2.3. Standard microbiological analysis Heterotrophic plate counts (HPC) were determined in accordance with the Standing Committee of Analysts (2012) procedure. A 1 mL volume of sample was mixed with 17.5 mL of molten Yeast Extract Agar (YEA, OXOID, UK) and incubated at either 37 °C (HPC 37) for 44 h or 22 °C (HPC 22) for 68h to give total viable counts at 37 and 22 °C (TVC37 and TVC22), respectively. Analyses were performed in dupli- cate. The determination of coliforms, including Escherichia coli, was carried out in accordance with Standing Committee of Analysts (2016) procedures. A 100 mL sample volume was filtered onto a 0.45 um membrane filter which was transferred to an MLGA plate (OXOID, UK). Plates were incubated at 30 °C for 4-5 h followed by 14-15 h at 37 °C.