Evaluation of triacylglycerol composition in commercial infant formulas on the Chinese market: A comparative study based on fat source and stage

Serum lipidomic profiling of dairy calves fed milk replacers containing animal or vegetable fats

Vegetable fat blends are commonly used as fat sources in milk replacers (MR) for calves, but their composition differs considerably from that of bovine milk fat. The aim of this study was to investigate the serum lipid profile of pre-weaned calves fed twice-daily MR containing 30% fat (% DM). Upon arrival, 30 male Holstein-Friesian calves (BW = 45.6 ± 4.0 kg, age = 2.29 ± 0.8 d) were randomly assigned to 2 experimental diets (n = 15 per treatment): one MR was derived from either vegetable fats (VG; 80% rapeseed and 20% coconut fats) or animal fats (AN; 65% Packer's lard and 35% dairy cream). The 2 MR formulas contained 30% fat, 24% CP, and 36% lactose. Calves were housed indoors in individual pens with ad libitum access to chopped straw and water. Daily milk allowances were 6.0 L from d 1 to 5, 7.0 L from d 6 to 9, and 8.0 L from d 10 to 35, divided into 2 equal meals and prepared at 13.5% solids. An untargeted liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) method was employed to analyze the lipid profiles in the serum of calves sampled from the jugular vein at 35 d of age. In total, 594 lipids were characterized, comprising 25 different lipid classes. Principal component analysis (PCA) showed significant separation between VG and AN, indicating different lipid profiles in the serum. An orthogonal partial least squares discriminant analysis (OPLS-DA) classification model was used to further validate the distinction between the 2 treatment groups. The model exhibited a robust class separation and high predictive accuracy. Using a Volcano plot (fold change threshold ≥1.5 and false discovery rate ≤0.05), it was observed that calves fed AN had higher levels of 39 lipid species in serum than calves fed VG, whereas 171 lipid species were lower in the AN group. Lipid classes, such as phosphatidylcholine (PC), phosphatidylethanolamine (PE), sphingomyelin (SM), triglycerides (TG), lysophosphatidylcholine (LPC), and lysophosphatidylethanolamine (LPE), were different. In particular, PC and PE were observed at lower levels in calves fed AN, possibly indicating shifts in cell membrane characteristics, intracellular signaling, and liver functions. In addition, a decrease in certain triglyceride (TG) species was observed in calves fed AN, including a decrease in TG species such as TG 36:0 and TG 38:0, possibly related to variations in the content of certain fatty acids (FA) within the AN MR, such as C10:0, C12:0, C14:0, and C18:0 compared with the VG MR. Calves fed AN had lower levels of LPC and LPE, and lyso-phosphatidylinositol (LPI), SM, and phosphatidylinositol (PI) species than calves fed VG, suggesting shifts in lipoprotein and lipid metabolic pathways. In conclusion, these results deepen the understanding of how lipid sources in MR can modulate the serum lipidome profiles of dairy calves.

Research on commercial milk formulas for young children: A scoping review

A scoping review of publications about commercial milk formulas intended for or consumed by children 12-36 months (CMF 12-36) was conducted. This review aimed to comprehensively map the existing literature, identify key concepts in the field and understand its evolution through time. A total of 3329 articles were screened and 220 were included, published between 1986 and 2024. Most works were published after 2016 (70.0%) and in high-income countries (71.8%). Original studies were the vast majority (81.8%) of publications. Most publications dealt with feeding practices or analysed the composition and/or contamination of specific products (44.1% and 35.9%), but since the late 2000s, publications about marketing, policy, legislation, and consumer perception started to appear. Most published works (65.5%) did not focus exclusively on CMF 12-36 and included formulas for other demographics or other foods. About half of the works (55.5%) did not consider CMF 12-36 to be a breast milk substitute. We found 81 distinct product denominations used to refer to CMF 12-36, Growing Up Milk was the most common (25.9%). CMF industry was involved in 41.8% of all analysed works, and industry participation and funding were not always clearly informed (22.5% lacked a conflict of interest statement, and 25.5% did not present any information about funding). In the last decade, publications about CMF 12-36 have increased in volume and diversified in scope and subject matter. CMF-industry participation has always been and still is present in the field, so possible vested interests should be taken into account when appreciating the literature.

