Quality Characteristics of Cumin Seed and Pomace: Antioxidant Activity, Bioactive Compounds, and Mineral Content

Cumin (Cuminum cyminum L.) is a prominent medicinal and aromatic plant extensively utilized in spice and essential oil production. However, the cumin pomace remaining after essential oil extraction is often treated as a low-value byproduct or waste. This study aimed to determine the functional properties of cumin pomace, a low-value byproduct or waste remaining after essential oil extraction, including its bioactive compounds, minerals, and antioxidant activity, and to identify its potential as a value-added secondary raw material by comparing it with cumin seeds. Cumin seeds were subjected to hydrodistillation for essential oil extraction, and the resulting pomace was used for further analysis. Extracts were prepared from both seeds and pomace using 70% ethanol, and extract yields were calculated. Antioxidant activity was determined using the DPPH radical scavenging assay; ICP-OES analyzed mineral content; and GC-MS identified bioactive components. The results indicated that the extract yield from cumin seeds (13.8%) was higher than that from pomace (6.6%). Conversely, the antioxidant activity of the cumin pomace (0.082 mg TE mL⁻¹) was found to be approximately four times higher than that of the seeds (0.020 mg TE mL⁻¹). Although a reduction in mineral content was observed following hydrodistillation, the pomace retained the mineral distribution pattern observed in the seeds. GC-MS analysis revealed that significant bioactive compounds, including isopulegol, ethyl palmitate, cuminalcohol, and linoleic acid ethyl ester, persisted at meaningful levels in the pomace. Furthermore, the partial retention of cuminaldehyde and cuminalcohol-the characteristic aromatic constituents of cumin-demonstrates that this byproduct preserves its aromatic and antioxidant potential. These findings suggest that cumin pomace is not merely a production waste but a valuable raw material with significant potential for upcycling in the food, cosmetic, and pharmaceutical industries.