Lipidomics: a comprehensive review in navigating the functional quality of animal and fish products

ABSTRACT

Lipidomics is a rapidly expanding field of study that provides a comprehensive approach to the analysis of lipids in meat and fish food products. Lipidomics has become an important tool for evaluating the functional quality of animal and fish products as well as their potential health benefits. This review article provides an overview of the current state of the art in lipidomics for food assessment and its application in improving the quality and nutritional value of animal and fish food. This review covers a wide range of topics, including an examination of the lipid content and composition of animal and fish products, the effect of processing and storage conditions on lipid quality, and the potential health benefits of consuming lipid-rich animal and fish products. It also covers the important roles that lipids play in animal and fish products, such as their impact on flavor, texture, and stability. The article concludes with a discussion of the future directions of lipidomics research and the potential applications of this technology in the food industry. This review article provides valuable information for researchers, food scientists, and industry professionals who are interested in exploring the functional quality of animal and fish products through the lens of lipidomics.

KEYWORDS:

• Lipidomics
• lipid
• food quality
• animal products
• fish products

Introduction

In recent years, we have used a method known as “lipidomics” to gain a better understanding of complex metabolic lipid networks in biological processes. To develop the complete characterization of lipid species, most lipidomics systems have used MS and computational methods.^[1] The first step in the lipidomics approach is qualitative and quantitative analysis of lipid composition.^[2] Lipidomics is a relatively new research area that is rapidly progressing due to recent advances in bioinformatics data analysis, and systems biology methods that are correlated with other omics platforms.^[3] This study is also a rapidly growing field that focuses on the study of lipid molecules and their function in biological systems.^[4] Lipidomics has emerged as a valuable tool in food science and nutrition research, providing a thorough and in-depth analysis of the lipid composition of food products.^[5] Lipidomics has recently been applied to the evaluation of food derived from animal and fish products, providing valuable information on the quality, safety, and authenticity of these food products.

The lipid composition of food products can provide valuable information about the product’s authenticity, origin, and processing history. Lipidomics, for example, can be used to identify contaminants and adulterants in food products, determine the geographic origin of fish products, and evaluate the health benefits of various food products.^[6,7] Lipidomics can also be used to determine how processing and storage affect the lipid composition of food products, providing valuable information to the food industry for quality control and product development.^[5]

In animal products, lipidomics has been used to assess the quality and authenticity of meat^[8,9] and dairy products.^[10,11] Lipidomics, for example, has been used to determine animal breed, age, and feeding habits, as well as to detect the presence of contaminants such as hormones and antibiotics in animal products.^[12,13] Lipidomics has been used in fish products to determine species, geographical origin, and freshness, as well as to detect contaminants such as heavy metals and persistent organic pollutants.^[14] Lipidomics has also been used to evaluate functional ingredients in food, such as omega-3 fatty acids and conjugated linoleic acids. Because of their health benefits, these functional ingredients are becoming increasingly important in the food industry, and lipidomics provides a reliable method for determining their presence and quality in food products.^[15]

The systematic study of lipids, including their structure, function, and interactions in biological systems, is known as lipidomics. The lipidomics approach requires both quantitative and qualitative methods. Mass spectrometry (MS) is a highly sensitive tool for identifying various lipid categories, subcategories, and individual species in a biological system.^[16] Many food scientists have studied the lipidomics approach using MS technology^[17]. The ultra-performance liquid chromatography (UPLC) instrument (Waters Corporation USA) was introduced in 2004 and has played an important role in the advancement of the LC/MS technique for metabolomics. The UPLC system’s significant advancement, which includes the efficient use of a high-pressure resistant column with a 1.7 mm carrier and a pump with a maximum pressure of 100 MPa. As a result, analysis time is reduced, development insensitivity is reduced, and peak ability is increased. Several international companies, including Shimadzu Corporation (Kyoto, Japan) and Agilent Technologies (Palo Alto, CA, USA), have expanded an ultra-high performance liquid chromatography system that can be used with pressures greater than 100 Mpa.^[18] One constraint associated with the application of lipidomics in the assessment of animal and fish products as food is to the occurrence of lipid oxidation within the product. Lipid oxidation is a contributing factor to alterations in lipid composition, hence complicating the assessment procedure.^[19] Figure 1 depicts the flow diagram of the overall lipidomics procedure in animal and fish products

Figure 1. The Flow Diagram of Overall Lipidomics Procedure.

The purpose of this article review is to assess the use of lipidomics in the evaluation of food derived from animal and fish products. The review’s aim is to: 1). summarize the current state of knowledge about the use of lipidomics in the assessment of food from animal and fish products; 2). Assess the benefits and drawbacks of lipidomics in assessing food quality, safety, and authenticity; 3). Describe the potential applications of lipidomics in the food industry and research; 4). Provide insights into the future directions of lipidomics in the evaluation of animal and fish products as food.

This review critically evaluates the literature on lipidomics in food from animal and fish products and provides a comprehensive overview of the current state of knowledge in this field. This review provides insights into the potential applications of lipidomics in the food industry and food research, emphasizing the benefits of this approach.

