Biological activity of extracts of food industry by-products prepared using eutectic solvents

Nusproizvodi prehrambene industrije često predstavljaju problem zbog zbrinjavanja, ali su ujedno i bogat izvor biološki vrijednih spojeva, kao što su fitokemikalije. Posljednjih se godina eutektička otapala (DES) istražuju kao alternativna otapala za zelenu ekstrakciju, a u ovom radu su korištena za ekstrakciju biološki aktivnih spojeva iz biljnog materijala. Pripremljeni su ekstrakti komine grožđa, komine masline i prešane lanene pogače pri prethodno optimiranim uvjetima s eutektičkim otapalima i konvencionalnim otapalima. Nadalje, pripremljenim ekstraktima spektrofotometrijskom metodom je određen udio polifenolih spojeva, antioksidacijski kapacitet ORAC metodom te je ispitana biološka aktivnost na trima staničnim linijama (HeLa, MCF-7, HEK293T). Najveći udio polifenolnih spojeva ekstrahiran je iz komine grožđa s eutektičkim otapalom kolin-klorid:limunska kiselina, a isti ekstrakt imao je najveći antioksidacijski kapacitet te najizraženiji inhibitorni učinak na stanične linije. Tretiranim humanim tumorskim staničnim linijama određen je i tip stanične smrti te je indukcija apoptoze izražena nakon tretmana ekstraktom komine grožđa pripremljenog u zakiseljenom etanolu.Recurring problem in food industry is disposal of by-products which are also a rich source of biologically active compounds, such as phytochemicals. In recent years deep eutectic solvents (DES) are investigated as alternative solvents for green extraction and in this paper they are used for extraction of biologically active compounds from plant materials. Extracts from grape pomace, olive pomace and flaxseed pressed cake were prepared in optimized conditions with eutectic and conventional solvents. Furthermore, total polyphenols were analyzed using spectrophotometric method, antioxidant capacity was determined using ORAC method and biological activity was tested on three cell lines (HeLa, MCF-7, HEK93T). Grape pomace in DES exhibited the highest value of polyphenols, the highest antioxidant activity and the most prominent inhibitory effect on cell lines. Type of cell death was determined for treated human tumor cell lines and the induction of apoptosis was most significant after treatment with acidified ethanol