A family of South Africans who moved to the US missed their beloved biltong meat snack so much that they started producing it for family and friends. It is now a full-time business called Ayoba-Yo - a term used to express excitement or amazement - which is attempting to compete with American favourite jerky and working with Kraft Heinz on its development. Andy Coyne talks to company co-owner Wian van Blommestein about its prospects.