The effects of dairy processes and storage on insulin-like growth factor-I (IGF-I) content in milk and in model IGF-I-fortified dairy products

J Dairy Sci. 2006 Feb;89(2):402-9. doi: 10.3168/jds.S0022-0302(06)72104-X.


The effects of several dairy processes on insulin-like growth factor-I (IGF-I) concentrations in milk and the storage stability of IGF-I-fortified dairy products were examined. The IGF-I content in raw milk determined by radioimmunoassay was significantly changed by the strength of heat treatments. In commercial manufacture of whole milk dry powder, IGF-I concentration was not significantly changed. A significant reduction in IGF-I content was found as the result of fermentation with a commercial starter culture. The IGF-I content in fortified milk and dried milk powder exhibited no significant changes over the tested storage periods (12 d for milk, 4 wk for dried milk powder), but the IGF-I content in the yogurt decreased significantly during storage. The use of IGF-I was varied by lactic strains and was apparent in the viable cells. When IGF-I was encapsulated using the surface-reforming process, the remaining IGF-I content after fermentation was significantly higher compared with that of the untreated control. Therefore, enteric coating of IGF-I before fermentation might be an effective method for the prevention of IGF-I degradation during fermentation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dairy Products / analysis*
  • Fermentation
  • Food Handling / methods*
  • Food Preservation / methods*
  • Food, Fortified / analysis*
  • Hot Temperature
  • Insulin-Like Growth Factor I / analysis*
  • Insulin-Like Growth Factor I / ultrastructure
  • Lactobacillus / metabolism
  • Milk / chemistry*
  • Yogurt / analysis


  • Insulin-Like Growth Factor I