Maaeluvõrgustiku teenistus

GOOD PROJECT EXAMPLE: Development of a Technology for Processing Raspberry (Rubus sp.) Seed Oil

The problem to be solved

Tedre Farm, located on the hills of Otepää, has been growing raspberries for over twenty years. The majority of the berry crop is sold fresh during the harvesting period in summer. The two main problems in the wholesale are short storage life and damages during transport. In addition, the changing weather conditions in Estonia have an impact on the berry crop. Therefore, raspberries not suitable for fresh consumption should be deep-frozen and technological solutions for the processing of raspberries should be researched to ensure full valorisation of the berries.

The aim of the project was to find the best environmentally sustainable technology for the valorisation of the residues (mostly seeds) generated from processing raspberries. 

“Raspberry seeds contain extremely valuable oil and various processing technologies can be used for oil extraction.” Ave Kikas, the research partner of the project

Project outcomes

A pilot project on frozen residues of raspberries was carried out by the Plant Valor Laboratory of Polli Horticultural Research Centre of the Institute of Agricultural and Environmental Science of the Estonian University of Life Science. The most suitable method for separating seeds from the residues of raspberries was identified and then seeds were separated from the residues of raspberry juice production. Raspberry seeds contain extremely valuable oil that can be extracted by using different processing technologies. In this project, regular cold press method (screw press) was compared to supercritical extraction method and various optimization tests were carried out to find the best technological option. Both chosen technologies are environmentally friendly.

To assess the most suitable technology selected in the pilot project, the quality indicators of extracted raspberry oil and the most important bioactive compounds in the oil were analysed and their storage life was estimated. The fractions were tested to improve the quality parameters. The technological solutions developed as a result of the project enable raspberry producers to valorise raspberries more efficiently and develop new valorised products.