Cold pressing of flaxseed produces high-quality oil along with a nutritionally rich by-product—flaxseed cake. While the cold-pressing process is valued for its minimal processing and preservation of oil quality, it is also characterized by low resource utilization efficiency and significant by-product generation. Specifically, the production of 1 kg of flaxseed oil results in approximately 2 kg of residual cake. Given its high protein content (approximately 35–40%), flaxseed cake holds considerable potential as a source of bioactive peptides and other value-added compounds

In this study, flaxseed cake obtained from cold pressing was milled and sieved to a particle size below 0.6 mm. Its chemical composition (protein, oil, fiber) was analyzed. Controlled enzymatic hydrolysis was performed with Trypsin for 2 h. An E/S ratio was 5 %, and the temperature used for hydrolysis was 37 °C. The antioxidant capacity of the non-hydrolyzed sample and hydrolysate was determined.

Protein content was 37 %, oil was about 21 %, and fiber was approximately 28 %. The results showed a degree of hydrolysis of about 5 % and a significant increase in antioxidant activity. By determining the concentration of flaxseed powder required to inhibit 50 % of the DPPH free radicals, it was observed that this concentration was significantly (p < 0.05) higher in the non-hydrolyzed sample (11.0 mg/mL) compared to the hydrolysate (9.1 mg/mL).