Histamine in Australian wines - a survey between 1982 and 2009

Biogenic amines are found in a range of fermented foods and beverages, including wine. Absorption of these compounds in elevated concentrations may induce headaches, gastro-intestinal and respiratory distress. The main biogenic amines found in wine are histamine, tyramine, cadaverine and putrescine. Even though concentrations of histamine in wine are generally ten-fold lower than found in some fresh and other fermented foods, their presence may contribute to an adverse reaction when consumed in combination with other histamine-containing foods. It is well established that the main contribution of biogenic amines in wines is from lactic acid bacteria metabolism, especially during or after malolactic fermentation (MLF). A survey for histamine content of Australian red and white wines produced during 1982–1990 demonstrated a wide range of concentrations (mean 1.58 and 0.21 mg/L, respectively). A second survey of histamine content in red and white wines produced during 2003–2009 (mean 1.75 and 0.59 mg/L, respectively) showed that there were minimal changes in the mean histamine concentration over the period of the two sets of wines. All 238 Australian wines from 1982–1990 and 99 of 100 wines from 2003–2009 were below the former regulatory recommended limit of 10 mg/L for histamine in wine and were low compared to other wine-producing countries. Seven other biogenic amines measured in the Australian wines from 2003–2009 also had low means compared to other wine-producing countries.Eveline J. Bartowsky and Creina S. Stockle

Implications of new research and technologies for malolactic fermentation in wine

The initial conversion of grape must to wine is an alcoholic fermentation (AF) largely carried out by one or more strains of yeast, typically Saccharomyces cerevisiae. After the AF, a secondary or malolactic fermentation (MLF) which is carried out by lactic acid bacteria (LAB) is often undertaken. The MLF involves the bioconversion of malic acid to lactic acid and carbon dioxide. The ability to metabolise L-malic acid is strain specific, and both individual Oenococcus oeni strains and other LAB strains vary in their ability to efficiently carry out MLF. Aside from impacts on acidity, LAB can also metabolise other precursors present in wine during fermentation and, therefore, alter the chemical composition of the wine resulting in an increased complexity of wine aroma and flavour. Recent research has focused on three main areas: enzymatic changes during MLF, safety of the final product and mechanisms of stress resistance. This review summarises the latest research and technological advances in the rapidly evolving study of MLF and investigates the directions that future research may take.Krista M. Sumby, Paul R. Grbin, Vladimir Jirane