ME-PRO^®: The effect and presence of anti-nutritional factors in soy products

ME-PRO^® is a microbially treated product made with GMO-free soybean hulls. A special production process (fermentation) is used, which on the one hand increases the protein content and protein digestibility, and on the other hand substantially reduces the anti-nutritional substances. This is in contrast to other soy protein concentrates (SPCs), which are often only treated with enzymes or alcohol. In this newsletter, we will take a closer look at the effect of anti-nutritional factors (ANFs) and their presence in soy products compared to our product ME-PRO^®!

Presence of ANFs in soybean products

ANFs originate from secondary metabolism in plants and are therefore found in many feed ingredients, including soy. In plants, ANFs can play a role in growth regulation, the formation of colour and odour compounds and protection against harmful organisms. Increased intake of ANFs can have problematic consequences, especially in monogastric animals. For example, this can lead to reduced feed intake and reduced production results. Moreover, ANFs can reduce the digestibility of nutrients and interfere with metabolism. The two most relevant ANFs in soy products, namely trypsin inhibitor and phytic acid, will be discussed in more detail below.

Trypsin inhibitor

The main anti-nutritional factor in soy products is trypsin inhibitor. Soybeans contain protease inhibitors that specifically inhibit the effect of the proteolytic digestive enzyme trypsin and also inhibit the effect of both trypsin and chymotrypsin. In the digestive process these enzymes produced by the body split proteins into peptides and amino acids. Inhibiting these enzymes seriously disrupts protein digestion. Raw soybeans and untreated soybean hulls can contain more than 25 mg of trypsin inhibitors per gram of product! Heating the product deactivates most of the heat-sensitive trypsin inhibitors. This is for instance important when using soy in the feed for young animals. Trypsin inhibitors are not demonstrable in ME-PRO^® (see Table 1), making it an ideal product for use in feed for young animals.

Phytic acid

Many plants store phosphorus in the form of phytic acid. Because monogastric animals lack the enzyme phytase, phosphorus in the form of phytate cannot be absorbed. Moreover, phytic acid also binds various other minerals such as calcium, iron, magnesium and zinc. These compounds are not soluble and cannot be absorbed from the intestine. Furthermore, protein digestion in the animal can also deteriorate as phytic acid can also bind proteins, creating poorly-soluble complexes. The phytic acid content of ME-PRO^® is significantly reduced compared to other SPCs (see Table 1).

Table 1. Concentration of trypsin inhibitor and phytic acid (mg/g product) in ME-PRO® and other SPCs.

	Trypsin inhibitor	Phytic acid
ME-PRO®	Not demonstrable	0.8
Alcohol extracted SPC*	2 – 3	6.0

*van Eys et al. (2004)

E.F.S. is a distributor of the product ME-PRO^®! Would you like to know more about this product? Please contact the E.F.S. team.