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.

Medium- and Long-Chain Triacylglycerol: Preparation, Health Benefits, and Food Utilization

Medium- and long-chain triacylglycerol (MLCT) is a structured lipid with both medium- and long-chain fatty acids in one triacylglycerol molecule. Compared with long-chain triacylglycerol (LCT), which is mainly present in common edible oils, and the physical blend of medium-chain triacylglycerol with LCT (MCT/LCT), MLCT has different physicochemical properties, metabolic characteristics, and nutritional values. In this article, the recent advances in the use of MLCT in food formulations are reviewed. The natural sources and preparation of MLCT are discussed. A comprehensive summary of MLCT digestion, absorption, transport, and oxidation is provided as well as its health benefits, including reducing the risk of overweight, hypolipidemic and hypoglycemic effects, etc. The potential MLCT uses in food formulations, such as infant formulas, healthy foods for weight loss, and sports foods, are summarized. Finally, the current safety assessment and regulatory status of MLCT in food formulations are reviewed.

Chemoenzymatic Synthesis of ABC-Type Enantiostructured Triacylglycerols by the Use of the p-Methoxybenzyl Protective Group

This report demonstrates the first asymmetric synthesis of enantiopure structured triacylglycerols (TAGs) of the ABC type presenting three non-identical fatty acids, two of which are unsaturated. The unsaturated fatty acids included monounsaturated oleic acid (C18:1 n-9) and polyunsaturated linoleic acid (C18:2 n-6). This was accomplished by a six-step chemoenzymatic approach starting from (R)- and (S)-solketals. The highly regioselective immobilized Candida antarctica lipase (CAL-B) played a crucial role in the regiocontrol of the synthesis. The synthesis also benefited from the use of the p-methoxybenzyl (PMB) ether protective group, which enabled the incorporation of two different unsaturated fatty acids into the glycerol skeleton. The total of six such TAGs were prepared, four constituting the unsaturated fatty acids in the sn-1 and sn-2 positions, with a saturated fatty acid in the remaining sn-3 position of the glycerol backbone. In the two remaining TAGs, the different unsaturated fatty acids accommodated the sn-1 and sn-3 end positions, with the saturated fatty acid present in the sn-2 position. Enantiopure TAGs are urgently demanded as standards for the enantiospecific analysis of intact TAGs in fats and oils.

Novel Human Milk Fat Substitutes Based on Medium- and Long-Chain Triacylglycerol Regulate Thermogenesis, Lipid Metabolism, and Gut Microbiota Diversity in C57BL/6J Mice

Human milk is naturally rich in medium- and long-chain triacylglycerols (MLCT), accounting for approximately 30% of the total fat. However, infant formula fat is prepared using a physical blend of vegetable oils, which rarely contains MLCT, similar to human milk. The differences in MLCT between human milk and infant formulas may cause different lipid metabolisms and physiological effects on infants, which are unknown. This study aimed to analyze the metabolic characteristics of formula lipid containing novel human milk fat substitutes based on MLCT (FL-MLCT) and compare their effects with those of the physical blend of vegetable oils (FL-PB) on lipid metabolism and gut microbiota in mice. Compared with the FL-PB group, the FL-MLCT group showed increased energy expenditure, decreased serum triacylglycerol level, and significantly lower aspartate aminotransferase level, epididymal and perirenal fat weight, and adipocyte size. Moreover, the abundances of Firmicutes/Bacteroidota, Actinobacteriota, and Desulfovibrionaceae were significantly decreased in the FL-MLCT group. Novel human milk fat substitutes MLCT could inhibit visceral fat accumulation, improve liver function, and modulate the mice gut microbiota composition, which may contribute to controlling obesity.

