By John Vandenbroucke
Nobody knows when people started to make bread but we do know that Egyptians where making bread already around 7000 BC.
Since the early beginning people have tried to improve their bread and they did that by incorporating natural bread improvers, sugar, butter, nuts, honey and milk.
Each of those natural ingredients has its own functionality:
- Sugar and honey will make the bread soft, help the yeast development, give a nice color to the crust and will increase the nutritional value of the bread.
- Butter will make the dough mixing easier, will soften the bread crumb, will improve shelf life, give a good bite (mouthfeel) and a nice aroma to the bread.
- Milk will add nutritional value to the bread, will help to improve the crumb structure of the bread, enhance the flavor and the aroma and will make the crust thin and the lactose in the milk will give a nice color to the crust.
The use of milk has constantly changed over time: from liquid milk, to spray dried milk powder (WMP and SMP) and the latest trend is fat filled powder
Fat filled milk powder will be the subject of this article. What is fat filled milk powder? Fat filled milk powder is a powder obtained by spray drying a vegetable oil on a dairy carrier. To better understand the composition of a fat filled powder we have to look first at the composition of milk in particular spray dried milk powder; Whole Milk Powder (WMP) is the powder obtained by spray drying the cows milk without adding any additive or without altering the composition of the liquid milk before spray drying. A spray dried milk powder contains around 24% milk protein, 27% milk fat, and 45% lactose. No doubt a premium ingredient with an excellent nutritional value but it is very expensive and it has a low functionality in the bread baking.
The functionality of spray dried whole milk in bread making is low because milk is tailor made with the purpose to feed the calf. The composition of whole milk powder and skimmed milk powder does not meet at all the requirements of the baker. Using full cream milk or skimmed milk powder is in fact “over-engineering”, an inefficient use of an expensive premium ingredient.
It is possible to separate each component of the milk: protein, lactose and the fat (fat separation is done that since more than 1000 th of years by making butter).
To make an economical and functional use of those ingredients we will need to recombine the milk powder components but before we do that we have to understand how each of the milk components can be used to produce a better bread.
What is the role of milk protein in the bread baking?
To find out we will have to look at the wheat flour composition and on how wheat flour forms the network that can hold the carbodioxide during the fermentation.
Enzymes against milk protein
Bread can only be made with wheat flour because the gluten in wheat flour are the only gluten that can form a network able hold the carbodioxide during fermentation. To make a good bread the wheat flour should have minimum 13% protein and the flour should have a good enzyme activity
With such a flour the yeast development will be optimal and the dough will have good elasticity. This will prevent that air cells will burst during the oven spring.
If the wheat flour has been milled from sprouted wheat than it will be difficult to make a nice bread (even if the protein is high!) because such a wheat flour has a low enzyme activity. Because of a low enzyme activity the gluten will not develop properly.
Wheat flour contains 2 important enzymes: Diastase and Protease. It is the protease in wheat flour that strengthens the gluten and improves the ability to contain the gas during fermentation. An other enzyme that has a direct influence on strengthening the gluten is xylanase. This enzyme is normally contained in “bread improvers (together with mineral yeast food and eventually softeners)”.
To strengthen the gluten the baker will add or wheat protein in the form of dry gluten or he can add a bread improver. The milk protein from SMP or from whole milk powder will not be of any influence on the structure of the gluten and a milk protein can also not improve the structure of the crumb.
Only xylanase and protease will be able to form a strong gluten network. Those 2 enzymes are present in an active gluten powder and you can find them also in good bread improvers.
In picture 1 you have a bread made with 4% SMP and a low quality bread improver and on the right a similar loaf in which the SMP has been replaced by a fat filled powder with 5% Milk Protein and 45% vegetable fat and good bread improver was used (containing xylanase and protease). The crumb structure is much better.
On the picture 1 you see that the crumb structure is more open because of a not so good wheat flour. Although an expensive skimmed milk powder was used it could clearly not improve the crumb structure while on the right a very small amount of enzymes could improve the gluten structure resulting in a much better loaf.
Replacing skimmed milk powder by a fat filled powder in combination with a good bread improver had also other improvements clearly visible on the bread at the right: the crust was much thinner, the bite (mouthfeel) was improved a lot, the bread had a very nice milky aroma and milk taste and the shelf life was longer.
All this could be obtained at a significant cost saving for the bakery industry.
While most the bakery industries are working with a good quality of wheat flour (high in protein and with a high enzyme activity) and with a good bread improver, they do not need to improve the gluten structure. It will be enough in most of the applications to replace simply the SMP or WMP by a good quality fat filled milk powder. I have used the example of a weak gluten development only to show that milk protein, even at a high dosage, will not contribute in producing a better bread.
Fat source in fat filled powder
A fat filled powder should contain a percentage of fat that is at least equal to that of WMP = 27%. But most of the fat filled milk powders are containing 33% fat or even more. The fat is mostly RBD (Refined, Bleached and Deodorized) palm oil. The oil used in the production of fat filled powders does not contain partially hydrogenated fat and hence is cholesterol free.
The milk solids (protein and lactose) are reconstituted, palm oil is added, this mixture is than thoroughly blended, pasteurized, homogenized and than spray dried. The result is a modified milk powder with a high functionality at a much lower cost than a skimmed milk - or whole milk powder.
The composition of a fat filled milk powder is really tailor-made to meet the requirements of the bakery industries.
A fat filled powder has a shelf life of min 1 year if stored as recommended by the producer.
John Vandenbroucke International Food Hongkong