Comparison of macronutrient contents in human milk measured using mid-infrared human milk analyser in a field study vs. chemical reference methods.

Macronutrient contents in human milk are the common basis for estimating these nutrient requirements for both infants and lactating women. A mid-infrared human milk analyser (HMA, Miris, Sweden) was recently developed for determining macronutrient levels. The purpose of the study is to compare the accuracy and precision of HMA method with fresh milk samples in the field studies with chemical methods with frozen samples in the lab. Full breast milk was collected using electric pumps and fresh milk was analyzed in the field studies using HMA. All human milk samples were thawed and analyzed with chemical reference methods in the lab. The protein, fat and total solid levels were significantly correlated between the two methods and the correlation coefficient was 0.88, 0.93 and 0.78, respectively (p  <  0.001). The mean protein content was significantly lower and the mean fat level was significantly greater when measured using HMA method (1.0 g 100 mL-1 vs 1.2 g 100 mL-1 and 3. 7 g 100 mL-1 vs 3.2 g 100 mL-1 , respectively, p  <  0.001). Thus, linear recalibration could be used to improve mean estimation for both protein and fat. There was no significant correlation for lactose between the two methods (p  >  0.05). There was no statistically significant difference in the mean total solid concentration (12.2 g 100 mL-1 vs 12.3 g 100 mL-1 , p  >  0.05). Overall, HMA might be used to analyze macronutrients in fresh human milk with acceptable accuracy and precision after recalibrating fat and protein levels of field samples.