Triacylglycerol regioisomers in human milk resolved with an algorithmic novel electrospray ionization tandem mass spectrometry method

Enhancing the Thermostability and Catalytic Activity of the Lipase from Rhizopus oryzae via Introducing N-Glycosylation

Lipase from Rhizopus oryzae (ROL) exhibits remarkable sn-1,3 stereoselectivity and catalytic activity, but its poor thermostability limits its applications in the production of 1,3-dioleoyl-2-palmitoyl glycerol (OPO, a high-quality substitute for human milk fat). In this work, a semirational method was proposed to engineer the thermostability and catalytic activity of 4M (ROL mutant in our previous study). First, a computer-aided design is performed using 4M as a template, and N-glycosylation mutants are then recombinantly expressed and screened in Pichia pastoris, the optimal mutant N227 exhibited a half-life of 298.8 h at 45 °C, which is 7.23-folds longer than that of 4M. Its catalytic activity also reached 1043.80 ± 61.98 U/mg, representing a 29.2% increase compared to 4M (808.02 ± 47.02 U/mg). Molecular dynamics simulations of N227 suggested that the introduction of glycan enhanced the protein rigidity, while the strong hydrogen bonds formed between the glycan and the protein stabilized the lipase structure, thereby improving its thermostability. The acidolysis reaction between oleic acid (OA) and glycerol tripalmitate (PPP) was successfully carried out using immobilized N227, achieving a molar conversion rate of 90.2% for PPP. This engineering strategy guides the modification of lipases, while the glycomutants obtained in this study have potential applications in the biosynthesis of OPO.

Progress in triacylglycerol isomer detection in milk lipids

In triacylglycerols (TAGs), position differences of fatty acids on the glycerol skeleton produce various TAG isomers. These TAG isomers have different pathways of digestion, absorption, and utilization in infants, thereby affecting TAG nutritional properties of TAGs. Here, we review the progress of research on methods for detecting TAG isomers, and identify direction and thought for improving these methods, including novel chromatographic combinations, perfect algorithm, and improved equipment. The ensuing optimization of these methods is expected to provide robust guarantee for the gradual improvement of milk-derived TAG isomer detection, and is an important prerequisite for infant formula to mimic the structured lipids of human milk.

Chemical Composition of Fat Bloom on Chocolate Products Determined by Combining NMR and HPLC-MS

To reduce unwanted fat bloom in the manufacturing and storage of chocolates, detailed knowledge of the chemical composition and molecular mobility of the oils and fats contained is required. Although the formation of fat bloom on chocolate products has been studied for many decades with regard to its prevention and reduction, questions on the molecular level still remain to be answered. Chocolate products with nut-based fillings are especially prone to undesirable fat bloom. The chemical composition of fat bloom is thought to be dominated by the triacylglycerides of the chocolate matrix, which migrate to the chocolate's surface and recrystallize there. Migration of oils from the fillings into the chocolate as driving force for fat bloom formation is an additional factor in the discussion. In this work, the migration was studied and confirmed by MRI, while the chemical composition of the fat bloom was measured by NMR spectroscopy and HPLC-MS, revealing the most important triacylglycerides in the fat bloom. The combination of HPLC-MS with NMR spectroscopy at 800 MHz allows for detailed chemical structure determination. A rapid routine was developed combining the two modalities, which was then applied to investigate the aging, the impact of chocolate composition, and the influence of hazelnut fillings processing parameters, such as the degree of roasting and grinding of the nuts or the mixing time, on fat bloom formation.

1,3-Dioleoyl-2-palmitoyl-glycerol and 1-oleoyl-2-palmitoyl-3-linoleoyl-glycerol: Structure-function relationship, triacylglycerols preparation, nutrition value

Based on multivariate statistics, this review compared major triacylglycerols (TAGs) in animal milk and human milk fat from China and other countries. Human milk fat differs from animal milk fat in that it has longer acyl chains and higher concentrations of 1,3-dioleoyl-2-palmitoyl-glycerol (O-P-O) and 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (O-P-L). O-P-L is a significant and distinct TAG in human milk fat, particularly in China. 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL) is human milk's major triglyceride molecule of O-P-L, accounting for more than 70%. As a result, OPL has piqued the interest of Chinese academics. The synthesis process and nutritional outcomes of OPL have been studied, including changes in gut microbiota, serum lipid composition, improved fatty acid and calcium absorption, and increased total bile acid levels. However, current OPL research is limited. Therefore, this review discussed enzymatic preparation of 1,3-dioleoyl-2-palmitoyl-glycerol (OPO) and OPL and their nutritional and physiological activity to direct future research direction for sn-2 palmitate and OPL.

Fabrication of Human Milk Fat Substitute: Based on the Similarity Evaluation Model and Computer Software

We aimed to obtain the optimal formula for human milk fat substitute (HMFS) through a combination of software and an evaluation model and further verify its practicability through an animal experiment. The results showed that a total of 33 fatty acid (FA) and 63 triglyceride (TAG) molecular species were detected in vegetable oils. Palmitic acid, oleic acid, linoleic acid, 18:1/16:0/18:1, 18:2/16:0/18:2, 18:1/18:1/18:1 and 18:1/18:2/18:1, were the main molecular species among the FAs and TAGs in the vegetable oils. Based on the HMFS evaluation model, the optimal mixed vegetable oil formula was blended with 21.3% palm oil, 2.8% linseed oil, 2.6% soybean oil, 29.9% rapeseed oil and 43.4% maize oil, with the highest score of 83.146. Moreover, there was no difference in the weight, blood routine indices or calcium and magnesium concentrations in the feces of the mice between the homemade mixed vegetable oil (HMVO) group and the commercial mixed vegetable oil (CMVO) group, while nervonic acid (C24:1) and octanoic acid (C8:0) were absorbed easily in the HMVO group. Therefore, these results demonstrate that the mixing of the different vegetable oils was feasible via a combination of computer software and an evaluation model and provided a new way to produce HMFS.

