A high performance liquid chromatography (HPLC) method was established to determine the contents of three aldehydes (malondialdehyde, acrolein, and 4-hydroxyhexenal) in infant formula milk powder, and the effect of storage temperature on the content of three aldehydes in infant formula milk powder was studied. The analytical figures of merit including linearity, accuracy, recovery, detection limit and quantitation limit were determined. The external standard method was used to quantify the analytes. The results indicated that this method exhibited good linearity in the range between 0 and 40 μg with a correlation coefficient (R2) greater than 0.999, and the detection limits for malondialdehyde, acrolein, and 4-hydroxyhexenal were 0.3, 0.4, and 0.3 mg/kg, respectively. The quantitation limits were 0.8, 1.0 and 0.8 mg/kg, respectively. The average recoveries for spiked samples were in the range of 88.29%–96.87%, with relative standard deviation (RSD) less than 10%. With increasing storage temperature above 40 ℃, the contents of the three aldehydes showed an upward trend, and a significant increase was observed in the contents of malondialdehyde and acrolein. This method has the characteristics of rapidity, high accuracy, and good reproducibility, which is suitable for the determination of the three aldehydes in infant formula milk powder.

In this study, the nootropic, antifatigue and antioxidant effects of two commercial milk fat globule membranes (MFGM) in BALB/c male mice were evaluated and the possible mechanisms were elucidated. Normal saline was used a control. The experimental results showed that MFGM could improve learning and cognitive ability spatial memory ability in mice, extend exhaustive swimming time, significantly increase glycogen levels, and greatly improve fatigue- and oxidative stress-related indicators, indicating its nootropic, antifatigue and antioxidant effects. However, the effects of the two MFGMs, which are produced by different methods and have different compositions, were different.

The monosaccharide composition and antioxidant activity of extracellular polysaccharides from Lactobacillus plantarum were analyzed. Crude polysaccharides were obtained from the fermentation broth of Lactobacillus plantarum by water extraction and alcohol precipitation and were fractionated into two fractions (DZ-1 and DZ-2) by DEAE-52 cellulose column chromatography. The monosaccharide components of DZ-1 and DZ-2 were analyzed by gas chromatography, and their antioxidant activity was tested using 1,1-diphenyl-2-picrylhy drazyl (DPPH), hydroxyl radical, and 2,2’-diazo bis-3-ethyl benzothiazoline-6-sulfonic acid (ABTS) cation radical scavenging assays. DZ-1 was a homopolysaccharide composed of only glucose units, while DZ-2 was a heteropolysaccharide composed of arabinose and galactose with a content ratio of 46.03:53.89. Both DZ-1 and DZ-2 had the ability to scavenge DPPH, hydroxyl and ABTS cation radicals.