Scientists address broccoli shelf-life, antioxidant content

Broccoli has come under the spotlight as one of the healthiest vegetables thanks to a profile of powerful antioxidants, and a spate of studies investigating its potential to protect against diseases, including some cancers.

The term 'super-broccoli' has been applied to the projects of some researchers who are working to boost the antioxidant content of the cruciferous vegetable. Professor Richard Mithen of the Institute of Food Research, for instance, has bred a variety with three times the sulphoraphane - a compound seen to have anti-cancer properties.

Most recently, a team from the University of Warwick's plant research department is claiming the 'super' epithet for the new varieties it is working on.

Researcher Dr Graham Teakle told NutraIngredients.com that his team is taking a different tack to Prof Mithen, focusing on keeping the vegetable fresh for longer, which in turn also keeps antioxidant levels higher for longer.

"For example levels of vitamin C, an antioxidant, deteriorate rapidly as broccoli starts to age,"​ he said.

Approaches taken to slowing down the broccoli ageing process include preventing water loss, which makes the plant go floppy, and maintaining the green colour.

The work is being carried out through a cross breeding programme. This is not genetic modification, but a process whereby different varieties are selected according to their properties and encouraged to breed - as they would if they grew side-by-side in nature.

This project has been underway for four or five years already, but it is expected to be about a decade before a new variety will reach supermarket shelves. This, said Dr Teakle, is because most of the varieties are annual, so only one round of breeding can be done each year.

When the research is complete, however, it will benefit not only consumers whose broccoli will be more nutritious at the age at which they buy it, but also supermarkets since the vegetable will fit in with their usual 4-day vegetable delivery cycles (broccoli currently has its own 3-day cycle).

Warwick University has been involved in cruciferous vegetable research for around 25 years, and has a seed bank comprising more than 6,000 plants.

Another area for the Warwick broccoli researchers is developing an environmentally-friendly broccoli that has greater resistance to aphids and bacteria Xanthomonas campestris and therefore requires less pesticide use.

Dr Teakle and colleagues are this week attending the Chelsea Flower Show, in a bid to build awareness of the benefits of horticultural science beyond merely attractive-looking flowers.

As well as encouraging budding scientists to consider becoming involved with plants, they want to communicate to both consumers and government funding bodies that research in this area can yield very real benefits, for people's health and for businesses'.