Advanced Tandem Mass Spectrometric Analysis of Complex Mixtures of Triacylglycerol Regioisomers: A Case Study of Bovine Milk Fat

Comprehensive analysis of triacylglycerol (TAG) regioisomers is extremely challenging, with many variables that can influence the results. Previously, we reported a novel algorithmic method for resolving regioisomers of complex mixtures of TAGs. In the current study, the TAG Analyzer software and its mass spectrometric fragmentation model were further developed and validated for a much wider range of TAGs. To demonstrate the method, we performed for the first time a comprehensive analysis of TAG regioisomers of bovine milk fat, a very important and one of the most complex TAG mixtures in nature containing FAs ranging from short to long carbon chains. This analysis method forms a solid basis for further investigation of TAG regioisomer profiles in various natural fats and oils, potentially aiding in the development of new and healthier foods and nutraceuticals with targeted lipid structures.

Lipids and lipid signaling molecules in human milk and infant formula, a chemical characterization of relevant biochemical components

Breastfeeding is the gold standard in infant nutrition and continuous researches aim to optimize infant formula composition as the best alternative available. Human milk lipid content provides more than 50% of energy requirements for infants together with essential vitamins, polyunsaturated fatty acids, and other bioactive components. While fatty acids and vitamins human milk content has been extensively studied and, when needed those have been added to infant formulas, less is known about polyunsaturated fatty acids functional derivatives and other bioactive components. Here we describe the comparison of lipid compositions in breast milk from 22 healthy volunteers breastfeeding mothers and the six most common infant formula devoting particular attention to two families of signaling lipids, endocannabinoids, and eicosanoids. The main differences between breast milk and formulas lie in a variety of saturated fatty and unsaturated fatty acids, in the total amount (45-95% less in infant formula) and a variety of endocannabinoids and eicosanoids (2-AG, 5(s)HETE, 15(S)-HETE and 14,15-EET).

Detection and analysis of triacylglycerol regioisomers via electron activated dissociation (EAD) tandem mass spectrometry

Triacylglycerols (TGs) are important components of human diet. The positional distribution of fatty acids (FAs) on the glycerol backbone affects the chemistry and physical properties of fats. Especially for infants, the structure of TGs plays an important role in the growth and development. However, limited by detecting technology, accurately identifying regioisomers of ABA/AAB and BAC/ABC/ACB type TGs is a significant challenge for human milk utilization and the development of infant formula. For this, we exploit a novel method for identifying the regioisomers of ABA/AAB and BAC/ABC/ACB type TGs within complex lipid mixtures, via used electron activated dissociation (EAD) tandem mass spectrometry. The distribution information of acyl chains at the sn-2 and sn-1/3 positions of glycerol backbone and double bonds in unsaturated FAs can be easily obtained by fragmenting TG ions with energetic electrons (15 eV). Then, the standard curve was established by correlating the peak area intensity of sn-2 characteristic product ion with the content of TG regioisomers standard. These analytical methods successfully enabled the identification and quantification of TG regioisomers in human milk, cow milk, infant formula, palm oil, and sunflower oil. Additionally, the distribution of the double-bond positions of unsaturated FAs in these samples was also identified. Compared to traditional methods, this approach eliminates the need for complex processing and analysis procedures, enabling rapid structural characterization of ABA/AAB and BAC/ABC/ACB type TGs within 17 min. Hence, we provide a rapid and convenient methodology for detecting and analyzing ABA/AAB and BAC/ABC/ACB type TG regioisomers, thereby offering valuable assistance in the development of specialized formulations and facilitating effective process control for ensuring the quality of edible oils and fats.

Differences in Absorption and Metabolism between Structured 1,3-Oleate-2-palmitate Glycerol and 1-Oleate-2-palmitate-3-linoleate Glycerol on C57BL/6J Mice

This study investigated differences in absorption and metabolism between 1,3-oleate-2-palmitate glycerol (OPO) and 1-oleate-2-palmitate-3-linoleate glycerol (OPL) using C57BL/6J mice. OPL was associated with higher postprandial plasma total triacylglycerol (TG), low-density lipoprotein cholesterol (LDL-C) concentrations, and the ratio of LDL-C to high-density lipoprotein cholesterol (HDL-C) compared to those of OPO (p > 0.05). OPO significantly increased postprandial oleic acid (OA) concentrations compared to OPL over the entire monitoring period (p < 0.05), while OPL significantly elevated linoleic acid (LA) levels compared to OPO (p < 0.05). After 1 month of feeding, the mice in both OPO and OPL groups showed lower final weight, weight gain, and liver TG, LDL-C, and LDL/HDL concentrations compared to the control (soybean oil) group. Lipidomics results showed that OPO increased the biosynthesis of very long-chain fatty acids and decreased the abundance of AcCa (16:1), AcCa (18:2), AcCa (18:1), AcCa (16:0), CarE (16:0), and CarE (16:1) relative to OPL. These lipid metabolites were positively correlated with liver TG, LDL-C, and LDL/HDL levels and negatively related to peroxisome proliferator-activated receptors α (PPARα) and acyl-CoA oxidase (ACOX1) expression. This study showed differences in physiologic functions between OPO and OPL and provided support for the future application of OPL in infant formula.

Dose-related effects of early-life intake of sn-2 palmitate, a specific positionally distributed human milk fatty acid, on the composition and metabolism of the intestinal microbiota

sn2 Palmitate in human milk plays an important role in the physiological health of infants by reducing mineral loss, improving stool hardness, and relieving constipation. Also, sn-2 palmitate modulates intestinal microbiota. However, it remains unclear whether the effects of sn-2 palmitate on infant gut microbiota are dose-dependent. In this study, we investigated the effects of low, medium, and high doses (600, 1,800, and 5,400 mg/kg body weight, respectively) of sn-2 palmitate on the structure, composition, and metabolic function of intestinal microbes in mice. Our results showed that high doses of sn-2 palmitate significantly modulated α- and β-diversity of the intestinal microbiota. The relative abundance of Lachnospiraceae_NK4A136_group decreased with increasing doses of sn-2 palmitate. In contrast, the abundances of Bacteroidetes phylum, Bacteroides, uncultured_Lachnospiraceae, and uncultured_Muribaculaceae were positively correlated with sn-2 palmitate doses. The number of genes predicted encoding autophagy-yeast, phospholipase D signaling pathway, and pentose and glucuronate interconversion metabolic functions of intestinal microbiota increased with increasing doses of sn-2 palmitate. In addition, low and medium doses of sn-2 palmitate significantly upregulated the arginine and proline metabolic pathways, and high doses of sn-2 palmitate significantly increased purine metabolism. Our results revealed that the effects of sn-2 palmitate intake early in life on the composition and metabolism of the intestinal microbiota of mice showed dose-related differences. The study is expected to provide a scientific basis for the development of infant formulas.

