A comprehensive analysis and comparison between vacuum and electric oven drying methods on Chinese saffron (Crocus sativus L.)

  • Chong Yao
  • Xiao-Dong Qian
  • Gui-Fen Zhou
  • Shu-Wei Zhang
  • Li-Qin Li
  • Qiao-Sheng GuoEmail author


The red stigmas of saffron are one of the most expensive spices in the world and serve as a traditional Chinese medicine. More saffron has been cultivated in China, and different drying technologies have been studied. However, a comprehensive and comparative analysis of different drying approaches has not been well studied. In this study, we compared electric oven and vacuum oven drying approaches on saffron. We found saffron was dried quicker under high vacuum drying mode with high temperature and the quicker drying rate provided, the more open microstructural interstices on the saffron surface. Both methods were best fit to Midilli and Kucuk model. Besides, the coloring, aroma and bitterness strength after drying showed the similar results. In sum, our data suggested the optimal drying temperature was 100 °C for 20 min for two evaluated methods, however considering the machine cost, the electric oven drying would be the first choice.


Saffron Thin layer drying Kinetic model Vacuum oven dry Electric oven dry 



This research was supported by Zhejiang Provincial Natural Science Foundation of China under Grant No. LQ15H280001 and National Natural Science Foundation of China (Nos. 81403032, 31600255), Huzhou Science and Technology Project (No. 2017GY34).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

10068_2018_487_MOESM1_ESM.tif (3.4 mb)
Fig.S1. Comparison of experimental and predicted moisture ratio for saffron drying using the Midilli et al. model. (A): electric oven drying; (B): vacuum oven drying (TIFF 3531 kb)
10068_2018_487_MOESM2_ESM.tif (3.1 mb)
Fig.S2. The linear correlation between lnMR and drying time. The color indicated different temperature conditions. (A): electric oven drying; (B): vacuum oven drying (TIFF 3146 kb)
10068_2018_487_MOESM3_ESM.tif (165 kb)
Fig.S3. The linear correlation between the value of lnDeff and 1/T. Electric oven drying is in pink and vacuum oven drying is in green. (TIFF 164 kb)
10068_2018_487_MOESM4_ESM.docx (14 kb)
Supplementary material 4 (DOCX 14 kb)
10068_2018_487_MOESM5_ESM.docx (14 kb)
Supplementary material 5 (DOCX 13 kb)


