Characterization and comparison of lipids in bovine colostrum and mature milk based on UHPLC-QTOF-MS lipidomics

Comparative lipidomics analysis of human colostrum, mature milk and yak mature milk

Yak milk is a promising lipid source substitute for infant formulas designed to mimic human milk. However, comparative studies on the lipid profiles between human and yak milk are scarce. To address this gap, in this study, we thoroughly analysed and compared the lipidome and fatty acid (FA) composition of human colostrum, human mature milk and yak mature milk. A total of 2686 lipid species from 30 lipid classes were identified in the three milk types. Notably, yak mature milk surpassed both human milk stages in the total content of lipid species, triglycerides (TG) and saturated FA. In particular, three potential lipid biomarkers, namely TG(6,0_8,0_14:0) + NH4, TG(16,0_6,0_8:0) + NH4 and TG(10,0_12,0_12,0) + NH4, were identified to differentiate yak mature milk from human colostrum and mature milk. Moreover, upon analysing the lipid metabolic pathways, it was found that the lipids involved in the pathways of acetylcholine synthesis, as well as starch and sucrose metabolism, may not manifest notable differences between yak mature milk and human colostrum, indicating the presence of similar neurodevelopment-regulating and metabolic characteristics in yak milk as in colostrum. Therefore, this comprehensive comparison offers novel insights into the potential of yak mature milk lipids to enhance the humanisation of infant formulas.

Unlocking the potential of donkey Milk: Nutritional composition, bioactive properties and future prospects

Donkey milk has garnered increasing attention due to its remarkable similarity to human milk and its diverse bioactive properties. Analysis of its composition shows that donkey milk is characterized by high lactose content, low protein, low fat, a balanced calcium-to‑phosphorus ratio, and abundant in vitamins C and D, making it a promising human milk alternative. Additionally, donkey milk contains a unique composition of whey proteins and polyunsaturated fatty acids, contributing to its beneficial health effects such as antimicrobial, anti-inflammatory, antioxidant, and hypoallergenic properties. This review provides a comprehensive analysis of the nutritional profile of donkey milk in comparison to other mammalian milk sources. Furthermore, it highlights its bioactive potential and discusses the current challenges and future opportunities for expanding its applications in the dairy and health industries. Despite its valuable properties, the development of donkey milk products remains limited due to low milk yield and high production costs. Further research and technological advancements are necessary to optimize its utilization and commercial potential.

Composition and structural characteristics of lipids in yak, buffalo, and cow colostrum based on untargeted lipidomics

Lipids play pivotal roles in supplying energy and promoting gut health. While yak and buffalo milk are known for their high nutritional values, the lipid compositions of yak colostrum (YC) and buffalo colostrum (BC) remain poorly explored. Here, untargeted lipidomics were applied to analyze YC, BC, and cow colostrum (CC). 546, 353, and 417 differential lipids were identified in the comparisons of YC-CC, BC-CC, and YC-BC, respectively. Compared to CC, YC exhibited a higher content of C18:2, while BC was marked by lower levels of saturated fatty acids. Additionally, specific lipid biomarkers were identified: triacylglycerol (TG) (16:0_10:0_22:6), TG (4:0_12:3_16:0), TG (4:0_8:0_18:2), TG (6:0_6:0_22:6), TG (6:0_8:0_22:6), and TG (6:0_8:0_8:0) were more for YC, while ceramide (Cer) (d19:1_24:1), diacylglycerol (DG) (36:2), hexosyl ceramide (Hex1Cer) (d37:1), TG (40:2e), TG (4:0_12:0_18:2), and zymosteryl (ZyE) (24:7) were biomarkers for BC. These findings provide a theoretical basis for optimizing the use of colostrum in various applications.

Lipidomics of coconut, almond and soybean milks - Detailed analysis of polar lipids and comparison with bovine milk

In this work, the lipidomic analysis on polar components of almond, coconut, and soy beverages was performed by liquid chromatography quadrupole time-of-flight mass spectrometry. A comparison with bovine milk was also performed. A total of 30 subclasses of polar lipids, belonging mainly to glycerophospholipids and sphingolipids, and a total of 572 molecular species were identified. Coconut showed various kinds of sphingolipids, belonging to hexosylceramides and sulfatides. Soy is particularly rich in molecular species of phospholipids. Fatty acids with chain length from 16 to 18 were the most common in almond. Numerous species of sphingomyelins were found in bovine milk, differently from plant-based beverages. Furthermore, a principal component analysis based on the polar lipid data was applied to discriminate samples, with 21 molecular species identified as biomarkers. This research opens interesting perspectives on vegetable beverages as bovine milk alternatives, especially in vegetarian and vegan diets.

Characterization and discrimination of donkey milk lipids and volatiles across lactation stages

The lipid and flavor in milk are key factors that affect its quality, which profiles during donkey lactation are not yet clear. In this study, the lipids and volatile compounds (VOCs) in donkey milk from stages of lactation were analyzed by using LC-MS and GC-IMS. A total of 1774 lipids were identified in donkey milk, spanning over 6 major categories and attributed to 30 subclasses. The 233 differentially expressed lipids were identified between donkey colostrum and mature milk, which participate in 20 metabolic pathways, including glycerophospholipid, linoleic acid, and sphingolipid. Additionally, 35 VOCs in donkey milk were identified, including 28.57% aldehydes, 28.57% ketones, 25.71% esters, and 8.57% alcohols. Of these VOCs, 15 were determined to be characteristic flavors in donkey milk, mainly including methyl 2-methylbutanoate, 2-pentanone, and butyl acetate. 11 significantly different VOCs were found between the groups. Acetone, 2-heptanone, and ethyl acetate-m were considered potential discriminatory markers.