Lipids and their functional characteristics

Lipids are a diverse group of organic compounds that are important in living organisms for energy storage, insulation, and structural support. They are also involved in many cellular processes, including the formation of cell membranes.^[20] Nonpolar lipids include primary lipids such as cholesterol and its esters, as well as triglycerides.^[21] The most common type of lipid is fat, also known as triglycerides. They are made up of a glycerol molecule and three fatty acid chains and serve as the body’s energy reserve. Polar lipids are primarily composed of lipids from the phospholipid, sphingolipid, rhamnolipid, and glycolipid classes. Phospholipids are a major component of cell membranes and play an important role in maintaining membrane fluidity and stability. They have a glycerol molecule, two fatty acid chains, and a phosphate group.^[22] Furthermore, phospholipids are classified into several groups based on phosphate classes, including Phosphatidylcholine (PC), Phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylglycerol, phosphatidylserine (PS), and phosphatidic acid.^[10]

Three primary lipid classes, glycerophospholipid, sphingolipid, and sterol, all contribute significantly to membrane structural regulation (Figure 2). PC, PE, PI, and PS are the primary glycerophospholipids found in the membrane. They are assigned differently in the exoplasmic and cytoplasmic functions of the plasma membrane and form a semi-permeable barrier to maintain cell integrity. Sphingolipids are the second primary lipid class found in the outer bilayer of membranes, where they play an important role in the formation of microdomains and the organization of their functions.^[23] These lipids are involved in cell signaling as well as the formation of the blood-brain barrier. They are made up of a sphingosine molecule and a chain of fatty acids. Hormones such as testosterone and estrogen are examples of steroids, as is cholesterol, which is an important component of cell membranes.^[24] Sterols are the third primary lipid class found in the cell membrane, where they regulate various membrane functions and biological cell systems.^[25] The majority of these lipid classes serve specific functions in controlling membrane function and regulating membrane receptor signaling.^[26]

Figure 2. The lipids classes that plays an important role in controlling membrane structure. PC: phosphatidylcholine; SM: sphingomyelin; PE: phosphatidylethanolamine; PI: phosphatidylinositol; PS: phosphatidylserine. Created with BioRender.com.

Lipids play a significant function in promoting health.^[27] Bioactive lipids, including omega-3 fatty acids, conjugated linoleic acid, carotenoids, and phytosterols, exert significant effects on enhancing overall health. The human body lacks the ability to produce these chemicals endogenously, necessitating their acquisition through dietary sources, such as meat. Bioactive lipids play crucial roles in maintaining health, including their functions as antioxidants and anti-inflammatory agents.^[28] Lipids serve as crucial constituents that are extensively employed as emulsifying agents in many dietary items.^[29] Lipids also serve as nutraceuticals, fulfilling a significant function in the provision of dietary supplements. Lipids, as a type of nutraceutical product, can significantly contribute to the functionality of health products.^[30]

Lipidomics

Figure 3 depicts an MS-based lipidomics approach, which can be divided into some key operations: preparation (lipid extraction), data gathering [Gas chromatography (GC)/Liquid chromatography (LC)-MS], and data processing (bioinformatics data analysis).

Figure 3. Lipidomic Approach for Navigating the Functional Quality of Animal and Fish Products.

Lipid extractions

The process of separating lipids from other biological components, such as proteins and carbohydrates, is known as lipid extraction.^[31] Lipid extraction can be performed in a variety of ways, including solvent extraction, which involves dissolving the lipids in a solvent like hexane or chloroform. The lipids are then separated from other biological components by filtering or centrifuging the mixture.^[32] A solvent, such as ethanol, is blended with the sample in the blending and centrifugation method to dissolve the lipids. The lipids are then separated from the other biological components by centrifuging the mixture. Ultrasonic extraction: In this technique, ultrasonic waves are used to break up the bonds between lipids and proteins and between lipids and carbohydrates, making it simpler to extract the lipids.^[33] Folch extraction is a technique that is frequently used to extract lipids from plant tissues. To dissolve the lipids, a mixture of solvents, including methanol and chloroform, is blended with the sample. The lipids are then separated from other biological components by centrifuging the mixture.^[31] The sample is mixed with a mixture of two immiscible liquids, such as polyethylene glycol and sodium sulfate, in the aqueous two-phase extraction technique to separate the lipids from other biological materials.^[34] Liquid-liquid extraction involves dissolving the lipids in a solvent, such as hexane or dichloromethane. The lipids are then separated from other biological components by shaking the mixture with water or another immiscible solvent.^[31,35]

The aforementioned lipid extraction procedure exhibits both advantages and disadvantages. A solvent including a blend of polar and nonpolar components is employed in order to enhance the extraction of lipids. One notable benefit of ultrasonic extraction is in its ability to effectively extract a greater quantity of lipids. The utilization of Folch extraction within the lipid extraction procedure has been found to enhance the efficiency of lipid extraction from the sample when using mixed solvents. On the other hand, liquid-liquid extraction is employed to isolate the residual solvent, resulting in the acquisition of pure lipids.^[36] One limitation of this approach is the time-consuming nature of the procedure.^[37]

Lipid data analyses

The process of interpreting and fully understanding the results of lipid analysis experiments is known as lipid data analysis.^[38] Lipid data analysis attempts to determine the composition, distribution, and changes in lipid levels in biological samples. There are several methods for analyzing lipid data, including Chromatography is a popular method for separating and analyzing lipids. Gas chromatography (GC), liquid chromatography (LC), and thin-layer chromatography (TLC) are three types of chromatography that can be used to separate and identify different lipid classes. Mass spectrometry is an effective lipid analysis tool that is frequently used in conjunction with chromatography to identify and quantify specific lipids in a sample.^[39] Mass spectrometry techniques include matrix-assisted laser desorption/ionization (MALDI), electrospray ionization (ESI), and atmospheric pressure chemical ionization (APCI). Nuclear magnetic resonance (NMR) spectroscopy is a nondestructive method for determining the composition of lipids in a sample that does not require separation. Statistical analysis is used to process and interpret lipid data, such as the identification of patterns and correlations in the data. This can involve multivariate statistical methods, such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA).^[9]

