Fate of Quinoxyfen Residues in Grapes, Wine, and Their Processing Products

详细信息    查看全文

• 作者：Paolo Cabras ; Alberto Angioni ; Vincenzo L. Garau ; Filippo M. Pirisi ; Franco Cabitza ; Mario Pala ; and Giovanni A. Farris
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2000
• 出版时间：December 2000
• 年：2000
• 卷：48
• 期：12
• 页码：6128 - 6131
• 全文大小：40K
• 年卷期：v.48,no.12(December 2000)
• ISSN：1520-5118

文摘

Quinoxyfen is a new fungicide that belongs to the family of the quinolines, recently introduced tocontrol powdery mildew (Uncinula necator). In this paper the fate of quinoxyfen residues from vineto wine and in their processing products was studied. After the last of four applications at therecommended rate, 0.38 mg/kg of residue was found on the grapes, which is under the legal limitfixed in Italy (0.5 mg/kg). The degradation rate was according to a pseudo-first-order kinetics (r =0.964) and the half-life was 7.24 days. Vinification was carried out with and without maceration.During the vinifications without maceration <50% of the residues passed from the grapes to themusts. Separation of the lees (8%) from the must by centrifugation caused no detectable residuesin centrifuged must. At the end of fermentation with and without maceration no quinoxyfen residueswere determinable in the wine. No effect on the alcoholic or malolactic fermentation was observedeven in the presence of higher quinoxyfen concentrations than those found in the grapes at harvesttime. During fermentation, the yeasts partially degraded the pesticides and completly adsorbedthem. Bacteria, on the other hand, do not have any degradative effect on the pesticides. The raisinsobtained by sun-drying did not contain any residues, whereas those obtained by oven-drying showthe same amount of residues as in the fresh grapes. During the sun-drying process the fruit weightdecreased by a factor of 4; the decrease in the oven-drying was equivalent. Samples of dregs andliquid lees, fortified with high levels of quinoxyfen. were double-distilled. The first dregs distillate,with an alcohol content of 32.1%, did not show any residues, whereas the first lees distillate, withan alcohol content of 34.5%, showed 7% of the initial residues. After the second lees distillation, theobtained product showed an alcoholic content of 81.2% and no residues of quinoxyfen (<0.01 mg/kg).Keywords: Residues; quinoxyfen; grapes; must; wine