Jiří Totušek

Broccoli juice treated by high pressure: chemoprotective effects of sulforaphane and indole-3-carbinol

Numerous animal and epidemiological studies have demonstrated that consumption of cruciferous vegetables is inversely correlated with cancer incidence. Using the short-term mutagenicity test—in vivo micronucleus test, we investigated inhibition of mutagenicity of 2-amino-3-methyl-3H-imidazo-(4, 5-f)-quinoline (IQ) and N-nitroso-N-methylurea (MNU) by broccoli juice treated by high pressure (500 MPa), for a period of 10 min. This technique of treatment suppresses the growth of micro-organisms at simultaneous conservation of nutritionally important substances (vitamins, polyphenols, and glucosinolates). We also investigated anticlastogenic activity of sulforaphane (SFN) and indole-3-carbinol (I3C). These two substances are found in inactive form (glucosinolate) in cruciferous vegetables. Fourteen-day’s application of broccoli juice and three-day’s application of I3C and SFN led to statistically significant inhibition of mutagenicity IQ and MNU. It seems that, broccoli juice treated by high pressure and its main biologically active substances show antimutagenic activity, which can affect the process of carcinogenesis.

Food safety issues of high pressure processed fruit/vegetable juices

The food safety issues of the high pressure pasteurized fruit/vegetable juices are the focus of this paper. The development of Hazard analysis and critical control points system for production of carrot, red beet and apple/broccoli/orange juice is given together with results of analysis of samples, challenge testing and storage tests. The anti-mutagenic activity in vitro tests are also presented. Procedures have been established for the start-up of experimental production of mentioned juices for the Czech food market. The development of other types of juices based on cruciferous vegetables is mentioned. The aim of this work is to provide the Czech population with information on functional foods that act against chemical mutagens, limiting carcinogenesis.

Influence of UV and Ozonised Water Treatment on Trans-resveratrol Content in Berry Skins and Juices of Franc and Green Veltliner Grapes

Landfeld A., Třiska J., Balik J., Strohalm J., Novotna P., Vrchotova N., Totusek J., Lefnerova D., Hic P., Tomankova E., Halama R., Houska M. (2015): Influence of UV and ozonised water treatment on trans-resveratrol content in berry skins and juices of Franc and Green Veltliner grapes. Czech J. Food Sci., 33: 267–276. Grapes from two varieties – Franc (red) and Green Veltliner (white) were processed using UV radiation at selected powers and times. Irradiated grapes were stored for 24, 48, and 72 h at room temperature. A second set of grapes was dipped into ozonised water. We tested the influence of ozone concentration, dipping time, and storage time. All experiments were performed using grapes harvested in 2009, 2010, and 2011. The two treatments were compared relative to trans-resveratrol content in grape skins and juices (prepared from treated grapes).