Proximate and fatty acid compositions oft en wild-caught and farmed fish species in mato grosso state, brazil

This study analyzed ten fish species (three farmed and seven wild-caught) to determine their centesimal composition (assessed by AOAC methods) and lipid profile (analyzed by GC-MS). Notably, "tambatinga" (farmed) and "piraputanga" (wild-caught) stood out with 28.66 % and 26.44 % protein content and 2.32 % and 3.71 % lipid content, respectively. Across all species, oleic acid was the predominant fatty acid, followed by linoleic acid. The sum of PUFAs ranged from 17.84 % in "matrinchã" to 7.85 % in "piraputanga". SFA varied from 49.93 % in "tambacu" to 39.90 % in "matrinchã", while MUFAs ranged from 44.34 % in "palmito" to 38.39 % in "tambaqui". "Matrinchã" had the highest average ω6 acid content (16.83 %), while "cachara" had the highest average for ω3 acids (5.73 %). "Piraputanga". "cachara", and "pincachara" exhibited the lowest ω6 levels. The analysis shows that fish have excellent nutritional values (proximate compositions) with few differences between species. "Pacu", "matrinchã", and "cachara" (wild-caught) demonstrated positive attributes, while "pincachara" (farmed) exhibited the highest nutritional quality in terms of fatty acid fraction. Based on quality indices (H/H), "pacu", "matrinchã" and "pincachara" are recommended choices for a healthy diet. This study adds valuable insights into the nutritional composition of fish species, which is essential for promoting regional development and local aquaculture.

Development and large-scale production of human milk fat analog by fermentation of microalgae

Background

Human milk contains a complex mixture of triacylglycerols (TAG), making it challenging to recreate using common ingredients.

Objective

The study aimed to develop an innovative fermentation technique to produce essential human milk TAG, effectively tackling a significant hurdle in infant nutrition.

Method

An in-depth analysis of the literature has been conducted to identify the specific TAG to be targeted. We used a microalgal oil production platform and a two-step procedure to modify its fatty acid and TAG composition. The palmitic acid (16:0) content has been increased by classical strain improvement techniques, followed by a step involving the expression of a lysophosphatidic acid acyltransferase (LPAAT) sequence capable of esterifying 16:0 specifically at the internal position (sn-2 palmitate) of TAG. Once the strain was stabilized, the fermentation was scaled up in a 50-L reactor to yield several kilograms of biomass. Subsequently, the oil was extracted and refined using standard oil processing conditions. Liquid chromatography-mass spectrometry was employed to monitor the TAG profile and the region specificity of 16:0 at the internal position (sn-2 palmitate) of TAG.

Results

The initial strain had a 16:0 level of 25% of total fatty acids, which was increased to 30% by classical strain improvement. Simultaneously, the oleic acid level decreased from 61% to 57% of total fatty acids. Upon expression of an exogenous LPAAT gene, the level of the 16:0 esterified in the internal position of the TAG (sn-2 palmitate) increased by a factor of 10, to reach 73% of total palmitic acid. Consequently, the concentration of oleic acid in the internal position decreased from 81% to 22% of total fatty acids, with TAG analysis confirming that the primary TAG species in the oil was 1,3-dioleoyl-2-palmitoyl-glycerol (OPO). The 50-L-scale fermentation trial confirmed the strain's ability to produce oil with a yield of >150 g of oil per liter of fermentation broth in a timeframe of 5 days, rendering the process scalable for larger-scale industrialization.

Conclusion

We have demonstrated the feasibility of producing a suitable TAG composition that can be effectively integrated into the formulations of infant nutrition in combination with other fats and oils to meet the infant feeding requirements.

Analysis for lipid nutrient differences in the milk of 13 species from a quantitative non-targeted lipidomics perspective

Lipids are essential organic components in milk and have been associated with various health benefits for newborns. However, a comprehensive analysis of lipid profiles across multiple species and levels has been lacking. In this study, we employed liquid chromatography-tandem mass spectrometry (LC-MS/MS) to accurately determine the absolute content of lipid molecules. It revealed that ruminants exhibit a higher concentration of short-chain fatty acids compared to non-ruminants. Additionally, we identified ALC (camel), MGH (horse), and DZD (donkey) as species that display similarities to components found in human milk fat. Remarkably, it reveals that porcine milk fat is characterized by long chain lengths, low saturation, and a high proportion of essential fatty acids. PS (22:5_18:2) could potentially serve as a biomarker in porcine milk. These unique characteristics present potential opportunities for the utilization of porcine milk. Overall, our findings provide valuable insights into the lipidomics profiles of milk from different species.

