Freeze Drying of Saffron (Crocus sativus L.)

This article was downloaded by: [Gebze Yuksek Tekn Enst] On: 19 August 2011, At: 00:53 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Drying Technology Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ldrt20 Freeze Drying of Saffron (Crocus sativus L.) Bahadir Acar a, Hasan Sadikoglu b & Mehmet Ozkaymak a a Department of Machine Education, Karabük University, Karabük, Turkey b Department of Chemical Engineering, Gebze Institute of Technology, Gebze, Kocaeli, Turkey Available online: 18 Aug 2011 To cite this article: Bahadir Acar, Hasan Sadikoglu & Mehmet Ozkaymak (2011): Freeze Drying of Saffron (Crocus sativus L.), Drying Technology, 29:14, 1622-1627 To link to this article: http://dx.doi.org/10.1080/07373937.2011.590263 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions This article may be used for research, teaching and private study purposes. Any substantial or systematic reproduction, re-distribution, re-selling, loan, sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.

Drying Technology, 29: 1622 1627, 2011 Copyright # 2011 Taylor & Francis Group, LLC ISSN: 0737-3937 print=1532-2300 online DOI: 10.1080/07373937.2011.590263 Freeze Drying of Saffron (Crocus sativus L.) Bahadir Acar, 1 Hasan Sadikoglu, 2 and Mehmet Ozkaymak 1 1 Department of Machine Education, Karabük University, Karabük, Turkey 2 Department of Chemical Engineering, Gebze Institute of Technology, Gebze, Kocaeli, Turkey Saffron obtained from the dried stigmas of a flower scientifically known as Crocus sativus L. is considered to be the most precious and expensive agricultural product due to its labor-intensive harvest and post-harvest processing. The post-harvest processing such as dehydration and storage conditions determine stability, quality, and economical value of the final product. The contents of crocin (degraded carotenoids) and safranal (carotenoid oxidation products) are the key components that characterize color, taste, and aroma characteristics of saffron. In this work, the quality parameters such as crocin and safranal contents of commercial saffron that were obtained by using the freeze-drying method and natural sun drying were studied. The sarfanal contents of the samples dried in a freeze dryer were found to be five times higher than the safranal contents of the samples dried naturally under the sun, while crocin contents of the samples dried in a freeze dryer were about 40% higher than the crocin contents of the samples dried naturally under the sun. These encouraging results indicate that the freeze-drying process can be used effectively for dehydration of saffron by minimal loss of safranal and crocin contents. Keywords Crocin; Drying; Freeze drying; Saffron; Safranal INTRODUCTION The world s most precious and expensive agricultural product is saffron, which has been intensively used for flavoring and coloring foods, dying textiles, and medical purposes since ancient times. Saffron is obtained from the dried stigmas of a flower scientifically known as Crocus sativus L., which is a member of the family Iridaceae. The areas that have cold winters and warm, dry summers are suitable for cultivation of saffron. Saffron is a sterile geophyte plant and does not set viable seed; therefore, it must be propagated from a tuberous-bulb formation, named corm. [1] In order to obtain 6 kg of saffron, 900,000 flowers and one hectare area are needed for cultivation. [2] Considering that each corm requires hand-planting, handpicking, and hand-separating, stigmas from flowers make saffron production an extremely time-consuming and labor-intensive cultivation process. Total saffron production in the world is approximately 190 tons per, year and Correspondence: Hasan Sadikoglu, Department of Chemical Engineering, Gebze Institute of Technology, P.O. Box 141, 41400, Gebze, Kocaeli, Turkey; E-mail: sadikoglu@gyte.edu.tr Iran produces about 90% of this total amount [3,4] while India, Spain, Greece, Azerbaijan, Egypt, China, Mexico, Italy, Morocco, and Turkey produce the rest. Dried stigmas of saffron have 10 12% water, 5 7% mineral matter, 5 8% fat, 12 13% protein, 20% reducing sugars, 6 7% pentosans, 9 10% gums and dextrins, and some free sugars while the essential oil content is about 0.3%. [5] The composition of saffron depends on variety, the region of cultivation, and the method of post-harvest processing (dehydration). Many researchers [6 10] reported that dried stigmas of saffron consist of more than 150 volatile and aroma-yielding compounds and several nonvolatile active compounds, some of which have been identified. The main compounds that determine the quality of saffron are: 1) carotenoids (b-and c-crocetin) crocetin (a - and b-carotenes) and its glycosidic form crocin, gentiobioside, glucoside, gentioglucoside and diglucoside that act as the coloring agent [5] ; 2) picrocrocin that is a monoterpene