Enzymatic Modification of Pomace Olive Oil with Natural Antioxidants: Effect on Oxidative Stability

Enzymatic lipophilization has been proposed as a cost-effective strategy to produce new liposoluble antioxidant compounds. In this study, modified oils rich in structured phenolipids were prepared via one-pot enzymatic acylation of hydroxytyrosol (HTYR), vanillyl alcohol (VA) and homovanillyl alcohol (HVA) with pomace olive oil (POO) in solvent-free conditions using immobilized lipase on biogenic nanoparticles. The effect of temperature (30-70 & DEG;C) and enzyme concentration (0.1-1%, w/w) on the efficiency of the bioprocess as well as the reusability of the nanobiocatalyst were thoroughly investigated. The modified oils exhibited increased antioxidant activity compared to the control oil according to DPPH and CUPRAC assays (p < 0.05). The oxidative stability of pomace olive oil was also significantly enhanced after modification, as depicted by the K-232 values and TBARS contents under accelerated oxidation at 60 & DEG;C (p < 0.05). Moreover, a fortified mayonnaise containing modified oil with HTYR was prepared that was noticeably stable compared to the control mayonnaise at 28 & DEG;C for 5 months (p < 0.05). Enzymatically modified oils have great potential for application in the nutraceutical and food industry, encouraging the exploitation of immobilized lipases as effective and green catalytic tools.

Automated summary

Enzymatic lipophilization using immobilized lipase on biogenic nanoparticles was employed to prepare modified oils rich in structured phenolipids. The effects of temperature and enzyme concentration on the bioprocess efficiency and nanobiocatalyst reusability were investigated. The modified oils showed enhanced antioxidant activity and improved oxidative stability. A fortified mayonnaise containing the modified oil exhibited increased stability compared to the control mayonnaise. Enzymatically modified oils have great potential for applications in the nutraceutical and food industry.