Valorization of sage (Salvia officinalis L.) by-product for recovery of bioactive compounds by novel extraction technique | Valorizacija sporednog proizvoda žalfije (Salvia officinalis L.) u cilju dobijanja bioaktivnih jedinjenja savremenim tehnikama ekstrakcije

The main aim of this dissertation was valorization ofsage (Salvia officinalis L.) by-product from filter-teafactory for recovery of high-value extracts withdesirable properties for application in food,cosmetics and pharmaceutical products.Conventional (maceration) and novel (ultrasoundassisted, microwave-assisted and subcritical waterextraction) extraction techniques were applied forpolyphenols recovery. Ethanol concentration wasoptimized in maceration process, while experimentaldesign and response surface methodology wereapplied for optimization of novel extractiontechniques. Polyphenols yield (total phenols andtotal flavonoids) and antioxidant activity,determined by various in vitro assays, wereinvestigated responses. Influence of main processparameters was determined for each technique:ultrasound-assisted extraction (temperature,extraction time and ultrasonic power), microwaveassisted extraction (ethanol concentration,extraction time and sample-solvent ratio) andsubcritical water extraction (temperature, extractiontime and HCl concentration in solvent). Liquidextracts obtained by novel extraction techniqueexhibited higher antioxidant activity determined byscavenging of DPPH and O2∙-radicals and reductionof Fe3+ and also provided higher polyphenols yieldcomparing to extracts obtained by maceration.Soxhlet extraction, hydrodistillation and supercriticalfluid extraction were applied for terpenoidsrecovery. Supercritical fluid extraction process wasoptimized by response surface methodology andoptimal conditions were pressure of 290 bar,temperature of 55˚C and CO2 flow rate of 0.4 kg/h,while predicted and experimentally obtained valuesof total extraction yield at these conditions were8.90 i 8.84%, respectively. According to chemicalanalysis, the most abundant compounds in lipidextracts and essential oil were oxygenatedmonoterpenes (α-thujone and camphor),oxygenated sesquiterpenes (viridiflorol) andditerpene polyphenols (epirosmanol).Sage liquid extracts obtained by conventional andnovel extraction techniques were spray dried inorder to obtain dry extract form. Physico-chemicalproperties (chemical profile, moisture content,hygroscopicity, rehydratation time, WAI and WSI)and biological activity (antimicrobial and antioxidantactivity) were determined in dry extracts and theirpotential application in food and pharmaceuticalformulations was discussed.