Sour wine and headaches a thing of the past
Cheese and wine are natural table partners. Unfortunately, they share another link in that they are both prone to spoilage by tryamine producing lactic acid bacteria (LAB). Produced naturally in the body, tyramine is broken down by an enzyme before it causes cellular havoc. However, when an excess is ingested, it can leave the sufferer with a rise in blood pressure and increased heart rate caused by constriction of the blood vessels. The European funded project DECARBOXYLASE set out to devise a speedy reliable test for the bacteria responsible. Previous to this new development, a plate test could be performed but it requires expensive equipment and takes up to three days for a result. Pathways involving the amine were studied and, on this basis, primers located in the appropriate gene to detect the amine producing LAB were developed. The primers were screened using some 200 LAB strains to see if the tyramine producers could be detected. Techniques polymerase chain reaction (PCR) and high performance liquid chromatography (HPLC) yielded exactly the same results. This therefore verified the effectiveness of the primers to indicate the presence of some very diverse LAB microbes. These included Lactobacillus brevis that also improves human immune function, notably against thrush infection. Another amine not exactly desirable in wine is histamine, responsible for that headache and possible allergic reactions. The team also developed primers for this unwanted perpetrator of the wine bottle. The sensitivity of the resulting histamine test is very high and is able to detect spoilage microbes at a very low level (two histamine producing microbes per millilitre of wine). Wine found with tyramine concentration above the recommended levels can be rejected from the market. A decrease in the amount of wine unfit for the shelf has obvious economic benefits. A better, safer wine on the table, not to mention a reduction in that hangover, has undeniable appeal for the consumer.