Lipid analysis encompasses the utilization of diverse analytical tools, such as GC, LC, TLC, MS, and NMR. There are variations in the target lipid molecules while performing lipid analysis on each of these equipments. The application of GC enables the investigation of lipids that possess volatile characteristics. In the context of lipid compound analysis, LC would be employed to assess a broader range of lipid compounds by considering their polarity and the interplay between the stationary phase and the mobile phase. TLC would be employed to evaluate the lipids that are specifically targeted. The proposed approach involves the utilization of MS technology to examine a broader range of lipids, leveraging the existing databases. This instrument would enable the analysis of untargeted lipids. NMR spectroscopy is employed for the analysis of lipids by utilizing their structural characteristics, which are subsequently compared with relevant databases.^[40] PCA and PLS-DA are the statistical methods employed for lipid analysis utilizing the aforementioned equipment. PCA can be utilized to characterize the lipid composition in each sample. The utilization of visual representations in this research would enhance the clarity of lipidomic data. PLS-DA is a statistical method utilized to forecast the specific lipids that serve as key factors in the authentication procedure. This method involves obtaining the R2 value, which serves as an indicator for determining the validity of the performed PLS-DA.^[41]

The processing of lipidomics data involves the utilization of several software tools. The LipidSearch software was utilized to analyze the lipid content. The lipidomic data obtained from MS analysis would be compared against the LipidSearch databases in order to identify the specific lipids contained in the sample.^[42] Chemometrics analysis can be performed using several software tools such as Minitab, Orange, and MetaboAnalyst for the implementation of PCA and PLS-DA. The analysis of PLS-DA cannot be conducted using software such as Minitab or Orange; instead, it necessitates the utilization of MetaboAnalyst.^[43]

Lipidomics application from animal and fish products

Lipidomics in meat product evaluation

Lipidomics can be used to analyze the lipid content and composition of various meat products in the context of meat product evaluation.^[44] This data can then be used to assess the nutritional value and quality of meat products. The analysis of the fatty acid composition of the lipids is an important aspect of lipidomics in meat product evaluation. Fatty acids are lipid building blocks that play an important role in human health. Factors such as the diet and genetics of the animal, as well as processing methods, can all influence the fatty acid composition of meat products.^[45] For example, the fatty acid composition of grass-fed meat products differs significantly from that of grain-fed meat products.^[46] Daley et al.^[144] reported variations in the fatty acid composition between grass-fed and grain-fed beef. Research studies have demonstrated that diets mostly consisting of grass have the ability to increase the levels of several beneficial fatty acids. These include total conjugated linoleic acid (CLA) isomers, Trans vaccenic acid (TVA), which serves as a precursor to CLA, and omega-3 (n-3) fatty acids. These findings are reported on a gram per gram fat basis.

Lipidomics can also be used to assess meat products’ oxidative stability.^[48] Lipid oxidation is a chemical reaction that can result in the formation of harmful compounds such as aldehydes and peroxides in meat products.^[45] According to a study conducted by Cai et al.^[49] it has been observed that lipid oxidation takes place in salt-dried yellow perch (Pseudosciaena polyactis) throughout the processing stage. The fatty acid composition of C18:0, C16:1n7, C19:0, and C22:6n3 exhibited alterations during the processing procedure. This phenomenon can be attributed to the process of lipid oxidation. Off-flavors, rancidity, and other quality defects in meat products can be caused by these compounds.^[50] Lipidomics can be used to quantify oxidation-related compounds in meat products and evaluate their oxidative stability.^[51] Furthermore, lipidomics can be used to assess the impact of processing methods on the lipid content and composition of meat products, such as cooking and storage.^[52] Zhang et al.^[92] shown that alterations in lipid composition occur throughout the process of heating. Chicken meat that undergoes high heating during processing exhibits a reduction in phospholipid content and an elevation in lysophospholipid levels. This information can be used to optimize processing conditions in order to maintain the quality and nutritional value of meat products.

Lipidomics is an effective method for determining the lipid composition of meat products such as sausages, and other meat products. Researchers can use this method to identify the major lipid classes and fatty acids present in these products, as well as the impact of processing methods and animal diet on the lipid profile^[53] Sausages are a popular meat product that is consumed all over the world and is valued for its rich flavor and convenience. Lipidomics has been used to determine the lipid profile of sausages as well as to assess the effect of processing methods on lipid composition. Lipidomics studies have revealed that sausages are a rich source of lipids, including phospholipids, cholesterol, and fatty acids,^[54] and that processing methods, such as cooking, can affect the product’s lipid composition and functional properties. Lipidomics has revealed new information about the lipid composition of meat products like sausages, as well as their relationship to functional properties and potential health benefits. According to a study conducted by Lv et al.^[55] it was found that the application of high pressure processing (HPP) can enhance the functional characteristics of sausages with reduced levels of fat and salt. HPP has been found to have a significant impact on various aspects of food quality. It has been observed that HPP can effectively reduce cooking loss, enhance color transformation, and improve textural qualities. Additionally, HPP has been shown to decrease the solubility of myosin and actin proteins, which are crucial components in meat products.

