Innovative research helps maintain markets for milk powder

By Rafael Jiménez-Flores, Ph.D., Cal Poly DPTC

Over the last two decades, the Dairy Products Technology Center (DPTC) has worked on programs and research for the continual improvement of milk powder, including projects on volatile flavor classifications, packaging studies for the improvement of transport and export, improvement of microbiological quality and spore counts, and composition.

Collaborations among DPTC scientists and quality managers in processing cooperatives throughout the San Joaquin Valley developed during the early 2000s resulted in the improvement of milk powder. Work from this partnership has yielded many practical results, among them a baseline of information and data on California milk powders that can be used in many ways. For example, we have gathered expertise over several cycles of milk production on the recurring environmental and industrial conditions influencing fluctuations in the milk powder properties during the production year and with seasonal changes. This is particularly true with non-fat dry milk (NFDM), which, unlike the world-traded skim milk powder (SMP), is not regulated to a minimum of 34 percent protein.Through research, we now know that NFDM produced in California is consistently higher in protein content than that produced in other areas – a key marketing tool.

Our milk powder microbial survey and spore improvement project at DPTC gave us a much better understanding of the production and processing conditions that impact the quality of the finished product. These projects started as California dairy initiatives when there was virtually no pressure to compete in the world market and most of the milk powder was sold as a commodity within the United States. Nevertheless,through the vision of the CDRF board, projects were implemented that have yielded very important basic information that paved the way to innovative research. Just one example is the analytical procedures developed for the elucidation of the geographical point of origin of milk powder.

The growth in the international trade of milk powder created the need for better analytical methods for the geographical identification of milk powder. The DPTC undertook a project, co-funded by CDRF and the US Dairy Export Council, with the goal of identifying analytical techniques that were compatible for the identification of the geographical point of origin. Given the extensive database of milk powder produced in California,valid comparisons were made from these powders and powders produced elsewhere.It was evident that no single technique could yield the sufficient accuracy and confidence to answer the basic “point of origin” question.

The challenge is that milk, like any other biological system, varies in composition according to the environment and feed, as well as the genetics and breed of the cow. Additionally, variations in milk composition and properties may be due to processing conditions. We suggest creating a certified laboratory in which unusual analyses of a complex and comprehensive nature can be performed for the benefit of the dairy industry.

Our data indicates that a combination of the analyses of color (and components responsible for this property), minerals (which reflect the soil and environment of the cows and their feed) and microbial ecology of the sample (which is a result of milk production environment, as well as processing conditions) can be used to determine the geographical location of a skim milk powder sample.

The results have given us new insights into milk powder and its properties in addition to being able to identify them. The mineral content of milk powders has significance in nutrition due to the need for accuracy in labeling minor minerals as nutrients. Color was an unexpectedly good indicator of the origin of milk. While color-generating components in milk have minor relevance, color in milk powder results from components in the original milk and those generated through processing.

Microbial ecology of milk powder is a subject we have studied for a long time, in particular concerning spore formers. Thanks to the wealth of information gathered on the California milk powder, we can distinguish it from many other powders produced elsewhere.

As the market for milk powder continues to grow, this will give California processors a marketable advantage in meeting the needs of national and international buyers.