New Achievements in High-Pressure Processing to Preserve Human Milk Bioactivity

Abstract

High-pressure processing (HPP) is a non-thermal technology that is being increasingly applied in food industries worldwide. It was proposed that this method could be used as an alternative to holder pasteurization (HoP; 62.5°C, 30 min) in milk banks but its impact on the immunologic, enzymatic and hormonal components of human milk has not yet been evaluated in detail. The aim of our study was to compare the effects of HPP in variants: (1) 600 MPa, 10 min (2) 100 MPa, 10 min, interval 10 min, 600 MPa, 10 min (3) 200 MPa, 10 min, interval 10 min, 400 MPa, 10 min (4) 200 MPa, 10 min, interval 10 min, 600 MPa, 10 min in temperature range 19–21°C and HoP on the leptin, adiponectin, insulin, hepatocyte growth factor (HGF), lactoferrin and IgG contents in human milk. HoP was done at the Regional Human Milk Bank in Warsaw at the Holy Family Hospital on S90 Eco pasteurizer (Sterifeed, Medicare Colgate Ltd). Apparatus U4000/65 (Unipress Equipment, Poland) was used for pascalization. Milk samples were obtained from women during 2–6 weeks of lactation. Post-treatment culture showed no endogenous bacterial contamination in any tested option. Concentrations of selected components were determined using ELISA tests. The level of all analyzed components were significantly decreased by HoP: leptin 77.86%, adiponectin 32.79%, insulin 32.40%, HGF 88.72%, lactoferrin 60.31@.%, IgG 49.04%. All HPP variants caused an increase in leptin concentration, respectively (1) 81.79% (2) 90.01% (3) 86.12% (4) 47.96%. Retention of insulin after HPP was (1) 88.20% (2) 81.98% (3) 94.76% (4) 90.31% HGF (1) 36.15% (2) 38.81% 97.15% (3) 97.15% (4) 43.02%, lactoferrin (1) 55.78% (2) 57.63% (3) 78.77% (4) 64.75%. Moreover, HPP variant as 200 + 400 MPa preserved IgG (82.24%) better than HoP and resulted not statistically significant change of adiponectin level (38.55%) compare to raw milk. Our results showed that HPP leads to preservation of adipokines, growth factor, and lactoferrin, IgG much better or comparable with HoP.

Innovative Techniques of Processing Human Milk to Preserve Key Components

“…Viruses such as HIV and CMV are also deactivated [7,31,43]. HPP was shown to be even more effective in comparison to holder pasteurization in the elimination of inoculated microbiological flora (total viable count microorganisms, S. aureus ) of raw milk [12]. A recent study showed that high pressure processing can be an effective method of eliminating bacteria which produce spores, like Bacillus cereus [13].…”

“…The latest research showed a reduced content and activity of lysozyme, lactoperoxidase and lactoferrin, while a shorter incubation time in higher temperature (75 °C, 15 s versus 62.5 °C, 30 min) proved to have better results as far as antibacterial properties were concerned [30]. Moreover, recent studies have shown a 40% reduction of lactoferrin concentration in HoP-treated milk [12]. This could explain the several-fold increase of bacteria in milk after pasteurization in comparison to fresh or frozen milk [49].…”

“…In a study by Ley et al the reduction of adiponectin and insulin was 33% and 46%, respectively [60]. Another study showed a reduction of HMV adiponectin, insulin and leptin concentration of 38%, 32% and 88% respectively, and also incubation at 57 °C reduced the number of bioactive peptides like leptin [12,61]. In contrast to temperature treatment, in four tested variants of high pressure: 600 MPa, 100 + 600 MPa, 200 + 400 MPa and 200 + 600 MPa the reduction in HPP content was 64%, 61%, 2% and 57%, respectively.…”

“…Compared to the thermal method, HPP lead to better retention of leptin and insulin. In the case of leptin, high pressure processing even caused an increase in concentration (148–186%) [12].…”

Changes in Human Milk Immunoglobulin Profile During Prolonged Lactation

“…Milk immunoglobulins are at least partially preserved after standard procedures of milk processing, but the effect is different for the analyzed classes of immunoglobulins. According to Escuder-Vieco and coworkers (44), the most thermostable immunoglobulin is IgG, showing the highest preservation rate (87-101%), followed by SIgA (concentration reduction of 12-46%), and the least IgM (concentration reduction of 27-75%), whereas high-pressure processing of breast milk had no or a small effect on Igs concentration (45,46). However, the available data can differ.…”