The Impacts of Fluidized and Static Bed Drying Methods on Bio-active Compounds and Antioxidant Properties of Saffron Petal

Document Type : Research Paper


1 Department of Food Science and Technology, Sabzevar Branch, Islamic Azad University, Sabzevar, Iran

2 Agricultural Engineering Research Department, Khorasan Razavi Agricultural and Natural Resources Research and Education Center, AREEO, Mashhad, Iran

3 Department of Food Science and Technology, Faculty of Agricultural Technology and Engineering, University of Tehran, Karaj, Iran


Saffron petal was dried from 85% to 10% moisture content with fixed layer bed (FLB), semi fluidized bed (SFB) and fully fluidized bed (FFB) at temperatures (t) of 35, 45 and 55 °C. The airflow (v) of FLB, SFB and FFB were 0.2, 0.7 and 1.7 ms-1, respectively. When the t/v ratio increased in each method, the dehydration time decreased considerably. The dehydration times and drying rates of saffron petal for FLB (v = 0.2 ms-1& t = 35 °C) and FFB (v = 1.7 ms-1& t = 55 °C) were “570 & 30 min” and “0.13 & 2.50 gH2O/min”, respectively. When the airflow increased from 0.2 to 0.7 and then to 1.7 ms-1, the phenolic, anthocyanin & antioxidant contents of dried saffron petal improved to about 6, 15 & 15% and then to 15, 20 & 42%, respectively.  However, by increasing air temperature from 35 to 45°, their phenolic and anthocyanin contents did not change significantly. However, sharp reductions of 20, 23 and 41% respectively were noticed in phenolic and anthocyanin contents and antioxidant activities of saffron petal when the drying temperature exceeded 45 and reached to 55 °C. Overall, the fresh saffron petal dehydrated at 45 °C with FFB had the highest phenolic and anthocyanin contents and antioxidant activities.