glycoside precursor of safranal, which has a bitter taste and is mostly responsible for the taste of saffron [6] ; 3) safranal (2,6,6-trimethyl-1,3-cyclohexadiene-1-carboxaldehyde) is the volatile oil that gives characteristic saffron odor and aroma. [6] Saffron has been intensively used as a spice for flavoring and coloring foods since ancient times; it has also been used in traditional medicine as a eupeptic, diaphoretic, expectorant, tranquilizer, aphrodisiac, emmenagogue, abortifacient, and in the treatment of hepatic disorders, flatulence, vomiting, spasm, dental and gingival pain, insomnia, depression, cognitive disorders, seizures, lumbago, cough, asthma, bronchitis, fever, colds, cardiovascular disorders, and cancer. [11] In recent years, researchers from all over the world have been conducting many studies regarding the pharmaceutical uses of saffron. These studies have shown that saffron and its active constituents have a promising future as a pharmaceutical ingredient and can be used to cure or to prevent illnesses of the nervous system (insomnia, paralysis), respiratory system (asthma, colds, coughs), cardiovascular system (heart disease), circulatory system (blood diseases, hypoxia), eye diseases (retina protective), infection diseases (scarlet fever, smallpox), muscular and bone 1622

FREEZE DRYING OF SAFFRON 1623 systems (paralysis, gout), genitourinary system (chronic uterine hemorrhage, amenorrhea, dysmorrhea), digestive system (flatulence, stomach disorders, colic), and cancer. [5,11 13] Freeze-drying, also known as lyophilization, is a separation process (the sublimation of frozen solvent (particularly water) content from the material being dried) widely used in biotechnology, fine chemicals, and the food and pharmaceutical industries. [14 16] Heat-sensitive materials, fine chemicals, biotechnological products and some pharmaceuticals, which might lose their quality (activity) in conventional evaporative drying, can be safely freezedried. [15,16] By comparing with the other conventional dehydration processes (evaporative drying, drum drying, spray drying, etc.), the highest quality dried product can be obtained by freeze-drying. The freeze-drying process is a multi-stage, relatively slow and expensive (initial investment and operating cost is high) process. Some researchers [16,17] have reported that the long drying time and high energy consumption of the freeze-drying process can be lowered by the addition of microwave power to the conventional freeze dryer. The freeze-drying of a certain product of interest includes the following steps: 1. preparation and formulation step (addition of the optimal amount of bulking agents, stabilizers, antioxidants, emulsifiers, cryoprotectors, and=or moisture-buffering agents to the material to be freeze-dried); 2. freezing step (liquid solutions, gel suspensions, or foodstuffs are cooled down to their solidification temperature to freeze the free water content in the material); 3. primary drying step (free or frozen water in the material being freeze-dried is removed by sublimation under high vacuum); 4. secondary drying step (a certain amount of bound water content of the material being freeze-dried is removed by desorption under the moderately high vacuum); 5. packaging and final storage (packing the certain amount of freeze-dried product with an appropriate packaging material in a sterile environment and storing the packed product in a controlled conditions to prevent water vapor and oxygen ingress and light). [18] In order to obtain freeze-dried products with the finest quality by keeping the prime properties (activity, stability, etc.) of the product being freeze-dried unchanged during all steps of the process, each step in the freeze-drying process is critical and requires extreme caution. Substantially long drying time, intensive energy requirement during freezing as long as primary and secondary drying steps, high initial investment cost along with labor and operating costs make freeze-drying a very expensive separation process. Because of its high cost, freeze drying is the method of separation of high market value products such as pharmaceuticals, fine chemicals, biotechnological products, and expensive foods. The key components that determine the quality of saffron are crocin, picrocrocin, and safranal. Higher amounts of these compounds mean higher quality of saffron. The success of processing saffron (from harvest to packaging the final product) heavily depends on preserving these active crucial compounds. The main objective of this work was to investigate the effect of freeze-drying on safranal and crocin contents of stigmas of saffron flowers. In this work, freeze-drying was used to dry stigmas of saffron. The chemical analysis of dried stigmas obtained by natural sun drying and freeze-drying was done with a high performance liquid chromatography (HPLC). MATERIALS