The health benefits of consuming lipids present in meat products are related to several diseases. Consumption of poultry meat, as part of a vegetable-rich diet, is associated with a risk reduction of developing overweight and obesity, cardiovascular diseases, and type 2 diabetes mellitus. Also, white meat (and poultry in particular) is considered moderately protective or neutral on cancer risk.^[56] Lipidomics can be used as a quality control in meat products. Lipid inspection is one of the alternatives to maintain the quality of meat products. According to Lv et al.^[55] showed lipid changes in chicken meat during the storage process. At 4°C Triacylglycerol (TAG), phosphatidylcholine (PC) and phosphatidylethanolamine (PE) significantly decreased, while lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine (LPE) increased. Guo et al.^[57] investigated that there are lipid changes during meat processing. PCA and OPLS-DA showed that the quality of mutton ham changed the most during the P3 fermenting stage, including TG(18:1/18:2/18:3), PE(20:5/18:1), and TG(16:1/18:1/18:4) that were significantly downregulated, and CE(20:3), FFA(24:6), LPC(20:3/0:0), and FFA(18:4) that were significantly upregulated.^[37]

Lipidomics in egg product evaluation

Lipidomics has greatly advanced our understanding of the lipid composition and potential health benefits of egg products,^[58] which are an important source of lipids, proteins, vitamins, and minerals. The analysis of the fatty acid composition of the lipids is an important aspect of lipidomics in egg product evaluation.^[52] The fatty acid composition of egg products can be influenced by factors such as the laying hen’s diet and genetics, as well as processing method.^[59,60] For example, eggs from free-range hens have a different fatty acid composition than eggs from caged hens.^[60] Fatty acids, namely n-3 polyunsaturated fatty acids, are significant macronutrients that are dense in calories. They play a crucial role in providing important nutrients and promoting a healthy body weight, which is a fundamental aspect of nutrition and overall well-being.^[61] Harlina et al.^[62] conducted a study examining the potential of salted duck egg supplemented with clove extract as a viable alternative egg product with a high content of essential lipids. The study found that the product contains significant amounts of PC and PE, which are the primary constituents of glycerophospholipid.

Lipidomics method could also be used to assess egg product oxidative stability.^[63] Lipid oxidation is a chemical reaction that can result in the formation of harmful compounds such as aldehydes and peroxides in egg products.^[64] These compounds can contribute to off-flavors, rancidity, and other quality defects in egg products.^[65] Lipidomics can be used to quantify the levels of oxidation-related compounds in egg products and assess their oxidative stability.^[66] Additionally, lipidomics can be used to evaluate the effect of processing methods, such as cooking^[67] and storage, on the lipid content and composition of egg products. This information can be used to optimize processing conditions in order to retain the quality and nutritional value of egg products. A variety of egg products, including salted duck eggs, pidan eggs, mayonnaise, chicken eggs, quail eggs, and duck eggs, have been evaluated using the lipidomics approach.

Salted duck eggs are a traditional Asian food product valued for their rich flavor and nutrient content. Researchers have used lipidomics to determine the unique lipid profile of salted duck eggs and to assess the impact of salting methods on the lipid composition. Lipidomics research has revealed that salted duck eggs are a rich source of lipids, including phospholipids and cholesterol, and that the salting process can alter the lipid composition and functional properties of the eggs. Furthermore, Harlina et al.^[62] investigated lipidomics profiling in egg treated with clove extract and discovered that 315 lipids were detected in egg samples, including glycerolipids, glycerophospholipids, glycosphingolipids, and neutral glycosphingolipids.

Pidan eggs are another traditional Asian food product valued for its rich flavor and high nutrient content. They contain a high concentration of lipids, including phospholipids and cholesterol, and the fermentation process can alter the lipid composition and functional properties of the eggs.^[68] Mayonnaise is a well-known condiment made from eggs and oil. Lipidomics has allowed researchers to determine the lipid profile of mayonnaise and assess the impact of processing methods on lipid composition.^[69] Mayonnaise is a rich source of lipids, including monounsaturated and polyunsaturated fatty acids and phospholipids, according to lipidomics studies and processing methods can affect the lipid composition and functional properties of the condiment.^[70]

Chicken, quail, and duck eggs are popular foods that are valued for their high nutrient content and versatility in cooking. Lipidomics can be used to analyze the lipid content and composition of various egg products in the context of egg product evaluation. Lipidomics has allowed researchers to determine the lipid profile of these eggs and assess the effect of species, diet, and processing methods on lipid composition. Lipidomics research has revealed that these eggs are a rich source of lipids, including phospholipids, cholesterol, and fatty acids, and that species, diet, and processing methods can all impact the lipid composition and functional properties of the eggs.^[71]

Lipidomics is able to provide an overview of the quality of eggs based on the process of obtaining and storing them. Luo et al.^[72] revealed that the component of triglycerides, phospholipids, and sphingolipids in egg yolk will decrease significantly during the storage process and Campos et al.^[73] mentioned that the lipid content of egg yolks will differ based on how the chickens are raised. Fatty acids esterified to the glycerol backbone of PL ranged between C16:0 and C22:6. On the other hand, fatty acids esterified to TAG ranged from C14:0 to C20:0. Major differences on the PL profile were observed regarding eggs from free-range hens and fed with vegetable origin food and eggs from the remaining conditions, once the former presented higher levels of PC (O-34:0), PC (34:1) and PE (34:1).

Lipidomics in dairy product evaluation

Lipidomics is a rapidly expanding field that has greatly advanced our understanding of lipid metabolism and food product functional quality. The evaluation of dairy products such as cheese, yogurt, dadih, kefir, and pasteurized milk has seen significant advances in lipidomics research. Lipidomics has provided new insights into the lipid composition and potential health benefits of dairy products.^[74,75,76]

The analysis of the fatty acid composition of the lipids is an important aspect of lipidomics in dairy product evaluation.^[77] The fatty acid composition of dairy products can be influenced by factors such as the dairy animal’s diet and genetics, as well as processing methods. Dairy products from grass-fed animals, for example, have a different fatty acid composition than dairy products from grain-fed animals.^[78]

Lipidomics can also be used to assess dairy products’ oxidative stability. Lipid oxidation is a chemical reaction that can result in the formation of harmful compounds such as aldehydes and peroxides in dairy products. Off-flavors, rancidity, and other quality defects in dairy products can be caused by these compounds. Lipidomics can be used to quantify oxidation-related compounds in dairy products and evaluate their oxidative stability.^[79]

