Triglyceride and fatty acid composition of ruminants milk, human milk, and infant formulae

Global levels and variations of breast milk fatty acids and triacylglycerols: A systematic review and meta-analysis

Understanding global temporal and spatial variations in breast milk composition is crucial for developing personalized infant nutrition strategies. This study analyzed 46,673 breast milk samples from 171 studies using a random-effects model to evaluate total fatty acids (TFA), sn-2 fatty acids (sn-2 FA), and triacylglycerols (TAG) across lactation stages, regions, and sample years. Results showed that saturated fatty acids (SFA) increased while unsaturated fatty acids (UFA) decreased with prolonged lactation, with corresponding changes in triacylglycerol profiles. Geographically, Africa had the highest SFA and lowest UFA, Asia had the highest PUFA, and Europe had the highest MUFA. Over time, SFA and SFA-dominant TAGs declined, while UFA and UFA-dominant TAGs rose. These variations reflect shifts in maternal diet, infant nutritional needs, and potential growth outcomes, highlighting the importance of monitoring breast milk lipids to optimize infant nutrition strategies.

Addition of Phospholipids Improved the Physical Stability and Fat Globule Structure of Processed Milk

The manufacturing processes for infant formula disrupt the structure of phospholipid-coated milk fat globules, thereby impacting the physical stability of the system. In this study, either soybean phospholipids (SPs) or egg yolk phospholipids (EYPs) were incorporated into the milk system to reduce this damage, and their effects on the stability and fat globule structure of processed milk were examined. The findings revealed that the addition of phospholipids improved the physical stability and fat globule structure of different processed milk. In pasteurized milk, the stability constant of samples with phospholipids decreased from 0.42 to 0.37 compared to phospholipid-free milk, but no significant difference was found between the EYP and SP groups. In homogenized milk, adding EYPs resulted in a smaller particle size (870.35 nm versus 953.39 nm) and stability constant (0.28 versus 0.30) than the addition of SP. Moreover, homogenized milk added with EYPs exhibited a denser phospholipid interface film which led to a more intact fat globule structure. Consequently, the milk powder particles in the spray-dried milk supplemented with EYPs showed a more uniform distribution and smoother surface. These findings suggested that EYPs were superior to SPs in restructuring fat globules and enhancing newly formed fat globule stability during milk powder processing. This offers valuable insights for improving the physical and structural properties of dairy products, such as infant formula.

Lipidomics of sheep and goat Milk-based infant formulae during in vitro dynamic digestion

Lipid hydrolysis process during IF digestion, particularly the characterization of the lipidome and the resulting lipid breakdown products, has not been thoroughly investigated. This study aimed to compare the lipid hydrolysis profiles during the in vitro dynamic digestion of IFs made from whole sheep and goat milk. Using a lipidomics platform and multivariate statistical analysis, we observed changes in complex lipid levels during digestion. In the gastric compartment, we noted a progressive hydrolysis of triacylglycerols, phosphatidylcholines, and sphingomyelins. Conversely, lipolysis breakdown products like monoacylglycerols (e.g., MG(16:0), MG(18:0)), diacylglycerols, lysophosphatidylcholines (LPC 16:0, LPC 18:1, LPC 18:2), and free fatty acids increased in the intestinal compartment. The lipolysis trends were similar for both types of infant formulas, with long-chain fatty acid triglycerides (C > 46) exhibiting lower digestibility compared to medium-chain fatty acid triglycerides. Overall, these results indicate that sheep milk can be used as an ingredient in the manufacturing of IF.

Parity changed fecal microbiota of sows and its correlation with milk long-chain fatty acid profiles

The goal of this study was to characterize the fecal microbiota profiles of gestating sows, along with the fecal microbiota and milk fatty acid contents of lactating sows and their correlations with reproductive performance at different parities. The results showed that the microbiota of third parity gestating sows contained a greater abundance of Prevotella compared to the other two parity groups, while lactating sows exhibiting higher reproductive performance at fifth parity exhibited a greater abundance of Lactobacillus species. The lactating sows with higher reproductive performance also exhibited higher total monounsaturated fatty acid (MUFA) and higher total polyunsaturated fatty acid (PUFA) levels relative to sows with lower reproductive performance at all three analyzed parities, especially sows at fifth parity produced the lowest total saturated fatty acid (SFA) levels, and showed the highest C18:1n9c and C18:2n6c concentrations. In correlational analyses, the abundance of Oligella, Lactobacillus, and Corynebacterium was highly positively correlated with C18:1n9c, C18:2n6c, and C20:4n6. Overall, these results provide a rational basis for efforts to improve sow reproductive performance through the provision of precisely regulated nutrition. KEY POINTS: • Clear differences in the fecal microbiota were evident between sows of different parities. • Lactating sows with high reproductive performance showed distinct milk fatty acid profiles.

