Full Fat Soy Shelf Life
In previous blogs, I have discussed the shelf life of texturized soy protein, along with ExPress® meal and ExPress® soy flour. However, I omitted the shelf life of extruded full fat soy (EFFS).
Recently, I visited a customer in South America that is looking to export full fat soy via land to a neighboring country. His concern was the level of moisture and if it could survive the trip and remain a high quality, fresh ingredient. I told him that EFFS has a long shelf life if extruded properly (at the right temperature), and stored properly (away from light, water, heat). One of the main reasons is because it has very low moisture (~5-7% post extrusion) and very low levels of FFA (~1%).
Our customer understood that a more dense, dry meal is an added nutritional benefit and better for shipping, but his next concern was about the % shrink due to the moisture loss in the extrusion process. He would be competing with local EFFS where they add back water after extrusion to get to 10% moisture, basically diluting their product. Insta-Pro does not recommend adding water to full fat soy due to the possibility of adding contaminants, bacteria, mold, etc. What they need to educate their customer on is that they are getting a more dense, higher quality ingredient and they are not buying water at the EFFS price.
Regarding the shelf life of EFFS, the product changes over time like any other product, but high-shear dry extrusion does an excellent job of keeping it stable for 9 months or longer.
The Wisconsin Alumni Foundation investigated the shelf life of full fat soy over a 9-month period at high storage temperatures and relative humidity. They tested samples at 37.8° C and 45% relative humidity and 45° C and 25%. The conclusion is the FFA levels remained below 1% for the full 39 weeks, and the peroxide values remained under 3%, both at acceptable levels.
In summary, having a dry, dense full fat soy, along with relatively dry, dark and cool storage conditions permits you to store your EFF for extended periods, which allows you to use or sell it at times when soy might not be available for processing.