Cheese is a widely known dairy product that is high in lipids such as saturated and unsaturated fatty acids, waxes, and phospholipids.^[76] Lipidomics has enabled the identification of the distinct lipid profile of various types of cheese, such as cheddar, blue, and mozzarella, as well as the identification of factors that influence the lipid composition of cheese, such as the type of milk used, the addition of starter cultures, and aging methods.^[47,80] Cheese’s lipid composition has been linked to its flavor, aroma, and texture, as well as potential health benefits such as anti-inflammatory and anti-cancer properties.^[81,82]

Another dairy product that is highly valued for its health benefits is yogurt. Lipidomics has revealed new information about yogurt’s lipid composition and its relationship to functional properties such as viscosity and mouthfeel.^[83] Researchers discovered that the type of milk used, the addition of starter cultures, and processing methods such as pasteurization and homogenization can all affect the lipid composition of yogurt.^[84] The lipidomics approach has enabled the identification of the key lipids responsible for the functional properties of yogurt as well as the development of new processing methods that preserve the quality and health benefits of this important dairy product.^[75]

Dadih, kefir, and pasteurized milk are other dairy products that have received attention in lipidomics research. Dadih is an Indonesian fermented dairy product that is high in lipids, vitamins, and minerals. Lipidomics has provided new insights into the lipid composition of dadih and its relationship to functional properties such as viscosity and acidity.^[85] Kefir is a fermented dairy product high in probiotics that has been linked to a variety of health benefits such as improved digestive health and immunity.^[86–88] The effect of fermentation on kefir’s lipid profile and identification of the key lipids responsible for its functional properties. Pasteurized milk is a popular dairy product high in lipids, proteins, and minerals.^[89] Lipidomics has revealed new information about the lipid composition of pasteurized milk and how it relates to functional properties like viscosity and creaminess.^[48] Lipidomics research in dairy products has a bright future in terms of improving our understanding of their functional quality and potential to benefit human health.

Consumption of lipids in dairy products provides many health benefits. Consumption of this product will benefit bone health. In individuals with arthritis, consumption of this product does not affect the worsening of the disease. Consumption of dairy products will also not increase the risk of cardiovascular disease.^[90] Lipidomics can be a strategy for quality control in dairy products. Lipidomics is able to see changes in lipids during dairy product processing; these changes will be used as a reference for product quality control. Study by Jia et al.^[91] explained that fermented goat milk undergoes changes in lipid composition. After fermentation, organic acid, peptide and medium- and long-chain fatty acid contents in brown goat milk samples increased significantly. A total of 108 metabolites and 174 lipids related to sensory quality were identified. Heterocyclic compounds, as intermediates of Maillard reaction, modified color, taste, and aroma, while changes in triglyceride content reduced the impact of off-odor, greatly improving sensory quality of fermented brown goat milk. Meanwhile, Zhang et al.^[92] explain how heat changes during processing alter the lipid composition of milk. Heat treatment resulted in further lipid oxidation reactions and a reduction in the amount of mild oxidation products. Moreover, the levels of lysophospholipids and free fatty acids (including oxidized free fatty acids) can be used to distinguish UHT-treated milk. In turn, oxidized phosphatidylcholine, oxidized phosphatidylethanolamine, ether-linked phosphatidylethanolamine, diacylglycerol, triacylglycerol, and oxidized triacylglycerol can be used to differentiate raw, pasteurized, and ESL milk.

Lipidomics in honey and its by-products

The evaluation of honey and its byproducts, such as bee pollen, propolis, and royal jelly, has seen significant advances in lipidomics research. Lipidomics has provided new insights into the lipid composition and potential health benefits of these products, which are highly valued for their medicinal and nutritional properties.

Honey is made up of a variety of lipids, such as fatty acids, waxes, and phospholipids, all of which contribute to its distinct flavor, aroma, and health benefits.^[93,94] Lipidomics has enabled the identification of the distinct lipid profile of honey from various geographical origins and floral sources, as well as the identification of factors influencing the lipid composition of honey, such as environmental conditions, bee species, and harvesting methods.^[95] Honey’s lipid composition has been linked to potential health benefits such as antibacterial, antiviral, and anti-inflammatory properties.^[96]

Honeybee byproducts such as pollen, propolis, and royal jelly are highly valued for their medicinal and nutritional properties. Lipidomics has revealed new information about these products’ lipid composition and its relationship to their health benefits.^[95] Bee pollen, for example, is high in polyunsaturated fatty acids and tocopherols, which have been linked to its anti-inflammatory and antioxidant properties.^[97] Propolis, on the other hand, is made up of a wide variety of lipids, such as fatty acids, waxes, and phytosterols, all of which contribute to its antibacterial and antiviral properties.^[98] Royal jelly contains a high concentration of lipids, including fatty acids, waxes, and phospholipids, which contribute to its distinct flavor and aroma as well as its potential health benefits, such as improved skin health and immune function.^[95] The future of lipidomics research in honey and its byproducts holds great promise for better understanding their functional quality and potential to benefit human health.

Lipids in honey and its by-products have an important role for health. Natural honey consumption could improve lipid profile and anthropometric parameters, and propolis supplementation could enhance lipid profile and glycemic markers. This suggests that honey consumption can reduce the risk of cardiovascular disease.^[99] The lipidomic approach can be a tool for quality control of honey and its by-products. Differences in the lipid composition of long-lived and unaged honey have been published by Li et al.^[48] and Yan et al. ^[95]. In this research sphingomyelins (SM) and glycerophosphoethanolamines (GPE) detected in long-lived honey. This can be used as a marker to determine the quality of honey products.