Camel milk polar lipids ameliorate dextran sulfate sodium-induced colitis in mice by modulating the gut microbiota

Milk contains abundant polar lipids, which are vital constituents of biological membranes. These polar lipids are present in the human diet as phospholipids and sphingolipids. Nevertheless, the limited focus has been on the attributes and role of camel milk polar lipids (MPL). In this study, camel MPL were isolated, and the composition of their lipidome was determined using ultra-high-performance liquid chromatography-tandem MS. This study characterized a total of 333 polar lipids, which encompassed glycerophospholipids and sphingolipids. Camel milk is rich in polar lipids, mainly phosphatidylethanolamine, sphingomyelin, and phosphatidylcholine. The results indicated that MPL intervention relieved the clinical symptoms and colon tissue damage in mice with dextran sulfate sodium-induced colitis, along with suppressing the expression of proinflammatory cytokines. Moreover, the administration of MPL partially alleviated mouse gut microbiota dysbiosis by increasing the abundance of probiotics (such as Lachnospiraceae_NK4A136_group and Muribaculaceae) and decreasing the number of harmful bacteria (such as Bacteroides and Parabacteroides). This study was conducted to investigate the potent protective effects of MPL in camel milk treatments on a mouse model of colitis and provided new ideas for the application of camel milk.

Comprehensive review of milk fat globule membrane proteins across mammals and lactation periods in health and disease

Milk fat globule membrane (MFGM) is a three-layer membrane-like structure encasing natural milk fat globules (MFGs). MFGM holds promise as a nutritional supplement because of the numerous physiological functions of its constituent protein. This review summarizes and compares the differences in MFGM protein composition across various species, including bovines, goats, camels, mares, and donkeys, and different lactation periods, such as colostrum and mature milk, as assessed by techniques such as proteomics and mass spectrometry. We also discuss the health benefits of MFGM proteins throughout life. MFGM proteins promote intestinal development, neurodevelopment, and glucose and lipid metabolism by upregulating tight junction protein expression, brain function-related genes, and glucose and fatty acid biosynthesis processes. We focus on the mechanisms underlying these beneficial effects of MFGM proteins. MFGM proteins activate key substances in in signaling pathways, such as the phosphatidylinositol 3-kinase/protein kinase B, mitogen-activated protein kinase, and myosin light chain kinase signaling pathways. Overall, the consumption of MFGM proteins plays an essential role in conferring health benefits, some of which are important throughout the mammalian life cycle.

Proteomic and antimicrobial peptide analyses of Buffalo colostrum and mature Milk whey: A comparative study

Buffalo colostrum is the initial mammary secretion after parturition, consisting of nutritional and bioactive components. In this study, we conducted a proteomic analysis of buffalo colostrum whey to identify bioactive proteins and peptides. A total of 107 differentially expressed proteins (DEPs) were identified in buffalo colostrum whey compared to those in mature milk. Gene Ontology analysis revealed that DEPs were primarily associated with immune response and tissue development. KEGG pathway enrichment suggested that colostrum actively enhances nascent immunity involved in interleukin and interferon signaling pathways. Furthermore, candidate antimicrobial peptides (AMPs) of whey protein hydrolysates from buffalo colostrum were characterized, which exhibits broad-spectrum activity against gram-positive and gram-negative pathogens. Overall, this study improves our understanding of protein variations in buffalo lactation, and contributes to the development of AMPs from buffalo colostrum.

Reveal the mechanism of hepatic oxidative stress in mice induced by photo-oxidation milk using multi-omics analysis techniques

INTRODUCTION

Photo-oxidation is recognized as a contributor to the deterioration of milk quality, posing potential safety hazards to human health. However, there has been limited investigation into the impact of consuming photo-oxidized milk on health.

OBJECTIVES

This study employs multi-omics analysis techniques to elucidate the mechanisms by which photo-oxidized milk induces oxidative stress in the liver.

METHODS

Mouse model was used to determine the effect of the gavage administration of milk with varying degrees of photo-oxidation on the mouse liver. The damage degree was established by measuring serum markers indicative of oxidative stress, and with a subsequent histopathological examination of liver tissues. In addition, comprehensive metabolome, lipidome, and transcriptome analyses were conducted to elucidate the underlying molecular mechanisms of hepatic damage caused by photo-oxidized milk.

RESULTS

A significant elevation in the oxidative stress levels and the presence of hepatocellular swelling and inflammation subsequent to the gavage administration of photo-oxidized milk to mice. Significant alterations in the levels of metabolites such as lumichrome, all-trans-retinal, L-valine, phosphatidylglycerol, and phosphatidylcholine within the hepatic tissue of mice. Moreover, photo-oxidized milk exerted a pronounced detrimental impact on the glycerophospholipid metabolism of mice liver. The peroxisome proliferator-activated receptors (PPAR) signaling pathway enrichment appreciated in the animals that consumed photo-oxidized milk further supports the substantial negative influence of photo-oxidized milk on hepatic lipid metabolism. Gene set enrichment and interaction analyses revealed that photo-oxidized milk inhibited the cytochrome P450 pathway in mice, while also affecting other pathways associated with cellular stress response and lipid biosynthesis.

CONCLUSION

This comprehensive study provides significant evidence regarding the potential health risks associated with photo-oxidized milk, particularly in terms of hepatic oxidative damage. It establishes a scientific foundation for assessing the safety of such milk and ensuring the quality of dairy products.

