Instant lassi was prepared from cows' milk standardized to 4% fat and 8.5% solids-nonfat and heated to 85°C for 30 min, followed by cooling at 37°C and adding 50% v/v lactic acid to adjust the pH to 3.4, 3.6 and 3.8. The sugar was added at the rate of 8%, 10% and 12% and mixed thoroughly in a Waring blender. The synthetic flavours vanilla, strawberry and pineapple were also added at the rate of 0.2% and stored at refrigeration temperature.

Aspergillus parasiticus NRRL 2999 and Aspergillus flavus K3 were examined for aflatoxin production in khoa. The inoculated khoa samples were examined after incubation for 2 weeks at 5, 28 and 37 C. Aflatoxin penetrated to a depth of 4 cm in the inoculated khoa samples stored at 28 and 37 C.