  1. Acar B, Sadikoglu H, Doymaz I. Freeze-drying kinetics and diffusion modeling of saffron (Crocus sativus L.). J. Food Process Pres. 39: 142–149 (2015)CrossRefGoogle Scholar
  2. Acar B, Sadikoglu H, Ozkaymak M. Freeze drying of saffron (Crocus sativus L.). Dry. Technol. 29: 1622–1627 (2011)CrossRefGoogle Scholar
  3. Ahrazem O, Rubio-Moraga A, Nebauer SG, Molina RV, Gómez-Gómez L. Saffron: its phytochemistry, developmental processes, and biotechnological prospects. J. Agric. Food Chem. 63: 8751–8764 (2015)CrossRefGoogle Scholar
  4. Akhondi E, Kazemi A, Maghsoodi V. Determination of a suitable thin layer drying curve model for saffron (Crocus sativus L) stigmas in an infrared dryer. Sci. Iran. 18: 1397–1401 (2011)CrossRefGoogle Scholar
  5. Akhondzadeh S, Shafiee Sabet M, Harirchian MH, Togha M, Cheraghmakani H, Razeghi S, Vossoughi A. A 22-week, multicenter, randomized, double-blind controlled trial of Crocus sativus in the treatment of mild-to-moderate Alzheimer’s disease. Psychopharmacology. 207: 637–643 (2010)CrossRefGoogle Scholar
  6. Bolhassani A, Khavari A, Bathaie SZ. Saffron and natural carotenoids: Biochemical activities and anti-tumor effects. Biochim. Biophys. Acta. 1845: 20–30 (2014)PubMedGoogle Scholar
  7. Calín-Sánchez Á, Figiel A, Wojdyło A, Szarycz M, Carbonell-Barrachina ÁA. Drying of garlic slices using convective pre-drying and vacuum-microwave finishing drying: kinetics, energy consumption, and quality studies. Food Bioprocess Technol. 2: 398–408 (2014)CrossRefGoogle Scholar
  8. Carmona M, Zalacain A, Pardo JE, López E, Alvarruiz A, Alonso GL. Influence of different drying and aging conditions on saffron constituents. J. Agric. Food Chem. 53: 3974–3979 (2005)CrossRefGoogle Scholar
  9. Chahine N, Nader M, Duca L, Martiny L, Chahine R. Saffron extracts alleviate cardiomyocytes injury induced by doxorubicin and ischemia-reperfusion in vitro. Drug Chem. Toxicol. 39: 87–96 (2016)CrossRefGoogle Scholar
  10. Chayjan RA, Kaveh, M. Physical parameters and kinetic modeling of fix and fluid bed drying of terebinth seeds. J. Food Process Preserv. 38: 1307–1320 (2014)CrossRefGoogle Scholar
  11. Christodoulou E, Kadoglou NPE, Kostomitsopoulos N, Valsami G. Saffron: a natural product with potential pharmaceutical applications. J. Pharm. Pharmacol. 67: 1634–1649 (2015)CrossRefGoogle Scholar
  12. Erbay Z, Icier F. A review of thin layer drying of foods: theory, modeling, and experimental results. Crit. Rev. Food Sci. Nutr. 50: 441–464 (2010)CrossRefGoogle Scholar
  13. Ertekin C, Firat MZ. A comprehensive review of thin-layer drying models used in agricultural products. Crit. Rev. Food Sci. Nutr. 57: 701–717 (2017)CrossRefGoogle Scholar
  14. Farokhnia M, Shafiee Sabet M, Iranpour N, Gougol A, Yekehtaz H, Alimardani R, Akhondzadeh S. Comparing the efficacy and safety of Crocus sativus L. with memantine in patients with moderate to severe Alzheimer’s disease: a double-blind randomized clinical trial. Hum. Psychopharmacol. 29: 351–359 (2014)CrossRefGoogle Scholar
  15. García-Rodríguez MV, López-Córcoles H, Alonso GL, Pappas CS, Polissiou MG, Tarantilis PA. Comparative evaluation of an ISO 3632 method and an HPLC-DAD method for safranal quantity determination in saffron. Food Chem. 221: 838–843 (2017)CrossRefGoogle Scholar
  16. Gregory MJ, Menary RC, Davies NW. Effect of drying temperature and air flow on the production and retention of secondary metabolites in saffron. J. Agric. Food Chem. 53: 5969–5975 (2005)CrossRefGoogle Scholar
  17. Himeno H, Sano K. Synthesis of crocin, picrocrocin and safranal by saffron stigma-like structures proliferated in vitro. Agric. Biol. Chem. 51: 2395–2400 (1987)Google Scholar
  18. Hossain MB, Barry-Ryan C, Martin-Diana AB, Brunton NP. Effect of drying method on the antioxidant capacity of six Lamiaceae herbs. Food Chem. 123: 85–91 (2010)CrossRefGoogle Scholar