Safety evaluation of INFAT® PLUS: Acute, genetic, teratogenic, and subchronic (90-day) toxicity studies

INFAT®PLUS, is a sn-2 palmitate enriched fat ingredient intended for infant formula. A battery of toxicological studies was conducted in accordance with the Food Safety Toxicological Assessment GB-15193 (China), to confirm the safety of INFAT®PLUS. In the acute oral toxicity test, the LD50 of INFAT® PLUS was higher than 53.4 g /kg BW and 26.7 g/kg BW for ICR mice and SD rats, respectively. In a subchronic study, INFAT® PLUS was administered by oral gavage to SD rats with maximal daily dose of 8.90 g/kg BW for 90 days. No treatment-related clinical signs or mortalities were observed. The no-observed-adverse-effect level (NOAEL) was set at 8.90 g/kg BW. Similarly, no evidence of genotoxicity effect was noted in several in vitro and in vivo tests, including bacterial reverse mutation (Ames) test, mouse erythrocyte micronucleus test, and chromosome aberration test of mouse spermatogonia/spermatocyte. For the teratogenic evaluations, no toxicological signs were observed in both pregnant SD rat and fetuses, and the NOAEL of INFAT® PLUS was determined to be 8.90 g/kg BW. Based on the obtained results we concluded that INFAT® PLUS was found non-toxic under the experimental conditions, and the totality of the safety data supports its use for infant nutrition.

The triacylglycerol structure and composition of a human milk fat substitute affect the absorption of fatty acids and calcium, lipid metabolism and bile acid metabolism in newly-weaned Sprague-Dawley rats

In this study, the effect of sn-2 palmitic triacylglycerols (sn-2 palmitic TAGs) and the ratio between the two major sn-2 palmitic TAGs (OPL to OPO ratio) in a human milk fat substitute (HMFS) on growth, fatty acid and calcium absorptions, and lipid and bile acid metabolic alterations was investigated in Sprague-Dawley rats. After 4 weeks of high-fat feeding, rats fed with the HMFS containing a sn-2 palmitic acid content of 57.87% and an OPL to OPO ratio of 1.4 showed the lowest TAG accumulation in their livers and hypertrophy of perirenal adipocytes, compared to the groups fed with fats containing a lower sn-2 palmitic acid content or a lower OPL to OPO ratio. Meanwhile, synergistically improved absorption of fatty acids and calcium and increased levels of total bile acids (BAs), especially for the tauro-conjugated BAs (TCDCA, TUDCA, TαMCA, TβMCA, TDCA and TωMCA), were observed in rats by both increasing the sn-2 palmitic acid content and the OPL to OPO ratio in HMFS. In addition, the levels of total BAs and tauro-conjugated BAs were negatively correlated with serum TAG, TC, and LDL-c levels and positively correlated with HDL-c levels according to Spearman's correlation analysis (P < 0.05). Collectively, these findings present new nutritional evidence for the potential effects of the TAG structure and composition of a human milk fat substitute on the growth and lipid and bile acid metabolism of the host in infancy.

1-Oleate-2-palmitate-3-linoleate glycerol improves lipid metabolism and gut microbiota and decreases the level of pro-inflammatory cytokines

Numerous studies have shown that 1-oleate-2-palmitate-3-linoleate (OPL) is the most abundant TAG in Chinese human milk, which is significantly different from human milk in other countries, where 1,3-oleate-2-palmitate (OPO) is the most abundant TAG. However, there have been few studies revealing the nutritional outcomes of OPL. Hence, the present study investigated the effects of an OPL supplementation diet on mice's nutritional outcomes, including liver lipid parameters, inflammation, lipidomes in the liver and serum, and the gut bacterial community. A high OPL (HOPL) diet decreased body weight, weight gain, liver TG, TC and LDL-C, and TNF-α, IL-1β, and IL-6 in mice relative to low OPL (LOPL) diet. Lipidomics results showed that HOPL feeding elevated the level of anti-inflammatory lipids, such as very long-chain Cer, LPC, PC and ether TG in the liver, and serum PC, and reduced the level of oxidized lipids (liver OxTG, HexCer 18:1;2O/22:0) and serum TG. In the gut, intestinal probiotics, including Parabacteroides, Alistipes, Bacteroides, Alloprevotella and Parasutterrlla, were enriched in the HOPL-fed group. Meanwhile, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis results showed that the HOPL diet up-regulated energy metabolism and the immune system. Correlation analysis further showed that there was a relationship among the gut bacteria, lipidome profile, and nutritional outcomes. Altogether, these results indicated that an OPL-supplemented diet improved lipid metabolism and gut bacteria, reducing the level of pro-inflammatory cytokines.

Progress of Mass Spectrometry-Based Lipidomics in the Dairy Field

Lipids play important biological roles, such as providing essential fatty acids and signaling. The wide variety and structural diversity of lipids, and the limited technical means to study them, have seriously hampered the resolution of the mechanisms of action of lipids. With advances in mass spectrometry (MS) and bioinformatic technologies, large amounts of lipids have been detected and analyzed quickly using MS-based lipidomic techniques. Milk lipids, as complex structural metabolites, play a crucial role in human health. In this review, the lipidomic techniques and their applications to dairy products, including compositional analysis, quality identification, authenticity identification, and origin identification, are discussed, with the aim of providing technical support for the development of dairy products.

Fabrication of immobilized lipases for efficient preparation of 1,3-dioleoyl-2-palmitoylglycerol

This study aims to fabricate immobilized lipases for efficient preparation of 1,3-dioleoyl-2-palmitoyl-glycerol (OPO) through acidolysis of glycerol tripalmitate (PPP). Twelve (three types) supports and five lipases were studied carefully. Among them, the immobilized Thermomyces lanuginosa lipase (TLL) samples exhibited overall better performance than that of other immobilized lipases. Particularly, organic groups functionalized SBA-15 (R-SBA-15) supported TLL (TLL@R-SBA-15) samples gave PPP conversion from 97.70 to 99.00 % and OPO content from 59.52 to 64.73 %. After optimization, PPP conversion up to 99.07 %, OPO content 73.15 % and sn-2 palmitic acid content 90.09 % were obtained with TLL@C₁₈H₃₇-SBA-15 as catalyst. Moreover, TLL@C₁₈H₃₇-SBA-15 exhibited better acidolysis performance from 50 °C than that from 60 to 80 °C, which helped inhibit acyl migration. In addition, after 5 cycles of reuse, TLL@C₁₈H₃₇-SBA-15 retained 81.04 % (based on OPO content) and 98.88 % (based on sn-2 palmitic acid content) of its initial activity, indicating it had an attractive prospect in future applications.