Pseudo-targeted lipidomics insights into lipid discrepancies between yak colostrum and mature milk based on UHPLC-Qtrap-MS

Yak milk is essential to maintain the normal physiological functions of herders in Tibetan areas of China. However, the lipid components of yak colostrum (YC) and mature milk (YM) have not been systematically studied. We employed a quantitative lipidomics to comprehensively describe the alterations in the milk lipid profile of lactating yaks. Herein, totally 851 lipids from 28 lipid subclasses in YC and YM were identified and screened for 43 significantly different lipids (SDLs; variable importance in projection > 1, fold change < 0.5 or > 2 with P < 0.05), with cholesterol ester (CE, 16:0) and triacylglycerol (TAG, 54:6 (20:5), 50:1 (16:0), 56:6 (20:5)) were the potential lipid biomarkers. Fourteen SDLs were modulated downwards, and 29 SDLs were modulated upwards in YM. Moreover, by analyzing lipid metabolic pathways in these SDLs, glycerophospholipid metabolism was the most critical. Our results furnish integral lipid details for evaluating yak milk's nutritional quality.

Comparison of the Lipid Composition of Milk Fat Globules in Goat (Capra hircus) Milk during Different Lactations and Human Milk

Goat milk is considered the optimal substitute for human milk and is characterized by variations in the lipid composition of its fat globules across lactation phases. Therefore, the objective of this study was to thoroughly analyze the differences between goat milk during different lactations and human milk, aiming to offer scientific guidance for the production of functional dairy products. Compared with transitional and mature milk, the findings indicated that the total membrane protein content in goat colostrum exhibited greater similarity to that found in human milk. Additionally, goat milk exhibited higher milk fat globule size, as well as a higher total lipid and protein content than human milk. A total of 1461 lipid molecules across 61 subclasses were identified in goat milk and human milk. The contents of glycerides and glycerophospholipids were higher in goat colostrum, whereas sphingolipids and fatty acids were more abundant in human milk. Meanwhile, the compositions of lipid subclasses were inconsistent. There were 584 differentially expressed lipids identified between human and goat milk, including 47 subclasses that were primarily involved in the metabolism of glycerophospholipids, sphingolipids, and triglycerides. In summary, for both the membrane protein and the lipid composition, there were differences between the milk of different goat lactations and human milk.

The application of omics technologies for understanding tropical plants-based bioactive compounds in ruminants: a review

Finding out how diet impacts health and metabolism while concentrating on the functional qualities and bioactive components of food is the crucial scientific objective of nutritional research. The complex relationship between metabolism and nutrition could be investigated with cutting-edge "omics" and bioinformatics techniques. This review paper provides an overview of the use of omics technologies in nutritional research, with a particular emphasis on the new applications of transcriptomics, proteomics, metabolomics, and genomes in functional and biological activity research on ruminant livestock and products in the tropical regions. A wealth of knowledge has been uncovered regarding the regulation and use of numerous physiological and pathological processes by gene, mRNA, protein, and metabolite expressions under various physiological situations and guidelines. In particular, the components of meat and milk were assessed using omics research utilizing the various methods of transcriptomics, proteomics, metabolomics, and genomes. The goal of this review is to use omics technologies-which have been steadily gaining popularity as technological tools-to develop new nutritional, genetic, and leadership strategies to improve animal products and their quality control. We also present an overview of the new applications of omics technologies in cattle production and employ nutriomics and foodomics technologies to investigate the microbes in the rumen ecology. Thus, the application of state-of-the-art omics technology may aid in our understanding of how species and/or breeds adapt, and the sustainability of tropical animal production, in the long run, is becoming increasingly important as a means of mitigating the consequences of climate change.

Comprehensive analysis of phospholipid in milk and their biological roles as nutrients and biomarkers

Phospholipids (PL) have garnered significant attention due to their physiological activities. Milk and other dairy products are important dietary sources for humans and have been extensively used to analyze the presence of PL by various analytical techniques. In this paper, the analysis techniques of PL were reviewed with the eight trigrams of phospholipidomics and a comprehensive fingerprint of 1295 PLs covering 8 subclasses in milk and other dairy products, especially. Technology is the primary productive force. Based on phospholipidomics technology, we further review the relationship between the composition of PL and factors that may be involved in processing and experimental operation, and emphasized the significance of the biological role played by PL in dietary supplements and biomarkers (production, processing and clinical research), and providing the future research directions.

Transcriptome analysis of the Bactrian camel (Camelus bactrianus) reveals candidate genes affecting milk production traits

BACKGROUND

Milk production traits are complex traits with vital economic importance in the camel industry. However, the genetic mechanisms regulating milk production traits in camels remain poorly understood. Therefore, we aimed to identify candidate genes and metabolic pathways that affect milk production traits in Bactrian camels.

METHODS

We classified camels (fourth parity) as low- or high-yield, examined pregnant camels using B-mode ultrasonography, observed the microscopic changes in the mammary gland using hematoxylin and eosin (HE) staining, and used RNA sequencing to identify differentially expressed genes (DEGs) and pathways.

RESULTS

The average standard milk yield over the 300 days during parity was recorded as 470.18 ± 9.75 and 978.34 ± 3.80 kg in low- and high-performance camels, respectively. Nine female Junggar Bactrian camels were subjected to transcriptome sequencing, and 609 and 393 DEGs were identified in the low-yield vs. high-yield (WDL vs. WGH) and pregnancy versus colostrum period (RSQ vs. CRQ) comparison groups, respectively. The DEGs were compared with genes associated with milk production traits in the Animal Quantitative Trait Loci database and in Alashan Bactrian camels, and 65 and 46 overlapping candidate genes were obtained, respectively. Functional enrichment and protein-protein interaction network analyses of the DEGs and candidate genes were conducted. After comparing our results with those of other livestock studies, we identified 16 signaling pathways and 27 core candidate genes associated with maternal parturition, estrogen regulation, initiation of lactation, and milk production traits. The pathways suggest that emerged milk production involves the regulation of multiple complex metabolic and cellular developmental processes in camels. Finally, the RNA sequencing results were validated using quantitative real-time PCR; the 15 selected genes exhibited consistent expression changes.

