A total of 187 samples of commercially available milk and yogurts
were collected from local supermarkets, all over South Korea.
It consisted 64 milk (33 plain, 31 skim), 59 plain yogurts (30 drinking,
29 paste) and 64 fruit mixed yogurts (34 paste, 30 drinking). In
each category, the samples belonged to different brands or flavours,
purchased in triplicate at different times, during July–November
2012. All the samples were kept in their original packages and
transferred to the laboratory in an ice box, properly labelled and
stored in refrigerator. These were processed for analysis within
one week of their purchase, well before the expiry date.