Extraction of Phenolic Compounds from Cherry Seeds: A Preliminary Study

Agri-food waste has proved to be a valuable bioresource that can be used to obtain a variety of valuable materials, ingredients and chemicals. The optimum conditions for extracting bioactive compounds from sweet cherry seeds (SCS) with different solvents and temperatures were tested in this work. The choice criteria were based on the most efficient extracting capacity while looking for cleaner techniques with lower health or environmental impacts. Some extracting solvents (methanol, ethanol and water) were tested in different combinations and temperatures. The obtained extracts were evaluated for total phenolic compounds and some families of phenolics as well, using spectrophotometric methods. The results obtained showed that the highest extraction of total phenolic compounds was at 70 degrees C with 60:40 ratio water:ethanol (2.65 mg GAE/g), while maximum flavonoids were obtained at 80 degrees C and 50% ethanolic aqueous solution (7.26 mg QE/g). The highest value for ortho-diphenols was 21.47 mg GAE/g for 50 degrees C and water:ethanol 50:50 solution. The highest proanthocyanidins and flavonols were obtained for 50:50 solution at 70 degrees C (6.43 mg CE/g and 3.88 mg QE/g, respectively), while the same solution at 80 degrees C allowed obtaining maximum phenolic acids (1.68 mg CAE/g). The extraction of anthocyanins was found to vary significantly with concentration and temperature, being highest in the range 35-40 degrees C, when using an 80:20 water:ethanol solution. Hierarchical clustering showed three clusters, while factor analysis resulted in two factors and four groups of samples. In conclusion, it was found that extracts obtained from sweet cherry seeds have relevant bioactive compounds with applications in the food, pharmaceutical or cosmetic industries.