Lipidomics in Animal Fats Products

This study of lipids and their functions, known as lipidomics, has been applied to the analysis of a variety of animal fat products, including gelatin, collagen, butter, ghee, tallow, lard, and poultry fats. This method has resulted in a better understanding of the chemical composition and functional quality of these products, which has the potential to influence their use in a variety of applications.

Gelatin and collagen are proteins derived from animal tissue that are widely used as gelling agents as well as for functional properties such as the ability to form a gel or foam.^[100,101] According to lipidomics research, gelatin and collagen can contain trace amounts of lipids, which can affect their functional properties and stability.^[102] Understanding the lipid content and composition of these products can help to improve their use and processing, as well as their functional quality.

Butter, ghee, tallow, lard, and poultry fats are examples of animal fat products that are widely used in cooking and food preparation, as well as non-food applications such as cosmetics and pharmaceuticals. Lipidomics has provided new insights into the fatty acid composition of these fats and demonstrated that the fatty acid composition of different types of animal fats can vary greatly.^[8] Butter and ghee, for example, have a higher proportion of short- and medium-chain fatty acids than tallow and lard, which are higher in long-chain fatty acids.^[86,103] These fatty acid composition differences can have a significant impact on the functional properties of fats as well as their health effects.

Consumption of lipids in animal fat has health effects. For hypotensive patients, lipid consumption can maintain blood pressure stability. In cardiovascular patients, consumption of lipids in animal fat has no effect on cancer patients, so cancer patients are still recommended to consume lipids as nutrients in their body.^[104]

Lipidomics has also revealed the presence of bioactive lipids in animal fat products, such as conjugated linoleic acid (CLA) and trans fatty acids.^[105] CLA is a polyunsaturated fatty acid that has been linked to a variety of health benefits, including weight loss and increased insulin sensitivity.^[106,107] Trans fatty acids, on the other hand, have been linked to an increased risk of cardiovascular disease and are known to be harmful to human health.

Another area of lipidomics interest in animal fat products is the presence of lipid oxidation products, which can contribute to fat rancidity and spoilage. According to lipidomics research, the rate of lipid oxidation varies greatly between different types of animal fats and is influenced by factors such as processing method and storage conditions.^[45] The application of lipidomics has provided valuable insights into the chemical composition and functional quality of these products, and it has the potential to inform their use and processing, resulting in better quality and health outcomes.

Lipidomics can be used as a reference to determine the quality of lipid composition during the production process. Research conducted by Brink et al.^[108] describe the lipid composition of milk fat globule membrane (MFGM) present in infant formula milk. Lipidomic analysis identified a total of 393 lipid species across both positive and negative ionization modes, with the major classes detected being triglycerides, sphingomyelins, and several phospholipids. Across all samples, triglycerides comprised at least 50% of total lipids, with phosphatidylcholine and sphingomyelin being the second and third most abundant lipid classes, respectively.

Lipidomics in fish product evaluation

Lipidomics has gained a lot of attention in the food industry recently, especially in the context of fish products. Fish and seafood are known for their high lipid content, which includes both essential and non-essential fatty acids, making them an important source of lipids in the human diet.^[109] Fish products are high in lipids, including essential fatty acids like omega-3s. Lipidomics can be used to analyze the lipid content and composition of various fish products in the context of fish product evaluation. This data can then be used to assess the nutritional value and quality of the fish products.

Long-chain omega-3 fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are abundant in fish fillets.^[93,94] These fatty acids have been shown to have a variety of health benefits, including a lower risk of cardiovascular disease, stroke, and certain types of cancer.^{[110, 111]} Various factors, such as fish species, age, diet, and environment, can influence the lipid content of fish fillets.^[112–114]

Canned fish, such as tuna and salmon, are also a convenient source of lipids. Canned fish, unlike fresh fish, can be stored for long periods of time and is widely available, making it an accessible source of omega-3 fatty acids for many people.^[115,116] The lipid content of canned fish varies depending on the method of processing and the type of fish used. According to some studies, the lipid content of canned fish can be altered during the canning process, resulting in the formation of potentially harmful compounds such as trans-fatty acids.^[117]

Smoked fish, such as salmon and cod, is another commonly used type of lipid-rich fish product.^[118] Smoking can alter the lipid content of fish, resulting in the formation of harmful compounds such as polycyclic aromatic hydrocarbons (PAHs).^[119] However, the benefits of eating smoked fish outweigh the risks because they are high in omega-3 fatty acids and other essential lipids.^[118]

Caviar, or sturgeon roe, is a luxury food that is high in lipids and has a distinct flavor and texture. The lipid content of caviar varies depending on the species of sturgeon and the method of processing used. Some caviar species are high in omega-3 fatty acids, while others are high in other essential fatty acids like oleic acid.^[120]

Surimi, also known as imitation crab meat, is a type of fish product made of minced fish and other ingredients. The lipid content of surimi varies depending on the species of fish used and the method of processing. Some surimi products are high in lipids and a good source of omega-3 fatty acids, while others are low in lipids.^[121,122]

Traditional condiments made from fermented fish include fish sauce and paste. Fish sauce is widely used in Asian cuisine, whereas fish paste is used in a wide range of dishes worldwide. Depending on the species of fish used, these products are high in lipids and can be a good source of omega-3 fatty acids.^[123–125]

