## 1 Introduction  
Hops (_Humulus lupulus_ L.), family Cannabaceae, are perennial herbaceous species of flowering plants valued in pharmacognosy for their sedative, antioxidant and antimicrobial properties [1]. These plants have been widely used as one of the essential ingredients in the brewing industry to confer organoleptic characteristics such as bitterness, aroma and taste to beers [2]. In line with market and consumer growing demands for natural products, currently, besides traditional sedative hop products (teas, extracts, inctures, etc. ), there is an increasing interest in innovative hop preparations based on their phytochemicals and bioactive potential [3]. Recent reviews highlight the diverse health-promoting effects of hops: anxiolytic, antioxidative, antidiabetic, anti-inflammatory, antitumor, anticarcinogenic and neuroprotective activities are attributed to the structural diversity of secondary metabolites present in hops [3, 4, 5, 6]. As a result, hops and their extracts, besides their extensive use in the brewing industry that utilizes 90% of worldwide production, have started finding use in other food, nutraceuticaltical, agricultural, pharmaceutical or cosmetic applications [3, 4]. Therefore, there is an increasing interest in manufacturing high-quality hop-origin products, enriched with valuable essential oils, bitter acids and prenylflavonoids with the desirable organoleptic and bioactive properties [3, 5, 6, 7]. As summarized in recent reviews, the recovery of valuable lipophilic _H. lupulus_ fraction, primarily essential oils and hop bitter acids, can be achieved either conventionally by Soxhet extraction or hydrodistillation, or assisted by intensifying technologies; for example, microwave-assisted hydrodistillation, pulsed electric fields, pressurized liquid extraction, etc. [4; 7]. The ongoing demand for sustainable processes emphasizing environmental and safety aspects (i.e., avoiding harmful residual solvents in the extract) has incentivized the use of neoteric solvents and particularly supercritical fluids [8; 9]. Among them, supercritical carbon dioxide extraction (SFE-CO\({}_{2}\)) of hops is a pioneer of commercial applications for this technique [7; 9]. Supercritical CO\({}_{2}\) hop extracts can serve both as valuable aroma bearing and high-bittering-potential bearing products, offering higher shelf life and bioactive compound stability than hop cones or pellets [3; 7]. Generally, the commercial SFE-CO\({}_{2}\) is performed at relatively low pressures (up to 15 MPa) as a one-stage process with liquid or supercritical CO\({}_{2}\) to jointly recover aroma-rich fractions and a fraction of bitter acids from hops or their byproducts [7; 10; 11; 12]. Moreover, aroma and bittering substances can be separated during two-stage SFE-CO\({}_{2}\) to formulate different products to be used at the various stages of the brewing process [7]. However, prolonged extraction time is characteristic of the industrial SFE-CO\({}_{2}\) of hops, while the products are basically tailored to the brewing industry's needs [7; 13; 14]. Due to the constant development of novel _H. lupulus_ extract applications [3], single-variety _H. lupulus_ extracts with different properties and bioactive compound assemblies will be required to meet the demands of the functional food, nutraceuticalal, pharmaceutical and cosmetic industries. The so-called dual-purpose hop varieties, which are rich in essential oil and bitter acids [6], such as _Ella, Citrus, Columbus, Galaxy_ and others, can serve as a promising feedstock for these purposes. Given our group's interest in the utilization of emerging techniques to recover high added-value constituents from various feedstocks and agroindustrial residues [15; 16; 17; 18; 19], the present work is aimed at developing an effective SFE-CO\({}_{2}\) process for production of natural dual-purpose hop extracts from _Ella_ (previously named _Stella_) variety with high yield and strong oxygen radical scavenging capacity (ORAC).