Technical Talk – November 2010
October 25, 2010
By John Michaelides
After focusing on flour, eggs, sugar, yeast and other ingredients in
recent Tech Talk columns, it’s time to turn our attention to the role
milk and milk ingredients play in your baking. Milk can be obtained from
various animals including cows, goats, sheep, buffalo, camels and
reindeer. The predominant source of milk in North America is the cow.
After focusing on flour, eggs, sugar, yeast and other ingredients in recent Tech Talk columns, it’s time to turn our attention to the role milk and milk ingredients play in your baking. Milk can be obtained from various animals including cows, goats, sheep, buffalo, camels and reindeer. The predominant source of milk in North America is the cow. The composition of the milk is affected by many factors, such as the animal breed, season, and feed. Whole milk is basically a fluid containing about 12.5 per cent solids. The basic solids are composed of 3.4 per cent protein, 4.75 per cent sugar (lactose), 3.65 per cent fat and 0.70 per cent minerals. The proteins in milk are mainly caseins (three per cent), lactalbumin (0.6 per cent) and lactoglobulin (0.24 per cent). The minor proteins are not coagulated by acid, but they are heat-sensitive and remain in the whey during the cheese making process.
|The use of milk products in fresh and frozen baked and confectionary goods has gone up 20 per cent from 2005 to 2010, says the CDC.
The main carbohydrate in milk is lactose, a disaccharide containing glucose and galactose. This sugar is not as sweet as sucrose (only 16 per cent as sweet), but it provides some sweetness, giving whole milk its characteristic taste. Lactose is further processed by enzymes to produce galacto-oligo-saccharides (GOS). These are functional ingredients that provide health benefits through their prebiotic activity.
In whole milk, fat is present in the form of microscopic globules. It tends to float to the surface due to its lower specific gravity, separating into cream. Cream is a functional ingredient often used by the food processing industry. Indeed, according to the Canadian Dairy Commission’s (CDC) Special Milk Class Permit Program (SMCPP), the use of cream in food processing has increased by more than 30 per cent since 2006. Cream can be further processed (churned) to invert the oil in water emulsion system of the cream to water in oil. This forms butter, another very functional ingredient, especially in the baking industry. Butter provides the characteristic flavour and colour in many baked goods, as well as playing a functional role. It contains carotene (a precursor of vitamin A) and xanthophyl (yellow colour substances), the phospholipids lecithin and cephalin, and the fat soluble vitamins A, D and E. Although it does contain cholesterol, butter also contains many healthy compounds. This, combined with its characteristic flavour, is making butter a more desirable ingredient in food products. Indeed, the CDC SMCPP reports butter usage has increased by over 50 per cent increase since 2006. A byproduct of the butter production process is buttermilk. Buttermilk powder is very functional in baking systems because it contains high amounts of protein (38 per cent), providing nutrition and lecithin, an emulsifier with health benefits.
Dried milk powders also represent a significant portion of dairy ingredients that are used in the formulation of baked goods. These include whole milk and skim milk powders. These powders provide the advantage of convenience for commercial use and storage compared to the liquid milk. In addition, the process of dehydration (mostly spray drying) has an effect on the proteins that enhances their functionality. Indeed, unheated milk causes slack doughs and decreases in the loaf volume of baked goods. Skim milk powder is more frequently used in baking formulations. It is a valuable ingredient because it adds nutrition and improves the physical quality and characteristics of the baked goods. Sodium caseinate can also be obtained from skim milk. It is produced by acidifying skim milk and spray drying it into a powder. Sodium caseinate is a functional ingredient containing more than 90 per cent protein, with very high water binding and fat-water emulsifying capacity. Although very functional, skim milk powders have been in decline as a baking ingredient due to their higher cost. However, information from CDC’s SMCPP indicates the use of whole milk powder in food processing has increased by more than 50 per cent since 2006.
A number of functional ingredients are also produced from whey. Whey is the byproduct of cheese making. It retains most of the lactose, all of the water soluble-vitamins and minerals and most of the non-casein proteins. Two basic types of whey are usually generated: sweet whey from the rennet coagulation process of cheese making and acid whey from the acid coagulating process. Further processing whey results in the production of whey protein concentrates and isolates with specific functionalities in baked goods, such as egg white replacement. Dried whey provides good functionality in the formulation of baked goods like bread, sweet goods, cookies and cakes. Specifically, it improves flavour, crust browning, volume, texture and tenderness. In addition, dried whey helps extend the shelf life of baked goods.
According to Mark Lalonde, CDC’s chief of marketing programs, “The use of butter in baking continues to grow at a steady pace. Cheese used in frozen breads [cheese bread] is also on the rise. Dairy ingredients perform well in fresh recipes but also retain their integrity in terms of flavour and texture when frozen [or] thawed. This is especially true in the case of frozen butter croissants and cookies.”
On a milk equivalent basis, Lalonde says dairy ingredients used in fresh and frozen baked goods and confectionery products rose from 5.6 million hectolitres of milk in 2005 to 6.7 million hectolitres in 2010 – an increase of 20 per cent!
Fermented milk products are now finding their way into fresh and frozen baked goods. Yogurt and milk powder are also growing in popularity thanks to the many functional benefits they offer, according to Lalonde. Including yogurt in a recipe makes for a moister muffin, and adding whole milk powder (WMP) allows a baker to control the source and amount of moisture added to the recipe. For this reason, Lalonde says pancake and waffle mixes are using more and more WMP (26 per cent milk fat). Using WMP also offers a true milk fat flavour profile.
The CDC has introduced a funding support program for product development and innovation to help companies incorporate milk ingredients in their formulations. More information on the Matching Investment Fun program can be found at http://www.milkingredients.ca/DCP/app/filerepository/06FE99CD4CA546F69AE86897B31A0807.PDF
Dr. John Michaelides is Guelph Food Technology Centre’s director of research and technology. For more information, or fee-for-service help with product or process development needs, please contact the GFTC at (519) 821 1246, or at firstname.lastname@example.org
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