The Impact of Linoleic Acid on Infant Health in the Absence or Presence of DHA in Infant Formulas

Both linoleic acid (LA) and α-linolenic acid (ALA) are essential dietary fatty acids, and a balanced dietary supply of these is of the utmost importance for health. In many countries across the globe, the LA level and LA/ALA ratio in breast milk (BM) are high. For infant formula (IF), the maximum LA level set by authorities (e.g., Codex or China) is 1400 mg LA/100 kcal ≈ 28% of total fatty acid (FA) ≈ 12.6% of energy. The aims of this study are: (1) to provide an overview of polyunsaturated fatty acid (PUFA) levels in BM across the world, and (2) to determine the health impact of different LA levels and LA/ALA ratios in IF by reviewing the published literature in the context of the current regulatory framework. The lipid composition of BM from mothers living in 31 different countries was determined based on a literature review. This review also includes data from infant studies (intervention/cohort) on nutritional needs regarding LA and ALA, safety, and biological effects. The impact of various LA/ALA ratios in IF on DHA status was assessed within the context of the current worldwide regulatory framework including China and the EU. Country averages of LA and ALA in BM range from 8.5-26.9% FA and 0.3-2.65% FA, respectively. The average BM LA level across the world, including mainland China, is below the maximum 28% FA, and no toxicological or long-term safety data are available on LA levels > 28% FA. Although recommended IF LA/ALA ratios range from 5:1 to 15:1, ratios closer to 5:1 seem to promote a higher endogenous synthesis of DHA. However, even those infants fed IF with more optimal LA/ALA ratios do not reach the DHA levels observed in breastfed infants, and the levels of DHA present are not sufficient to have positive effects on vision. Current evidence suggests that there is no benefit to going beyond the maximum LA level of 28% FA in IF. To achieve the DHA levels found in BM, the addition of DHA to IF is necessary, which is in line with regulations in China and the EU. Virtually all intervention studies investigating LA levels and safety were conducted in Western countries in the absence of added DHA. Therefore, well-designed intervention trials in infants across the globe are required to obtain clarity about optimal and safe levels of LA and LA/ALA ratios in IF.

Preparation of functional oils rich in diverse medium and long-chain triacylglycerols based on a broadly applicable solvent-free enzymatic strategy

To address the problems of long reaction times and limited range of adaptation in enzymatic synthesis medium- and long-chain triacylglycerols (MLCTs), a broadly applicable solvent-free enzymatic interesterification strategy was proposed. Candida sp. lipase (CSL) was immobilized on hydrophobic hollow mesoporous silica spheres (HHSS) to construct a biocatalyst designated as CSL@HHSS with a 15.3 % immobilization yield and a loading amount of 94.0 mg/g. The expressed activity and the specific activity were 20.14 U/g and 173.62 U/g, which were 4.6 and 5.6 times higher than that of free CSL, respectively. This biocatalyst demonstrated higher activity, wider applicability, and excellent reusability. Linseed oil, sunflower oil, perilla seed oil, algal oil, and malania oleifera oil were applied as substrates to produce MLCTs with medium-chain triacylglycerols (MCT) catalyzed by CSL@HHSS through interesterification in yields ranging from 69.6 % to 78.0 % within 20 min. Specific fatty acids, including linolenic acid, oleic acid, DHA, and nervonic acid (the first reported), were introduced into MLCT's skeleton, respectively. The structures were finely analyzed and identified by GC and UPLC-MS. The catalytic efficiency value of CSL@HHSS in catalyzing interesterification between linseed oil and MCT (70 ℃, 20 min, lipase 6 wt%) is 0.86 g/g∙min, which is the highest ever reported. This paper presents an effective and sustainable strategy for functional MLCTs production.

Fast Triacylglycerol Fingerprinting in Edible Oils by Subcritical Solvent Chromatography

Supercritical fluid chromatography (SFC) has witnessed a resurge of interest in the last decade, motivated by substantial progress in hardware capabilities and the development of specifically tailored packing materials. Meanwhile, the technique has been transitioning to the use of mobile phases in which an organic co-solvent is mixed to carbon dioxide under subcritical conditions (subFC). The use of a mobile phase modifier will also affect the selectivity, and extend the range of SFC-amenable compounds, including lipids. In this research, a subFC method was developed for the separation of triacylglycerols (TAGs) in edible oils of vegetable origin, namely borage, corn, hazelnut, olive, palm, peanut, and soybean oil. For all the samples investigated, elution of the TAG species was achieved within 8 min, the only exception being borage oil (14 min run), characterized by TAGs spanning in a wide range of partition number (PN 36–56), as constituted by fatty acids differing for alkyl chain lengths (CN 14–24), and degree of unsaturation (DB 0–9). The coupling to mass spectrometry (MS) detection allowed for the average parameters of fatty acid composition to be derived in the oil TAG constituents. A total of 121 TAGs were identified by subFC-MS, with reduced analysis time and solvent consumption (1.5 mL per analysis) compared to common chromatographic approaches. Key features of the method developed hereby are low toxicity, costs, and environmental impact. Notably, the achieved separations were conducted at room temperature, which is beneficial in terms of column life.

Effects of the Novel LaPLa-Enriched Medium- and Long-Chain Triacylglycerols on Body Weight, Glycolipid Metabolism, and Gut Microbiota Composition in High Fat Diet-Fed C57BL/6J Mice

The roles of medium- and long-chain triacylglycerols (MLCT) on health benefits under high fat diet (HFD) conditions remain in dispute. This study was conducted to investigate the effects of novel LaPLa-rich MLCT on the glycolipid metabolism and gut microbiota in HFD-fed mice when pork fat is half replaced with MLCT and palm stearin (PS). The results showed that although MLCT could increase the body weight in the mouse model, it can improve the energy utilization, regulate the glucose and lipid metabolism, and inhibit the occurrence of inflammation. Furthermore, 16S rRNA gene sequencing of gut microbiota indicated that PS and MLCT affected the overall structure of the gut microbiota to a varying extent and specifically changed the abundance of some operational taxonomic units (OTUs). Moreover, several OTUs belonging to the genera Dorea, Streptococcus, and g_Eryipelotrichaceae had a high correlation with obesity and obesity-related metabolic disorders of the host. Therefore, it can be seen that this new MLCT has different properties and functions from the previous traditional MLCT, and it can better combine the advantages of MLCT, lauric acid, and sn-2 palmitate, as well as the advantages of health function and metabolism. In summary, this study explored the effects of LaPLa-enriched lipids on glycolipid metabolism in mice, providing theoretical support for future studies on the efficacy of different types of conjugated lipids, intending to apply them to industrial production and subsequent development of related products.

