Ash was prepared by taking 1 ml of milk samples in silica crucibles followed by heating on hot plate to complete charring. The charred samples were incinerated in a muffle furnace at 550 °C for 3–4 h till white ash was obtained. In case of khoa and paneer, 1 g of crushed samples were taken and charred followed by ashing in muffle furnace at 550 °C for 6 h.