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.

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.

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.

Effects of lipids from multiple sources on glyceride composition, concentration, and structure of infant formulas benchmarked to human milk

The important parameters affecting the nutritional properties of lipids were analyzed and compared between human milk (HM), infant formulas (IFs), mammalian milk, and substitute fat, including molecular species, fatty acid composition, glyceride content, and important structural triacylglycerols (TAGs). The molecular species of triacylglycerols with functional fatty acids were significantly different between HM and IFs, and their contents in HM were significantly higher than those in IFs. Accordingly, the evaluation scores of fatty acid composition and glyceride content in IFs were less than 50 compared to HM. Although the introduction of vegetable oils effectively improved the unsaturation of IF lipid, the excessive addition of TAGs rich in oleic and linoleic acid resulted in an imbalance of TAG composition and structure. Only 36.84 % of IFs were supplemented with structured lipids, but those still lacked sn-2 palmitate TAGs. The adoption of multiple lipids and novel processing technologies is required for novel IFs to match the composition, content, positional structure and spherical membrane structure of HM as closely as possible.

Effects of Human Milk Fat Substitutes on Lipid Metabolism in First-Weaned Rats

Although numerous studies indicate that formula-fed infants are more prone to obesity than breastfed ones, the underlying reasons have not been fully elucidated. This study aimed to determine the impact of human milk fat substitutes (HMFS) on the lipid metabolism of first-weaned Sprague Dawley rats. The findings revealed that administering HMFS did not affect the body weight of the rats (control: 298.38 ± 26.73 g, OPO (1,3-dioleic acid-2-palmitoyl triglyceride): 287.82 ± 19.85 g and HMFS: 302.31 ± 19.21 g), but it significantly decreased their body fat content (control: 28.70 ± 1.17 cm3, OPO: 22.51 ± 1.10 cm3 and HMFS: 14.90 ± 0.95 cm3) (p < 0.05). Lipidome analysis revealed that glycerophospholipid was the primary differentiating lipid present in the liver of HMFS-fed rats. The abundance of Bacteroides significantly increased in the intestine of HMFS-fed rats (p < 0.05), and their short-chain fatty acid (SCFA) content significantly increased (p < 0.05). The multi-omics correlation analysis established the "Bacteroidetes-SCFAs-Glycerophospholipid pathway" as a potential mechanism by which administering HMFS affects body fat buildup in first-weaned rats. Additionally, it was found that HMFS administration significantly promoted lipid metabolism in the rat liver at both the gene and protein levels (p < 0.05). These findings serve to underscore the nutritional benefits of HMFS for infants.

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.

Lipid Profiles of Human Milk and Infant Formulas: A Comparative Lipidomics Study

Infant formulas (IFs) are prevalent alternatives for human milk (HM), although their comparative lipid profiles have not been fully investigated. We adopted lipidomics to analyze and compare in-depth the lipid patterns of HM and IFs. The results indicated that the distribution of fatty acids (FAs) and the structure of triacylglycerols varied substantially in the analyzed samples. A total number of 425 species were identified during the analysis. HM was abundant in triacylglycerols that contained unsaturated and long-chain FAs (>C13), while triacylglycerols in IFs were mainly comprised of saturated and medium-chain FAs (C8-C13). Higher levels of sphingomyelin were observed in HM. Furthermore, HM and IF1 contained 67 significantly differential lipids (SDLs), and 73 were identified between HM and IF2. These SDLs were closely associated with nine metabolic pathways, of which the most significant was the glycerophospholipid metabolism. The results shed light on the differences between the lipid profiles of human and infant formula milks, and provide support for designing Chinese infant formula.

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.

Profiling of triacylglycerol composition in the breast milk of Chinese mothers at different lactation stages

Triacylglycerol (TAG) is the primary constituent of human milk fat and plays a vital role in the healthy development of infants. But few studies reported the sophisticated profile of TAG molecular species in human breast milk and its temporal changes during a prolonged lactation period. An efficient ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) method was adopted to examine TAGs. A total of 128 TAGs in 296 human breast milk samples collected during postnatal 0 to 400 days were identified. The changes in the human milk TAG profile mainly took place in the early stages of lactation (postnatal 0-45 days), and the TAG profile became stable in mature milk after 200 days of lactation. Odd chain fatty acids (OC-FAs) may be important markers for identifying human breast milk of different lactation stages. This study could provide evidence for developing safe and efficacious human-milk substitutes for children without access to human breast milk.

