Recovery of bioactive compounds for valorization of chestnut (Castanea sativa) components

European chestnut (Castanea sativa), which belongs to the angiosperm family Fagaceae, originated in ancient times in the eastern Mediterranean region, and actually it is considered a significant tree in agricultural and forestry economy. For many centuries, chestnut fruits represented one of the most important food resources of rural areas. Currently in Campania (Italy), C. sativa occupies a main place among the plants and covers more than 40% of the national production. In recent years, chestnut has become increasingly important because of positive health effects as it is a rich source of bioactive compounds, including phenols with high activity against oxidative damages. Nowadays, the need to replace synthetic antioxidants used in the pharmaceutical, cosmetic and food industries, whose safety has been questioned, has promoted the research of new sources of natural antioxidant molecules. The undervalued products obtained from the agriculture and forestry could be used as an inexpensive supply of such compounds. The aim of this work is the evaluation of the effect of different extraction techniques on the recovery of bioactive compounds from chestnut components. Chestnut leaves and shells, used in this study, were from a specific cultivar from Campania. The extraction of phenolic compounds was carried out using different solvents and temperatures. Total phenols content was determined by the Folin-Ciocalteu method and the results were expressed as mg of gallic acid equivalents per g of dry matter. We would highlight that in this research only environmental friendly solvents (water and 60% ethanol) were utilized and therefore, they could be safely used for applications in the food industry. Out of the tested methods, the best one for chestnut leaves was the 60% ethanol at room temperature, while for chestnut shells resulted the water at boiling point. Phenolic content was more higher for leaves; moreover, ortho-diphenolic content was determined in each sample and results reproduced the same trend of those obtained for total phenols. The chestnut leaves and shells extracts showing highest phenolic amount were tested for antioxidant properties. The radical scavenging activity (RSA) of the extracts was monitored using the stable free radical DPPH and was expressed as % RSA. Further studies are needed to determinate the best extraction method useful to recover the major amount of bioactive compounds from other components of C. sativa, such as fruits and flowers.