Investigating carotenoid loss after drying and storage of

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1. Literature review
Two types of asymmetric cleavage of trans-"-carotene, 7’-8’ and 9’-10’, lead to the
formation of "-cyclocitral and "-apo-8’carotenal; "-ionone and "-apo-10’carotenal
respectively (Figure 1-20).
-
Trans-β-carotene
+
β-apo-8’-carotenal β-cyclocitral
+
β-apo-10’-carotenal β-ionone
Figure 1-20: 7’-8’ and 9’-10’cleavage of !-carotene and formation of 5,6 epoxy-!ionone
and dihydroactinidiolide (DHA) from !-ionone. Mordi et al. (1993); Waché
et al. (2003).
The cleavages can arise from autoxidation (Mordi et al. 1993) or enzymatic reactions
(Waché et al. 2003). Epoxidation of "-ionone into 5,6 epoxy-"-ionone and thermal
rearrangement of 5,6 epoxy-"-ionone into dihydroactinidiolide (DHA) has been
previously described (Mordi et al. 1993; Waché et al. 2003) (Figure 1-20).
Norisoprenoids formed after oxidation of β-carotene include β-ionone (fragrance of
roses), 5,6-epoxy-β-ionone, β-cyclocitral (flower fragrance with fruit tones), limonene
(odour of oranges), DHA (sweet, tea-like odour). These compounds are used in
perfumery. The production of aromas from carotenoids has also been widely studied.