This study used dried rosebuds from 24 newly crossbred Korean roses (Rosa hybrida) from Gumi Floriculture Research Institute (Gumi, Republic of Korea) in 2021, which are (1) Lover Shy, (2) Lovely Scarlet, (3) Loving Heart, (4) Red Perfume, (5) Luminus, (6) Mirinae Gold, (7) Betty, (8) Bichina, (9) Aileen, (10) Onnuri, (11) Yunina, (12) Jaemina Red, (13) Jinseonmi, (14) Chilbaegri, (15) Tamina, (16) Tamnari, (17) Pretty Velvet, (18) Peach Grace, (19) Pink Love, (20) Pink Perfume, (21) Hanaro, (22) Hanaram, (23) Hanggina, and (24) Ice Wing. Since total rosebud extracts were higher in antioxidative activity than petal extracts, in addition to having higher yield, we used total rosebuds [38 (link)].
Based on our previous study, the rosebuds were extracted with 80% ethanol to achieve high polyphenol content [39 (link)]). The dried rosebuds were pulverized in a rotor mill (Laval Lab Inc., Laval, QC, Canada), immersed in 80% ethanol in an ultrasonic water bath, heated at 60~70 °C for 2 h, and then ultrasonic-extracted for 1 h. Actually, the extraction solvent/solid ratio was set to 49:1 (980 mL 80% ethanol/20 g dried rosebuds). After extraction, the mixture was cooled, filtered, and then concentrated under a reduced pressure to 50 brix using a vacuum evaporator (Rotary Vacuum Evaporator N-N series; Eyela, Tokyo, Japan), and then used as a test sample.
Free full text: Click here