The product also looks to prevent loss of volume, and ultimately reduce energy consumption and wastage during the milling process, said the partners.
Developed in collaboration between the two companies, the new Perstorp technology is being exclusively distributed by Devenish.
The product is applied during the milling process, said Janus Fouche, product manager, Devenish. It is mixed with clean water before being sprayed onto the feed in the mixer.
Moisture evaporation
Between 1% and 3% of feed volume is lost during the manufacturing process due to variability in raw materials used and moisture evaporation during the grinding and pelleting process, resulting in lower actual moisture content compared to formulated levels, noted the companies.
There are multiple responses to the problem. The moisture loss can be corrected to formulated levels, improving quality, and financial returns. But just adding water creates free water. The dryer the particles the more hydrophobic they get making it harder for water to be absorbed. Excess free water can also create an environment for microbials to grow, they explained.
The Devenish and Perstorp technology enables the controlled re-introduction of the moisture that is lost in the feed manufacture process - the propionic acid esterified to glycerol, along with organic acids, and surfactants in the product allow moisture to penetrate the feed particles more effectively during milling - the moisture addition is better absorbed into the feed particle, enabling optimal moisture levels to be retained throughout the production process, thereby ensuring consistent feed moisture and quality, said Fouche.
The organic acids are esterified to the glycerol allowing feed to be protected from mold growth for longer, he added.
Development phase
The prompt for the development of the technology came in 2018. One of Devenish’s customers in Nigeria was experiencing feed milling losses, Fouche told us.
When Devenish investigated the issue, it found the problem was linked to moisture loss, at the incoming raw material stage, all the way through to final feed production. Looking around for solutions, Fouche said the team realized options were limited– industry had tended to rely on technology that had been in existence for over 40 years– typically ammonium propionate or surfactants– to ensure moisture was incorporated back into the feed.
In looking for more effective approaches, Devenish engaged Perstorp, as it had a long-standing relationship with the specialty chemicals firm, he said. Following further exploration, the companies hypothesized that Perstorp’s mold inhibition technology, based on propionic acid esterified to glycerol, in combination with surfactants, might be effective in terms of tackling moisture loss.
“We worked together on the development of the technology and we applied it to a customer’s process and had a huge amount of success with it, not just in retaining moisture but also in terms of maintaining feed quality. We started looking at the milling process as well, seeing what effect the technology had on the conditioner, on steam absorption, what effect it had on the pelleting process, looking at the impact it had on energy use and throughput. We found that it enabled better steam absorption and optimal energy usage during pelleting. We then introduced it to other customers, where we had repeated success,” he reported.
Commercial trials
The companies have carried out 17 commercial trials at feed mills since then, using external milling consultants to record the savings in terms of energy consumption and other performance parameters, said Fouche. “We have seen around 12% reduction in energy used in the pelleting process, improvement in steam uptake, and consistent improvements in pellet durability.”
The studies also show that up to 3% moisture can be reintroduced into feed using the technology in pelleted feed and up to 4% in extruded feed, with no adverse impact on either animal performance or product quality, he confirmed.