As a dietary supplement, fish oils and Omega-3 supplements derived from fish are becoming increasingly popular. These products are a concentrated source of omega-3 fatty acids and can be a good option for people who do not eat enough fish. The lipid content of fish oil supplements varies depending on the species of fish used and the method of processing.^[113] The analysis of the fatty acid composition of the lipids is an important aspect of lipidomics in fish product evaluation. Factors such as fish species, feeding habits, and habitat, as well as processing methods, can all influence the fatty acid composition of fish products. For example, fatty fish species have a different fatty acid composition than lean fish species.^[126]

Lipidomics can also be used to assess the oxidative stability of seafood. Lipid oxidation is a chemical reaction that can result in the formation of harmful compounds such as aldehydes and peroxides in fish products. Off-flavors, rancidity, and other quality defects in fish products can be caused by these compounds.^[127] Lipidomics can be used to quantify oxidation-related compounds in fish products and evaluate their oxidative stability.^[128] Furthermore, lipidomics can be used to assess the impact of processing methods on the lipid content and composition of fish products, such as cooking, smoking, and storage.^[128,129] This information can be used to optimize processing conditions in order to preserve the quality and nutritional value of fish products.

Lipidomics can answer the quality of fish products. The quality of fish products is influenced by the processing process, one of which is due to temperature. A total of eight lipid species variables (LPS, LPG, LPI, DG, LPC, TG, LPE, and Cer) and 137 individual lipids variables showed significant differences among raw, steamed, boiled, and roasted tilapia fillets. Changes in lipid composition during processing can be used as a reference to determine which process has the best lipid composition.^[130] The summary lipidomics for control quality of animal and fish products show as Table 1.

Table 1. Lipidomics for Quality Control of Animal and Fish Products.

No	Author	Title	Objectives	Extraction Method	Analysis data	Results	References
1	Zhang et al	Lipidomic profile changes of yellow-feathered chicken meat during thermal processing based on UPLC-ESI-MS approach	Chicken meat	Folch Method	PCA, PLS-DA, OPLS-DA	Significant decreases of phospholipides, increases of lysophospholipid found with increasing heating temperature	^[Citation131]
2	Chiesa et al	Lipidomics profile of irradiated ground meat to support food safety	Chicken meat	Bligh and Dyer Method	PCA, Volcano Plot (VP)	The oxidized glycerophosphoethanolamines and oxidized glycerophosphoserines were identified in irradiated turkey meat	^[Citation132]
3	Liu et al	Evaluation of changes in egg yolk lipids during storage based on lipidomics through UPLC-MS/MS	Egg yolk	Solvent Extraction	PCA, OPLS-DA	PCA and OPLS-DA showed that egg yolk lipids changed significantly with prolonged storage and egg yolk quality changed the most when stored up to 21 days	^[Citation52]
4	Meng et al	UHPLC-Q-Orbitrap-based untargeted lipidomics reveals the variation of yolk lipids during egg storage	Egg yolk	Bligh and Dyer Method	PCA	This strategy yielded 1508 features within the lipid database coupled with 74 significantly different lipids (P < .05, fold change > 1.2 or < 0.83), mainly triglycerides, phospholipids, and sphingolipids. Most of them were decreased after storage	^[Citation141]
5	Harlina et al	Quantification of Lipidomics Profiling Using UPLC-QE-HESI- Lipid Analysis on the Salted Duck Egg Incorporated with Clove Extract.	Salted Eggs	Bligh and Dyer Method	One-Way Analysis of Variance	The contents of phosphatidylcholine, lyso-phosphatidylcholine, phosphatidylethanolamine, and monosialo-dihexosyl ganglioside in egg yolks treated with 0.5% (w/v) clove are significantly higher than those in the control group (p < .05), in which phosphatidylcholine and phosphatidylethanolamine are the main components of glycerolphospholipid.	^[Citation62]
6	Xu et al	Short communication: Decrease of lipid profiles in cow milk by ultra-high-temperature treatment but not by pasteurization	Cow milk	Lipid Extraction	PCA, OPLS-DA	Ninety-four TG were identified and all were present at significantly lower concentrations in UM than in RM or PM, and free fatty acid contents were significantly higher in UM than in RM and PM	^[Citation142]
7	Furse et al	Fermentation of milk into yogurt and cheese leads to contrasting lipid and glyceride profiles	Milk	Lipid And Triglyceride Fraction Extraction	PCA	The lipid and glyceride profile of yogurts was varied to fresh milk	^[Citation134]
8	Martin et al	Honey bee caste lipidomics in relation to life-history stage and the long life of the queen	Honey bee	Extraction with MTBE	Two-way analysis of variance	After emergence, worker bees further increased their level of PUFA by 5-fold across most phospholipid classes. In contrast, the membrane phospholipids of adult queens remained highly monounsaturated throughout their adult life	^[Citation135]
9	Morfin et al	First insights into the honey bee (Apis mellifera) brain lipidome and its neonicotinoid-induced alterations associated with reduced self-grooming behavior	Honey bee	Bligh and Dyer Method	PLS-DA	Compared to all other organisms, healthy bee brain lipidomes contain unusually high levels of alkyl-ether linked (plasmanyl) phospholipids (51.42%) and low levels of plasmalogens (plasmenyl phospholipids; 3.46%)	^[Citation136]
10	Senoran et al	Lipidomic and Proteomic Profiling of the Milk Fat Globule Membrane from Different Industrial By-Products of the Butter and Butter Oil Manufacturing Process	Butter	Folch Method	One-way analysis of variance	The patterns of polar lipids and proteins indicated that buttermilk (BM), butterserum (BS), and their mix (BM-BS blend) are the most suitable by-products to be employed as starting material for the isolation and purification of MFGMs	^[Citation137]
11	Castro-Gomes et al	In-Depth Lipidomic Analysis of Molecular Species of Triacylglycerides, Diacylglycerides, Glycerophospholipids, and Sphingolipids of Buttermilk by GC-MS/FID, HPLC-ELSD, and UPLC-QToF-MS	Buttermilk	PLE and FC Methods	Non-parametric Mann-Whitney post-hoc test	The fatty acid profile was comparable to that of the milk fat but with a highly diverse composition of fatty acids. The TAG (16:0/16:0/6:0) and TAG (16:0/16:0/8:0) were the predominant saturated TAG species and TAG (14:0/18:1/16:0) and TAG (16:0/16:0/18:1) presented the highest content of monounsaturated TAG species	^[Citation138]
12	Chen et al	Freshness analysis based on lipidomics for farmed Atlantic salmon (Salmo salar L.) stored at different times	Salmon	Bligh and Dyer Method	KEGG Functional Pathway Enrichment Analysis.	The contents of four lipids were significantly increased from the tenth day, namely, lysophosphatidylcholine (LPC) (17:0), LPC (18:0), LPC (22:2), and phosphatidylcholine (PC) (18:4/16:1). LPC (17:0) and LPC (18:0) are produced by PC (18:4/16:1) hydrolysis	^[Citation143]
13	Gowda et al	Detection and characterization of lipids in eleven species of fish by non-targeted liquid chromatography/mass spectrometry	Fish	Folch Method	PCA and Cluster Correlation Analysis	Multivariate principal component analysis revealed the distinct lipid composition in shishamo smelt and Japanese sardine compared to other fish types	^[Citation140]