A Comparative Study on the Composition and Structure of Human Milk Phospholipids and its Natural Resources: Based on a Similarity Evaluation Model

Human milk phospholipids (HMPLs) play an indispensable role in the neurodevelopment and growth of infants. In this study, a total of 37 phospholipid fatty acid (PLFA) species and 139 phospholipid molecular species were detected from human milk and other natural phospholipid sources (including 5 animal-derived species and 2 plant species). Moreover, a similarity evaluation model for HMPLs was established, including phospholipid classes, PLFAs, and phospholipid molecular species, to evaluate their natural substitutes. The closest scores for HMPL substitute in these three dimensions was 0.89, 0.72, and 0.77, which belonged to mare milk, goat milk, and camel milk, respectively. The highest comprehensive similarity score was obtained by camel milk at 0.75, while the lowest score was observed in soybean phospholipid (0.22). Therefore, these results not only monitored the stereochemical structure of HMPLs and their substitutes, but also further provided new insights for the development of infant formulae.

Nutrition, production, and processing of virgin omega-3 polyunsaturated fatty acids in dairy: An integrative review

With improving living standards, functional and healthy foods are accounting for an increased share in human food. The development of dairy products that are rich in virgin omega-3 polyunsaturated fatty acids (n-3 PUFAs) has become a topic of interest. Virgin n-3 PUFA milk can provide high-quality protein and calcium, as well as provide n-3 PUFAs to improve human health. This review aims to investigate the effect of virgin n-3 PUFAs in milk on human health and discuss the content of virgin n-3 PUFAs in milk regulated by dairy animal diet and the effect of food processing on the content of virgin n-3 PUFAs in dairy production. The interaction between n-3 PUFAs and proteins in milk is the key to improving the nutritional value of n-3 PUFAs in milk. n-3 PUFA supplementation in the diet of dairy animals is the key method to improve n-3 PUFAs in raw milk, as well as to adjust the types of virgin n-3 PUFAs. Compared with a common source, virgin n-3 PUFAs in milk show higher antioxidant activity, but elevated temperatures and long-term thermal processing should be avoided.

Cow Milk Fatty Acid and Protein Composition in Different Breeds and Regions in China

Cow milk is rich in proteins, fats, carbohydrates, and minerals; however, its precise nutrient content varies based on various factors. In the current study, we evaluated the differences in the fatty acid and protein contents of milk and the factors associated with these differences. To achieve this, samples were collected from seven types of cows in different regions. These included samples from three dairy breeds: Chinese Holstein milk from Beijing, China (BH), Chinese Holstein milk (HH) and Jersey milk (JS) from Hebei province, China; and four dairy/meat breeds: Sanhe milk (SH) from Inner Mongolia Autonomous Region, China, Xinjiang brown milk (XH) and Simmental milk (SI) from Xinjiang Uygur Autonomous Region, China, and Shu Xuanhua milk (SX) from Sichuan province, China. Breed significantly affects total fat, fatty acid, and protein contents. Additionally, geographic region significantly affects the contents of different fatty acids, α-lactalbumin, and lactoferrin. JS has the highest total fat and casein contents. XH samples contain significantly higher unsaturated fatty acid content than BH samples and do not differ significantly from JS. Additionally, the low β-lactoglobulin and high lactoferrin contents in XH samples may be favorable for the growth and development of infants. Our results may inform the development of dairy products from different cow breeds and advance the process of accurate breed identification.

Impact of dietary regime on the metabolomic profile of bovine buttermilk and whole milk powder

INTRODUCTION

Bovine milk contains a rich matrix of nutrients such as carbohydrates, fat, protein and various vitamins and minerals, the composition of which is altered by factors including dietary regime.

OBJECTIVES

The objective of this research was to investigate the impact of dietary regime on the metabolite composition of bovine whole milk powder and buttermilk.

METHODS

Bovine whole milk powder and buttermilk samples were obtained from spring-calving cows, consuming one of three diets. Group 1 grazed outdoors on perennial ryegrass which was supplemented with 5% concentrates; group 2 were maintained indoors and consumed a total mixed ration diet; and group 3 consumed a partial mixed ration diet consisting of perennial ryegrass during the day and total mixed ration maintained indoors at night.

RESULTS

Metabolomic analysis of the whole milk powder (N = 27) and buttermilk (N = 29) samples was preformed using liquid chromatography-tandem mass spectrometry, with 504 and 134 metabolites identified in the samples respectively. In whole milk powder samples, a total of 174 metabolites from various compound classes were significantly different across dietary regimes (FDR adjusted p-value ≤ 0.05), including triglycerides, of which 66% had their highest levels in pasture-fed samples. Triglycerides with highest levels in pasture-fed samples were predominantly polyunsaturated with high total carbon number. Regarding buttermilk samples, metabolites significantly different across dietary regimes included phospholipids, sphingomyelins and an acylcarnitine.

