Comparative Analysis of the Physicochemical Parameters of Breast Milk, Starter Infant Formulas and Commercial Cow Milks in Serbia

Abstract

Data on the physical properties of cow milk and infant formulas are important since they indicate the differences in physicochemical and rheological characteristics and compatibility with natural breast milk. This fact is important not only for quality control but also for the use of these commercial products as infant diet supplements or as complete breast milk substitutes. This study was undertaken to determine refractive index, surface tension, pH, electrical conductivity, viscosity and titratable acidity of the UHT cow milk, starter infant formulas and breast milk of Serbian mothers in order to compare commercial milk formulations with natural human milk. The paper also presents the measured data of some physical parameters of human milk about which there is little information in the literature. It has been also demonstrated how these parameters were changed by freezing and prolonged storage of breast milk.In this study, 8 commercial cow milks, 6 starter infant formulas and 15 different samples of colostrum, transition and mature breast milk were included. The titratable acidity, pH, electrical conductivity, refractive index, viscosity and surface tension were measured by using standardized techniques. It has been found that infant formulas available on the Serbian market differ in physicochemical parameters compared to breast milk. Regarding these parameters, none of the analyzed formulas fully corresponded to breast milk. It has been also shown that measurement of physical parameters is simple and inexpensive way to monitor the milk shelf-life which is important for human milk banks.

Prediction of basic drug exposure in milk using a lactation model algorithm integrated within a physiologically based pharmacokinetic model

“…For tramadol, disposition in milk was only studied in the early lactation phase in the colostrum milk (2–4 days postpartum) from paired single point concentrations (Ilett et al., 2008) and from steady state AUCs (Salman et al., 2011). Due to the lack of measured pH information in the original study, a weighted mean value of 7.24 (n = 96) from three independent clinical studies for colostrum milk was used (Ansell et al., 1977; Morriss et al., 1986; Sunarić et al., 2016), which resulted in the adequate prediction of the M/P ratio (range: 1.82–2.03). Similarly, the predicted RIDD (2.24%–3.27%) and corresponding IDD (0.12–0.17 mg/kg/day) values closely matched the reported values of 2.16%–2.60% (C avg method) and 0.11–0.13 mg/kg/day, respectively (Table 1).…”

“…Tramadol elimination was described using enzyme kinetics derived from the retrograde model to incorporate CYP2D6, CYP3A4, and CYP2B6 metabolic pathways and a renal clearance of 7.24 L/h (Ultram (Tramadol hydrochloride; Janssen Pharmaceutical Companies). A measured median milk creamatocrit value of 4.4% (range 1.0%–13.2%) (Salman et al., 2011) and a milk pH value of 7.24 (n = 96) derived from the three independent clinical studies for transition milk (2–4 days postpartum) (Ansell et al., 1977; Morriss et al., 1986; Sunarić et al., 2016) were incorporated in the lactation model, while the rest of the model parameters and equations were incorporated as described in the previous section.…”

“…The default model uses the first order absorption, minimal PBPK distribution, and CYP2C9, CYP2D6, and CYP3A4 enzymes to describe its disposition kinetics. The mean milk pH value of 7.1 was recorded for 0.13–25 months postpartum lactating women considered in the clinical studies (Abduljalil et al., 2021; Ansell et al., 1977; Morriss et al., 1986; Sunarić et al., 2016). These input parameters were coupled to the lactation PBPK model, and the remaining milk physiological default values were used.…”

Physicochemical properties and health benefits of camel milk and its applications in dairy products

“…Camel milk viscosity, which ranges between 1.32-1.44 mPa.s, is the highest compared with cow's milk and human milk [71]. The viscosity of Indian camel milk was 1.77 mPa.svs 1.54 mPa.s for cow's milk [61].…”

“…In the UAE, the surface tension of camel milk samples ranges from 58.35 to 58.37 dynes/cm [70]. Sunarić et al [71] displayed that the surface tension of camel milk was the highest compared to cow milk (42.3-52.1 dynes/cm) and human milk, 47.73±1.50 dyne/cm, reflecting a higher content of proteins and non-polar molecules results in lower values of the surface tension [72].…”