High performance liquid chromatography with evaporative light-scattering detection (HPLC-ELSD) was adopted to determine 1,3-dioleoyl-2-palmitoylglycerol (OPO) and 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL) in 36 samples of 12 brands of formula milk powder for infants and young children at three age groups. Gas chromatography coupled with a hydrogen flame ionization detector was employed to measure the content of palmitic acid at the sn-2 position of triglyceride. Results revealed that fat contents in 32 samples significantly exceeded the nutrition label values. Among 18 samples of OPO-enriched milk powder, seven had OPO levels lower than the nutrition label values. OPO was detected in all 18 samples of non-OPO-fortified milk powder. OPO was more abundant than OPL in 34 samples. The proportions of saturated fatty acids (20.31%–50.12%) and monounsaturated fatty acids (33.13%–54.89%) in the formula were relatively high, whereas the proportion of polyunsaturated fatty acids (14.20%–31.76%) was slightly low. The relative content of sn-2 palmitic acid in the OPO-enriched milk powder was significantly higher than that in the non-OPO-fortified milk powder. This study provides valuable insights for research on the ‘humanization’ of lipids in infant formula.

In this study, in order to investigate the effect of gelation on the hardness, oil-holding capacity and rheological properties of oils and fats, oleogels were prepared by mixing coconut oil and/or palm kernel oil as oil base with candelilla wax. The results showed that candelilla wax enhanced the hardness and oil-holding capacity of oils and fats, and it could overall increase the apparent viscosity and modulus, indicating strong gelation. Furthermore, in order to clarify the effects of wax-based oleogels on chocolate quality, chocolate was made with the oleogels as oil base and stored at fluctuating temperatures of 25/32 ℃. The fatty acid and triglyceride composition, color, crystal form and micromorphology of chocolate were analyzed. It was found that gelation resulted in the generation of a new β’ crystal form, and the formation of feather-shaped and spherical crystals inside the crystal; the oil was encapsulated in the dense crystalline network, preventing its migration, retarding the blooming of chocolate and making the chocolate system more stable. In conclusion, this study provides a theoretical basis for the construction of wax-based oleogels and a reference for the development and application of fat substitutes for chocolate.