New Industrial Uses of Dairy Products

by Robert G. Bursey, Senior Vice President for Dairy Foods and Nutrition Research, National Dairy Promotion and Research Board, Arlington, VA.

Milk, as it comes from the cow or is delivered from the farm, represents a complex mixture of ingredients and biochemicals which, if separated and/ or modified, have chemical properties and functional attributes that lend themselves to a wide array of nonfood applications.

In many respects, raw milk from the cow is analogous to crude oil that is extracted from the earth, cracked, and separated into vinyls, acrylics, gasoline, motor oil, grease, and other fractions that can be further processed and used as components in any number of consumer goods. Petroleum is today more than just a source of energy to power an engine. It is a feedstock (raw material) used to make literally thousands of products that touch almost every facet of our lives. The same is possible with milk. Unlike our knowledge about petroleum, however, our understanding of the full potential of nonfood uses of the ingredients in milk is still in its infancy.

The list of nonfood uses of the components of milk that have already proved to be both technically achievable and commercially feasible is long and varied. The potential would appear almost endless, constrained only by the limits of our imagination, the availability of resources to explore and develop them, and the economic reality of exploiting them.

Milk, as it comes from the cow or is delivered from the farm, represents a complex mixture of ingredients and biochemicals. These components lend themselves to a wide array of nonfood applications. USDA 014-33-23

Continued efforts to identify and develop nonfood uses for all agricultural commodities are critical. As non-or less-renewable natural resources become increasingly scarce, the need to define agricultural products as substitutes for these resources becomes even more important. The need to invest in developing these technologies today is critical because of the lengthy time typically required to deliver an innovation to the marketplace economically.

The next few pages suggest just a few of the many possible nonfood uses for each component in milk. Milk and other dairy products are complex mixtures of biochemicals, minerals, water, and combinations of these compounds. The biochemicals in dairy products can generally be classified as carbohydrates, proteins, and fats. Nonfood uses of compounds derived from each of these three biochemical fractions are already products of commerce and the list of such applications continues to grow.

Carbohydrates

The major carbohydrate found in milk is lactose, or milk sugar. Considered a simple carbohydrate, lactose is similar to table sugar in chemical composition but is much less sweet. For some time, and to some extent even today, lactose has been considered a byproduct or potential waste product from the processing of many dairy items such as cheese. Exploration of nontraditional commercial uses of lactose was hampered by the low cost of sugar, which could often be substituted for lactose in many of its more novel applications as a potentially useful surplus commodity.

However, lactose has for many years been used by the pharmaceuticals industry as an excipient and diluent for drugs. Often, the active ingredients in pharmaceuticals, the actual medications, cannot be used in their pure forms. In addition, drugs must be released under proper conditions and over a regulated time period to have their greatest effect. Similarly, the effective dose of a drug is often quite small and sometimes tastes bad. Lactose dilutes the active ingredient in a medication to help ensure that a uniform dose is being ingested, and that the medication is delivered in a form that is convenient and agreeable (in size, shape, and taste) for the user. It also establishes the appropriate conditions and time-release qualities to make medication as effective as possible.

Lactose is also split into its constituent simple sugars, glucose and galactose, which may be further biologically or chemically modified to form alcohols, lactic or acetic acids, or more complex products such as penicillin. In these applications, lactose must compete with the less expensive sugars and starches that become the commercially preferable feedstocks. However, the economics of these relationships often change, leaving such uses as potential future opportunities. (One is reminded of the increase in the use of ethanol in motor fuels as the cost of petroleum soared during the 1970's.) The alcohol and aldehyde derivatives of lactose appear to offer great promise for commercial application in the chemical industry, where the competition is less plentiful and the finished-product cost higher.

Chemical derivatives of lactose, the Lacticol esters (the alcohol form of lactose to which a fatty acid has been attached), are known to have potential as surface active agents and emulsifiers. These fatty acid derivatives of lactose can be used in toothpaste and other toiletries because they are derived from natural ingredients and tend to be nontoxic. Their use has also been demonstrated as quenching agents in the hardening of steel.

Lacticol has been used as a raw material for the production of polyurethane foams. These foams have demonstrated their effectiveness as home insulating material as well as for use in packaging. Lacticol has also demonstrated potential in the manufacture of urea formaldehyde resin adhesives. This compound has even been dried and pressed into briquettes for use as fireplace logs. The commercial viability of these applications is again limited by the relative cost of lactose compared to other agricultural sources of fibers, starches, and sugars.