Future of Structured Lipids: Enzymatic Synthesis and Their New Applications in Food Systems

Structured lipids (SLs) refer to a new type of functional lipid obtained by modifying natural triacylglycerol (TAG) through the restructuring of fatty acids, thereby altering the composition, structure, and distribution of fatty acids attached to the glycerol backbones. Due to the unique functional characteristics of SLs (easy to absorb, low in calories, reduced serum TAG, etc.), there is increasing interest in the research and application of SLs. SLs were initially prepared using chemical methods. With the wide application of enzymes in industries and the advantages of enzymatic synthesis (mild reaction conditions, high catalytic efficiency, environmental friendliness, etc.), synthesis of SLs using lipase has aroused great interest. This review summarizes the reaction system of SL production and introduces the enzymatic synthesis and application of some of the latest SLs discussed/developed in recent years, including medium- to long-chain triacylglycerol (MLCT), diacylglycerol (DAG), EPA- and DHA-enriched TAG, human milk fat substitutes, and esterified propoxylated glycerol (EPG). Lastly, several new ways of applying SLs (powdered oil, DAG plastic fat, inert gas spray oil, and emulsion) in the future food industry are also highlighted.

Comparative Lipidomics Analysis of Human and Ruminant Milk Reveals Variation in Composition and Structural Characteristics

In the present study, the different lipidomes between human milk and ruminant milk were compared. The 471, 376, 467, and 87 differential lipids were identified in human versus cow, goat, sheep, and camel groups, respectively. According to multivariate statistical analysis, lipids in human and camel milk were closer but differed from other milk. The distributions of long-chain and polyunsaturated fatty acids of triglycerides (TGs), the proportions of functional TGs (OPO, OPL, and PPO), and many kinds of phospholipids (PLs) (PS, PI, GD, GM3, and Cer) in human milk were similar to those in camel milk. The similar structure of TGs and proportion of PLs in human milk to camel milk might contribute to their similar digestion and bioactivity properties. Camel milk could be considered as a new resource of lipid base for infant formula. Minor PLs should also be considered for designing formula. Our results provide a new sight for humanized lipids in infant formula.

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.

Digestion of Medium- and Long-Chain Triacylglycerol and sn-2 Palmitate in Infant Formula: A Study Based on Dynamic In Vitro Simulation of Infant Gastrointestinal Lipolysis

In this study, lipolysis of triacylglycerols (TAGs) in infant formula (IF) composed of different oils and supplied with different structured TAGs, including medium- and long-chain triacylglycerol (MLCT) and sn-2 palmitate, was studied using a dynamic digestion model simulating the infant gastrointestinal tract. The molecular species of digestion products released during digestion, including diacylglycerols, monoacylglycerols (MAGs), and free fatty acids, as well as undigested TAGs, were identified and quantified using liquid chromatography-mass spectrometry. We observed clearly different lipolysis degrees (LDs), with diversity in digestion products of different IFs. IFs supplied with MLCT showed moderate medium-chain fatty acid release during gastric digestion and higher LD after intestinal digestion. The presence of sn-2 palmitate in IF was associated with higher content of MAG-16:0 in digestion products. The species and contents of digestion products in IF were highly influenced by structured TAGs.

Evaluation of total, sn-2 fatty acid, and triacylglycerol composition in commercial infant formulas on the Chinese market: A comparative study of preterm and term formulas

Preterm infants with physiological immaturity require higher lipid provision than term infants. This study compared the lipid composition, including total, sn-2 fatty acid, and triacylglycerol (TAG) compositions in 14 preterm formulas and 25 term formulas in the Chinese market, in 2020-2021. Preterm formula had higher medium-chain fatty acid (MCFA) and comparable C22:6n-3 (DHA) contents than term formula. Notably, significantly lower C16:0 and C18:0 (p < 0.001) were distributed on the sn-2 position in preterm formula. Two hundred and thirteen kinds of TAG molecular species were identified using UPLC-Q-TOF-MS. In preterm formula, significantly higher Ca-Ca-Cy and Ca-Ca-Ca (p < 0.001) existed. These clear distinctions showed the challenge of the progress in preterm formula, such as DHA status, MCFA pattern, and TAG esterified with palmitic acid on the sn-2 position.