CONCLUSION

In conclusion the results reveal a significant impact of a pasture-fed dietary regime on the metabolite composition of bovine dairy products, with a particular impact on lipid compound classes.

Simulated in vitro infant digestion and lipidomic analysis to explore how the milk fat globule membrane modulates fat digestion

We hypothesized that the addition of milk fat globule membranes (MFGMs) to infant formula would improve its lipolysis, making it more similar to human milk (HM) and superior to commercial infant formula (CIF) in fat digestion. Therefore, we prepared two model infant formulas (MIFs) by adding MFGMs to dairy ingredients in different ways and compared their fat digestion behavior with those of HM and CIF. MFGMs were added alone (MIF1) and with other milk-based materials (MIF2) before homogenization. The addition of MFGMs reduced the flocculation of lipids and proteins in the gastric phase and promoted lipolysis in the intestine phase. The amount of free fatty acids released followed the order of HM > MIF1 > CIF ≥ MIF2. After digestion, the number of different glyceride species between each sample and HM reached 64 (MIF1), 73 (MIF2), 67 (CIF1), and 72 (CIF2). In conclusion, the fat digestion of MIF1 had the highest similarity with HM.

Effects of endogenous DHA milk and exogenous DHA milk on oxidative stress and cognition in SAMP8 mice

In this study, Senescence Accelerated Mice (SAMP8) were supplemented with exogenous DHA milk, endogenous DHA milk, normal milk, or 0.9 % saline solution. Enzyme-linked immunosorbent assay (ELISA), gas chromatography (GC), ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI MS/MS), and Morris water maze were used to characterize the effects of diet on oxidative stress and cognition in SAMP8 mice. Supplementation endogenous DHA milk or exogenous DHA milk can enhance the antioxidant capacity of mice organs. Endogenous DHA milk increased the superoxide dismutase (SOD) activity of mice brain and serum than normal milk and 0.9 % saline solution (P ≤ 0.05), as well as increased SOD activity of mice liver and glutathione peroxidase (GSH-Px) activity of mice brain than normal milk (P ≤ 0.05). Exogenous DHA milk increased SOD activity of mice brain than normal milk and 0.9 % saline solution, as well as increased SOD activity of mice serum than 0.9 % saline solution (P ≤ 0.05). Several polar lipid relative content, such as 18:0/18:2 PS, 17:0 Ceramide, and 20:4 LPC in mice brain was affected by dietary supplementation with DHA-containing milk. Lipid oxidation metabolites in mice brain were not affected by DHA-containing milk. Endogenous DHA milk increased the number of platform location crossing times of mice in the Morris water maze test, compared with Exogenous DHA milk, normal milk, and 0.9 % saline solution (P ≤ 0.05).

A comprehensive evaluation of milk protein molecular weight distribution based on exclusion chromatography dataset

Molecular weight is one of the main characteristic parameters of proteins, which is the basis for the functional properties of milk protein. This research aims at establishing molecular weight distribution pattern of milk protein based on exclusion chromatography. The method selected Na3PO4-Na2SO4 (0.1 M, pH 6.7) buffer as the mobile phase and detected at 220 nm by HPLC-UV. The protein molecular weight distributions were determined and compared for human milk, bovine milk, and infant formula. The proportion of macromolecular proteins is much higher in infant formula compared to human or bovine milk. The protein molecular weights of human and bovine milk are significantly different around 90, 20, 14, and 2 kDa. The results provide holistic compare of bovine milk, human milk, and infant formula through protein molecular distribution. The new evaluation indicators for protein will drive technological simulation of infant formula.

3-Monochloropropane-1,2-diol reduced bioaccessibility of sn-2 palmitate via binding with pancreatic lipase in infant formula during gastrointestinal digestion