CONCLUSIONS

This study identified DEGs and metabolic pathways affecting maternal parturition and milk production traits. The results provides a theoretical foundation for further research on the molecular mechanism of genes related to milk production traits in camels. Furthermore, these findings will help improve breeding strategies to achieve the desired milk yield in camels.

An overview of food lipids toward food lipidomics

Increasing evidence regarding lipids' beneficial effects on human health has changed the common perception of consumers and dietary officials about the role(s) of food lipids in a healthy diet. However, lipids are a wide group of molecules with specific nutritional and bioactive properties. To understand their true nutritional and functional value, robust methods are needed for accurate identification and quantification. Specific analytical strategies are crucial to target specific classes, especially the ones present in trace amounts. Finding a unique and comprehensive methodology to cover the full lipidome of each foodstuff is still a challenge. This review presents an overview of the lipids nutritionally relevant in foods and new trends in food lipid analysis for each type/class of lipids. Food lipid classes are described following the LipidMaps classification, fatty acids, endocannabinoids, waxes, C8 compounds, glycerophospholipids, glycerolipids (i.e., glycolipids, betaine lipids, and triglycerides), sphingolipids, sterols, sercosterols (vitamin D), isoprenoids (i.e., carotenoids and retinoids (vitamin A)), quinones (i.e., coenzyme Q, vitamin K, and vitamin E), terpenes, oxidized lipids, and oxylipin are highlighted. The uniqueness of each food group: oil-, protein-, and starch-rich, as well as marine foods, fruits, and vegetables (water-rich) regarding its lipid composition, is included. The effect of cooking, food processing, and storage, in addition to the importance of lipidomics in food quality and authenticity, are also discussed. A critical review of challenges and future trends of the analytical approaches and computational methods in global food lipidomics as the basis to increase consumer awareness of the significant role of lipids in food quality and food security worldwide is presented.

A Review of Plant-Based Drinks Addressing Nutrients, Flavor, and Processing Technologies

Plant-based drinks have garnered significant attention as viable substitutes for traditional dairy milk, providing options for individuals who are lactose intolerant or allergic to dairy proteins, and those who adhere to vegan or vegetarian diets. In recent years, demand for plant-based drinks has expanded rapidly. Each variety has unique characteristics in terms of flavor, texture, and nutritional composition, offering consumers a diverse range of choices tailored to meet individual preferences and dietary needs. In this review, we aimed to provide a comprehensive overview of the various types of plant-based drinks and explore potential considerations including their nutritional compositions, health benefits, and processing technologies, as well as the challenges facing the plant-based drink processing industry. We delve into scientific evidence supporting the consumption of plant-based drinks, discuss their potential roles in meeting dietary requirements, and address current limitations and concerns regarding their use. We hope to illuminate the growing significance of plant-based drinks as sustainable and nutritious alternatives to dairy milk, and assist individuals in making informed choices regarding their dietary habits, expanding potential applications for plant-based drinks, and providing necessary theoretical and technical support for the development of a plant-based drink processing industry.

Lipidomics of coconut, almond and soybean milks - Comprehensive characterization of triacylglycerol class and comparison with bovine milk

Nowadays, plant-based milk consumption, as part of a healthy diet, is continuously increasing. In this paper, for the first time a lipidomic analysis on molecular species of triacylglycerol (TG) fraction of plant-based beverages (almond, soy, coconut) was performed by liquid chromatography quadrupole time-of-flight mass spectrometry. A total of 557 TG molecular species was measured, showing significantly different profiles between milk alternatives, compared with bovine milk. The most abundant TG molecular species were TG 18:1_18:1_18:1 and 18:1_18:1_18:2 for almond, TG 18:2_18:2_18:2 and 16:0_18:2_18:2 for soy, TG 12:0_10:0_12:0 and 12:0_12:0_14:0 for coconut. Unconventional fatty acids were detected in almond and soy. The main TG with ethereal linkage were TG-O 56:2, TG-O 56:4, and TG-O 56:5, while the main oxygenated TG was TG 54:5;1O. A total of 30 molecular species were identified as biomarkers for milk differentiation by principal component analysis, providing an interesting support for milk authentication and detection of adulteration on a larger sampling.

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

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

Lipidomics of Sannen goat milk subjected to pasteurization and spray drying based on LC-ESI-MS/MS

The purpose of this study was to evaluate the effects of pasteurization and spray drying on goat milk lipids by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) and multiple variable statistics. A total of 1061 lipids assigned to 29 subclasses in raw and thermal-treated groups were identified. One hundred and 85 different lipids (DLs) (VIP ≥ 1 and |Log₂FC| ≥ 1.0) were selected from pairwise comparisons of goat milk by different treatments. Glycerophospholipids were the most affected subclasses by thermal processes, especially by spray drying. Five potential lipid markers [(DG (16:1_18:0), TG (18:1_22:1_18:2), Cer (t17:2/31:0), LPC (0:0/20:0), and LPS (20:0/0:0] were used to distinguish different treated goat milk. Moreover, glycerophospholipid metabolism was the primary pathway of DLs. These results would provide more details of lipid profiles in thermally treated (pasteurization and spray drying) goat milk.

Quantitative lipidomic analysis of chicken egg yolk during its formation

BACKGROUND

The accumulation of lipids in egg yolk during its formation represents a knowledge gap between food science and animal science research to which researchers in either field have not paid sufficient attention. Therefore, the egg yolk samples during different periods of formation (yellow follicle, YF; small hierarchical follicles, SF; and the largest hierarchical follicle, LF) were prepared, and their fatty acid compositions and lipidomes were quantitatively compared.