Preparation of Human Milk Fat Substitutes: A Review

Human milk is generally regarded as the best choice for infant feeding. Human milk fat (HMF) is one of the most complex natural lipids, with a unique fatty acid composition and distribution and complex lipid composition. Lipid intake in infants not only affects their energy intake but also affects their metabolic mode and overall development. Infant formula is the best substitute for human milk when breastfeeding is not possible. As the main energy source in infant formula, human milk fat substitutes (HMFSs) should have a composition similar to that of HMF in order to meet the nutritional needs of infant growth and development. At present, HMFS preparation mainly focuses on the simulation of fatty acid composition, the application of structured lipids and the addition of milk fat globule membrane (MFGM) supplements. This paper first reviews the composition and structure of HMF, and then the preparation development of structured lipids and MFGM supplements are summarized. Additionally, the evaluation and regulation of HMFSs in infant formula are also presented.

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.

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.

Simulated In Vitro Infant Gastrointestinal Digestion of Infant Formulas Containing Different Fat Sources and Human Milk: Differences in Lipid Profiling and Free Fatty Acid Release

Simulated in vitro infant gastrointestinal digestion of human milk and four infant formulas containing different fat sources was analyzed and compared in this study. Although there are disadvantages brought about by its larger droplet size than infant formulas, human milk exhibited a higher lipolysis level due to the presence of MFGM interfacial layers. Higher hydrolysis efficiency of infant formulas (IFB, IFC, and IFM) was due to the presence of MFGM/phospholipid-enriched materials. Human milk released higher free fatty acid levels, especially long-chain fatty acid, and less undigested TAG molecules at the end of digestion than infant formulas. Human milk had a higher proportion of MAG and DAG linked to long-chain fatty acid. Furthermore, several lipids were identified as potential biomarkers that could be used to further analyze differences in the biological properties of human, bovine, and caprine milk. This comprehensive analysis might be fruitful to formulate an infant formula closest to human milk.

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.

TAILOR-MS, a Python Package that Deciphers Complex Triacylglycerol Fatty Acyl Structures: Applications for Bovine Milk and Infant Formulas

Liquid chromatography tandem mass spectrometry (LC/MS) and other mass spectrometric technologies have been widely applied for triacylglycerol profiling. One challenge for targeted identification of fatty acyl moieties that constitute triacylglycerol species in biological samples is the numerous combinations of 3 fatty acyl groups that can form a triacylglycerol molecule. Manual determination of triacylglycerol structures based on peak intensities and retention time can be highly inefficient and error-prone. To resolve this, we have developed TAILOR-MS, a Python (programming language) package that aims at assisting: (1) the generation of targeted LC/MS methods for triacylglycerol detection and (2) automating triacylglycerol structural determination and prediction. To assess the performance of TAILOR-MS, we conducted LC/MS triacylglycerol profiling of bovine milk and two infant formulas. Our results confirmed dissimilarities between bovine milk and infant formula triacylglycerol composition. Furthermore, we identified 247 triacylglycerol species and predicted the possible existence of another 317 in the bovine milk sample, representing one of the most comprehensive reports on the triacylglycerol composition of bovine milk thus far. Likewise, we presented here a complete infant formula triacylglycerol profile and reported >200 triacylglycerol species. TAILOR-MS dramatically shortened the time required for triacylglycerol structural identification from hours to seconds and performed decent structural predictions in the absence of some triacylglycerol constituent peaks. Taken together, TAILOR-MS is a valuable tool that can greatly save time and improve accuracy for targeted LC/MS triacylglycerol profiling.

