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Factors influencing the lead content of wine
Author(s) -
Rankine B. C.
Publication year - 1957
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740080803
Subject(s) - wine , chemistry , winery , food science , winemaking , bottle , contamination , titratable acid , tannin , materials science , biology , ecology , composite material
Winemaking procedures, materials and equipment were examined for their influence on the lead content of wine. Unwashed grapes contained from less than 0.01 to 0.98 p.p.m. of lead (mean 0.13 p.p.m.), depending on the extent of surface contamination which was partly due to lead arsenate spray residue. Grapes, washed with acid to remove surface contamination, contained from less than 0.01 p.p.m. to 0.10 p.p.m. (mean 0.05 p.p.m.). Fermentation removed from solution 11 to 45% (mean 30%) of the lead present in the grape juice. Fining agents, fortifying spirit and acids normally added to wine did not significantly alter the lead content, nor was it lowered by the Möeslinger blue fining, which is used in some countries to remove copper and iron. Brass winery equipment and rubber wine hoses were found to be sources of contamination, but stainless steel, plastic, and glass equipment and a filter pad examined were not. Maturation of young wine produced a slight decrease but refrigeration and ion‐exchange treatment produced no significant alteration in lead content. Contact with various types of cask wood, paraffin wax, bottle corks and also wine analysed before and after shipment to England led to no significant change. The influence of wine type and composition on the extent of lead contamination was examined. Contamination was not found to be related to sulphur dioxide content, titratable acid or pH but was higher in sweet fortified wines than in dry wines, and in these wines added sulphur dioxide and tartaric acid produced a further increase. The influence of lead bottle capsules was not investigated as these are known to be a major source of contamination. The method of determination of lead is given.