A novel and controllable method for simultaneous preparation of human milk fat substitutes (OPL, OPO and LPL): two-step enzymatic ethanolysis-esterification strategy

A novel and effective approach based on the two-step ethanolysis-esterification strategy was proposed for the controllable and simultaneous preparation of 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL), 1,3-dioleoyl-2-palmitoyl-glycerol (OPO) and 1,3-dilinoleoyl-2-palmitoyl-glycerol (LPL) with adjustable proportions. Enzymatic ethanolysis of fractionated palm stearin was carried out to yield 2-monopalmitoylglycerol (79.4 ± 0.6 %) with over 91.0 % purity at the optimal conditions. The immobilized Candida sp. lipase (CSL) on octyl-functionalized ordered mesoporous silica (OMS-C₈) was applied to re-esterify 2-monopalmitoylglycerol with oleic acid and linoleic acid for the simultaneous production of OPL, OPO, and LPL. The total content in the final products was 81.5 %, with 91.3 % of palmitic acid (PA) content at the sn-2 position. Besides, OPL/OPO/LPL was conveniently prepared with suitable proportions for worldwide infants by adjusting the ratio of acyl donors. This paper provides a novel and effective two-step ethanolysis-esterification strategy for the development of human milk fat substitutes (HMFS).

Triacylglycerol regioisomers containing palmitic acid analyzed by ultra-performance supercritical fluid chromatography and quadrupole time-of-flight mass spectrometry: Comparison of standard curve calibration and calculation equation

Triacylglycerol (TAG) regioisomers containing palmitic acid (16:0) was identified using ultra-performance supercritical fluid chromatography and quadrupole time-of-flight mass spectrometry (UPSFC-Q-TOF-MS) and quantified using calibration curve method and calculation equation method. There were negative linear correlation between [R_A-A]⁺/[R_A-A]⁺+[R_A-B]⁺ and content of sn-A-B-A (%) for AAB/ABA type TAGs, [R_{sn-1 FA-sn-3 FA}]⁺/[R_B-C]⁺+[R_A-C]⁺+[R_A-B]⁺ and content of fatty acid (FA) at sn-2 position (%) for BAC/ABC/ACB type TAGs. The difference between calculation equation and standard curve method was acceptable. The TAG regioisomers in human milk, mammalian milk, lard and fish oil were identified and quantified using the developed methods. This study provided a reliable and facile method for analysis of the TAG regioisomers, which was capable of the selection of oil materials for infant formula production.

Medium- and long-chain triacylglycerols and di-unsaturated fatty acyl-palmitoyl-glycerols in Chinese human milk: Association with region during the lactation

The triacylglycerols (TAGs) of medium- and long-chain triacylglycerols (MLCT) and di-unsaturated fatty acyl-palmitoyl-glycerols (UPU) in human milk provide better nutritional effects, and should be prioritized as crucial focuses on neonatal nutrition research. However, little has been done on the influences of the lactation stage and regional diversity on MLCT and UPU. In this study, we collected 204 human milk samples during colostrum, 1st and 4th month from the north (Baotou), central (Beijing), east (Jinan), southwest (Kunming), southeast (Shenzhen), and northwest (Xining) regions of China. There were 122 species of TAGs detected with UPLC-Q-TOF-MS, including 60 kinds of MLCT and 15 kinds of UPU. The MLCT and UPU type TAGs in human milk were ~27 and ~38%, respectively. The sum content of MLCT and UPU in human milk was stable. Compared to the regional diversity, lactation stages showed more obvious influences on MLCT and UPU composition. Moreover, a summary of TAG studies indicated that Chinese human milk showed a higher ratio of O-P-L to O-P-O than in western countries.

Chemical characterization and solvent fractionation of tilapia oil for its potential application as human milk fat substitute

The natural source of human milk fat substitute (HMFS) is a field worth exploring. In this study, tilapia oil was extracted and analyzed. In the triacylglycerol fraction, the contents of sn-2 palmitic acid and total sn-1,3 oleic acid and linoleic acid were 48.01% and 66.62%, respectively. The optimal solvent fractionation conditions were determined to be a tilapia oil-to-acetone ratio of 1:8 (w/v), crystallization temperature of -30°C, and crystallization duration of 16 h, giving a solid fraction yield of 64.20%. In fractionated tilapia oil, the total content of 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL) and 1,3-dioleoyl-2-palmitoylglycerol (OPO) increased by 20.38%, as determined by reversed-phase liquid chromatography. Ultra-high-performance combined-phase chromatography combined with quadrupole time-of-flight mass spectrometry analysis showed that OPL (17.45%) was the most abundant triacylglycerol in fractionated tilapia oil, followed by OPO (13.90%). Fractionated tilapia oil is thus an excellent source of OPL and has great potential for incorporation in HMFS. PRACTICAL APPLICATION: Human milk fat substitutes are an important component of infant formulas. This work provides an excellent natural source of oil rich in OPL, which has great potential in the field of preparing human milk fat substitutes highly similar to human milk fat.

Role of lipidomics in assessing the functional lipid composition in breast milk

Breast milk is the ideal source of nutrients for infants in early life. Lipids represent 2–5% of the total breast milk composition and are a major energy source providing 50% of an infant’s energy intake. Functional lipids are an emerging class of lipids in breast milk mediating several different biological functions, health, and developmental outcome. Lipidomics is an emerging field that studies the structure and function of lipidome. It provides the ability to identify new signaling molecules, mechanisms underlying physiological activities, and possible biomarkers for early diagnosis and prognosis of diseases, thus laying the foundation for individualized, targeted, and precise nutritional management strategies. This emerging technique can be useful to study the major role of functional lipids in breast milk in several dimensions. Functional lipids are consumed with daily food intake; however, they have physiological benefits reported to reduce the risk of disease. Functional lipids are a new area of interest in lipidomics, but very little is known of the functional lipidome in human breast milk. In this review, we focus on the role of lipidomics in assessing functional lipid composition in breast milk and how lipid bioinformatics, a newly emerging branch in this field, can help to determine the mechanisms by which breast milk affects newborn health.