RESULTS

The fatty acid profiles and lipidomes of egg yolks at the three stages of formation were significantly different. The relative content of oleic acid and palmitic acid were increased, but that of the main polyunsaturated fatty acids (linoleic acid, linolenic acid and docosahexaenoic acid) was decreased in the SF period to the LF period. Among the 786 lipid molecular species identified, 150 and 46 differentially abundant lipids (DALs) were identified in the pairwise comparison of YF/SF (early stage of egg yolk formation) and SF/LF (late stage of egg yolk formation), respectively. Triglycerides and diglycerides, represented by TG(14:0/18:1/20:1) and DG(18:1/18:1/0:0), were decreased, whereas free fatty acids (especially free unsaturated fatty acids) were greatly increased during yolk formation. The changes in phospholipids were complex; the relative abundance of phosphatidylcholine [represented by PC(18:0/22:5)] decreased, whereas phosphatidylethanolamine [represented by PE(18:0/18:0)] increased. In addition, the relative abundance of lysophosphatidylcholine [represented by LPC(18:1/0:0)] was increased during egg yolk formation.

CONCLUSION

The transport and accumulation of lipids into the egg yolk is dynamically adjusted during its formation, and the transport and timing of different lipid molecular species are different. © 2022 Society of Chemical Industry.

Characterization and discrimination of volatile organic compounds and lipid profiles of truffles under different treatments by UHPLC-QE Orbitrap/MS/MS and P&T-GC-MS

The lipid profiles of the truffles with different treatments were determined by ultra-high-performance liquid chromatography-Quadrupole-Exactive Orbitrap mass spectrometry (UHPLC-QE Orbitrap/MS/MS) and the volatile organic compounds (VOCs) were identified by purge-and-trap-gas chromatography-mass spectrometry (P&T-GC-MS). A total of 37 lipid molecular species and 28 VOCs were tentatively identified. Lysophophatidylcholine (LPC), triacylglycerol (TG) and sphingomyelin (SM) in heat-drying truffles, phosphatidic acid (PA) in freeze-drying and fresh truffles might be the key lipids that bound VOCs. Furthermore, the correlation between lipids and VOCs were analyzed by 19 differential lipids and 7 VOCs. The findings indicated that TG 18:2/18:2/18:2 and Cardiolipin (CL) 16:0/16:0/18:2/18:2 might be the key lipid molecule species for the formation of 2-methoxyphenol. The study helps to understand the effect of different treatments on the lipid profiles and provides the mechanistic insights to the relationship between the lipids and VOCs of truffles.

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.

Effect of homogenization on lipid profiling in Saanen goat milk based on UHPLC-QTOF-MS lipidomics

Homogenization might change the lipid composition of goat milk. This study aimed to investigate the lipid profiles, and identify different lipids (DLs) of raw goat milk (RGM) and homogenized goat milk (HGM) using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) and multivariate statistics. Fifty-six DLs (VIP ≥ 1 and |Log₂FC| ≥ 1.0) were identified from 1057 lipids assigned to 29 subclasses in RGM and HGM. Notably, there were many phosphatidylcholines (PCs) decreased after homogenization, while lysophosphatidylcholines (LPCs) were opposite. Our results provide more details on the impact of homogenization on goat milk lipids.

Comparative Lipidomic Analysis Reveals the Lactational Changes in the Lipid Profiles of Chinese Human Milk

Human milk (HM) lipid plays a crucial role in infant development, whereas its complex lipid profiles and its dynamic changes during prolonged lactation have not been investigated yet. Comparative lipidomic analyses were employed in investigating the lipid profiles of breast milk covering all lactation stages herein. Results revealed significant differences between colostrum and the remaining lactations. A total of 237 species of glycerolipids (GLs) and 231 phospholipids (PLs) were identified. Colostrum had the most abundant lipid species and was enriched with triacylglycerols (TGs) with a high molecular weight. TG(17:1/18:1/24:1), TG(24:1/24:1/26:1), TG(24:0/24:1/26:1), and SM(d20:1/14:1) were characteristic lipids of colostrum. Differential lipid species which were responsible for distinguishing the adjacent lactations were also indicated. Our findings can help deepen the overall understanding of HM lipid profiles and its dynamic changes, which will facilitate the development of infant formulas suitable for Chinese babies in diverse age groups.

Naturally forming benzoic acid orientates perilipin to facilitate glyceride-type polyunsaturated fatty acid degradation via fermentation behavior

Naturally forming benzoic acid in fermented dairy products accumulates in organisms and biomagnifies through collateral transport. The association between benzoic acid agglomeration and susceptible lipid nutrients remains obscure. Horizontal analysis of lipidomic alteration in response to benzoic acid was conducted and the spatially proteomic map was constructed using label-free quantitative proteomics. From synergistic integration of multi-omics in benzoic acid accumulated fermented goat milk model, the biological processes of significant proteins mostly focused on glyceride-type polyunsaturated fatty acids degradation (143.818 ± 0.51 mg/kg to 104.613 ± 0.29 mg/kg). As a physiological barrier shield, perilipin, which is coated on the surface of lipid droplets, protects triacylglycerols from cytosolic lipases, thus preventing triglyceride hydrolysis. The expression of perilipin decreased by 90% compared with the control group, leading to the decrease of triglycerides. Benzoic acid suppressed phosphatidylethanolamines and phosphatidylcholines synthesis by attenuating choline phosphotransferase and ethanolamine phosphotransferase. Less diglyceride generated by the dephosphorylation of phosphatidic acid entered choline phosphotransferase and ethanolamine phosphotransferase-mediated glycerophospholipid metabolisms. Fermentation of goat milk at a low temperature and less incubation time leads to the production of less benzoic acid and mitigation of lipid nutrient loss. The present study delineated the molecular landscape of fermented goat milk containing endogenous benzoic acid and further dissected the trajectory guiding lipid alteration to advance control of benzoic acid residue.

