Pasteurization Efficiency of a HTST System for Human Milk

Abstract

An economical, small scale heat processing device was studied for rapid and efficient pasteurization of human milk while preserving immunoglobulins A,G and M. Using a continuous flow HTST milk pasteurizer, human milk inoculated with E. coli (10 6 CFU/mL) or S. aureus (10 7 CFU/mL) was heated at 71ЊC at flow rates of 5.9, 12.3 and 18.9 mL/ min. All conditions completely inactivated both microorganisms and resulted in negative alkaline phosphatase activity indicating complete pasteurization. Heat processing of bovine milk at 71ЊC, at 5.9 mL/min resulted in retention of 30% of the ␥-glutamyl transpeptidase (GGTP) activity. Lower residual activity could therefore indicate overpasteurization. Pasteurization at 71ЊC for 9.0 sec (12.3 mL/min) resulted in retention of 74% of IgA, 75% IgG, and 68% IgM.

Kinetic and Thermodynamic Parameters for Heat Denaturation of Bovine Milk IgG, IgA and IgM

“…However, Dhar et al (1996) found a higher retention for human IgA than for IgG at 71 to 74ЊC, probably due to different experimental conditions. Resmini et al (1989a) obtained three immunoglobulin fractions from bovine milk by reversed-phase HPLC, from which they considered the IgG fraction as the more thermostable.…”

Pasteurization of human milk by a benchtop High-Temperature Short-Time device

“…sIgAs represents the 363 majority of IgA in HM (Goldsmith et al, 1983). In early reports, the retention of sIgAs and /or the 364 total IgAs following HTST was found to be complete (Goldblum et al, 1984), decreased with 365 respect to raw milk (about 60% for Dhar et al, 1996) and equal to that of HoP with respect to raw 366 milk (63% according to Goldsmith et al, 1983 pasteurization (Mayayo et al, 2016). In all these reports, lysozyme activity was determined using a 378…”

Vitamin Content of Breast Milk From HIV-1-Infected Mothers Before and After Flash-Heat Treatment

“…Flash-heat is similar to the commercial HTST methods, which heat to 72°C for 15 seconds and have been shown to effectively kill bacteria and cytomegalovirus yet have limited impact on vitamins, lactoferrin, and IgA. Thus, HTST is viewed as the preferable heating technique for human milk 18,24,25. Pilot data also suggest that nutritional properties are retained after flash-heat in breastmilk collected from healthy mothers in the United States 26.…”