearin can be incorporated, which is always at a discount to palm oil. Table 3 shows selected margarine formulae suitable for direct blending and for intreresterification. Their solid contents are shown in Chart 5.

There are great many possibilities for interesterified margarine blends, and Table 4 illustrates some of them, together with their solid contents.

Composition	Pos:PKOF	PO:PKO	POF:PKO	POS:SBO	POS:RSO ( LE )	POS:CSO
( 1 )	( 60 : 40 )	( 80 : 20 )	( 90 : 10 )	( 40 : 60 )	( 40 : 60 )	( 20 : 80 )
M. PT ( °C )	35.5	35.5	33.2	32.3	36.0	34.0
SFC ( % )10 °C	52.7	57.5	41.6	17.5	19.4	18.8
15	43.7	49.5	30.2	10.7	12.7	10.3
20	30.0	37.1	20.8	5.9	9.6	6.5
25	19.3	25.8	13.8	3.9	5.7	3.7
30	11.4	17.4	7.8	2.5	3.7	2.8
35	3.8	9.3	4.3	0.8	3.6	2.2
37	0.4	4.3	2.3	0.9	2.3	1.1
40	-	2.6	0.8	-	1.6	0.4

Table 4: Randomized Blends for margarines

COMPOSITION (1)
PO = Palm Oil
PKO = Palm Kernel Oil
POS = Palm Stearin
RSO = Rapeseed Oil ( low erucic acid ) POF = Palm Olein
PKOF = Palm Kernel Olein
SBO = Soya bean Oil
CSO = Cottonseed Oil

Margarines For The Bakery

The professional baker often prefers to use margarine in the production of cakes instead of a (100% fat) shortening. Margarines usually have added color and flavor, which contribute to the end product, and are therefore particularly suited to use in butter cream fillings.

Bakery margarines are formulated to a higher solids content than table margarines to ensure good baking properties. A tested formula is given in Table 5.

	Cake ( F )	Pastry ( E )
Hardened Palm Oil ( 40 - 42 °C )	-	60
Palm Stearin ( I. V. 43 )	50	30
Palm Kernel Olein	-	10
Palm Kernel Oil	15	-
Hardened Soya Bean Oil 46 °C	15	-
Palm Olein	20	-

Table 5: Bakery Margarines

For the preparation of puff pastry, a special fat is required, and is usually processed into a margarine. Puff pastry is prepared by arranging the pastry dough and the margarine in alternate layers, and then by a repeated process of rolling out, folding and rolling again, a large number of fine layers is built up. In the final dough before baking, up to 250 separate layers have been formed.

Baking is carried out in a rather hot oven. As the temperature rises, the water in the pastry vaporizes and is inhibited from escaping by the thin layers of unmolten fat. As a result, the pastry layers are forced apart to give the crisp characteristic layered texture.

Pastry margarine test baking: The control is a commercial product; the experiment (on right) is based on the formula E in Table 5.

The fat used in puff pastry must therefore be somewhat tough and very plastic, so that it can be rolled out repeatedly without mixing into the dough. It must also not melt too quickly during baking. Table 5 shows the formula of a successful pastry margarine based on palm oil, and the solids content profile is shown in Chart 5. The results of a baking test in comparison with a commercially available pastry margarine are illustrated in the photograph (top).

Trans-Fatty Acid Free Product

The desirability of reducing trans-fatty acids in foods was discussed in the nutrition section on Nutritional aspects of fats. Several models blends having a zero content of trans-fatty acids are given in the above sections. For convenience, they are listed here.

Shortenings - Formula 2 + 3 in Table 2
Vanaspati - Formula 2
Margerine - Formula B, C and D on Table 3,
       as well as the interesterified blends shown in Table 4 Top Menu

Puff Pastry Margerine

The following trans-free formula has satisfactory performance:

Palm stearin (I.V. 43) 80%
Soya bean oil 20%