Production of γ-aminobutyric acid by microorganisms from different food sources.

Background: γ-Aminobutyric acid (GABA) is a potentially bioactive component of foods and pharmaceuticals. The aim of this study was screen lactic acid bacteria belonging to the Czech Collection of Microorganisms, and microorganisms (yeast and bacteria) from 10 different food sources for GABA production by fermentation in broth or plant and animal products.

Results: Under an aerobic atmosphere, very low selectivity of GABA production (from 0.

Effect of a polyamine biosynthesis inhibitor on the quality of grape and red wine.

Background: The quality of berries and red wines is influenced by the cultivar. The aim of this study was to determine the effect of a polyamine biosynthesis (PA) inhibitor on some red grapevine cultivars with a genetically lower quality of grapes and wines. O-Phosphoethanolamine was used as a PA inhibitor because of its positive effect on the quality of some small berries.

Regulation of the phenolic profile of berries can increase their antioxidant activity.

The changes of the antioxidant activities (AOA), antiradical activities (ARA), low-density lipoprotein (LDL) oxidation, and total contents of phenolics, anthocyanins, flavonols, hydroxybenzoic acids, and hydroxycinnamic acids in black currant and black chokeberry, after treatment with ornithine decarboxylase inhibitor, a polyamine inhibitor (O-phosphoethanolamine, KF), and a phenol biosynthesis stimulator (carboxymethyl chitin glucan, CCHG), were analyzed spectrophotometrically. Gallic acid, hydroxycinnamic acids, and selected flavonol contents was analyzed by RP-HPLC. Both regulators increased the AOA measured as inhibition of peroxidation (IP) in black chokeberry, 1.

Antioxidant capacity changes and phenolic profile of Echinacea purpurea, nettle (Urtica dioica L.), and dandelion (Taraxacum officinale) after application of polyamine and phenolic biosynthesis regulators.

The changes of the antioxidant (AOA) and antiradical activities (ARA) and the total contents of phenolics, anthocyanins, flavonols, and hydroxybenzoic acid in roots and different aerial sections of Echinacea purpurea, nettle, and dandelion, after treatment with ornithine decarboxylase inhibitor, a polyamine inhibitor (O-phosphoethanolamine, KF), and a phenol biosynthesis stimulator (carboxymethyl chitin glucan, CCHG) were analyzed spectrophotometrically; hydroxycinnamic acids content was analyzed by RP-HPLC with UV detection. Both regulators increased the AOA measured as inhibition of peroxidation (IP) in all herb sections, with the exception of Echinacea stems after treatment with KF. In root tissues IP was dramatically elevated mainly after CCHG application: 8.

Content of phenolic compounds and free polyamines in black chokeberry (Aronia melanocarpa) after application of polyamine biosynthesis regulators.

The total contents of anthocyanins, flavonoids, and phenolics in 60 samples of black chokeberries (Aronia melanocarpa), after treating with catabolites of polyamine biosynthesis (KPAb) and ornithine decarboxylase inhibitor, were analyzed spectrophotometrically, and quercetin and free polyamine contents were analyzed by RP-HPLC with UV detection. The average total contents of the individual substances and phenolic subgroups in control berries were as follows (mg x kg(-1)): anthocyanines, 6408; flavonoids, 664; phenolics, 37,600; quercetin, 349. KPAb decreased total contents of anthocyanines and phenolics only slightly but significantly increased the content of flavonoids.