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  • Real Pork Trust Consortium

The Good, the Bad, and the Ugly of Soybean Meal Components

Shown here in a field on a pig farm, soybeans are a major source of protein for pigs, and their components can be bad based on how soybean meal is extracted
Soybeans, pictured here being grown on a pig farm, are a main source of protein in pigs' diets. Photo: National Pork Board, Des Moines, Iowa.

Dr. Pedro Urriola, an Assistant Professor of Animal Science at the University of Minnesota, was part of a research team that wanted to understand how the methods used to extract soybean meal influenced the chemical components of soybean meal, which is a large source of protein for pigs. The research findings about soybean meal proteins, fat, and lipids from mechanical extraction are discussed below.

Major Finding

Rancid proteins (the bad) and fat (the ugly) occur in various concentrations in soybean meal, which is the most common source of protein in pigs’ diets. The bad and ugly contrast with variable concentrations of antioxidants (the good).

This study found soybean meal extracted mechanically had higher concentrations of bad proteins and ugly fats than soybean meal extracted using solvents. Interestingly, the concentration of bad proteins and lipids was associated with the chemical properties of the soybean meals.


Why It Matters

Soybean meal is the most common source of protein in the diets of pigs in the U.S., and the availability of soybean meal is expected to increase significantly due to the recent application of the renewable fuels standard. Oxidation of lipids (sometimes called rancidity) can occur in the proteins and fat in soybean meal. When oxidation of lipids occurs in feed, the resulting taste causes pigs to eat less, therefore challenging their antioxidant systems and creating a problem for farmers who want to provide good sources of food for their animals.

Therefore, it is essential to generate awareness among fuel producers that their oil extraction methods potentially impact the quality of the soybean meal and, thus, pigs’ desire to consume that soybean meal and receive antioxidants.


How the Research Was Conducted

For this study, scientists examined two types of soybean meal. There were 54 samples that used solvent to create the soybean meal and eight samples that used mechanical methods to extract soybean meal. To explore all chemical components in each sample, scientists used chemometric analysis, which combines the techniques of liquid chromatography and mass spectroscopy. The chemometric analysis helped scientists see how much the protein in the soybean meal had changed through oxidation. Then, they were able to assess if the amount of protein oxidation in a sample was related to the type of soybean oil extraction methods or other non-protein components. Samples used in this study were collected from a University of Minnesota soybean meal database between 2020 and 2021.


Learn More

To learn more about the impacts of soybean meal on the pork industry and the food you eat, read the full peer-reviewed journal article.

The Good, The Bad, and The Ugly of Soybean Meal Components
Download PDF • 234KB


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