بررسي خصوصيات آنتي اكسيداني بذر و اثر روش خشك كردن بر خواص فيزيكوشيميايي كرفس كوهي

چكيده انگليسي :

Evaluation of Seed Antioxidant Activity and Effect of Drying Method on Physicochemical Properties of Wild Celery Kelussia Odoratissima Mozaff Plant Fereshteh Mokhtari f mokhtari@ag iut ac ir February 28 2012 Department of Food Science and Technology Isfahan University of Technology Isfarahn 84156 83111 IranDegree M Sc Language FarsiSayed Amir Hossein Goli amirgoli@acc iut ac irJavad Keramat keramat@acc iut ac irAbstractKelussia odoratissima Mozaff blonging to apiaceae family is a native Iranian herb This plant withlocal name of klus has been consumed as food and condiments by residents near its habitat and asa cough suppressant and a remedy for inflammation hypertension rheumatoid arthritis Foodoxidation is undesirable and leads to lower nutritional value and quality in the product Oxidativespoilage could change physical properties such as color and texture of the food which might bedangerous for human health Free radicals produced in oxidation process could participate inseveral undesirable chemical reactions in food and human body leading to secondary productswhich are harmful In order to scavenge free radicals and reduce oxidation rate in food products antioxidants are utilized Today synthetic antioxidants are widely used in processed foods but withsafety tests and their results it is observed that these compounds are harmful Therefore today theefforts have been done to replace these compounds with natural ones In this research after methanolic extraction and determination of total phenolic content in seedextract antioxidant activity was examined by model systems carotene bleaching assay diphenyl picryl hydrazyl DPPH and Ferric reducing power Extract antioxidant activity wascompared with synthetic antioxidant such as tert Butyl hydroquinone TBHQ Butylatedhydroxytoluene BHT and natural antioxidants Ascorbic Acid tocopherol Total phenoliccontent was determined by means of spectrophotometery using Folin Ciocalteu reagent andreported based on gallic acid equivalent Generally in DPPH and reducing power models theantioxidant activity of the seed extract was less effective than ascorbic acid and TBHQ butcomparable and greater than tocopherol and BHT Although in carotene bleaching assay theantioxidant activity of BHT was greater than the seed extract but difference was not significant TBHQ had the most antioxidant activity and ascorbic acid had lower activity in this assay Also in this study the effect of different drying methods on the physicochemical properties vitaminC chlorophyll total phenol and color of leaves and stems of this plant was examined The totalphenolic content was increased in the dried plant compared to fresh one Among the differentmethods of drying oven drying freeze drying microwave drying air drying and solar drying thesamples dried in air drying method showed highest total phenolic content The total phenoliccontent dried in oven and freeze drying methods had not significant difference In microwavemethod probably due to drying is quick and there is no enough time to break the cell structure andextraction of phenolic compounds total amount of these compounds was less than that of othermethods Microwave and freeze drying methods led to more preservation of vitamin C andchlorophyll as well as color Vitamin C and chlorophyll compounds are sensitive to heat and woulddestroy rapidly Vitamin C and chlorophyll concentration in freeze drying method was more thanthe other drying methods because in this method there is no heat as one of the most destructivefactors on vitamin C In microwave method due to short drying time higher levels of vitamin Cand chlorophyll were retained Keywords Kelussia odoratissima Mozaff Total phenolics Antioxidant activity Drying

مختاري، فرشته

بررسي خصوصيات آنتي اكسيداني بذر و اثر روش خشك كردن بر خواص فيزيكوشيميايي كرفس كوهي

تركيبات فنوليك , فعاليت آنتي اكسيداني