Extraction Conditions for Phenolic Compounds with Antioxidant Activities from White Rose Petals

Abstract The extract of white rose petals has an antioxidanteffect and can be used to treat allergic disease. The purpose of thisstudy was to identify optimal conditions for extracting anti-oxidative compounds from white rose petals with 2,2-diphenyl-1-picrylhydrazyl scavenging activities. A response surface methodologybased on a central composite design was used to investigate theeffects of three independent variables: ethanol concentration (X 1 ),extraction temperature (X 2 ), and extraction time (X 3 ). Theestimated optimal conditions for obtaining phenolic compoundswith antioxidant activities were as follows: ethanol concentrationof 42% (X 1 ), extraction time of 80 min (X 3 ), and extractiontemperature of 75 o C (X 2 ). The estimated optimal conditions forobtaining flavonoid compounds with antioxidant effects were anethanol concentration of 41% (X 1 ), extraction time of 119 min(X 3 ), and an extraction temperature of 75 o C (X 2 ). Under theseconditions, predicted response values for the phenolic andflavonoid contents were 243.5 mg gallic acid equivalent/g drymass and 19.93 mg catechin equivalent (CE)/g dry mass,respectively.Keywords anti-oxidative compounds · response surface methodology · total flavanoid contents · total phenolic contents · white rose petalsIntroductionPhenolic compounds are naturally occurring bioactive phytochemicalsfound in plants (Cowan, 1999; Kris-Etherton et al., 2002). Thechemical structures of these reagents consist of a hydroxyl groupbonded directly to one or more aromatic benzene rings (Cai et al.,2006). Many types of phenolic compounds including flavonoids,anthocyanins, and carotenoids are found in a wide range of foodssuch as herbs, vegetables, and legumes (Rauha et al., 2000; Zhengand Shiow, 2001; Cai et al., 2004; Lopez-Amoros et al., 2006;Huang et al., 2007). Phenolic compounds possess antioxidantproperties that help protect against free radical damage bydonating a hydrogen atom, and reduce the risk of various diseasesassociated with oxidative stress (Rice-Evans et al., 1996; Kahkonenet al., 1999). Therefore, consumption of natural antioxidantscontaining phenolic compounds may help protect the human bodyagainst various disorders such as cancer, diabetes, and cardiovasculardisease (Rao et al., 1995; Stephens et al., 1996; Padayatty et al.,2003; Bajpai et al., 2005; Al-Mustafa and Al-Thunibat, 2008).Roses are ornamental plants grown in gardens or parks. Manyspecies of roses have long been used in herbal and folk medicinesto alleviate menstruation problems, treat blood circulation disorders,and control cancer growth (Kwon et al., 2006; Shafei et al., 2010;