AND METHODS Plant Materials and Chemicals Saffron flowers were harvested in the Davutlar village of Safranbolu in Karabük province of Turkey. The name of the Safranbolu region comes from saffron, which means plenty of saffron. The saffron flowers were harvested in the early morning between 5:30 7:30 a.m. and brought indoors, where stigmas were separated from the flowers by hand. Some stigmas were dried naturally under the sun, which is the conventional method used by farmers to dry the stigmas. The rest of the stigmas were freeze-dried. The standards of safranal and crocin were purchased from Sigma Aldrich (Madrid, Spain), while all the other reagents used were of analytical grade. Drying of Stigmas One of the most important steps in post-harvest processing for fresh stigmas of saffron flowers is the drying. The method of drying has a significant effect on quality parameters (color, aroma, and taste) of commercial saffron. The drying method used to reduce the moisture of stigmas to around 10% varies from region to region and country to country, and depends on the availability of technical equipment. Natural sun drying is widely used in India, [19,20] toasting is commonly used in Spain and Iran, and heated dark rooms are the traditional method used in Greece [20] and Turkey. Freeze-Drying of Stigmas The pilot scale freeze dryer (Virtis Ultra 25 XL, NY, USA) was used for freeze-drying experiments. The temperature of the freeze dryer can be set from 40 C to 60 C, while the condenser temperature can be set as low as 70 C. The vacuum pump of the freeze dryer is capable of supplying vacuum as low as 15 Pa. Approximately 10 g of stigmas of the saffron flower are placed in the tray of the freeze dryer and the temperature of the plates of the freeze dryer are set to 40 C for 4 hours for complete

1624 ACAR ET AL. freezing. The initial temperature of the heating plates of the freeze dryer was 30 C and increased gradually to 5 C, not causing any melting and scorching of the stigmas of the saffron. Drying chamber pressure was set to 50 Pa and kept constant during drying. The freeze-dried samples were packed with oxygen- and water-vapor-impermeable packaging material prior to chemical analysis. The primary drying stage of freeze-drying is a mass transfer limited process because the rate-controlling mechanism of the process is the mass transfer. The drying chamber pressure should be kept at its minimum value (at least it should be well below the ice vapor pressure of the sample being freeze-dried) to increase water vapor mass flux through the pores of the dried material due to the sublimation during the primary drying stage. [21,22] The secondary drying stage of freeze-drying is a heat transfer limited process because the rate-controlling mechanism of the process is the heat transfer. During the heat transfer limited secondary drying stage, the removal of bound water from the solid phase of the dried layer can be enhanced by increasing the heat transfer capacity of the dried matrix by using moderately high chamber pressure. The theoretical [21,22] and experimental [23] studies indicated that using a low chamber pressure during the primary drying stage and a moderately high chamber pressure during the secondary drying stage can be an advantage. In freezedrying of the stigmas of the saffron, it is not possible to distinguish the primary and secondary drying stages. Therefore, the drying chamber pressure was kept constant, and the heating plate temperatures of the freeze dryer were set to relatively low temperature and increased gradually so as not to deteriorate (not melting and not scorching) the samples during freeze drying. The temperature profile of the heating plates during freeze-drying is given in Figure 1. FIG. 2. Calibration curves for a) safranal and b) crocin. Sun Drying of Stigmas Approximately 40 g of stigmas of the saffron flower were placed in a clean piece of cloth and were laid under the sun for 12 hours. The average ambient temperature was 18 C while relative humidity was about 40%. Chemical Analysis of the Sample The safranal and crocin contents of samples dried naturally under the sun and using a freeze dryer were analyzed with a system (Agilent 1100 series, Santa Clara, CA, USA). An Agilant Luna C18, 4.6mm 250 mm, 5 m column was used in the analyses. The flow rate was 0.5 ml=min while column temperature was 30 C. Sample injections were made at 20 ml for all samples and standards. A solvent system of methanol and acetic acid (A: methanol, B: 1% acetic acid (in water)) was used as mobile phase and gradient elution was used for the analyses. The standard solutions were prepared to construct the calibration curves in the range of 0.2 10 mg=ml and 5 100 mg=ml for safranal (Figure 2a) FIG. 1. Temperature profile of the heating plates during freeze drying. FIG. 3. Standard chromatograms for 5 mg=ml safranal and 50 mg=ml crocin solutions.