Infant formula supplemented with 1,3-olein-2-palmitin regulated the immunity, gut microbiota, and metabolites of mice colonized by feces from healthy infants

Infant formula is currently an important food to cope with insufficient breastfeeding. Although 1,3-olein-2-palmitin (OPO) has been used in infant formula, its effects on the immune system, gut microbiota, and metabolites for infants remain unclear. This study constructed a mouse model of colonizing healthy infant feces using antibiotic treatment and fecal microbial transplantation. Thus, the gap between the infant formula supplemented with OPO and human milk in mouse serum biochemistry, immune system, intestinal microbiota, short-chain fatty acid production, and metabolites was evaluated. Our results showed that regarding IL-9, IL-10 levels, fecal secretory IgA, and endotoxin, formula supplemented with OPO and human milk types had comparable levels. Additionally, OPO slightly increased the content of short-chain fatty acids. The 16S rRNA gene sequence analysis and metabonomics analysis demonstrated that feeding different foods affects the gut microbiota of mice; in particular, supplementing formula feeding with OPO enriched the abundance of bifidobacteria. Furthermore, feeding different foods leads to unique intestinal content of metabolites, and the gut microbiota regulates the metabolites' differences. Our results reveal a brand new perspective of OPO regarding gut microbiota and metabolites.

Role Medium-Chain Fatty Acids in the Lipid Metabolism of Infants

Human breastmilk, the ideal food for healthy infants, naturally contains a high concentration of medium-chain fatty acids (MCFAs, about 15% of total fatty acids). MCFAs are an important energy source for infants due to their unique digestive and metabolic properties. MCFA-enriched oils are widely used in an infant formula, especially the formula produced for preterm infants. Recently, there has been a growing interest in the triglyceride structure of MCFAs in human milk, their metabolism, and their effects on infant health. This study summarized the MCFA composition and structure in both human milk and infant formula. Recent studies on the nutritional effects of MCFAs on infant gut microbiota have been reviewed. Special attention was given to the MCFAs digestion and metabolism in the infants. This paper aims to provide insights into the optimization of formulations to fulfill infant nutritional requirements.

Advances in analysis, metabolism and mimicking of human milk lipids

Human milk lipids differ from the milk lipids of other mammals in composition and positional distribution of fatty acids. Analysis and detection technology of lipids is key to understanding milk lipids, and thus the concentrations, compositions and distribution characteristics of milk lipids are discussed. Differences between human milk lipids and their substitutes in form, composition and structure affect their digestion, absorption and function in infants. Characteristics and mimicking of human milk lipids have been intensively studied with the objective of narrowing the gap between human milk and infant formulae. Based on the existing achievements, further progress may be made by improving detection techniques, deepening knowledge of metabolic pathways and perfecting fat substitutes. This review detailed the characteristics of human milk lipids and related detection technologies with a view towards providing a clear direction for research on mimicking human milk lipids in formulae to further improve infant nutrition.

A Comparative Study of Milk Fat Extracted from the Milk of Different Goat Breeds in China: Fatty Acids, Triacylglycerols and Thermal and Spectroscopic Characterization

Goat milk (GM) is an excellent alternative to cow milk and has recently been used in commercial infant formula preparation due to its superior fat composition. Here, the fatty acid (FA) composition, triacylglycerol (TAG) molecular species, thermal behavior and infrared spectra of extracted milk fat from the milk of the two main breeds of dairy goat bred in China (Guanzhong GM (GZG) and Xinong Saanen GM (XSG)) are investigated. Gas chromatography, Fourier-transform infrared spectroscopy, differential scanning calorimetry and ultra-performance convergence chromatography with quadrupole time-of-flight mass spectrometry are applied. The obtained results evidence significant fat compositional differences based on the breed that produced the considered GM. The major FAs in both GM fats were capric (C10:0), myristic (C14:0), palmitic (C16:0), stearic (C18:0) and oleic (C18:1 n-9c). GZG presented a higher content of medium-chain saturated FAs, while XSG had higher unsaturated FAs with higher ratios of L/Ln and n-6/n-3. A total of 339 and 359 TAGs were detected and quantified in GZG and XSG, and the major TAGs were those of m/z 740.6712 (14.10 ± 0.27%) and m/z 684.6094 (10.94 ± 0.02%), respectively. Milk TAGs of GZG and XSG showed 24–54 and 26–54 total acyl carbon numbers with a 0–4 and 0–5 double bond number at 68 and 72 various retention times, respectively. Thermal analysis showed that all GM fat samples melted below normal body temperature. Infrared spectra revealed higher absorption values of GZG milk fat. This study provides valuable information to the dairy industry sector about GM fat produced in China, assessing the appropriateness of Chinese GM fat to be applied in Chinese infant formula.

A multimodal analytical method to simultaneously determine monoacetyldiacylglycerols, medium and long chain triglycerides in biological samples during routine lipidomics

Background

Monoacetyldiglycerides (MAcDG), are acetylated triglycerides (TG) and an emerging class of bioactive or functional lipid with promising nutritional, medical, and industrial applications. A major challenge exists when analyzing MAcDG from other subclasses of TG in biological matrices, limiting knowledge on their applications and metabolism.

Methods

Herein a multimodal analytical method for resolution, identification, and quantitation of MAcDG in biological samples was demonstrated based on thin layer chromatography-flame ionization detection complimentary with C30-reversed phase liquid chromatography-high resolution accurate mass tandem mass spectrometry. This method was then applied to determine the MAcDG molecular species composition and quantity in E. solidaginis larvae. The statistical method for analysis of TG subclass composition and molecular species composition of E. solidaginis larvae was one-way analysis of variance (ANOVA).

Results

The findings suggest that the proposed analytical method could simultaneously provide a fast, accurate, sensitive, high throughput analysis of MAcDG from other TG subclasses, including the fatty acids, isomers, and molecular species composition.