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.

Quantification of phospholipids and glycerides in human milk using ultra-performance liquid chromatography with quadrupole-time-of-flight mass spectrometry

Human milk lipids, which are an important source of energy and affect growth and development of infants, require a comprehensive method for its qualitative and quantitative analysis. This work describes a method for the analysis of phospholipids, glycerides, free fatty acids and gangliosides in human milk by ultra-performance liquid chromatography using a C18 column with quadrupole-time-of-flight mass spectrometry (Q-TOF-MS). The lipids were extracted by liquid-liquid extraction and phospholipids were separated by solid phase extraction (SPE). The chromatographic columns with two different specifications (4.6 mm × 150 mm, and 3 mm × 50 mm) were used to detect phospholipids and glycerides in human milk, respectively. The sphingolipids and glycerides were analyzed in positive ion mode, and the glycerophospholipids and free fatty acids were analyzed in negative ion mode. Both internal and external standards were used for absolute quantification in this experiment. 483 species of lipids, including phospholipids, glycerides, free fatty acids and gangliosides, in human milk were analyzed using UPLC-Q-TOF-MS with high sensitivity and good linearity, with coefficient of correlation above 0.99, the relative standard deviation of accuracy and precision less than 10%. The results in a large number of human milk samples showed that this method was suitable for qualitative and quantitative analysis of lipids in human milk, even for other mammalian milk and infant formulae.

Technical note: colorimetric methods for accurate determination of nutrient composition in beef cow colostrum and milk

Our objectives were to develop colorimetric methods to accurately measure nutrient concentrations of beef cow colostrum and milk, to determine if the yield of colostrum from a single rear quarter is representative of complete collection of colostrum in beef cows, and to compare data from our developed colorimetric methods with Fourier transform infrared spectroscopy (FTIR) analysis to determine the accuracy of FTIR for beef cow colostrum and milk. In Exp. 1, colostral weight and volume of the most full rear quarter were compared with complete collection of colostrum from post-calving, unsuckled beef heifers. Both volume and weight had r2 = 0.85 (P < 0.001) between single-quarter and 4 quarter yields. In Exp. 2, colostrum (n = 35) and milk at d 35 (n = 42) and d 60 (n = 38) of lactation were collected from multiparous, fall-calving, crossbred beef cows. Subsamples were submitted for FTIR analysis and frozen for colorimetric analysis. Colorimetric analyses were developed for lactose, triglycerides (measure of fat), protein, and urea N. To validate method accuracy, spike recoveries were determined for lactose (96.8% average) and milk protein (100.1% average), triglyceride concentration was compared with fat concentration determined by the Mojonnier method (r2 ≥ 0.91, P < 0.001), and colostral or milk urea N was compared with serum urea N from the same sampling day (r2 ≥ 0.72, P < 0.001). Coefficients of determination between colorimetric methods and FTIR were determined for colostrum, d 35 milk, and d 60 milk. Colostral lactose concentration from FTIR was positively associated (r2 = 0.24, P = 0.01) with colorimetric analysis, but there was no relationship (r2 ≤ 0.09, P ≥ 0.14) between methods for colostral fat, protein, or urea N. Milk nutrient composition was positively associated for all nutrients measured at d 35 (r2 = 0.28 to 0.58, P < 0.001), and coefficients of determination strengthened for all nutrients measured at d 60 (r2 = 0.38 to 0.82, P < 0.001). In conclusion, colostrum yield of a single rear quarter can be used to indicate complete collection of colostrum for beef cows, and colorimetric methods developed have adequate accuracy for beef cow colostral and milk nutrient analysis. Based on our analyses, nutrient composition of beef cow colostrum was not accurately analyzed by FTIR. Accuracy of FTIR for beef cow milk varies with component and may be affected by the day of lactation.

Nutritional lipidomics for the characterization of lipids in food

Lipids represent one out of three major macronutrient classes in the human diet. It is estimated to account for about 15-20% of the total dietary intake. Triacylglycerides comprise the majority of them, estimated 90-95%. Other lipid classes include free fatty acids, phospholipids, cholesterol, and plant sterols as minor components. Various methods are used for the characterization of nutritional lipids, however, lipidomics approaches become increasingly attractive for this purpose due to their wide coverage, comprehensiveness and holistic view on composition. In this chapter, analytical methodologies and workflows utilized for lipidomics profiling of food samples are outlined with focus on mass spectrometry-based assays. The chapter describes common lipid extraction protocols, the distinct instrumental mass-spectrometry based analytical platforms for data acquisition, chromatographic and ion-mobility spectrometry methods for lipid separation, briefly mentions alternative methods such as gas chromatography for fatty acid profiling and mass spectrometry imaging. Critical issues of important steps of lipidomics workflows such as structural annotation and identification, quantification and quality assurance are discussed as well. Applications reported over the period of the last 5years are summarized covering the discovery of new lipids in foodstuff, differential profiling approaches for comparing samples from different origin, species, varieties, cultivars and breeds, and for food processing quality control. Lipidomics as a powerful tool for personalized nutrition and nutritional intervention studies is briefly discussed as well. It is expected that this field is significantly growing in the near future and this chapter gives a short insight into the power of nutritional lipidomics approaches.

