Blog series 5: Drying increases the value added of bones to 100% – processing bones into meat and fish protein

The previous posts have dealt with the value increase of bone from the broth business perspective: we have covered the broth and sauce manufacturing process and broth line module equipment, animal fat processing, the automation system of the line and, most recently, the degree of completion of the line installation.

In this post, we move on to the bone drying system that is the second significant process in increasing bone value in the overall management of the bone side streams in the food industry. The drying process increases the value added of bones to 100% when the bones are processed into different dry sections, such as dry protein high in whites, while reducing the bone waste amounts of the food processing plant to the minimum.

SHS drying equipment

The SHS dryer offered by Coctio is based on patented Finnish drying technology. In addition to the bone side streams and other side sections of food processing plants, the drying equipment is also suited to material streams generated in the processing of other branches of industry that are difficult to process, such as the industrial upgrading of further dried materials and drying sludge from the wood processing industry and sewage plants.

Drying equipment that is suitable for bone processing can be built in various sizes according to capacity requirements. The capacity depends on how much water should be extracted in a drying process of one hour. The evaporation capacity can vary from 10 to 4,000 kg of water per hour.

The SHS drying equipment is an independent equipment entity that the customer may purchase either as an individual equipment entity or it can be connected to the Coctio stock and sauce line in order to dry and upgrade the bone remains resulting from the cooking process.

A dryer evaporating 1,600 l of water per hour to be delivered to a customer in autumn 2016

We are currently building a dryer that is able to evaporate 1,600 l of water per hour for a Finnish company upgrading meat industry by-products. The dryer will be delivered to the customer in early autumn 2016. We will provide more information on the dryer delivery in the course of the summer.

How does the SHS drying system work?

The drying technology of bones (or any other industrial section to be dried) is based on the use of superheated steam in the drying process, hence also the term SHS (superheated steam).

The drying equipment and method are very simple: 

1. Products to be dried are fed into the constantly running drying chamber operating in a vacuum.
2. The product is heat-treated in the chamber with the help of superheated steam to a boiling point in order to evaporate any water from the product.
3. The dried product is then moved to the dry section of the chamber and on to a storage silo, for example, for further processing.

The evaporated water leaves the drying process as 90-degree condensation water that can be reused in the plant’s other industrial processes or, for example, utilised in the production of district heating.

Since the drying process takes place in a vacuum, no air is formed inside the system, only steam, making the process both fire- and explosion-risk free. No offending smells are generated by the process.

Uses of bone drying in pet food, foodstuffs and in the fodder and fertiliser industry

After the drying, the bone and meat mixtures are separated from each other. Both the meat and bone sections are easy to upgrade into several commodities for the markets.

The meat section is pressed into grained dry protein of approx. 5 mm in size. Depending on whether fish cleaning sections or slaughter animal bones are used, the end result will be meat or fish protein high in whites that is an excellent raw material due to its high protein content for dried pet food. The meat and fish protein can also be used as a raw material in the food industry, because the drying method is extremely hygienic. In addition, the stainless steel equipment meets the health and safety requirements set for food production making the use of dry protein in human nutrition very safe.

Any remaining bone section can be further crushed and ground into bone powder that can be utilised as nutrient fodder for fur animals and in fertilisers.

Want more info about our SHS Dryer system?