Introduction Bread Making Cake Making

Biscuits and Pastry Conclusion

Introduction
Never before has there been such a choice of fats in the chiller compartment of the supermarket. A recent survey found 20 different varieties ranging from traditional butter with 81.5% fat to a low fat spread containing only 40% fat.
Between these there are polyunsaturated spreads based on sunflower, canola spreads with omega-3 fatty acids, monounsaturated olive oil spreads, spreads with and without any dairy products, reduced fat spreads of all varieties and for those who read labels some spreads very low in trans fatty acids.

Recent introductions to the spreads market have included two brands containing plant sterols to aid in cholesterol management, a reduced fat butter and a spread based on a mixture of avocado and olive oils. All of these can be spread on toast or put in a sandwich.

But what else can they be used for? Can they be used in baking? If so what sort of baking? Does this represent an opportunity to produce baked goods containing less calories from fat or do recipes need to be modified to compensate for the reduced fat?

If a fat is to be classed as a margarine under FSANZ it must consist of at least 80% fat. If it has less than this amount it is classed as a spread. Most spreads are 70% or 75% fat. Table 1 shows typical fat contents of butter, margarine and spreads. It can be noted that the amount of salt varies considerably.
N.B. very few genuine margarines remain on the NZ market.

Table 1. Comparison between Butter, Margarine (Polyunsaturated), Spreads and “Light” Products

	% Fat	% Moisture	% Salt
Butter	81.5	16	2.4 – 2.6
Polyunsaturated Margarine	80	16	1.0 – 2.0
Typical Spread	70 – 75	20 – 25	1.0 – 1.8
Light Spread	60	35 –40	1.0
Low Fat Spread	40	60	1.0

All butter, margarine and spreads are water in oil emulsions. Margarine and spreads contain added emulsifiers such as lecithin and monoglycerides to aid in the emulsion preparation. Butter in contrast contains milkfat lecithin, a natural emulsifier.

Spreads were originally designed for table use and not specifically for baking. A consideration of the function of fats in baking should help us to decide which spreads to use for baking. Fat plays a different role in each baking application. For this reason in commercial practice a different formulation would be used for each purpose. But at home you do not really want to have three or four products in the refrigerator – two may suffice.

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Bread Making
In bread making fat provides flavour but more importantly lubricates the dough. This helps to retain the gases released during baking thus ensuring a well risen loaf which will have a soft crumb and will stay fresh longer.

Because bread dough contains a considerable amount of water the water content of the fat used should not matter. However to achieve optimum results with a reduced fat spread more of the product should be used and the water added should be adjusted accordingly. In practice when using a home bread maker it has been found that some reduced fat spreads are not readily incorporated into the bread dough. This is because the spreads are made with a tight emulsion to bind the high amounts of water with the reduced fat.
For the same reason reduced fat spreads on toast do not melt in the same way as butter.

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Cake Making
The function of fat in cakes is more complex.
Cakes are usually made by either the creaming method or the all in one method. The role of fat is different in each case.

In the creaming method the fat is beaten with the sugar until it becomes light, fluffy and pale in colour. The water in oil emulsion changes to an oil in water emulsion. During this process air is being incorporated into the batter and the volume increases. The air in the batter is important because it forms nuclei or sites into which other gases, water vapour from the moisture and carbon dioxide from the baking powder, migrate and expand on heating.

It is important that the batter is stable enough to retain these gases and produce a cake with a light texture. The solids profile and crystal size of the fat have a major influence on aeration performance. Even butters having the same fat content but sourced from different countries will produce different results. If a spread has good creaming properties with sugar and is able to trap and retain air then it should give an acceptable cake.
However the performance of each spread will depend on its solids profile and its crystalline structure. The only way for the home baker to assess this is by experimentation.

Fats containing 70% – 75% fat should give reasonable results. If they are substituted gram for gram in a recipe a cake would result containing approximately 10% less fat than the same cake made with traditional butter. The home baker might achieve a better cake if a small calculation were made and 10% more spread were added. A digital weighing scale would make this easy.

If using a reduced fat spread e.g. 60% fat the same reasoning would apply but now 25% more spread would be needed. This, however, is theoretical. The creaming process involves a dynamic balance of fat, sugar and water. A reduced fat spread with its higher proportion of water might upset this balance with unfavourable results.

Cakes or muffins made by the all in one method generally mix together all the liquid ingredients with baking soda in one bowl and all the dry ingredients including baking powder in another bowl. The two are then combined together before baking. In this method the rising agents are the baking soda and the baking powder.

The fat has no aeration function but as in bread making it will help to retain the gases released during baking. This will provide a good texture to the finished cake. In order to achieve the optimum result the amount of spread used should be adjusted to give the same amount of fat as in the original recipe. The amount of water or milk used should also be adjusted. i.e. reduce the water in the recipe by however many extra grams of spread are added.

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Biscuits and Pastry
The lower the fat content of a spread the greater the proportion of water. What will be the effect of this water in biscuit and pastry making?

Biscuits and pastry are made with “shortening “. The fat is rubbed into the flour. The molecules of fat surround the flour particles and exclude water. This prevents the development of gluten in the dough. The fat is said to shorten the dough. Any increase in water in the mixture will tend to encourage development of gluten, which will make biscuits hard and pastry heavy. Commercial bakers use different formulations for short pastry, Danish pastry and puff pastry. A 75% spread could be used to make shortcrust pastry or for biscuits but none of the reduced fat or low fat spreads are suitable for Danish or puff pastry.

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In Conclusion
The availability of so many different types of spreads, margarines and butter gives the consumer choice about which type of fat they want on their bread and in their baking.

Butter is the traditional home bakery fat against which all others are judged. Its success as a bakery product is due to its solid fat profile and crystalline structure. It also has good flavour stability and mouth feel. It can be used in bread, cakes, muffins and all pastries. It has the disadvantage of having a high proportion of saturated fat, which raises blood cholesterol. Butter keeps best at 4º – 8ºC but is then too hard to be used as a spread and for cake making butter needs to be brought to room temperature before use.

Margarines were originally developed overseas during the war years as an alternative to butter when this was not available. Polyunsaturated margarines were produced in the hope that they would help in the fight against heart disease. Interest in the Mediterranean diet has since inspired the development of spreads based on monounsaturated fatty acids from olive oil, canola oil and avocado oil.
The early margarines and spreads contained up to 15% of trans fatty acids. These act in the body like saturated fats so there has been a move to produce spreads with minimum amounts of trans fats. Do read the nutritional information on the bottom of the tubs.

Obesity is a major problem and this has created a demand for reduced and low fat spreads. These can be used in some baking for example cakes, but inferior results will be obtained unless adjustments are made to the recipe. Even then different spreads will give different results and so some experimentation in the kitchen will be required. In the future there is scope for the enlightened food technologist to produce a reduced fat spread with the right properties to make it suitable for baking.

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