The Relation between Drying Conditions and the Development of Volatile Compounds in Saffron (Crocus sativus)

Abstract

Saffron is derived from the stigmas of the flower Crocus sativus L. The drying process is the most important post-harvest step for converting C. sativus stigmas into saffron. The aim of this review is to evaluate saffron's post-harvest conditions in the development of volatile compounds and its aroma descriptors. It describes saffron's compound generation by enzymatic pathways and degradation reactions. Saffron quality is described by their metabolite's solubility and the determination of picrocrocin, crocins, and safranal. The drying process induce various modifications in terms of color, flavor and aroma, which take place in the spice. It affects the aromatic species chemical profile. In the food industry, saffron is employed for its sensory attributes, such as coloring, related mainly to crocins (mono-glycosyl esters or di-glycosyl polyene).

Keywords: flavor and odor pathways; saffron; volatile compounds.

Figure 1

Crocus sativus L. plant parts.

Figure 2

Enzymatic pathway in C. sativus and saffron chemical degradation of aromatic compounds from zeaxanthin.

Figure 3

Zeaxanthin degradation by CCD, compounds generation in C9 (4-ketoisophorone, isophorone, dihydrooxophorone, 2-hydroxy-isophorone); C10 safranal similar structures (HTTC, 5,5-dimethyl-2-methylene-3-cyclohexene-1-carboxaldehyde, 3,3,4,5-tetramethylcyclohexan-1-one, 2,6,6-trimethyl-4-oxo-2-cyclohexen-1-carbaldehyde, -cyclocitral, 2,4,4-trimethyl-3-carboxaldehyde-5-hydroxy-2,5-cyclohexadien-1-one); C11 (-homocyclocitral) and C13 (ionone, 2-cyclohexen-1-ol, 3-(1-buten-1-yl), 2,4,4-trimethyl, megastigma-4,6(E),8(E)-triene).

Figure 4

Saffron volatile compounds generation from crocetins esters by thermal degradation.