Lipidomics and Transcriptome Reveal the Effects of Feeding Systems on Fatty Acids in Yak’s Meat

The differences of fatty acids in yak’s meat under graze feeding (GF) and stall feeding (SF) regimes and the regulation mechanism of the feeding system on the fatty acids content in yak ’s meat was explored in this study. First, the fatty acids in yak’s longissimus dorsi (LD) muscle were detected by gas liquid chromatography (GLC). Compared with GF yaks, the absolute content of ΣSFAs, ΣMUFAs, ΣUFAs, ΣPUFAs and Σn-6PUFAs in SF yak’s LD were higher, whereas Σn-3PUFAs was lower; the relative content of ΣMUFAs, ΣPUFAs, Σn-3PUFAs and ΣUFAs in SF yak’s LD were lower, whereas ΣSFAs was higher. The GF yak’s meat is healthier for consumers. Further, the transcriptomic and lipidomics profiles in yak’s LD were detected by mRNA-Sequencing (mRNA-Seq) and ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS), respectively. The integrated transcriptomic and lipidomics analysis showed the differences in fatty acids were caused by the metabolism of fatty acids, amino acids, carbohydrates and phospholipids, and were mainly regulated by the FASN, FABP3, PLIN1, SLC16A13, FASD6 and SCD genes in the PPAR signaling pathway. Moreover, the SCD gene was the candidate gene for the high content of ΣMUFA, and FADS6 was the candidate gene for the high content of Σn-3PUFAs and the healthier ratio of Σn-6/Σn-3PUFAs in yak meat. This study provides a guidance to consumers in the choice of yak’s meat, and also established a theoretical basis for improving yak’s meat quality.

Milk polar lipids composition and functionality: a systematic review

Polar lipids including glycerophospholipids and sphingophospholipids are important nutrients and milk is a major source, particularly for infants. This systematic review describes the human and bovine milk polar lipid composition, structural organization, sources for formulation, and physiological functionality. A total of 2840 records were retrieved through Scopus, 378 were included. Bovine milk is a good source of polar lipids, where yield and composition are highly dependent on the choice of dairy streams and processing. In milk, polar lipids are organized in the milk fat globule membrane as a tri-layer encapsulating triglyceride. The overall polar lipid concentration in human milk is dependent on many factors including lactational stage and maternal diet. Here, reasonable ranges were determined where possible. Similar for bovine milk, where differences in milk lipid concentration proved the largest factor determining variation. The role of milk polar lipids in human health has been demonstrated in several areas and critical review indicated that brain, immune and effects on lipid metabolism are best substantiated areas. Moreover, insights related to the milk fat globule membrane structure-function relation as well as superior activity of milk derived polar lipid compared to plant-derived sources are emerging areas of interest regarding future research and food innovations.

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.

Analysis and comparison of lipids in Saanen goat milk from different geographic regions in China based on UHPLC-QTOF-MS lipidomics

The lipids in goat milk from Guangdong Province (GGM), Shaanxi Province (SGM), and Inner Mongolia Province (NGM) were analyzed and compared using untargeted lipidomics. A total of 16 lipid sub-classes and 638 lipid molecules were identified in the three groups. The main lipids were diacylglycerol (DG), triacylglycerol (TG), and glycerophosphatidylethanolamine (PE). The contents of glycerophosphatidylcholine (PC), PE, glycerophosphatidylinositol (PI), sphingomyelin (SM), glucosylceramide (GlcCer), lactosylceramide (LacCer), DG, and TG were significantly different (P < 0.05) in three groups. Moreover, 173 significantly different lipids were screened out, and 13 lipid molecules could be applied as potential lipid markers for identifying the geographic region of goat milk. In addition, the related metabolic pathways were also analyzed. A hypothetical scheme was drawn by linking the most relevant metabolic pathways. This work will provide basics for the establishment of the Saanen goat milk traceability system and provide comprehensive lipid information for the goat milk of different regions.

SWATH-MS2&1: Development and Validation of a Pseudotargeted Lipidomics Method for the Analysis of Glycerol Esters in Milk

Glycerol ester (GE) is a kind of important lipid in milk, which varies greatly depending on many factors. In this study, a novel pseudotargeted lipidomics strategy, named SWATH-MS2&1, was developed for the detection of GEs in milk and the Folch method was selected for the sample preparation. The developed method exhibited a competitive alternative to the acknowledged pseudotargeted strategy, including wider coverage (12 more GEs detected), higher repeatability (12 more GEs, whose coefficient of variation < 0.3), better linearity (5 more GEs, whose R² > 0.8), and similar sensitivity (only 2 GEs less than P-MRM after dilution). SWATH-MS2&1 was applied in the investigation of GEs from different milk samples. The orthogonal partial least-squares difference analysis of 219 GEs identified from SWATH-MS2&1 showed satisfying differentiation of different milk samples, and 76 GEs were screened out as potential markers. Our findings demonstrated that SWATH-MS2&1 could offer an accurate method to measure a wide spectrum of GEs in milk.

Insights into the Research Trends on Bovine Colostrum: Beneficial Health Perspectives with Special Reference to Manufacturing of Functional Foods and Feed Supplements

Bovine colostrum (BC) is the initial mammary secretion after parturition, which is nature's bountiful source consisting of nutritional and bioactive components present in a highly concentrated low-volume format. All mammalian newborns require colostrum to enhance physiological processes such as lifelong immunity, gastrointestinal development, and resistance to microbial infections. The genetic, environmental, and processing methods can all have an impact on the biochemical contents of BC and its supplements. BC and its derivatives have been intensively researched for their potential use in functional foods, medicines, and animal feed. Evidence from clinical studies suggests that BC products are well-tolerated, nontoxic, and safe for human ingestion. Functional foods, feed, and pharmaceutical formulations based on bovine colostrum are playing noteworthy roles in the development of innovative products for promoting health and the prevention of chronic illnesses. This systematic review sheds light on recent research on (a) the effects of processing techniques on BC components, (b) emerging techniques used in the isolation and identification of novel components, (c) BC-based functional foods for human consumption and animal feed supplements, and (d) the role of BC in current drug delivery, as well as future recommendations.

