Dragon's Den is on BBC One and iPlayer, 8pm on Thursday 14 March.

The entrepreneurs bidding for the Dragons' investment in this episode are a landlord who has invented a thermostat for rental properties, a 'free-from' businesswoman offering a snackable granola, a mum who has developed a natural range of play make-up for children, and a founder who thinks he’s discovered a way to dispense eye and ear drops easily.

Speaking about the show, now in its 21st series, original dragon Deborah Meaden says: "People might think Dragons’ Den hasn’t changed but it has and in quite significant ways…which is right because business is people and the way we live and work changes. I definitely think it reflects the more relaxed business style….we see more laughter and chat between the Dragons, obviously a big shift towards IT and web-based businesses and of course social media has changed the way we all tell our stories. And the big plus for me, everyone tackles their position on sustainability".

Steven Bartlett says: "I think people still enjoy Dragons’ Den because it's a show that celebrates entrepreneurship and innovation. People love to see how the Dragons interact with the entrepreneurs and each other. The competitive element makes for great television and it’s those moments where we are up against each other that can occasionally get a bit heated that adds another layer of entertainment for viewers. Ultimately, it's a show that inspires people to follow their dreams and start their own businesses. It shows that anyone with a good idea and a lot of hard work can achieve success".