Infant formula contains 3-monochloropropane-1,2-diol esters (3-MCPDE), which are formed during the deodorization step of vegetable oil refining. The European Food Safety Authority stated that 3-MCPDE can be hydrolyzed in the gastrointestinal tract to free-form 3-monochloropropane-1,2-diol (3-MCPD), which has potential toxicity and can be rapidly absorbed. Evaluating the effect of 3-MCPD on nutrition absorption is a prerequisite for establishing effective management strategies. A total of 66 crucial lipid molecules associated with 3-MCPD were identified based on debiased sparse partial correlation analysis. 3-MCPD affected triglyceride hydrolyzation and increased the concentration of undigested sn-2 palmitate (9.57 to 17.06 mg kg-1). 3-Monochloropropane-1,2-diol reduced the bioaccessibility of fatty acids, and more short- (31.42 to 58.02 mg kg-1) and medium-chain fatty acids (17.03 to 26.43 mg kg-1) remained unabsorbed. Lipidomic profiles of infant formula models spiked with different 3-MCPDE levels were investigated, and the results were consistent with the experiments with the commercial formula indicating lipid alteration was mainly affected by the digestive 3-MCPD. The formation of 3-MCPD ester-pancreatic lipase with the binding energy of -4.9 kcal mol-1 was more stable than triglyceride-pancreatic lipase (-4.0 kcal mol-1), affecting triglyceride hydrolyzation. 3-Monochloropropane-1,2-diol was bound to Glu13 and Asp331 residues of the pancreatic lipase via hydrogen bonds, which resulted in a conformational change of pancreatic lipase and spatial shielding effect. The existence of the spatial-shielding effect reduced the accessibility of pancreatic lipase and further affected triglyceride hydrolyzation. These findings indicated that 3-MCPD obstructed nutrient acquisition and laid the foundation for the subsequent nutrition enhancement design.

Novel trends and challenges in fat modification of next-generation infant formula: Considering the structure of milk fat globules to improve lipid digestion and metabolism of infants

Differences in the composition and structure of lipid droplets in infant formula (IF) and human milk (HM) can affect the fat digestion of infants, leading to high risk of metabolic diseases during later stages of growth. Recently, interest in simulating HM fat (HMF) has gradually increased due to its beneficial functions for infants. Much research focuses on the simulation of fatty acids and triacylglycerols. Enzymatic combined with new technologies such as carbodiimide coupling immobilization enzymes, solvent-free synthesis, and microbial fermentation can improve the yield of simulated HMF. Furthermore, fat modification in next-generation IF requires attention to the impact on the structure and function of milk fat globules (MFG). This review also summarizes the latest reports on MFG structure simulation, mainly related to the addition method and sequence of membrane components, and other milk processing steps. Although some of the simulated HMF technologies and products have been applied to currently commercially available IF, the cost is still high. Furthermore, understanding the fat decomposition of simulated HMF during digestion and assessing its nutritional effects on infants later in life is also a huge challenge. New process development and more clinical studies are needed to construct and evaluate simulated HMF in the future.

Fatty acid, triglyceride, and kinetic properties of milk fat fractions made by the combination of dry fractionation and short-path molecular distillation

In this study, we aimed to detect the physicochemical properties of distilled products (residue and distillate) obtained from anhydrous milk fat (AMF) and its dry fractionation products (liquid and solid fractions at 25°C [25 L and 25 S]). The results showed that the saturated fatty acids and low- and medium molecular-weight triglycerides were easily accumulated in the distillate, and the percentage of unsaturated fatty acid and high molecular-weight triglycerides in the residue were higher, and these components in 25 S and 25 L were influenced more significantly than those in the AMF. In addition, the distillate had larger melting ranges in comparison with the distilled substrate, while the melting ranges of residue was smaller. The triglycerides were presented as the mixture crystal forms (α, β', and β crystal) in 25 S, AMF, and their distilling products, and it was transformed gradually to a single form as the increasing of distilling temperature. Moreover, the accumulated pattern of triglycerides was double chain length in 25 S, AMF, and their distilling products. These results provide a new approach to obtain the milk fat fractions with different properties, and the findings of this study enrich the theoretical basis of milk fat separation in practical production.

A new insight into the polar lipid composition in mature breast milk and ewe milk with comparative lipidomics analysis

Polar lipids play essential biological functions in energy storage, both as structural components of cell membranes and as signaling molecules. In this study, a comprehensive UHPLC-QTRAP-MS-based lipidomic analysis of mature breast milk (BM) and ewe milk (EM) was conducted. Through the analysis, a total of 362 polar lipid species from 14 subclasses were characterized, including 60 phosphatidylethanolamines (PEs), 59 phosphatidylcholines (PCs), 38 phosphatidylinositols (PIs), 35 sphingomyelins (SMs), and 34 ceramides (Cers). Of these, 139 lipid molecules were screened as significantly differentially expressed polar lipids (SDPLs) between the two kinds of milk based on the following criteria: a variable importance in projection (VIP) value > 1.0, a false discovery rate-adjusted P-value < 0.0001, and a fold change (FC) of either > 2.0 or < 0.5; these included 111 upregulated and 28 downregulated SDPLs in EM compared to BM. Among these SDPLs, the content of PE (16:1_18:0) was found to be significantly higher in EM compared to BM (FC = 69.5853, P < 0.0001). Moreover, sphingolipid metabolism and glycerophospholipid metabolism were determined to be vital metabolic pathways. This was derived from the finding that PE, PC, SM, and PI were key lipid metabolites in the two kinds of milk that were related to these two metabolic pathways. This study provides new insights into the characterization of SDPLs in mammalian milk, and also provides a theoretical basis for optimizing infant formula.