New quality scale for onions

Onions designed for specific purposes could soon reach the shelves, thanks to a long-term analysis of taste and texture by European scientists.

Eight teams of European scientists have been working for five years on the improvement of fresh and dried products from this ordinary vegetable.

Genetic analysis, using molecular markers, showed that it is in principle possible to develop onions with defined taste and texture properties according to different possible presentations. Dried onions need to be strong in taste and lower in water content, whereas onions consumed fresh as in salads need to be milder.

The scientists - led by Dr Chris Kik​ at the Plant Research International in The Netherlands - identified genes involved in features - such as taste - and selected those varieties containing the desired quality characteristics for further breeding.

The level of organo-sulphur compounds, partly responsible for the taste and odour of onions, were analysed. Their discoveries led the scientists to develop a new indicator of onion flavour quality.

Following investigations on the level of non-structural carbohydrates (fructans, dry matter), they found that this trait also presents considerable genetic variation in onions.

A European research network called Allium​ has been formed to promote a better use of research results and facilitate future research on the onions, one of the most widely cultivated horticultural crops in Europe.