Table 1 shows that the lipidomics approach can be used to assess the quality of animal and fish products. Lipids in chicken meat will change when stored at higher temperatures. Significant decreases in phospholipid, increases in lysophospholipid were found with increasing heating temperature. Chicken meat will also change when radiation is applied during storage. This shows that lipidomics can be used to authenticate meat quality.^{[131,132,133]} Research by Liu et al.^[52] and Du & Ahn^[133] in egg yolk indicates that there are lipid changes during storage. Chemometric analysis is a tool to answer significantly with prolonged storage and egg yolk quality changed the most when stored up to 21 days. Triglycerides, phospholipids, and sphingolipids decreased after storage. The lipidomics approach by looking at lipid changes in egg yolk during storage can be used as a reference to determine the quality of eggs. Lipidomics can also be used for dairy quality control. The low triglyceride content of unpasteurized cow’s milk, and the varying lipid and glyceryl content of yogurt from fresh milk indicate that lipid changes occur during each dairy production process.^[118] Lipidomics can also be used for honey quality control by looking at where the honey comes from. This can be seen in increased their level of PUFA by 5-fold across most phospholipid classes produced by immature bees as well as healthy bee brain lipidomes contain unusually high levels of alkyl-ether linked (plasmanyl) phospholipids (51.42%) and low levels of plasmalogens (plasmenyl phospholipids; 3.46%).^[135,136] Butter and buttermilk are products of animal fats that can be characterized by a lipidomics approach. Research results from Senorans et al.^[137] and Castro-Gómez et al.^[138] showed that the fatty acid profile was comparable to that of the milk fat but with a highly diverse composition of fatty acids. The difference in lipid composition of butter from each industry can be used as a reference for quality control. Lipidomics combined with multivariate analysis can also be used to reference the quality of fish. Changes lysophosphatidylcholine (LPC) (17:0), LPC (18:0), LPC (22:2), and phosphatidylcholine (PC) (18:4/16:1). LPC (17:0) and LPC (18:0 which decreased during storage can be used as a reference for fish quality.^[139–140]

Conclusion and future perspectives

To summarize, lipidomics is a rapidly growing field that has garnered a great deal of attention in the context of animal and fish products. Lipidomics provides valuable information about the lipid content and composition of animal and fish products, which has been used to assess their functional quality and potential health benefits. Recent advances in lipidomics have enabled a more comprehensive understanding of the impact of processing and storage conditions on lipid quality, as well as the potential health benefits of consuming lipid-rich animal and fish products. However, there are still challenges that the lipidomics community faces in navigating the functional quality of animal and fish products. These include the need for standardization in sample preparation and analysis methods, the need for more comprehensive studies on the impact of processing and storage conditions on lipid quality, and the need for a better understanding of the role of lipids in human health. In the future, lipidomics has the potential to play a major role in the animal and fish products industry. More sophisticated analytical tools, as well as the integration of lipidomics with other omics technologies, will enable for a more comprehensive understanding of the functional quality of animal and fish products. Furthermore, the application of lipidomics in the development of functional foods and dietary supplements has the potential to transform the food industry and improve public health. In general, lipidomics is a promising field with a promising future in the animal and fish products industries. Lipidomics’ continued advancement and integration with other omics technologies will provide a more comprehensive understanding of the functional quality of animal and fish products, as well as their potential health benefits.

Author contributions

Conceptualization, P.W.H.; Methodology, F.G., R.S. and J.S.; Validation, P.W.H.; Formal analysis E.S., T.Y. and J.S.; Investigation, V.M. and P.W.H.; Resources, P.W.H.; Data curation, V.M., and R.S.; Writing – original draft preparation, V.M. and P.W.H.; Writing – review and editing, V.M., P.W.H., F.G., and R.S.; Visualization, P.W.H.; Supervision, P.W.H.; Project administration, P.W.H.; Funding acquisition, P.W.H. All authors have read and agreed to the published version of the manuscript.

Acknowledgments

The first author extends thank to the Universitas Padjadjaran, Indonesia for the funding support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data presented in this study are available on request from the corresponding author.

Additional information

Funding

The work was supported by the Internal Funding of Universitas Padjadjaran, Indonesia (Grant No. 1549/UN6.3.1/PT.00/2023).