The Netherlands annually produces approximately 1.5 megatons of onions, or 1,500,000 kilograms (Holland Onion Association, 2020), making it the world leader in onion exports. In the processing of these onions, a residual stream of approximately 30 kilotons, 30,000 kilograms, of sorted-out onions, trimmings, and peels is generated each year. Currently, these byproducts are underutilized in low-value applications. The project Mild Extraction of Essential Oils and Fats from Onion Residual Streams by MNEXT and Biorefinery investigates the possibilities of valorizing these residual streams into high-value applications.
Given the increasing interest in valorizing residual streams in high-value applications, the valuable components in onion peels, including proteins and essential oils, offer innovative circular and biobased application possibilities in the food and chemical sectors. This awareness is also growing in the onion processing sector.
More efficient production method
MNEXT and Biorefinery Solutions (BRS) aim to develop a production method where oils and fats are separated while keeping the proteins intact. Currently, it is already possible to produce flavorings from essential oils and fats extracted from onion residual streams. However, the drawback of this process is that the proteins lose their structure and are not usable as high-quality raw materials. To achieve a better production method, BRS aims to unlock the material under mild chemical process conditions. The other present components will then be recovered in subsequent steps. This will make the process more energy-efficient and result in lower (indirect) CO2 emissions. In this way, the project Mild Extraction of Essential Oils and Fats from Onion Residual Streams contributes to the materials and energy transition.