Comparative Lipidomics Analysis of Human Milk and Infant Formulas Using UHPLC-Q-TOF-MS

The lipidome and fatty acid composition of human milk and different infant formulas with animal- and/or plant-based fat sources are analyzed and compared in this study. The results obtained using positive and negative ionization modes indicate that there are 48 and 71 lipid species, respectively, that are common between the human milk and infant formulas. Moreover, the fatty acid composition in infant formulas varies significantly, depending on the fat source. Human milk is rich in triacylglycerols that contain linoleic acid, α-linolenic acid, arachidonic acid, and docosahexaenoic acid. Meanwhile, the triacylglycerols in IFB comprise long-chain fatty acids at the sn-1,3 position. Compared to human milk, IFC has the same level of sphingomyelin species. Based on univariate and multivariate analyses, there are 37, 34, 31, and 36 lipid species that can be used to distinguish between human milk and infant formulas. Overall, the results reported herein are useful in designing new milk formulas that better mimic human milk.

Characterization of lipid profiling in three parts (muscle, head and viscera) of tilapia (Oreochromis niloticus) using lipidomics with UPLC-ESI-Q-TOF-MS

A lipidomic evaluation was performed on the tilapia muscle, head and viscera, including studying the composition, distribution and stereospecific characteristics of fatty acids and lipid species. The head and viscera lipids were significantly richer than the muscle lipids. Triacylglycerols were the predominant fraction (over 80% of total lipid in the muscle and head). Additionally, polyunsaturated fatty acids had higher percentages in phospholipids (30.35-52.05% of total fatty acids) than in triacylglycerols (18.11-25.15%). The C52:2 and C52:3 were the most abundant triacylglycerols, which indicates the potential application in infant food. Moreover, 622, 530 and 513 lipids were identified using ultraperformance liquid chromatography-quadrupole time-of-flight-mass spectrometry in the muscle, head and viscera, respectively. The three tilapia parts were distinguished using multivariate analysis. Five fatty acids and 33 lipid species were considered as the potential biomarkers. This comprehensive analysis will help to evaluate the lipid nutritional values and facilitate exploitation in tilapia consumption and processing.

Stool Saponified Fatty Acid, Behavior, Growth, and Stool Characteristics in Infants Fed a High-OPO Formula: A Randomized, Double-Blind Clinical Trial

Objective: 1,3-Dioleoyl-2-palmitoylglycerol (OPO) is an ideal structured triglyceride for infant formula, with a similar structure to human milk fat. We conducted this randomized, double-blind controlled, single-center trial to evaluate the effects of an OPO formula in infants. Study Design: One hundred seventy-four healthy term infants <14 days old were assigned to the standard formula-fed group (n = 55), high sn-2 palmitic acid (OPO) formula-fed infants (n = 58), and breastfed (BF) group (n = 61). The primary endpoint was the total saponified fatty acid content in feces at week 6 and week 12. Results: Infants from the OPO group had lower concentrations of fecal saponified fatty acids than those from the standard formula group (p < 0.0001) at week 6 and week 12. The frequencies of crying per day and per night of infants in the OPO group were significantly less than those of infants in the standard formula group (p < 0.0001). After 12 weeks of feeding, the length of infants was significantly higher in the OPO group than in the other two groups (p = 0.002). Infants in the OPO group had a significantly lower stool calcium concentration and a higher stool frequency per day than infants in the standard formula group. Conclusion: In summary, a high concentration of OPO in formula is beneficial to the growth and development of infants.

Quantitative profiling of glycerides, glycerophosphatides and sphingolipids in Chinese human milk with ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry

Human milk lipids are an important energy source and essential nutrients for the growth and development of infants. The UPLC/Q-TOF-MS was used to qualitatively and quantitatively analyze human milk lipids. Totally, 411 species of lipids were identified, in which the content of OPL was generally higher than that of OPO; SM (75.38 mg/L, 40.39%), PE (51.12 mg/L, 27.39%) and PC (40.10 mg/L, 21.49%) had the highest contents among polar lipids, mainly including SM42:2:2 (22.24 mg/L), PE36:2 (C18:0-C18:2, 21.39 mg/L) and PC36:2 (C18:0-C18:2, 19.80 mg/L). In human milk, TAG56:7 (137.14 mg/L), TAG56:8 (59.49 mg/L), TAG58:8 (65.90 mg/L) and TAG58:9 (49.99 mg/L) were the main sources of AA and DHA; PE was an important source of AA and DHA in polar lipids; and linoleic acyl in glycerides and phospholipids had higher contents than other polyunsaturated fatty acyls. These results provided the scientific basis for the simulation of human milk at molecular level.

