Valorization of date palm by-products (Phoenix dactylifera L.) in cake fortification: Nutritional enrichment, antioxidant retention, and shelf-life extension

Date palm processing yields underutilized by-products-fiber-rich date press cake (DPC) and lipid-rich date seed oil (DPSO)-with potential as multifunctional, sustainable ingredients. This study assessed their incorporation into cakes (DPC: 12.5-50 %; DPSO: 25-100 %) to improve nutritional, antioxidant, and shelf-life properties. Cakes with DPC had high phenolic and flavonoid contents (TP ≈ 548 mg GAE/100 g, TF ≈ 87 mg QE/100 g), with LC-MS confirming retention of catechin, chlorogenic acid, and quercetin post-baking. These contributed to 94.6 % DPPH radical scavenging, outperforming BHT. DPSO, rich in oleic acid (115.22 μg/g), reduced malondialdehyde by 94 %. Notably, both DPC and DPSO enhanced shelf-life: microbial counts after 21 days were 30-35 % lower than control. DPC-fortified cakes exceeded RDAs for Fe, Mn, and Zn, while remaining below ULs, confirming safety. Sensory evaluation supported acceptability at 12.5 % DPC and all DPSO levels. These findings demonstrate the thermal stability and dual functionality of DPC and DPSO in clean-label bakery applications.