Since the invention of beer by the Sumerian people in 5000 BC, alcohol was the main reason of the interest of consumers on beer. Dnly in the beginning of the 20th century alcohol-free beer was demanded and since then technology has advanced dramatically in the production of those beverages. The aim on alcohol-free beer production is to have products that taste similarly to their alcoholic equivalents, the sole absence of alcohol and low concentrations of esters and higher alcohols and the higher concentration of aldehydes create a "worty" organoleptic impression of those products. Alcohol-free beers can be obtained by the restriction of alcohol formation during fermentation, the use of special yeast strains that consume or don't produce alcohol, the thermal removal of alcohol and by the removal of alcohol trough membrane processes. Membrane separated alcohol-free beers preserve more of the natural constituents of beer aroma and those products usually taste better than those obtained through other processes. Pervaporation techniques show a broad spectrum of use and can even be combined with other processes and perform the removal of undesired products or separation and recuperation of aromatic substances.

Summniarv. Gamimiia radiation at doses of 300 Krad or more inhibits the ripening of Bartlett pears (Pyrus commnunis L.). Immediately after irradiation there is a transitory burst of C2H4, which subsequently declines in fruits subjected to inhibitory doses. Ethylenie production associated with ripening begins at the same tinme in unirradiated fruits and those subjected to noninhibitory doses, but the latter produces much more C2H4 at the climacteric peak. Fruits subjected to inhibitory doses produce low levels of C2H4 unless subjected to exogenously applied C2H, whereupon they produce enough of the gas to iniduce ripening in unirradiated fruits.Pears subjected to 300 and

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Individual sesquiterpene hydrocarbons were isolated from black pepper oil by column chromatography followed by preparative and capillary gas chromatography. On the basis of matching retentions, infrared and, where applicable, ultraviolet spectra of isolated components, the following were identified as major compounds of the sesquiterpene hydrocarbon fraction: -elemene, -copaene, /3-elemene, a-m-bergamotene, -santaíene, a-rra«s-bergamotene, /3-caryophyllene, -humulene, /3-selinene, aselinene, /3-bisabolene, -cadinene, and calamenene.

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SUMMARY A dry table wine prepared from Passiflora edulis var. flavicarpa was found to contain the following volatile substances: methyl alcohol, ethyl alcohol, isobutyl alcohol, isobutyl alcohol, active amyl alcohol, n‐hexyl alcohol, 2‐phenethyl alcohol, acetaldehyde, diethyl acetal, 2‐butanone, 2,3‐butanedione, ethyl acetate, ethyl isovalerate, ethyl caproate, ethyl heptanoate, ethyl caprylate, ethyl caprate, ethyl laurate, isobutyl isobutyrate and isoamyl acetate. Probably present are: n‐butanol, ethyl isobutyrate, and n‐hexyl caproate. Gas chromatographic retention times are given for a number of unidentified components of the passion fruit wine volatiles. The compounds responsible, for the typical passion fruit wine aroma remain unidentified.

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