Design of new lipids from bovine milk fat for baby nutrition

The lipid phase of infant formulas is generally composed of plant-based lipids structured with a high concentration of palmitic acid (C16:0) esterified at the sn-2 position of triacylglycerol since this structure favors the absorption and metabolism of fatty acids. Palm oil is commonly used to make up the lipid phase of infant formulas due to its high concentration of palmitic acid and solids profile and melting point similar to human milk fat. However, the addition of palm oil to infant formulas has been associated with the presence of 3-monochloropropane-1,2-diol (3-MCPD) esters, a group of glycerol-derived chemical contaminants (1,2,3-propanotriol), potentially toxic, formed during the refining process of vegetable oil. Bovine milk fat obtained from the complex biosynthesis in the mammary gland has potential as a technological alternative to replace palm oil and its fractions for the production of structured lipids to be used in infant formulas. Its application as a substitute is due to its composition and structure, which resembles breast milk fat, and essentially to the preferential distribution pattern of palmitic acids (C16:0) with approximately 85% distributed at the sn-1 and sn-2 position of triacylglycerol. This review will address the relationship between the chemical composition and structure of lipids in infant nutrition, as well as the potential of bovine milk fat as a basis for the production of structured lipids in substitution for the lipid phase of vegetable origin currently used in infant formulas.

Evaluation of enzymatic interesterification in structured triacylglycerols preparation: a concise review and prospect

Enzymatic interesterification (EIE) is one of the emerging technologies in the specialty fats industry. EIE has several advantages over the conventional chemical interesterification method, such that the process has higher flexibility and efficiency, is environmentally friendly and the immobilized enzyme can be recycled besides of the lower requirement for substrate's acid value. The physical properties and nutritional qualities of the fats and oils are modified after EIE, depending on the change in the position of fatty acids on the triacylglycerol (TAG) molecules. Evaluation of the interesterification reaction are important and useful in terms of its technological applications. This paper summarizes the conventional methods and the advancement for evaluating EIE processes, e.g., determination of the change in slip melting points, solid fat contents, TAG with equivalent carbon numbers, and sn-2 fatty acid compositions of the end product. Nonetheless, these methods are not comprehensive because during the EIE process, acyl migration occurs. A novel and convenient evaluation model which is based on the fatty acid distribution on the glycerol-backbone is proposed as a perspective. This model can be employed to monitor the interesterification degree and acyl migration during a regiospecific EIE process, which serves as a reaction rule that can be employed to control and optimize the EIE process, thereby producing structured TAG with desired properties.

Comparative Lipidomic Study of Human Milk from Different Lactation Stages and Milk Formulas

In this report, we present a detailed comparison of the lipid composition of human milk (HM) and formula milk (FM) targeting different lactation stages and infant age range. We studied HM samples collected from 26 Polish mothers from colostrum to 19 months of lactation, along with FM from seven brands available on the Polish market (infant formula, follow-on formula and growing-up formula). Lipid extracts were analysed using liquid chromatography coupled to high-resolution mass spectrometry (LC-Q-TOF-MS). We found that the lipid composition of FM deviates significantly from the HM lipid profile in terms of qualitative and quantitative differences. FM had contrasting lipid profiles mostly across brands and accordingly to the type of fat added but not specific to the target age range. The individual differences were dominant in HM; however, differences according to the lactation stage were also observed, especially between colostrum and HM collected in other lactation stages. Biologically and nutritionally important lipids, such as long-chain polyunsaturated fatty acids (LC-PUFAs) containing lipid species, sphingomyelines or ether analogues of glycerophosphoethanoloamines were detected in HM collected in all studied lactation stages. The observed differences concerned all the major HM lipid classes and highlight the importance of the detailed compositional studies of both HM and FM.