Conclusion

This method would allow for MAcDG to be included during routine lipidomics analysis of biological samples and will have broad interests and applications in the scientific community in areas such as nutrition, climate change, medicine and biofuel innovations.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01650-w.

Regio- and Stereospecific Analysis of Triacylglycerols—A Brief Overview of the Challenges and the Achievements

The efforts to reveal, in detail, the molecular and intramolecular structures of one of the main lipid classes, namely, triacyl-sn-glycerols, which are now known to affect their specific and important role in all living organisms, are briefly overviewed. Some milestones of significance in the gradual but continuous development and improvement of the analytical methodology to identify the triacylglycerol regio- and stereoisomers in complex lipid samples are traced throughout the years: the use of chromatography based on different separation principles; the improvements in the chromatographic technique; the development and use of different detection techniques; the attempts to simplify and automatize the analysis without losing the accuracy of identification. The spectacular recent achievements of two- and multidimensional methods used as tools in lipidomics are presented.

Comparative Analysis of Triglycerides From Different Regions and Mature Lactation Periods in Chinese Human Milk Project (CHMP) Study

The kinds and proportions of triglycerides of human mature milk play an independent role in the growth of infants. In this study, the human milk samples obtained from eight different Chinese cities (Chengdu, Weihai, Lanzhou, Jinhua, Beijing, Guangzhou, Zhengzhou, and Harbin) and six sequential mature lactation times (30, 60, 90, 120, 150, and 180 days) were detected for the triglycerides. The result demonstrated that total 66 triglycerides were detected in mature human milk, with acyl carbon number (ACN) numbers were locating in the range of 34–54 and double bond (DB) numbers were locating in the range of 0–6. In addition, the percentage of OPO, OPL, and OOO was relatively higher than others, accounted for more than 4% of total triglycerides in all the lactation areas and times, and the percentage of U2S and LLL triglycerides was also richest in mature milk. Furthermore, it was obvious that lactation regions had more significant effect on the triglycerides compared with lactation time and the triacylglycerols (TAGs) of human milk in Guangzhou were clearly different from that in other regions. Therefore, the results of this study will provide data reference for the design of infant formula suitable for Chinese babies.

Identification and Quantification of Triacylglycerols Using Ultraperformance Supercritical Fluid Chromatography and Quadrupole Time-of-Flight Mass Spectrometry: Comparison of Human Milk, Infant Formula, Other Mammalian Milk, and Plant Oil

Triacylglycerol (TAG) components in human milk during different lactation periods, infant formulas with different fat sources, other mammalian milk (cow, goat, donkey, and yak milk), and plant oil (sunflower, rapeseed, corn, soybean, palm, palm kernel, and coconut oil) were analyzed and compared using ultraperformance supercritical fluid chromatography and quadrupole time-of-flight mass spectrometry (UPSFC-Q-TOF-MS). We identified 191 TAGs (86, 102, 101, and 54 TAGs in human milk, infant formula, mammalian milk, and plant oil, respectively). TAGs esterified with palmitic acid (16:0) were major TAG structures in human milk (59.08% of total TAGs) and contained 30 TAG types. The sn-O/P/O regioisomer constituted more than 80% of the O/P/O content of human milk, whereas the sn-O/O/P levels were higher in other samples. The carbon number (CN) 52 content was higher than the CN 54 content in human milk, with the opposite observed in infant formula. TAGs with CN < 40 content were abundant in cow, goat, and yak milk; donkey milk was rich in CN 52 content. TAGs composed of medium-chain fatty acids (MCFAs) and long-chain fatty acids (LCFAs) were rich in human milk, while TAGs with three MCFAs were rich in infant formula. The TAG characteristics of infant formula were directly related to its fat resource. TAGs with fewer double bonds were abundant in the plant oil formula; however, highly unsaturated TAGs were prominent in the cow and goat milk formulas, similar to plant oil and mammalian milk. Significant differences in the TAG distribution were observed among the different species.

Effects of the Major Structured Triacylglycerols in Human Milk on Lipid Metabolism of Hepatocyte Cells in Vitro

The effect of structured triacylglycerols [1-oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL), 3-dilinoleoyl-2-palmitoylglycerol (LPL), and 1,3-dioleoyl-2-palmitoylglycerol (OPO)] in human milk on the lipid metabolism was unclear. Hence, this study investigated the effects of different structured triacylglycerols and their mixtures (M) (OPL/LPL/OPO in M1, M2, and M3 were 1.5:0.5:1, 1.2:1.2:1, and 0.5:0.2:1, respectively) on lipid and expression levels of some critical proteins involved in lipid metabolism in LO2 cells. Results showed that there was more lipid accumulation in the LO2 cells exposed to 2,3-dioleoyl-1-palmitoylglycerol (POO) than OPL, LPL, and OPO (p < 0.05), and more lipid accumulation was observed in the OPL group compared to LPL and OPO groups (p < 0.05). Moreover, there was more lipid accumulation in the M3 group compared to M1 and M2 groups. The expression level of diacylglycerol acyltransferase was highest in the POO group compared to LPL, OPO, and OPL groups and was higher in the M3 group than M1 and M2 groups. The expression levels of acetyl-CoA carboxylase 1 and long-chain acyl-CoA synthetase 1 were highest in the OPL group compared to OPO and LPL groups. In comparison to OPO and LPL, OPL seemed to be more likely to increase the content of triacylglycerols and cholesterol in LO2 cells; therefore, whether this was beneficial to the growth and development of infants needs further verification.

Human Milk sn-2 Palmitate Triglyceride Rich in Linoleic Acid Had Lower Digestibility but Higher Absorptivity Compared with the sn-2 Palmitate Triglyceride Rich in Oleic Acid in Vitro

The digestion and absorption of different structural lipids in human milk may be different. Hence, by simulating in vitro infant digestion and Caco-2 cells to explore the effects of 1-oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL)/1,3-dilinoleoyl-2-palmitoylglycerol (LPL)/1,3-dioleoyl-2-palmitoylglycerol (OPO) and their mixtures (M) (OPL/LPL/OPO in M1, M2, and M3 were 1.5/0.5/1, 1.2/1.2/1, and 0.5/0.2/1, respectively) on digestion and absorption. The digestibility of the OPO group was higher than those of the OPL and LPL groups, and the M3 group was higher than the M1 and M2 groups. The synthesis and transport of triglycerides in Caco-2 cells in OPL and LPL groups were higher than the OPO group, and the M1 group was significantly higher than that of M3. The expression of FABP1, PPARα, and MTT protein in OPL and M1 groups was significantly higher than OPO and M3, respectively. There are differences in the digestion and absorption of differently structured lipids from this study.

