Extraction and detection of DNA from UHT milk during storage

Abstract

DNA plays an important role in molecular authentication of dairy products, both heat treatment and storage may impair the detection limit of the DNA-based method. In this study, DNA was extracted from commercial ultra-high temperature treated (UHT) milkfrom the different storage stages for monitoring DNA yield, purity, integrity, as well as by the specific detection of UHT milk composition in goat milk. Results showed that DNA yield and purity remained stable during the whole storage stage (P > .05). In addition, all the extracted DNA from UHT milk was degraded into short DNA fragments with 100–2000 bp, but these fragments can be still used for the amplification of long target sequence (>1000 bp). Furthermore, it was found that PCR could readily detect UHT milk composition in goat milk mixture, and gave a good sensitivity threshold (0.1%) during the storage of UHT milk, but the detection efficiency was gradually decreased.