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In this study the evolution of antioxidant activity was investigated during malting of different barley cultivars, and during the production of different types of beers on laboratory scale and in pilot brewery. Samples were taken at technologically important points of productions. Malts were produced from 3 spring and 3 winter barley cultivars. Two types of beers were brewed under laboratory conditions, and two in a pilot brewery. For the determination of antioxidant activity five commonly used assays were applied such as ABTS Radical Scavenging Activity, Cupric Reducing Antioxidant Capacity, DPPH Radical Scavenging Activity, Ferric Reducing Antioxidant Power and Total Polyphenol Content. Prior to malting it was observed that there are orders of magnitude differences between the antioxidant activities of the barley varieties. During malting, the biggest increase was noticed during steeping. Spring and winter cultivars showed similar trends during steeping and germination, but kilning had different effect on antioxidant activity of the varieties. The antioxidant activity of malts was always higher than the corresponding barleys. During the brewing process antioxidants were released to the highest extent during the early stages of mashing. Adequate sparging and hop boiling could further improve the antioxidant potential of the wort. Furthermore, differences between the equipment used for wort separation and hop boiling under laboratory conditions and in the pilot brewery had effect on antioxidant activity. In the course of malting and brewing by selecting the appropriate raw materials and technological parameters, the conditions for the release and retention of antioxidants can be optimized.

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Growth and metabolic activity of several new, human origin isolates of Bifidobacterium strains were investigated. All tested bifi dobacteria strains were grown well on the native soymilk medium without any additional nutrients. The fermentation processes cultured with initial cell concentrations in 10 5 -10 7 cfu/ml resulted in 10 8 cfu/ml after 8-12 h of incubation in soymilk, and were kept viable up to the end of fermentation (48 h). Volumetric productivities of B. bifi dum B3.2, B. bifi dum B7.1 and B. breve B9.14 were 1.6×1010 cfu/L.h, 4.5×10 10 cfu/L.h and 7.6×10 9 cfu/L.h, respectively, whereas these values of B. lactis Bb-12 and B. longum Bb-46 probiotic strains were 2.7×10 9 cfu/L.h and 1.0×10 10 cfu/L.h. The α-galactosidase activities were also detected in the intracellular fraction of the disrupted cells. Productions of lactic and acetic acids were in the range of 23-60 mmol/L and 2.4-5.6 mmol/L, respectively. Molar ratios of acetate to lactate in all tested strains varied from 0.05-0.1 that are very promising for further technological development of probiotic fermented soy-based food products.

In this study 40 Hungarian retail beers were evaluated for folic acid content, antioxidant profile and physicochemical parameters. The physicochemical parameters, folic acid content and antioxidant activity of alcohol-free beers were the lowest. Folic acid content of beers aged with sour cherries showed high values, more than 0.4 mg/l and an alcohol-free beer-based mixed drink made with lemon juice contained more than 0.2 mg/l of folic acid. Dark beers and beers aged with sour cherries had the highest antioxidant activity probably owing to their high extract content, components released from the fruits and special malts. These results highlight the possibility of achieving adequate folic acid and relevant antioxidant intake without excessive alcohol and energy consumption by selecting appropriate beer types.

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