Supermarket Secrets is going behind the scenes again to reveal how the supermarkets are using the latest technology and science to bring us our food. In this series, Gregg Wallace and consumer journalist Nikki Fox discover how much the Internet is transforming the way we shop and the food in our trolleys.

Tonight , the supermarkets fight to be the first with the latest food fashions. Gregg joins Tesco's Head of Plant Innovation as he invents new vegan meals that he claims will taste like meat, and sees how Asda are using ingenious growing techniques to make tomatoes sweeter than strawberries. Meanwhile, Nikki looks at the latest craze for sensory shopping.

The supermarkets know that shoppers don't show much allegiance to them any more, so what techniques are they coming up with to keep us coming back?