Sheila Dillon, who presented the awards, said that the judges wanted to choose a business that was making a real impact on its community and offered a model for sustainable retailing in the future.
She commented that Unicorn, which specialises in organic wholefood produce, provides â€œsome of the UKâ€™s freshest and cheapest produceâ€.
Unicorn offer competitive priced food because of its trading ethos. They buy direct from mainly local suppliers while its 40-strong workforce are paid just a living wage.
Unicorn spokesman Rob Alderson explained: â€œThis award gives people the chance to see there are living, breathing viable alternatives to the multiples. The key thing is to start changing mainstream grocery retail.
â€œWe have to show that itâ€™s possible to be both responsible and competitive and thereâ€™s no reason why all supermarkets canâ€™t be like this.
â€œAfter 12 years of trade at Unicorn this award means a lot. It will mean a whole lot more if, after the next 12 years, weâ€™re working in a much more responsible and sustainable grocery industry.â€