Impact of -irradiation or heat pasteurisation treatment on nutritional and immunological properties of human milk

The nutritional and microbiological quality of human milk (HM) before and after spray drying was compared. The results showed that the atomisation of untreated-HM did not significantly change protein, lactose and fat content. The immunoglobulins showed a retention from 70 to 82% for IgA, IgG and IgM. gamma-Irradiation (3, 5 and 10 kGy) of frozen and powdered milk as well as Holder pasteurisation (HoP; 62.5 degrees C for 30 min) of liquid milk were used to decontaminate milk. A dose of 5 kGy irradiation resulted in 99.7% destruction of the total aerobic flora in the powdered milk and in the frozen milk, while it was 95.1% for HoP-treated milk. Macronutrients and bioactive compounds (lysozyme and amylase) present in atomised HM were not affected by gamma-irradiation even at a dose of 10 kGy. Despite a slight increase in malondialdehyde, treatment with irradiation at 10 kGy did not alter the antioxidant potential. (C) 2021 Elsevier Ltd. All rights reserved.