Optimization of phenolics substance and antioxidant activities, in the extraction from prunus spinosa L. fruits by response surface methodology

Functional foods or plant-based foods have recently been an interesting topic for many scientists and food manufacturers. In recent years, it is preferred to use foods with high antioxidant capacity for healthy nutrition. With the increasing interest in foods with high antioxidant content, the number of studies in this direction is increasing. Foods with high antioxidant content play an important role in preventing various diseases such as cancer, diabetes, cardiovascular diseases caused by free radicals and delaying aging by reducing the formation of free radicals in the body. With the awareness about adequate, balanced, and healthy nutrition, the importance of fruits and vegetables, which have been known for many years and reported to be rich in antioxidants, has increased even more. In this context, it is important to determine the ideal extraction method for the Prunus spinosa L. species, which is important in terms of antioxidant activity. One of the biggest difficulties encountered in extraction studies is the difficulty of eliminating the effect of undesirable factors on the dependent variable. Experimental design technique and surface response methodology are used to control this difficulty in achieving the desired goal in optimization studies. These techniques have taken their place in many fields such as food, medicine, chemistry, agriculture in providing optimization to increase product quality or reducing costs, and determining the ideal extraction method. In this study, it was aimed to determine the effect of solvent, temperature, and time conditions on yield, total phenolic substance, total flavonoid, total anthocyanin, and free radical capture activity (DPPH-ABTS) of the fruits of the Prunus spinosa L. plant, which is one of the wild fruits with rich values in terms of antioxidant, anticarcinogenic activities. For optimization, 20 extracts in 3 replicates were obtained using the response surface methodology and the results were evaluated. It was determined that the total amount of phenolic substance in the P. spinosa L. fruit extracts obtained was 10.99-19.03 (gallic acid equivalent mg/g), the total amount of flavonoid substance was 8.47-0.05 (quercetin equivalent mg/g), and the total amount of anthocyanin substance ranged from 9.77-363.83 mgC3G/100g; that the IC50 values of free radical capture activity varied between 106.97-539.64 µg/ml (DPPH) and 49.34-101.59 µg/ml (ABTS). According to the results of the surface response methodology used to determine the effect of extraction temperature, extraction time, and ethanol concentration parameters defined as independent variables, it was statistically determined that the optimum conditions in the extract of P. spinosa fruit, the temperature, and time in total flavonoid content, ethanol concentration in anthocyanin content and temperature in DPPH radical scavenging activity were effective. The optimum conditions determined by the response surface methodology for the parameters of temperature, time, and solvent concentration, at which the P spinosa L. fruit is rich in total phenolic material and free radical capture activity, will contribute to the exploitation studies of the species.