What is Progres® and how is it produced?

Juhani Vuorenmaa, R&D Director

Progres® is the only resin acids containing feed ingredient in the market. Because it’s “a new kid in the block”, customers are often asking what is Progres® and its resin acids and how is it produced. A natural plant origin of the product leads also into logical questions on the homogeneity of its composition and stability in feed processing.

A natural and stable product produced by thermal distillation without added chemicals

Progres® contains resin acids of rosin which is the natural protection mechanism of coniferous trees (pine and spruce) against bacteria, parasites and fungi. Rosin has been used in traditional medicine in wound healing for centauries and in a way, we utilize nature’s wisdom in animal feeding.

Progres® is produced from crude tall (= pine and spruce) oil which is separated by skimming the fat soluble fraction from a side stream of pulping process called black liquor. The black liquor contains various wood chemicals, including phenols and monoterpenes. However, most of the phenols being mainly water soluble remain in the aqueous solution after the separation. Most of the monoterpenes remain also in the black liquor and can be further processed into turpentine by evaporation and distillation.

The first step in the Progres® production is evaporation of water from the crude tall oil. As monoterpenes have a boiling point at about 160°C the possible monoterpene residues are removed from the product in the evaporation and first distillation steps and the end product can only contain traces of them. Possible residues of phenols, being relatively high molecular weight compounds, are separated in the distillation process to pitch fraction which is used for energy. The other two fractions of the distillation are fatty acids and resin acids which are mixed into standardized composition with high purity in the Progres® production. The distillation of resin acids is happening in temperatures of over 200°C and feed processing and pelleting do not affect their stability.   

Homogeneous composition guarantees consistent performance effects

Progres® contains on average 9% resin acids and 90% fatty acids. Every batch is analyzed for resin acids and their total amount is declared in the certificate of analysis. The majority of the fatty acids consists of common vegetable fatty acids, such as linoleic and oleic acids. The resin acids fraction is a natural mixture of different resin acids, mainly abietic, dehydroabietic, pimaric and palustric acids. The share of different resin acids varies slightly in the crude tall oil depending on the geographical area and season. However, the crude tall oil sources are mixed in the raw material intake and the variation of resin acids in the end product is very low.

Resin acids are non-volatile, natural diterpene carboxylic acids of coniferous trees. Resin acids molecules have the same basic skeleton of three fused rings with lipophilic -CH3 and hydrophilic –COOH regions and have an average molecular weight of 302. They have low solubility in water and are mainly fat soluble which differs them totally from organic acids. 

The natural mixture of coniferous tree resin acids and fatty acids of Progres® is standardized. The variation of its composition is very low. Every production batch is analyzed for resin acids and its content can be guaranteed. Resin acids are non-volatile and stable in feed processing and storing and their content can be measured from the feed. This makes it different from many other plant derived feed ingredients and is a key to the consistent performance effects that have been seen in numerous scientific trials in different animal species.