Is romance recession-proof? Prestat hopes so. Valentine's Day is the third-most important trading period after Easter and Christmas for the luxury chocolatier. But with an assortment box of Rose & Violet Chocolate Crèmes carrying a £13.98 price tag, can the Queen's chocolatier persuade Lotharios to part with their cash this year?

It won't be easy, admits Nick Crean, who co-owns the £4m Prestat business with half-brother Bill Keeling. "I would be mad to suggest we're recession-proof, but we are working hard, remaining very focused, investing in our brand, being innovative in our chocolate products and sticking to what we are good at," he says.

Ahead of Valentine's Day, Prestat has been pushing new products including Pink Marc de Champagne Chocolate Truffles and its Pink Babes box - as well as its traditional pink heart boxes - through its website, its boutique in London's Piccadilly, upmarket retailers and hotels and, increasingly, the supermarkets.

As far as the latter are concerned, its new antioxidant-rich Choxi+ bars have already secured listings with Tesco and Waitrose and recently made their debut in Sainsbury's. Crean is confident the bars will attract a new audience for the brand. "There are three elements to Choxi+," he says. "First and foremost, it's an outstanding-tasting chocolate. Second, it comes from people who know about chocolate, and third, it's richer in antioxidants than any other product on the market."

Two and a half times richer, in fact. Playing the health card is a bold move and one that French chocolatier Antoine Dufour, who established the Prestat business in 1902, would not have foreseen. Back then the business sold truffles to London's chocolate cafés. Since Crean and Keeling's acquisition of Prestat's Piccadilly store in 1998, it has become its own supplier, set up an online shop and diversified into corporate chocolate. The purchase of supplier Marasu's in 2006 signalled a major expansion drive. Prestat's north London factory now produces 40,000 individual chocolates a day, supplying Fortnum & Mason among other high-end retailers. Crean believes being its own supplier gives Prestat an edge over other luxury chocolate retailers.

"We're one of the very few artisan chocolatiers that controls both our manufacturing and our retail," he says. "Because of this we get the manufacturing and the retail margin. If you control both margins, it gives you a greater competitive edge."

As does broadening the number of occasions on which people buy the luxury brand. Prestat will soon find out how well its Valentine's Day gift sets have gone down, but in the long term it may be mass-market products such as Choxi+ and mass-market outlets like supermarkets that hold the key. The next chapter in the story will include the rollout of more Choxi+ products and an attempt to crack America - a "complex" market, but one where acceptance of antioxidant-rich chocolate is high.

"If we were to turn over £10m I would say Bill and I were the luckiest people around," says Crean. As if owning your own chocolate shop were not lucky enough.