United Kingdom
December, 2002

Broccoli that stays green for longer could become a commercial reality thanks to research being carried out by Horticulture Research International (HRI).

Scientists working for the Horticulture Research International are conducting a comprehensive four-year study funded by the Department for Environment, Food and Rural Affairs (Defra) to investigate the factors that determine the shelf life of broccoli.

The study is considering cultural methods of extending the crop's shelf life, attempting to identify the genes and individual compounds responsible for this characteristic and investigating the factors that determine why the keeping quality of individual varieties vary.

The work has major long-term commercial implications for producers and retailers of what has become the UK's most popular brassica vegetable, largely because it is high in antioxidants, compounds increasingly regarded as being beneficial to human health. Broccoli's increasing popularity has meant that during the last decade, the value of the crop to UK producers has more than doubled to over £45 million and by even more to the retail sector. However, its main drawback remains a relatively short shelf life brought about by premature yellowing and a rapid loss of turgor, meaning it goes 'floppy' and looses both its textural and visual appeal very quickly.

UK-harvested broccoli is treated in a uniform manner and supplies generally reach the shops within 24 hours through a 'cool-chain' system. Despite this, even batches of heads from the same variety can vary in their shelf life. Retailers, therefore, have to remove unsold broccoli from their shelves after just two days, compared with three days for most other vegetables. In addition to increasing wastage and retail costs, this unpredictability also means consumers can never be certain how long the product will remain in good condition after they buy it.

Results from a previous Defra funded three-year study at HRI Wellesbourne demonstrated that differences in shelf life may be caused by variations in growing conditions before harvest, including factors such as temperature and water stress. The work also highlighted the impact of genetic differences on shelf life, as well as the fact that poorer varieties may have lower antioxidant levels.

Speaking at the launch of HRI's Annual Report in London on 4^th December, project leader Dr David Pink said the study could have major implications for broccoli producers, packers, retailers and consumers. He added "Ultimately, we hope the work being carried out at HRI will allow plant breeders to develop new varieties that retain their looks, flavour and nutrients for longer."