FREEZE DRYING OF SAFFRON 1625 and crocin (Figure 2b), respectively. The emprical equation of calibration curve for safranal was A safranal ¼ 142.51 (amount of safranal in mg=ml)-2.63 and corelation was R 2 ¼ 0.99993. The empirical equation of calibration curve for crocin was A crocin ¼ 22.54 (Amount of crocin in mg= ml) þ 5.73 and corelation was R 2 ¼ 0.99983. UV was used to detect safranal and crocin at the wave lengths of 310 and 440 nm, respectively. The analyses were done in quadruple. Figure 3 represents standard chromatograms for 5 mg=ml safranal and for 50 mg=ml crocin solutions, respectively. RESULTS AND DISCUSSION The safranal and crocin contents of the samples dried naturally under the sun and using a freeze dryer were analyzed by a HPLC. Calibration curves for safranal and crocin were constructed with a correlation coefficient R 2 > 0.999. The peak areas obtained from HPLC chromatograms for each sample were used to calculate safranal and crocin contents of the samples. Figure 4 shows average safranal contents of the four different samples dried naturally under the sun and using a freeze dryer. The sarfanal contents of the samples dried in a freeze dryer are about 5 times higher than the safranal contents of the samples dried naturally under the sun. This finding is in contrast to previous works, [20,24,25] where they reported that safranal content of dried stigmas obtained by traditional sun drying or shade drying or high temperature (65 C) oven drying was much higher than the dried stigmas obtained by freeze drying. Similar results were also reported by other researchers, [19,26,27] where they compare safranal contents of dried stigmas obtained by traditional sun drying or high temperature oven drying with the dried stigmas obtained by vacuum or low temperature cross-flow dryer. These researchers [19,26,27] reported that flavoring compounds FIG. 4. Comparison of safranal and crocin contents of commercial saffron dried in a freeze dryer (FD) and dried naturally under the sun (SD). glucose, safranal (2,6,6-trimethyl-1,3-cyclohexadiene-1- carboxaldehyde), and 4-hydroxy-safranal (2,6,6-trimethyl- 4-b-hydroxy-1-cyclohexene-1-carboxaldehyde) formed as results of thermal and enzymatic degradation of picrocrocin (4-(b-D-glucopyranosyloxy)-2,6,6-trimethyl-1-cyclohexene-l-carboxaldehyde). Safranal and isophorone derivatives that formed by enzymatic reduction and nonenzymatic oxidation and decarboxylation of safranal are the principle components that are responsible for flavor. [26] Raina et al. [19] reported that the samples dried in a vacuum dryer or in a cross-flow drier have more 4-hydroxysafranal content than the sample dried in a solar dryer, or in a hightemperature oven drying or in sun drying. They thought that 4-hydroxysafranal was a potential intermediate product in the formation of safranal from picrocrocin and the high value for 4-hydroxysafranal for vacuum-dried samples was a result of slow dehydration. In this work, we have found that safranal contents of freeze-dried samples were higher than the safranal contents of sun dried samples. Figure 5 represents the HPLC fingerprint chromatograms of safranal contents of the dried stigmas of saffron samples (both freeze dried and sun dried). Figure 4 also shows average crocin contents of the four different samples dried naturally under the sun and using a freeze dryer. Similar to safranal contents, the crocin contents of the samples dried in a freeze dryer are higher than the crocin contents of the samples dried naturally under the sun. Freeze-dried samples contained almost 40% more crocin than the sun-dried samples. The high crocin content in freeze-dried stigmas of the saffron could be the result of lower moisture content because the moisture can catalyze the degradation or hydrolysis of crocin into crocetin. [19,27] The intensity of color of the commercial saffron depends heavily on the crocin content that is inversely related to the moisture content. High moisture contents usually fade the color of saffron powder during storage. The low crocin content of the samples dried naturally under the sun can be attributed to longer drying time that increased enzymatic activity, resulting in more crocin degradation. During the freeze drying, extremely low water activity values are attained because free water is frozen and low drying temperatures prevent thermal and enzymatic degradation of the stigmas of the saffron. In contrast to freeze drying, drying under the sun causes enzymatic reactions to take place at a considerably higher rate due to the high drying temperatures. HPLC fingerprint chromatograms for safranal and crocin contents for freeze- and sun-dried saffron samples are shown in Figure 5 and Figure 6, respectively. Saffron powders produced (dehydrated) by using a freeze dryer along with a proper packaging material (high barrier to oxygen and water vapor) and storage conditions (storing in dry and dark place) can last longer without loosing their pigments (crocin) and flavors (safranal) for a long time.

