9954 J. Agric. Food Chem., Vol. 57, No. 21, 2009
Zelena et al.
parts per million concentrations only, all of the carotenoids were
readily degraded under the experimental conditions chosen.
Whereas the cleavage of zeaxanthin, lycopene, and neoxanthin
amounted to about 30%, almost 60% of the β-carotene was
degraded within 60 min under the same conditions. Considering
the obtained yields of volatiles and the presence of only trace
amounts of nonvolatile degradation products, there is still a
significant gap in the mass balance. Further investigations will
be necessary to close this gap and to fully understand the reaction
pathway.
Data on carotenoid degradation by peroxidases are rather
scarce. Kanner and Mendel (18) identified a carotenoid
bleaching enzyme in aqueous paprika extracts, which showed
typical characteristics of plant peroxidases. A carotenoid
degrading peroxidative activity was found in solubilized
thylakoid membranes of olives (19), and at least partial
degradation of β-carotene was observed with soybean and
horseradish peroxidase as well as with lactoperoxidase (20).
Different from the highly selectively acting plant carotenoid
cleavage enzymes, the peroxidase-catalyzed reaction resulted
in a broader spectrum of cleavage products. When an enzyme
model based on a ruthenium tetramesitylporphyrin catalyst
was used to degrade β-carotene, similar product spectra were
obtained (21, 22).
In conclusion, the extracellular peroxidases of M. scorodonius
efficiently degraded carotenoids to norisoprenoid flavor com-
pounds. The H2O2 required for the catalytic activity of the
peroxidases may be supplemented or generated in situ by the
addition of glucose and glucose oxidase. Apart from the produc-
tion of “bioflavors”, the novel enzymes could become interesting
tools in detergents and food-bleaching applications (23).
Figure 3. Enzymatic cleavage of β-carotene by extracellular enzymes of
M. scorodonius; HPLC-MS chromatogram (1 = β-apo-140-carotenal; 2 =
β-apo-120-carotenal; 3=β-apo-100-carotenal; 4=β-carotene-monoepoxide;
5=β-carotene-5,6-epoxide).
Table 3. Nonvolatile Degradation Products of Carotenes and Xanthophylls
Tentatively Identified by HPLC-DAD and HPLC-MS Analyses
product retention
time (min)
substrate
[M þ Hþ]
tentative identifiaction
β-carotene
21.3
23.5
24.4
33.0
40.1
311
351
377
553
553
β-apo-140-carotenal
β-apo-120-carotenal
β-apo-100-carotenal
β-carotene-monoepoxide
β-carotene-5,6-epoxide
lutein/zeaxanthin
15.5
19.5
20.8
23.5
40.9
327
367
393
433
585
3-hydroxy-apo-140-carotenal
3-hydroxy-apo-120-carotenal
3-hydroxy-apo-100-carotenal
3-hydroxy-apo-80-carotenal
lutein/zeaxanthin epoxide
violaxanthin/
neoxanthin
12.4
16.5
17.7
343
383
409
3-hydroxy-β-apo-140-carotenal-
5,6-epoxide
3-hydroxy-β-apo-120-carotenal-
5,6-epoxide
3-hydroxy-β-apo-100-carotenal-
5,6-epoxide
LITERATURE CITED
(1) Werkhoff, P.; Bretschneider, W.; Guntert, M.; Hopp, R.; Surburg,
H. Chirospecific analysis in flavor and essential oil chemistry B.
Direct enantiomer resolution of trans-R-ionone and trans-R-damas-
cone by inclusion gas-chromatography. Z. Lebensm. Unters. Forsch.
1991, 192, 111–115.
(2) Mayer, F.; Czerny, M.; Grosch, W. Sensory study of the character
impact aroma compounds of a coffee beverage. Eur. Food Res.
Technol. 2000, 211, 272–276.
(3) Schwartz, S. H.; Qin, X. Q.; Zeevaart, J. A. Characterization of a
novel carotenoid cleavage dioxygenase from plants. J. Biol. Chem.
2001, 276, 25208–25211.
(4) Schmidt, H.; Kurtzer, R.; Eisenreich, W.; Schwab, W. The carote-
nase AtCCD1 from Arabidopsis thaliana is a dioxygenase. J. Biol.
Chem. 2006, 281.
The formation of β-ionone-5,6-epoxide may result from the
cleavage of β-carotene-5,6-epoxide or from the epoxidation of
released β-ionone. β-Carotene-5,8-epoxide probably repre-
sents the direct precursor of dihydroactinidiolide (13).
3-Hydroxy-R-ionone was obtained from the degradation of
lutein, and 3-hydroxy-β-ionone was released from lutein and
zeaxanthin. Analogously, 3-hydroxy-β-ionone-5,6-epoxide
was formed from violaxanthin and neoxanthin (Figure 2).
These compounds have been described as flavor precursors
in, for example, carambola, nectarines, and tobacco (14, 15).
3-Hydroxy-β-ionone-5,6-epoxide has been postulated to be the
biosynthetic precursor of megastigma-7-ene-5,9-diol-3,6-ep-
oxide in tobacco (16). With lycopene as a substrate, the flavor
compounds 6-methyl-5-heptene-2-one and geranial were
formed. Both compounds are important constituents of the
flavor of tomatoes (17).
β-Apo-80-carotenal and β-apo-120-carotenal were selected as
representatives for nontetraterpenoid carotenes. The spectrum of
volatile cleavage products generated by peroxidase treatment was
dominated by β-ionone, dihydroactinidiolide, and β-cyclocitral
and thus was comparable to that obtained with β-carotene as
substrate (Table 2).
Nonvolatile breakdown products of carotenes and xantho-
phylls were separated and tentatively identified on the basis of
their UV-vis spectra (10) and molecular masses by HPLC-DAD
and HPLC-MS (Figure 3 and Table 3). Although the nonvolatile
carotenoid cleavage products listed above were detected in low
(5) Fleischmann, P.; Zorn, H. Enzymic pathways for formation of
carotenoid cleavage products. In Carotenoids;Vol. 4: Natural
Functions; Britton, G., Liaaen-Jensen, S., Pfander, H., Eds.; Birkhäuser:
Basel, Switzerland, 2008; Vol. 17, pp 341-366.
(6) Wache, Y.; Bosser-DeRatuld, A.; Lhuguenot, J.-C.; Belin, J.-M.
´
Effect of cis/trans isomerism of β-carotene on the ratios of volatile
compounds produced during oxidative degradation. J. Agric. Food
Chem. 2003, 51, 1984–1987.
(7) Zorn, H.; Langhoff, S.; Scheibner, M.; Nimtz, M.; Berger, R. G. A
peroxidase from Lepista irina cleaves β,β-carotene to flavor compounds.
Biol. Chem. 2003, 384, 1049–1056.
(8) Scheibner, M.; Hulsdau, B.; Zelena, K.; Nimtz, M.; Boer, L. de;
Berger, R. G.; Zorn, H. Novel peroxidases of Marasmius scorodonius
degrade β-carotene. Appl. Microbiol. Biotechnol. 2008, 77, 1241–
1250.
(9) Zelena, K.; Zorn, H.; Nimtz, M.; Berger, R. G. Heterologous
expression of the msp2 gene from Marasmius scorodonius. Arch.
Microbiol. 2009, 191, 397–402.
(10) Britton, G. UV/VIS spectroscopy. In Carotenoids;Vol. 1b: Spec-
troscopy; Britton, G., Liaaen-Jensen, S., Pfander, H., Eds.; Birkhäuser:
Basel, Switzerland, 1995; Vol. 2, pp 13-62.