Optimizing the extraction of bioactive components from sea buckthorn (Hippophae rhamnoides L.) pomace and development of antioxidant-enriched mayonnaise

Sea buckthorn pomace is rich in high-value biologically active compounds, which can provide functional properties for food products and pharmaceuticals. The aim of this study was to provide evidence for the valorisation of sea buckthorn pomace to obtain functional ingredients such as carotenoids, tocopherols and sterols that can find a potential applications while producing value-added products. Optimum conditions for supercritical carbon dioxide extraction (SFE-CO2) were determined based on Response surface methodology (RSM). Central composite design was used to optimize the SFE-CO2 extraction conditions (pressure, temperature, and time and modifier ethanol) to extract bioactive compounds. Proximate analysis of dried sea buckthorn pomace was performed by AOAC (moisture – 925.10; minerals – 900.02; crude protein – 960.52; crude fat – 920.39) official procedures. Total content of carotenoids was evaluated by UV – visible spectrophotometry. While content of tocopherols and phytosterols were determined by ultra-performance liquid chromatography – quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). Mayonnaise with sea buckhorn extract (concentrations 0.5%, 0.75%) produced by optimum conditions in order to improve its stability during storage (0; 14; 28 day) at room temperature. After RSM analysis, the optimal SFE extraction conditions for sea buckthorn pomace were: extraction temperature 35 °C, pressure 39 MPa with 5% ethanol as extraction modifier, and 2 h of extraction time. Under these conditions obtained yields were 14.39 g 100 gE−1 DW, carotenoids (175.92 mg 100 gE−1), α-tocopherol (72.46 mg 100 gE−1), and ergosterol (76.37 mg 100 gE−1). The developed process in this study is environmentally-friendly, and can be adopted for producing natural bioactive pigments for potential food industry applications. Some of the interesting results of obtained mayonnaise enriched with sea buckthorn pomace CO2 extracts will be presented.