1626 ACAR ET AL. FIG. 5. HPLC fingerprint chromatograms for safranal content of saffron samples obtained by freeze drying and natural sun drying. FIG. 6. HPLC fingerprint chromatograms for crocin content of saffron samples obtained by freeze drying and natural sun drying. CONCLUSION Even though the initial investment and operation costs are high, and the drying time is substantially long when compared with conventional evaporative drying, freeze drying is considered to be the method of separation (dehydration) for high market value products. The safranal and crocin contents that define the quality and market value of the commercial saffron were considerable higher in the sample dried in a freeze dryer than in the sample dried traditionally under the sun. The original shape and structure of the sample can be preserved during the freeze-drying process. The final freeze-dried commercial saffron not only contained high amounts of safranal and crocin but also contained lower moisture compared with the traditional and sun-dried saffron. Lower moisture content means higher crocin content because moisture can catalyze the degradation of crocin into crocetin during storage, resulting in fading in the color of the saffron powder. This work clearly showed that freeze drying can be used for dehydration of saffron with minimum safranal and crocin loss.

FREEZE DRYING OF SAFFRON 1627 The high cost of freeze drying can be compensated by the high recovery of safranal and crocin. ACKNOWLEDGMENTS The authors gratefully acknowledge Drs. Murat Özdemir and Mahmut Şeker for fruitful discussion. REFERENCES 1. Gresta, F.; Avola, G.; Lombardo, G.M.; Siracusa, L.; Ruberto, G. Analysis of flowering, stigmas yield and qualitative traits of saffron (Crocus sativus L.) as affected by environmental conditions. Scientia Horticulturae 2009, 119, 320 324. 2. Souret, F.F.; Weathers, P.J. The growth of saffron (Crocus sativus L.) in aeroponics and hydroponics. Journal of Herbs, Spices & Medicinal Plants 2000, 7(3), 25 35. 3. Gazor, H.R.; Chaji, H. Equilibrium moisture content and heat of desorption of saffron. International Journal of Food Science & Technology 2010, 45(8), 1703 1709. 4. Bolandi, M.; Shahidi, F.; Sedaghat, N.; Farhoush, R.; Mousavi-Nik, H. Shelf-life determination of saffron stigma: Water activity and temperature studies. World Applied Sciences Journal 2008, 5(2), 132 136. 5. Abdullaev, F.I. Cancer chemopreventive and tumoricidal properties of saffron (Crocus sativus L.). Experimental Biology and Medicine 2002, 227(1), 20 25. 6. Winterhalter, P.; Straubinger, M. Saffron-renewed interest in an ancient spice. Food Review International 2000, 16(1), 39 59. 7. Zargani, N.S.; Heinz, D.E. The volatile constituents of saffron. Lebensmittel-Wissenschaft und Technologie 1971, 4(2), 43 45. 8. Rödel, W.; Petrzika, M. Analysis of the volatile components of saffron. Journal of High Resolution Chromatography 1991, 14, 771 774. 9. Iborra, J.L.; Castellar, M.R.; Cánovas, M.; Manjón, A. TLC preparative purification of picrocrocin, HTCC and crocin from saffron. Journal of Food Science 1992, 3, 714 716. 10. Rios, J.L.; Recio, M.C.; Giner, R.M.; Mhnez, S. An update review of saffron and its active constituents. Phytotherapy Research 1996, 10, 189 193. 