  1. Hemmati Kakhki A, Rahimi S. Extraction of anthocyanin from petals of saffron (Crocus sativus L.) and its stability in a model beverage. Iranian Research Organization for Science. 1994.
  2. Goli SAH, Mokhtari F, Rahimmalek M. Phenolic compounds and antioxidant activity from saffron (Crocus sativus L.) petal. J Agric Sci. 2012;4:175-181.
  3. Chimi H, Cillard J, Cillard P, Rahmani M. Peroxyl and hydroxyl radical scavenging activity of some natural phenolic antioxidants. J American Oil Chem' Society. 1991;68:307-312.
  4. Heydari S, Rezaei R, Haghayegh GH. Effect of drying processes on stability of anthocyanin extracts from saffron petal. Evolving Trends in Engin and Techol. 2014;2:13-18.
  5. Mortazavi SA, Shafafi zenoozian M, Arianfar A, Niyazmand M, Asadinezhad S. Dehydration of foods. Ferdowsi University. 2008.
  6. Yaldýz O, Ertekýn C. Thin layer solar drying of some vegetables. Drying Technology. 2001;19:583-597.
  7. Toğrul İT, Pehlivan D. Modelling of drying kinetics of single apricot. J Food Engin. 2003;58:23-32.
  8. El-Beltagy A, Gamea G. Essa A.A. Solar drying characteristics of strawberry. J of Food Engin. 2007;78:456-464.
  9. Motevali A, Minaei S, Banakar A, Ghobadian B, Khoshtaghaza M.H. Comparison of energy parameters in various dryers. Energy Conversion and Manag. 2014;87:711-725.
  10. Jafari S.M, Ghanbari V, Ganje M, Dehnad D. Modeling the drying kinetics of green bell pepper in a heat pump assisted fluidized bed dryer. J Food Quality. 2016;39:98-108.
  11. Kaleta A, Górnicki K, Winiczenko R, Chojnacka A. Evaluation of drying models of apple (var. Ligol) dried in a fluidized bed dryer. Energy Conversion Management. 2013;67:179-185.
  12. Hemmati Kakhki A. Optimization of effective parameters on production of food color from Saffron petals. Agric Sci Techol. 2001;15:113-20.
  13. Javadi HS, Ahmadian S. Comparison of the effects of vacuum oven-, freeze-, solar-, and microwave-drying with traditional drying methods on the qualitative characteristics of ghaen saffron. Iranian J Nutr Sci Food Techol. 2007;2:69-76.
  14. Azami L, Babapour A, Garechahi M. Antimicrobial Effect of aqueous extract of saffron petals on some of food-borne bacterial pathogen. J Food Hygiene. 2012;2:63-73.
  15. Sharayei P, Chaji H. Optimazation of thin layer drying conditions of saffron petal using Response Surface methodology. Iranian Food Sci Techol Research J. 2018;14:877-889.
  16. Farhoush R. Extraction, Purification and Identification of Antioxidant Main Fraction of Salvia leriifolia leaf and studying its properties, in Facult of Agric. Ferdowsi University: Mashhad. 2004.
  17. Huang Jd, Yang L. Microencapsulation of anthocyanins from fruits of Berberis kaschgarica Rupr. J Food Sci. 2011;16:5-14.
  1. Mahdavi KK, Jafari SM, Ghorbani M, Hemmati K.A. Optimization of anthocyanin extraction in Saffron's petal with response surface methodology.2014.
  2. Ersus S, Yurdagel U. Microencapsulation of anthocyanin pigments of black carrot (Daucus carota L.) by spray drier. J Food Engin. 2007;80:805-812.
  1. Lotfi L, Kalbasi-Ashtari A, Hamedi M, Ghorbani F. Effects of enzymatic extraction on anthocyanins yield of saffron tepals (Crocos sativus) along with its color properties and structural stability. J Food Drug Analysis. 2015;23:210-218.
  2. Lotfi L, Kalbasi-Ashtari A, Hamedi M, Ghorbani F. Effects of sulfur water extraction on anthocyanins properties of tepals in flower of saffron (Crocus sativus L). J Food Sci Techol. 2015;52:813-821.
  3. Parker JC. Developing a herb and spice industry in Callide Valley, Queensland. Rural Industries Research & Development Corp. 1999.
  4. Sacilik K, Keskin R, Elicin AK. Mathematical modelling of solar tunnel drying of thin layer organic tomato. J Food Engin. 2006;73:231-238.
  5. Sacilik K, Elicin AK. The thin layer drying characteristics of organic apple slices. J Food Engin. 2006;73:281-289.
  6. Akpinar EK, Bicer Y, Yildiz C. Thin layer drying of red pepper. J Food Engin. 2003;59:99-104.
  7. Pangavhane D, Sawhney R, Sarsavadia P. Effect of various dipping pretreatment on drying kinetics of Thompson seedless grapes. J Food Engin. 1999;39:211-216.
  8. Mwithiga G. Olwal JO. The drying kinetics of kale (Brassica oleracea) in a convective hot air dryer. J Food Engin. 2005;71:373-378.
  9. Katsube T, Tsurunaga Y, Sugiyama M, Furuno T, Yamasaki Y. Effect of air-drying temperature on antioxidant capacity and stability of polyphenolic compounds in mulberry (Morus alba L.) leaves. Food Chem. 2009;113:964-969.
  10. Larrauri JA, Rupérez P, Saura-Calixto F. Effect of drying temperature on the stability of polyphenols and antioxidant activity of red grape pomace peels. J Agric Food Chem. 1997;45:1390-1393.
  11. Vega-Gálvez A, Di Scala K, Rodríguez K, Lemus-Mondaca R, Miranda M, López J, Perez-Won M. Effect of air-drying temperature on physico-chemical properties, antioxidant capacity, colour and total phenolic content of red pepper (Capsicum annuum, L. var. Hungarian). Food Chem. 2009;117:647-653.
  12. Vega-Gálvez ALMS, Lemus-Mondaca R, Bilbao-Sáinz C, Fito P, Andrés A. Effect of air drying temperature on the quality of rehydrated dried red bell pepper (var. Lamuyo). J Food Engin. 2008;85:42-50.
  13. Zaiton H, Suzila I, Ahmed-Mahir M.M.B, Salmah Y, ZAINI H.C. Quality of roselle tea as affected by drying temperatures and storage time. In Prosiding Seminar Kimia, Bersama: UKM-ITB VIII. 2009;190-196.
  14. Piga A, Del Caro A, Corda G. From plums to prunes: influence of drying parameters on polyphenols and antioxidant activity. J of Agricl Food Chem. 2003;51:3675-3681.
  15. Patras A, Brunton NP, O'Donnell C, Tiwari B.K. Effect of thermal processing on anthocyanin stability in foods; mechanisms and kinetics of degradation. Trends Food Sci Techol. 2010;21:3-11.
  16. Francis FJ, Markakis PC. Food colorants: anthocyanins. Critical Reviews Food Sci Nutr. 1989;28:273-314.
  1. Giusti MM, Wrolstad RE. Acylated anthocyanins from edible sources and their applications in food systems. Biochemical Engin J. 2003;14:217-225.
  2. Wojdyło A, Figiel A, Lech K, Nowicka P, Oszmiański J. Effect of convective and vacuum–microwave drying on the bioactive compounds, color, and antioxidant capacity of sour cherries. Food and Bio Techol. 2014;7:829-841.
  3. Madrau MA, Piscopo A, Sanguinetti AM, Del Caro A, Poiana M, Romeo FV, Piga A. Effect of drying temperature on polyphenolic content and antioxidant activity of apricots. European Food Research Techol. 2009;228:441.
  4. Cheigh HS, Um SH, Lee CY. Antioxidant characteristics of melanin-related products from enzymatic browning reaction of catechin in a model system. ACS Publications. 1995.
  5. Elizalde B, Bressa F, Rosa MD. Antioxidative action of Maillard reaction volatiles: influence of Maillard solution browning level. J American Oil Chemists' Society. 1992;69:331-334.
  6. Yen GC, Hsieh PP. Antioxidative activity and scavenging effects on active oxygen of xylose‐lysine maillard reaction products. J Sci of Food Agric. 1995;67:415-420.
  7. Severini C, Lerici C. Interaction between Maillard reaction and lipid oxidation in model systems during high temperature treatment. Ital. J Food Sci. 1995;2:189-196.