Enrichment of edible oil with sea buckthorn by‐products using ultrasound‐assisted extraction

Sea buckthorn (SBT) pomace, a by‐product of juice production, has been studied as a potential carotenoids source because such compounds are of great interest in the food industry. Ultrasound‐assisted extraction (UAE) has been used to improve the direct enrichment of edible oils (sunflower, rape seed, olive, and soya) with SBT carotenoids. These oils do not naturally contain carotenoids. After a preliminary study, a RSM has been used to maximize total carotenoid content of extracts and the influence of process variables on the UAE has been investigated. The results provided by the statistical analysis revealed that the optimized conditions were: sonication power of 0.67 W/g oil and a temperature of 35°C. The optimization parameters of this “green” process provide a greatly improved enrichment of the edible oil in terms of quantity and process time from 33.83 mg/L extract in 90 min obtained by conventional extraction to 51.64 mg/L extract in only 20 min by UAE. Ultrasound‐assisted carotenoids extraction from SBT by‐products appears to be a simple, rapid, and sustainable alternative to conventional procedures. Practical applications: Improving the value of low quality edibles is important for the food, cosmetic, or nutraceutical industry. It is done by adding ingredients such as carotenoids which are extracted by hexane or other solvents. In this study we show an innovative application of a direct extraction by maceration of by‐products in edible oil without solvent and eliminating evaporation and extraction unit operations. Using ultrasound, full extractions can now be completed in minutes with high reproducibility, reducing the consumption of solvent, simplifying manipulation and work‐up, giving higher purity of the final product, eliminating post‐treatment of waste water, and consuming only a fraction of the fossil energy normally needed for a conventional extraction method such as Soxhlet extraction, maceration, or steam distillation.