Phenolic Content, Antioxidant and Antimicrobial Properties of Hawthorn (_Crataegus orientalis_) Fruit Extracts Obtained via Carbohydrate-Assisted Extraction  
[PERSON]  
1 Department of Biotechnology and Microbiology, Faculty of Science and Informatics, University of Szeged, Kozeef fasor 52, H-6726 Szeged, Hungary; [EMAIL_ADDRESS] (C.Z.); [EMAIL_ADDRESS] (T.K.); [EMAIL_ADDRESS] (M.V.); [EMAIL_ADDRESS] (A.S.); [EMAIL_ADDRESS] (T.V.); kerekerekier  
processed into jam or beverages [3; 4]. Hawthorn fruits are rich sources of polyphenols, flavonoids, vitamins, organic acids, tannins, and other phytochemicals [5; 6]. Hawthorn fruit extracts exhibit several pharmacological activities, including anti-inflammatory, cardioprotective, gastoprotective, antimicrobial, immunostimulant, hypoglycaemic, and cytotoxic properties [2].  
Bioactive phenolics can possess health-protective effects, including antioxidant, antimicrobial, anti-inflammatory, and anti-cancer activities; they can be found in large amounts in cultivated or wild fruits [7]. Some phenolic compounds in hawthorn have shown significant inhibitory effects against \(\alpha\)-glucosidase, making them promising anti-diabetic agents [8]. Many of these phenolic compounds can be used in the food industry as additives in functional foods or as preservatives in packaged foods [9; 10; 11; 12; 13]. For instance, phenolic extracts were applied in yogurt [14], bread [15], fresh pasta [16], and cottage cheese [17] products and tested as a natural antioxidant additive. However, the majority of plant phenolics can be found in phenolic-saccharide complexes, mainly in ester and glycosidic linkages, in the plant cell wall, resulting in limited bioavailability for the phenolic compound.  
Free phenolic substances can be obtained in high amounts from their bounded form through a variety of extraction methods. Widely used chemical methods for the release of phenolics are the acid and alkaline hydrolysis methods; however, these treatments often result in increased yields of harmful byproducts as well as low-quality final products [18; 19]. Effective phenolic extraction techniques also include ultrasonic- and microwave-assisted treatments, as well as supercritical fluid extraction methods [20]. Green technology for antioxidant compound extraction is a subcritical water extraction method [21]. A non-thermal, nontoxic, specific, and eco-friendly approach is the enzyme-assisted technique for the substrate treatment [19; 22; 23]. For instance, the carbohydrate-cleaving enzymes, including cellobiohydrolases (EC 3.2.1.91) and \(\beta\)-glucosidase (EC 3.2.1.21), can hydrolyze the glycosidic bond between the phenolic compound and the sugar residue, releasing the phenolic aglycones [24]. Pectinases (EC 3.2.1.15) can decrease the tissue rigidity in plant cell walls, also supporting the phenolic release from the polyphenic-saccharide structures [25]. Although hawthorn fruit has a considerable number of phenolic glycosides, extracting them via enzyme-assisted approaches has not yet been investigated.  
In a previous study, the combination of a _Rhizomucor mielei_ cellulolytic enzyme cocktail produced on wheat bran and a commercial _Aspergillus niger_ pectinase was used for the successful extraction of antioxidative phenolic compounds with antimicrobial properties from black grape, apple, and pitahaya residues [26; 27]. Here, an attempt was made to apply the _R. mielei_ cellulase and _A. niger_ pectinase-containing enzyme mixtures to obtain free phenolic compounds from hawthorn fruits. Individual phenolic compound profiles as well as the antioxidant and antimicrobial capacities of the extracts were also examined.