A Comprehensive Review of Lipidomics and Its Application to Assess Food Obtained from Farm Animals

Lipids are one of the major macronutrients essential for adequate growth and maintenance of human health. Their structure is not only complex but also diverse, which makes systematic and holistic analyses challenging; consequently, little is known regarding the relationship between phenotype and mechanism of action. In recent years, rapid advancements have been made in the fields of lipidomics and bioinformatics. In comparison with traditional approaches, mass spectrometry-based lipidomics can rapidly identify as well as quantify >1,000 lipid species at the same time, facilitating comprehensive, robust analyses of lipids in tissues, cells, and body fluids. Accordingly, lipidomics is now being widely applied in various fields, particularly food and nutrition science. In this review, we discuss lipid classification, extraction techniques, and detection and analysis using lipidomics. We also cover how lipidomics is being used to assess food obtained from livestock and poultry. The information included herein should serve as a reference to determine how to characterize lipids in animal food samples, enhancing our understanding of the application of lipidomics in the field in animal husbandry.

Quantitative analysis of differentially expressed milk fat globule membrane proteins between donkey and bovine colostrum based on high-performance liquid chromatography with tandem mass spectrometry proteomics

This study was designed to provide novel insights into milk fat globule membrane (MFGM) proteins in donkey colostrum (DC) and bovine colostrum (BC) using quantitative proteomics. In total, 179 (DC) and 195 (BC) MFGM proteins were characterized, including 71 shared, 108 DC-specific, and 124 BC-specific proteins. Fifty-one shared proteins were selected as differentially expressed MFGM proteins, including 21 upregulated and 30 downregulated proteins in DC. Gene ontology analysis showed that these proteins were mainly enriched in cellular components, including the extracellular exosome, extracellular space, and plasma membrane. Additionally, they were further involved in metabolic pathways, including cholesterol metabolism, the peroxisome proliferator-activated receptor signaling pathway, and purine metabolism. Furthermore, several key protein factors with high connectivity were identified via protein-protein interaction analysis. These results provide more comprehensive knowledge of differences in the biological properties of MFGM proteins in DC and BC as well as pave the way for future studies of the nutritional and functional requirements of these important ingredients toward the development of dairy products based on multiple milk sources.

Molecular mechanism associated with the use of magnetic fermentation in modulating the dietary lipid composition and nutritional quality of goat milk

Standard fermentation (SF) mainly affected the metabolism of glycerophospholipid and sphingolipid, and increased the total lipid content of goat milk. Content of total lipid was decreased by magnetic fermentation compared with SF, mainly due to triacylglycerol and diacylglycerol. Comprehensive characteristic of lipids dynamic changes during standard and magnetic fermentation was performed using high-throughput quantitative lipidomics. Totally, 488 lipid molecular species covering 12 subclasses were detected, and triacylglycerol was the highest levels, followed by diacylglycerol and phosphoethanolamine in the whole fermentation stage. Specifically, except for ceramide and simple Glc series, the content of all polar lipids in SF was dropped and neutral lipids subjoined. Compared with SF, the decrease of triacylglycerol (1752.47 to 784.78 μg/mL), diacylglycerol (60.36 to 24.89 μg/mL) and simple Glc series (4.36 to 2.40 μg/mL) were observed, while ceramide (6.54 to 25.87 μg/mL) increased, suggesting magnetic fermentation as effective approach to potentially improve the nutritional of goat milk.

Novel insights into whey protein differences between donkey and bovine milk

In this study, we characterized and compared the whey proteins from donkey and bovine milk using HPLC-MS/MS-based proteomics. A total of 989 and 1534 whey proteins were characterized in donkey and bovine milk, respectively. Furthermore, 623 whey proteins were found in both groups, and 229 differentially expressed whey proteins (DEWPs) were identified. Among the common proteins, 66 DEWPs were upregulated and 163 were downregulated in donkey milk compared to those in bovine milk. Gene Ontology analysis revealed the cellular components, biological processes, and molecular functions of these DEWPs. Metabolic pathway analysis suggested that most DEWPs were associated with endocytosis, platelet activation, and phagocytosis. These results improve our understanding of the differences between donkey and bovine whey proteins and provide important information regarding these proteins as nutritional and functional factors in dairy product formulations from multiple milk sources.

The untargeted lipidomic profile of quarter milk from dairy cows with subclinical intramammary infection by non-aureus staphylococci

This observational study determined the lipidome of cow milk during subclinical intramammary infection (IMI) by non-aureus staphylococci (NAS), also defined as coagulase-negative staphylococci, using an untargeted approach. Among the pathogens causing bovine IMI, NAS have become the most frequently isolated bacteria from milk samples. Although the application of system biology approaches to mastitis has provided pivotal information by investigating the transcriptome, proteome, peptidome, and metabolome, the milk lipidome during mammary gland inflammation remains undisclosed. To cover this gap, we determined the milk lipidome of 17 dairy cows with IMI caused by NAS (NAS-IMI), and we compared the results with those of healthy quarter milk from 11 cows. The lipidome was determined following a liquid chromatography-quadrupole time-of-flight mass spectrometry approach. Sixteen subclasses of lipids were identified in both groups of animals. From 2,556 measured lipids, the abundance of 597 changed more than 10-fold in quarter milk with NAS-IMI compared with healthy quarters. The results demonstrate the influence of NAS-IMI on the milk lipidome, implying significant changes in lipid species belonging to the family of triacylglycerols and sphingomyelins, and contribute to the understanding of inflammatory processes in the bovine udder, highlighting potential novel biomarkers for improving mastitis diagnostics.