Design, Production and Quality Assessment of Antioxidant-Enriched Olive Paste Dips Using Agro-Food By-Products

This study focuses on the design, development and quality assessment of an innovative shelf-stable olive paste dip, aiming at the valorization of by-products of tomato processing and olive oil production (Product 1: OPD). Bioactive compounds (BACs), i.e., total carotenoids and phenolic components, were extracted from tomato and olive pomace, respectively. For further enrichment, BACs were incorporated in olive paste dips into a second product (OPDEnr) in encapsulated form (Product 2: OPD_Enr). The total carotenoids (TC) of OPD and OPD_Enr were 20.0 ± 2.0 and 30.2 ± 1.0 mg/kg, respectively. Similarly, the total phenolic content (TPC) and the antioxidant activity (AA) were 1.62 ± 0.08 and 3.05 ± 0.10 mg GAE/g, and 0.801 ± 0.075 and 0.976 ± 0.032 mg Trolox/g, respectively. The quality of the developed olive paste dip product prototypes was assessed using the Accelerated Shelf Life Testing (ASLT) methodology at a temperature range of 20-40 °C. Both OPD_Enr and OPD were microbiologically stable during storage (i.e., not exceeding 4 logCFU/g for total mesophilic counts), and no lipid oxidation evolution was observed (Peroxide Value, PV did not exceed 4 meq O₂/kg), while TC, TPC and AA values remained stable. The shelf life of OPD_Enr and OPD was determined based on the overall sensory quality and was found to be 120 and 211 d at 25 °C, respectively. OPD_Enr and OPD were characterized by a high quality (color and texture), with an overall sensory score of 8.0/9.0 and 9.0/9.0, respectively, in the acceptability-hedonic scale 1 (dislike extremely)-9 (like extremely), and they could potentially be consumed as an antioxidant-enriched olive paste dip.