3.7. Shelf life study Changes in microbial counts (aerobic bacteria, yeast and mould) in juices stored at refrigeration temperature (4 ± 1◦C)for 5 weeks are shown in Figs. 2 and 3. Shelf life of juice samples was evaluated according to the Institute of Food Science and Technology, IFST (1999). The acceptable maxi-mum microbial load including aerobic bacteria, and total yeast and mould in fruit juices are about 4 and 3 log CFU/ml, respectively. The aerobic plate counts (APC) in control (untreated juice) increased from 2.74 to 8.32 log CFU/ml after 5 weeks stor-age. While, yeast and mould counts (YMC) increased from 2.42to 6.10 log CFU/ml after 5 weeks storage. The rate of microbial growth observed in control was higher than UV-C treated juice samples during storage. The shelf life of UV-C treated juices, U15 (2 weeks), U30 (3–4 weeks), U60 (5 weeks) were longer than control (less than 1 week), in terms of micro-bial load (APC and YMC) limit. Hence, the shelf life of UV-C treated Chokanan mango juice stored at 4 ± 1◦C was extended for at least 4 weeks longer than freshly squeezed juice. Results obtained are in agreement with previous studies that reported prolonged shelf life in UV-C treated orange juice (Tran and Farid, 2004; Pala and Toklucu, 2013). Thermally pasteurized juice had almost no microorganism growth during 5 weeks storage, thus remaining below microbial load limit. This is a clear indication that thermally pasteurized juice has a shelf life for more than 5 weeks.