Unilever's Lipton Ice Tea brand is the best-known rival to Mangajo although the majority of the products are made from black tea rather than green tea and are marketed as a mainstream source of refreshment rather than a niche product.

Lipton was launched in the UK in 2002 and comes in flavours such as peach, lemon and mango, although more recently the brand has tapped into the health credentials of green tea with an orange flavour of the drink.

Major UK tea brands such as Tetley and Twinings have also entered both the green tea and iced tea cold drinks category in the past few years. Twinings produces chilled green tea in lemon and peach varieties as well as raspberry, cherry, peach and lemon iced teas. Tetley Ice T comes in raspberry & cranberry; lemon & lime; peach & orange; green tea & apple; and green tea & grapefruit. There are also light variants.

Smaller competitors include AriZona Drinks, which has flavours much more akin to Mangajo. The brand, which was launched in the UK in 2004, comes in 591ml bottles in green tea flavours such as ginseng and honey; mandarin orange; Asian plum and no carb blueberry. It has limited distribution with listings in Holland & Barrett and Whittard. The Saka mineral water brand also has two iced teas in its stable, in lemon and peach flavours

However, because Mangajo uses popular fruits such as goji berries, lemon and pomegranate, its main competition comes from more standard fruit juice brands, especially those targeted at women. These include Innocent's Juicy Water, Firefly tonics, and Feel Good Drinks.

According to Mangajo founder Alex Hannon, the healthy drinks market is becoming difficult to crack because of the wide variety of products now on offer. With the health benefits of green tea being widely published - its high antioxidant levels are purported to help fight cancer cells, help lower LDL cholesterol levels and inhibit the formation of blood clots - more brands are expected to enter the green tea market in the UK over the next 12 months. Mangajo could find the next few years its most challenging yet.