  19. Kanakis CD, Daferera DJ, Tarantilis PA, Polissiou MG. Qualitative determination of volatile compounds and quantitative evaluation of safranal and 4-hydroxy-2,6,6-trimethyl-1-cyclohexene-1-carboxaldehyde (HTCC) in Greek saffron. J. Agric. Food Chem. 52: 4515–4521 (2004)CrossRefGoogle Scholar
  20. Lopez A, Iguaz A, Esnoz A, Virseda P. Thin-layer drying behaviour of vegetable wastes from wholesale market. Dry. Technol. 18: 995–1006 (2000)CrossRefGoogle Scholar
  21. Lopresti AL, Drummond PD. Saffron (Crocus sativus) for depression: a systematic review of clinical studies and examination of underlying antidepressant mechanisms of action. Hum. Psychopharmacol. 29: 517–527 (2014)CrossRefGoogle Scholar
  22. Maghsoodi V, Kazemi A, Akhondi E. Effect of different drying methods on saffron (Crocus sativus L.) quality. Iran. J. Chem. Chem. Eng. 31: 85–89 (2012)Google Scholar
  23. Mongpraneet S, Abe T, Tsurusaki T. Accelerated drying of welsh onion by far infrared radiation under vacuum conditions. J. Food Eng. 55: 147–156 (2002)CrossRefGoogle Scholar
  24. Mortezapour H, Ghobadian B, Khoshtaghaza MH, Minaei S. Drying kinetics and quality characteristics of saffron dried with a heat pump assisted hybrid photovoltaic-thermal solar dryer. J. Agric. Sci. Technol. 16: 33–45 (2014)Google Scholar
  25. Mortezapour H, Ghobadian B, Minaei S, Khoshtaghaza MH. Saffron drying with a heat pump–assisted hybrid photovoltaic–thermal solar dryer. Dry. Technol. 30: 560–566 (2012)CrossRefGoogle Scholar
  26. Orikasa T, Koide S, Okamoto S, Imaizumi T, Muramatsu Y, Takeda J, Tagawa A. Impacts of hot air and vacuum drying on the quality attributes of kiwifruit slices. J. Food Eng. 125: 51–58 (2014)CrossRefGoogle Scholar
  27. Raina BL, Agarwal SG, Bhatia AK, Gaur GS. Changes in pigments and volatiles of saffron (Crocus sativus L.) during processing and storage. J. Sci. Food Agric. 71: 27–32 (1996)CrossRefGoogle Scholar
  28. Tong Y, Zhu X, Yan Y, Liu R, Gong F, Zhang L, Wang P. The influence of different drying methods on constituents and antioxidant activity of saffron from china. Int. J Anal. Chem. 2015: 953164 (2015)CrossRefGoogle Scholar
  29. Torki-Harchegani M, Ghanbarian D, Maghsoodi V, Moheb A. Infrared thin layer drying of saffron (Crocus sativus L.) stigmas: Mass transfer parameters and quality assessment. Chin. J. Chem. Eng. 4: 426–432CrossRefGoogle Scholar
  30. Tuberoso CIG, Rosa A, Montoro P, Fenu MA, Pizza C. Antioxidant activity, cytotoxic activity and metabolic profiling of juices obtained from saffron (Crocus sativus L.) floral by-products. Food Chem. 199: 18–27 (2016)CrossRefGoogle Scholar
  31. Xiaobin F, Xiaodong Q, Shuwen H, Chong Y, Yumei Y, Guifen Z. Extracted apocarotenoids from saffron stigmas and evaluated the quality of saffron. Nat. Prod. Res. 32: 225–228 (2018)CrossRefGoogle Scholar
  32. Zogzas NP, Maroulis ZB, Marinos-Kouris D. Moisture diffusivity data compilation in foodstuffs. Dry. Technol. 14: 2225–2253 (1996)CrossRefGoogle Scholar

Copyright information

© The Korean Society of Food Science and Technology and Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  • Chong Yao
    • 1
    • 2
  • Xiao-Dong Qian
    • 2
  • Gui-Fen Zhou
    • 3
  • Shu-Wei Zhang
    • 4
  • Li-Qin Li
    • 2
  • Qiao-Sheng Guo
    • 1
    Email author
  1. 1.Institute of Chinese Medicinal MaterialsNanjing Agricultural UniversityNanjingPeople’s Republic of China
  2. 2.Pharmaceutical DepartmentHuzhou Central HospitalHuzhouPeople’s Republic of China
  3. 3.Pharmaceutical CollegeZhejiang Chinese Medical UniversityHangzhouPeople’s Republic of China
  4. 4.Laboratory for Functional Foods and Human Health, Center for Excellence in Post-Harvest TechnologiesNorth Carolina Agricultural and Technical State UniversityKannapolisUSA

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