Effect of Drying Temperature and Air Flow on the Production and Retention of Secondary Metabolites in Saffron
- 29 June 2005
- journal article
- Published by American Chemical Society (ACS) in Journal of Agricultural and Food Chemistry
- Vol. 53 (15), 5969-5975
- https://doi.org/10.1021/jf047989j
Abstract
Safranal is the compound most responsible for the aroma of saffron spice and is, together with the suite of crocin pigments, the major determinant of the product quality. The content of safranal and pigments in saffron is determined by the method of postharvest treatment of the Crocus stigmas. A range of drying treatments involving different temperatures, with or without air flow, was applied to stigmas from three harvest dates. Dual solvent extractions combined with quantitative measurement using GC and HPLC-UV−vis techniques were used to analyze the secondary metabolite contents of the products. It was demonstrated that these methods overcame the previously reported problems in measuring the concentration of both pigments and safranal in saffron caused by the very different polarities and thus solubilities of these compounds. The results showed that a brief (20 min) initial period at a relatively high temperature (between 80 and 92 °C) followed by continued drying at a lower temperature (43 °C) produced saffron with a safranal content up to 25 times that of saffron dried only at lower temperatures. Evidence was provided suggesting that drying with significant air flow reduced the safranal concentration. The results, moreover, indicated that high-temperature treatment had allowed greater retention of crocin pigments than in saffron dried at intermediate temperatures (46−58 °C). The biochemical implications of the various treatments are discussed in relation to the potential for optimizing color and fragrance quality in the product. Keywords: Saffron; Crocus sativus L.; safranal; aroma quality; dehydration conversion; crocin pigments; carotenoid secondary metabolites; postharvest treatment; solvent extraction; GC-MS and HPLC-UV−vis analysisThis publication has 16 references indexed in Scilit:
- Influence of Different Drying and Aging Conditions on Saffron ConstituentsJournal of Agricultural and Food Chemistry, 2005
- Flavor Chemistry of SaffronPublished by American Chemical Society (ACS) ,2001
- Note. Safranal Content in Spanish SaffronFood Science and Technology International, 2001
- Development of an improved procedure for extraction and quantitation of safranal in stigmas of Crocus sativus L. using high performance liquid chromatographyFood Chemistry, 2000
- A quantitative high-performance liquid chromatographic method to analyse commercial saffron (Crocus sativus L.) products.Journal of Chromatography A, 1999
- Kinetic Studies of Saffron (Crocus sativusL.) Quality DeteriorationJournal of Agricultural and Food Chemistry, 1997
- Isolation and Identification of the Aroma Components from Saffron (Crocus sativus)Journal of Agricultural and Food Chemistry, 1997
- Determination of saffron (Crocus sativus L.) components in crude plant extract using high-performance liquid chromatography-UV-visible photodiode-array detection-mass spectrometryJournal of Chromatography A, 1995
- Methods for the analysis of the saffron metabolites crocin, crocetins, picrocrocin and safranal for the determination of the quality of the spice using thin-layer chromatography, high-performance liquid chromatography and gas chromatographyJournal of Chromatography A, 1992
- Biosynthesis of C20-carotenoids in Crocus sativusPhytochemistry, 1982