Unilever has signed a £21m licensing deal with Phytopharm, the UK biotech company, to use a form of the cactus plant as an ingredient for new Slim-Fast products.

Under the deal, Phytopharm will receive royalties on any products developed from the hoodia cactus, and in turn it will pay a royalty to the South African government’s research agency, which proved the cactus’s appetite-suppressant properties in the Eighties.

Unilever hopes the deal will revitalise the Slim-Fast brand, according to a report in the Independent today, which noted sales for the Slim-Fast brand were falling at a rate of 30% at one point last year.