Bovine Milk Triacylglycerol Regioisomer Ratio Shows Remarkable Inter-Breed and Inter-Cow Variation

Regioisomers (or positional isomers) of triacylglycerols (TAGs) of milk are known to show differential outcome in relation to human absorption. Quantitation of TAG regioisomers remains a big challenge due to the lack of facile chromatographic separation technique. The feasibility of using fragment ion intensity ratio to determine the ratio of co-eluting AAB/ABA-type regioisomer pairs was confirmed in this study. The ability of C30 stationary phase in resolving interfering TAG isomers was demonstrated for the first time. This allowed us to reveal the complexity of using fragment ion intensity to quantify 1,2-olein-3-palmitin (OOP), 1,3-olein-2-palmitin (OPO), 1,2-olein-3-stearin (OOS), and 1,3-olein-2-stearin (OSO) regioisomers in milk samples. A novel algorithm was proposed to consider the contribution of OPO/OOP and OSO/OOS double bond (DB)-isomers and to eliminate the interference of isobaric ions from other isomers, an aspect overlooked in previous studies. This liquid chromatography-mass spectrometry method that requires no pre-fractioning and a moderate chromatographic separation time of 36 min is simple and, thus, suitable for screening a large number of samples for genetic analysis of this trait. Preliminary results using a small cohort of animals showed that OPO/OOP ratio differs significantly between Jersey and Holstein cows, and a large variation was also observed across individual Holstein cows.

Chinese Breast Milk Fat Composition and Its Associated Dietary Factors: A Pilot Study on Lactating Mothers in Beijing

Regional differences were found in breast milk composition. This study intended to profile the composition of fatty acid (FA) and triacylglycerol (TAG) in Chinese breast milk and to explore its association with maternal diet. Breast milk samples and data of 52 lactating women at 60–90 days postpartum were collected. The FA composition was measured using gas chromatography–flame ionization detection (GC-FID), and the TAG profile was detected by an ultra-performance liquid chromatography system, coupled with accurate-mass quadrupole time-of-flight mass spectrometer. A semi-quantitative food intake frequency questionnaire and a one-time 24-h dietary recall were used to evaluate the previous month's and the short-term dietary intake, including dietary patterns, food groups, and nutrients. Oleic–palmitic–linoleic (OPL) is the most predominant TAG within the Chinese human milk, followed by oleic–palmitic–oleic (OPO), with an average OPL-to-OPO ratio of 1.35. Linoleic acid (LA) and oleic acid (OA) accounted for 23.9 and 32.0% of the total FAs, respectively. Among the food groups consumed during the preceding month, LA content was positively associated with the consumption of soybeans and soybean products (r = 0.311, p = 0.030), whereas a negative correlation was identified with seafood consumption (r = −0.302, p = 0.030). Negative correlations were found between the OA content and the consumption of soybeans and soybean products (r = −0.363, p = 0.009), livestock and poultry meat (r = −0.375, p = 0.006), nuts (r = −0.305, p = 0.028), as well as cooking oil (r = −0.445, p = 0.001). No significant associations were identified between the LA and OA contents and the dietary patterns. This study confirmed a high OPL level in Chinese breast milk and revealed associations of FAs with maternal dietary intake.

Short-chain fatty acid (SCFA) and medium-chain fatty acid (MCFA) concentrations in human milk consumed by infants born at different gestational ages and the variations in concentration during lactation stages

This study aimed to quantify the short-chain fatty acids (SCFAs) and medium-chain fatty acids (MCFAs) in human milk triacylglycerols (TAGs) and investigate their concentrations in human milk consumed during lactation by infants born at different gestational ages. One hundred and eighty milk samples from the mothers of 30 full-term, 10 early-preterm (≤32 weeks), 10 mild-preterm (32-34 weeks), and 10 near-term (34-37 weeks) infants were collected from the colostrum, transitional, and mature milk. The human milk TAGs were transferred into fatty-acid methyl esters via potassium methoxide in methanol and determined using gas chromatography (GC). The total SCFA (4:0) and MCFA concentrations (6:0 and 8:0) were highest in the mature milk (1.47 ± 0.66 mg g-1 fat from full-term infant milk), approximately 42.18% higher than those in transitional milk. Significantly higher SCFA and MCFA concentrations were found in full-term milk than in preterm milk (p = 0.001). The milk TAGs were analyzed using ultra-high-performance supercritical fluid chromatography with quadrupole-time-of-flight mass spectrometry (UHPSFC-Q-TOF-MS), which showed that the SCFAs and MCFAs were mainly esterified with long-chain fatty-acid groups (16:0, 18:1 n-9, and 18:2 n-6) at the glycerol backbone. The infants' daily SCFA intake from human milk was estimated; this was highest from mature milk for full-term infants (∼14 mg d-1) which was significantly different from that of preterm infants from colostrum and transitional milk (p < 0.001). The correlation between dietary SCFAs and MCFAs in human milk and nutrition in newborns, especially in the gut microbiotas of preterm infants, requires further study.

Facile and Green Production of Human Milk Fat Substitute through Rhodococcus opacus Fermentation

Human milk fat substitute (HMFS) is a class of structured lipids widely used in infant formulas. Herein, HMFS was prepared by Rhodococcus opacus fermentation. The substrate oils suitable for HMFS production were coconut oil (66.1-57.5%), soybean oil (17.5-26.5%), high oleic acid sunflower oil (5.4-4.5%), Antarctic krill oil (9-9.5%), and fungal oil (2%). Six HMFSs were prepared, among which HMFS V and VI were similar to human milk fat from Chinese in terms of fatty acid composition and triacylglycerol species. The sn-2 position of HMFS was occupied by palmitic acid (49.31 and 43.48% in HMFS V and VI, respectively). The major triacylglycerols were OPL, OPO, and LPL, accounting for 15.90, 9.49, and 6.84 and 17.52, 8.44, and 8.55% in HMFS V and VI, respectively. This study is the first to prepare structured lipids intended for infant formula through fermentation, providing a novel strategy for the edible oil industry.