Sweet, sour, salty, bitter and... umami. Have you heard of the fifth taste? Umami, meaning ‘delicious flavour’ in Japanese, was discovered by a chemist in Japan in 1908 but it took nearly 100 years for it to be recognised as a fifth distinct taste. It is described by many as a savoury or meaty taste. In this programme Ruth Alexander learns about the chemist who first discovered umami, and the industrially produced version he created – monosodium glutamate, or MSG. It’s a food additive that’s been the subject of health scares, but today it’s one of the most tested additives in our food and considered to be safe for consumption. Yukari Sakamoto, trained chef and food tour leader in Tokyo explains how umami features in Japanese cuisine; she says miso soup is one of the best examples of maximum umami flavour. Professor Barry Smith, Director of the Centre for the Study of the Senses in the UK, explains the science behind umami and MSG. Calvin Eng, chef and owner of Bonnie’s restaurant in Brooklyn New York, is one of a number of chefs trying to rehabilitate MSG’s reputation – he uses it not just in savoury dishes, but also desserts and drinks. If you would like to get in touch with the show, please email: thefoodchain@bbc.co.uk Presented by Ruth Alexander. Produced by Beatrice Pickup. (Image: a bowl of miso soup, containing tofu and spring onions. Credit: Getty Images/BBC)