11. Kianbakht, S.; Mozaffari, K. Effects of saffron and its active constituents, crocin and safranal, on prevention of indomethacin induced gastric ulcers in diabetic and non diabetic rats. Journal of Medicinal Plans 2009, 8, 30 38. 12. Premkumar, K.; Thirunavukkarasu, C.; Abraham, S.K.; Santhiya, S.T.; Ramesh, A. Protective effect of saffron (Crocus sativus L.) aqueous extract against genetic damage induced by anti-tumor agents in mice. Human & Experimental Toxicology 2006, 25, 79 84. 13. Pitsikas, N.; Zisopoulou, S.; Tarantilis, P.A.; Kanakis, C.D.; Polissiou, M.G.; Sakellaridis, N. Effects of the active constituents of Crocus sativus L., crocins on recognition and spatial rats memory. Behavioural Brain Research 2007, 183(2), 141 146. 14. Liapis, A.I.; Pikal, M.J.; Bruttini, R. Research and development needs and opportunities in freeze drying. Drying Technology 1996, 14, 1265 1300. 15. Sadikoglu, H.; Ozdemir, M.; Seker, M. Freeze-drying of pharmaceutical products: Research and development needs. Drying Technology, 2006, 24, 849 861. 16. Sadikoglu, H.; Liapis, A.I. Mathematical modelling of the primary and secondary drying stages of bulk solution freeze-drying in trays: Parameter estimation and model discrimination by comparison of theoretical results with experimental data. Drying Technology 1997, 15, 791 810. 17. Wang, R.; Zhang, Min.; Mujumdar, A.S.; Sun, J. Microwave freezedrying characteristics and sensory quality of ınstant vegetable soup. Drying Technology 2009, 27(9), 962 968. 18. Duan, X.; Zhang, M.; Mujumdar, A.S.; Wang, R. Trends in microwave-assisted freeze drying of foods. Drying Technology 2010, 28(4), 444 453. 19. Raina, B.L.; Agarwal, G.S.; Bhatia, A.K.; Gaur, G.S. Changes in pigments and volatiles of saffron (Crocus sativus L.) during processing and storage. Journal of the Science of Food and Agriculture 1996, 71, 27 32. 20. Kanakis, C.D.; Daferera, D.J.; Tarantilis, P.A.; Polissiou, M.G. Qualitative determination of volatile compounds and quantitative evaluation of safranal and 4-hydroxy-2,6,6-trimethyl-1-cyclohexene- 1-carboxaldehyde (HTCC) in saffron. Journal of Agricultural Food Chemistry 2004, 52, 4515 4521. 21. Sadikoglu, H.; Liapis, A.I.; Crosser, O.K. Optimal control of the primary and secondary drying stage of bulk solution freeze drying in trays. Drying Technology 1998, 16, 399 431. 22. Sadikoglu, H.; Ozdemir, M.; Seker, M. Optimal control of the primary drying stage of freeze drying process in vials using variational calculus. Drying Technology, 2003, 21(7), 1307 1331. 23. Pikal, M.J.; Shah, S.; Roy, M.L.; Putman, R. The secondary drying stage of freeze drying: Drying kinetics as a function of temperature and chamber pressure. International Journal of Pharmaceutics 1990, 60, 203 217. 24. Atefi, M.; Taslimi, A.; Hassas, M.R.; Mazloumi, M.T. Effects of freeze-drying processes on the qualitative characteristics of Iranian saffron. Iranian Journal of Food Science and Technology 2004, 1(2), 41 49. 25. Naviglio, D.; Conti, S.; Ferrara, L.; Santini, A. Determination of moisture in powder and lyophilised saffron (Crocus sativus L.) by Karl Fischer method. The Open Food Science Journal 2010, 4, 1 6. 26. Zarghami, N.S.; Heinz, D.E. Monoterpene aldehydes and isophorone related compounds of saffron. Phytochemistry 1971, 10, 2755 2761. 27. Zarghami, N.S.; Heinz, D.E. The volatile constitutents of saffron. Lebensmittel-Wissenschaft und-technologie 1971, 4, 2 4.