3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures
3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures
3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures
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Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology<br />
nol substances in cones. The highest content of polyphenols<br />
was detected in the aromatic cultivar Osvald’s clone K-72.<br />
Table II<br />
Phenol substances content in hop cones at the end of the<br />
vegetal period<br />
Cultivar Polyphenols [mg g –1 DM]<br />
K-31 16.2<br />
Bor 17.4<br />
Sládek 18.8<br />
K-72 21.1<br />
Aromat 11.2<br />
Premiant 20.0<br />
Zlatan 17.0<br />
Fig. 1. Comparison of the content of polyphenols in hop cones<br />
in 2006 and 2007<br />
Table III<br />
Flavonoids content in hop leaves during the vegetal period<br />
Cultivar Flavonoids [mg g –1 DM]<br />
06/07 * 09/07 *<br />
K-31 6.37 0.65<br />
Bor <strong>3.</strong>45 0.71<br />
Sládek <strong>3.</strong>24 0.76<br />
K-72 6.31 0.48<br />
Aromat 5.89 0.50<br />
Premiant 2.13 0.72<br />
Zlatan 5.03 0.61<br />
* 06/07 and 09/07 – date of sampling<br />
Table III and Table IV show the data on flavonoid content<br />
in leaves, compared with xanthohumol content. We<br />
noted a decline during the vegetal period in both cases, so as<br />
in phenol substances.<br />
Xanthohumol, prenylated flavonoid, was defined in<br />
extracts from hop cones. Its content, like the content of phenol<br />
substances and flavonoids, was the highest at the end of<br />
s811<br />
Table IV<br />
Averaged content of xanthohumol in hop leaves during the<br />
vegetal period<br />
Cultivar Xanthohumol [% wt.]<br />
9/2006 6/2007 9/2007<br />
K-31 0.009 0.055 0.014<br />
Bor 0.012 0.067 nd<br />
Sládek 0.013 0.068 0.014<br />
K-72 0.010 0.060 0.015<br />
Aromat 0.011 0.041 0.013<br />
Premiant nd 0.047 0.009<br />
Zlatan 0.011 0.039 0.016<br />
nd – no data<br />
Fig. 2. Flavonoids content in hop cones for 2006 and 2007<br />
Table V<br />
Averaged content of xanthohumol in hop cones for 2006 and<br />
2007 (cones sampled on September 22, 2006 and September<br />
24, 2007)<br />
Cultivar Xanthohumol [mg g –1 DM]<br />
2006 2007<br />
K-31 0.39 1.14<br />
Bor 1.98 <strong>3.</strong>11<br />
Sládek 1.11 8.87<br />
Aromat 0.49 0.62<br />
Zlatan 0.29 2.32<br />
vegetal period in cones (Figure 2). The level of xanthohumol<br />
was influenced by the climatic conditions (Table V).<br />
Conclusions<br />
The concentrations of secondary metabolites, phenol<br />
substances, and flavonoids depended on the vegetal period<br />
at first.<br />
The quantity of phenol substances was within the range<br />
of 5.00–8.83 mg g –1 of dry matter, for flavonoids 2.13–<br />
6.37 mg g –1 of dry matter in the leaves before flowering. The<br />
ranges decreased to 0.90–2.25 mg g –1 of dry matter of phenol
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