Triacylglycerols fingerprint of edible vegetable oils by ultra-performance liquid chromatography-Q-ToF-MS

Rapid classification of Camellia seed varieties and non-destructive high-throughput quantitative analysis of fatty acids based on non-targeted fingerprint spectroscopy combined with chemometrics

Camellia oil is a high-quality vegetable oil rich in unsaturated fatty acids (FAs), with quality standardization challenged by the diversity of Camellia seed varieties. This study compared spectroscopy techniques (Near-Infrared [NIR] vs Mid-Infrared [MIR] spectroscopy) and analytical models (Discriminant Analysis [DA], Partial Least Squares [PLS], and Artificial Neural Networks [ANN]), seeking to classify Camellia seed varieties and estimate oil and principal FAs composition. The PCA analysis effectively discriminated among various Camellia seed varieties, likely due to variations in their oil and principal FAs compositions. Significantly, the NIR-based DA model significantly outperformed MIR, achieving 100 % accuracy in distinguishing Camellia seed varieties. In terms of predicting the oil and principal FAs compositions in Camellia seeds, NIR-based predictions models outperformed those derived from MIR, with PLS models surpassing ANN models. This study validated the potential of NIR technology combined with chemometrics for rapid, high-throughput, non-destructive identification of Camellia seeds.

Evaluation of quality parameters, physicochemical and bioactive properties of licuri oil (Syagrus coronata)

This study aimed to conduct a comprehensive analysis of licuri (Syagrus coronata) oil, exploring its composition, quality parameters, bioactive profile, and physicochemical properties. Licuri oil was extracted by cold pressing from mature fruits and subjected to extensive chemical characterization, including lipid, protein, water content, peroxide value, acidity, trace metals, carboxylic acid, total polyphenol, carotenoids and tocols. The oil's lipid profile, including fatty acid, and triacylglycerol profile was also determined. Antioxidant capacity was determined by DPPH radical scavenging assay (IC50), melting and crystallization behaviors were examined via differential scanning calorimetry (DSC), complete rheological profile was assessed through stress - strain curves, and oil's oxidative stability determined by Rancimat apparatus. The analysis revealed that licuri oil has favorable characteristics, such as low water content (0.54 %), peroxide value within regulatory limits (5.83 mEq/kg), and low free fatty acid content (0.09 %). It is a rich source of lauric acid (45.01 %), with significant amounts of myristic (13.2 %), caprylic (12.34 %), and oleic acid (10.79 %), similar to coconut or palm kernel oils, largely applied in industry. The predominance of triglycerides derived from lauric acid contributes to its functionality, including an interesting melting and rheological profile, making it suitable for various food and cosmetic applications. Additionally, licuri oil exhibits a significant content of phenolic compounds (196.73 μg CAE/g) and tocols (7.79 μg/g), leading to improved oxidative stability (30.09 h at 110 °C), and antioxidant capacity, thus making licuri oil a healthier alternative to conventional oils.

Broadly adapted and efficient enzymatic transesterification production of medium and long-chain triglycerides via coconut oil and long-chain triacylglycerols

An applicable and highly efficient methodology for the preparation of medium- and long-chain triglycerides (MLCTs) via the enzymatic transesterification of coconut oil with long-chain fatty acid triglycerides, named camellia oil, olive oil, linseed oil, algal oil, and rapeseed oil, respectively, has been proposed. The novel system achieved equilibrium in 5 min, and the MLCT yield ranged from 78.7 to 83.8 %. This is the fastest record reported to date. The catalytic efficiency of the novel biocatalyst, CSL@HMS-C8, was 140 g/g•h, 1.43 times higher compared to the control (free lipase), and it retained 62.5 % of its relative activity after 15 cycles. A UPLC-MS provided an accurate structural analysis of the MLCTs, and molecular docking analysis was performed to understand the binding interactions between the protein and molecules. The method of preparing MLCT enriched with functional fatty acids in this paper is efficient, broadly applicable, economical, and promising for industrial applications.

Molecular networking and Paterno-Büchi reaction guided glycerides characterization and antioxidant activity assessment of Ganoderma lucidum spore oil

Ganoderma lucidum spore oil (GLSO) is a dietary supplement, with glycerides (GLs) recognized as its important active component. However, comprehensive profiling and accurate structural characterization of GLs in GLSO remain underexplored. In this study, 59 GLs from GLSO were identified by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF MS) and molecular networking (MN). The double bond isomers of these compounds were further resolved by the Paterno-Büchi (PB) reaction coupled with UPLC-Q-TOF MS, resulting in the identification of 36 unsaturated GLs, including 5 pairs of positional isomers. In summary, 64 GLs were characterized, consisting of 9 diacylglycerols (DGs) and 55 triacylglycerols (TGs). Additionally, the compositional variations, antioxidant activities, and relative isomer ratios of CC positional isomers of GLSO from eight different manufacturers were revealed, with 11 GLs correlating with antioxidant activity. This study enhances the understanding of the nutritional value of GLSO and lays a foundation for future quality standard formulation.

Identification and quantitation of multiplex camellia oil adulteration based on 11 characteristic lipids using UPLC-Q-Orbitrap-MS

Currently, the identification and quantification of complex adulteration of high-value vegetable oils are still challenging. In this study, the extreme vertex design method was adopted to design representative multivariate adulterated camellia oil samples. Thereafter, 11 characteristic lipid species were identified by considering the statistically significant difference and categorical contribution. A discriminant method and linear regression model were established based on 11 key lipids. The accuracy rate of the model was 100 %, which could correctly discriminate the camellia oil with an adulteration ratio as low as 2.5 %. The root mean square error (RMSE) of the regression equation was close to 0, and the coefficient of determination (R2P) was 0.9054. This method has been successfully applied to commercially available samples for validation purposes, detecting 27.3 % of camellia oil adulteration. Overall, the results indicate that the discriminating method and content prediction model can provide a potential strategy for authentication of multivariate vegetable oils.

Innovative applications of medium- and long-chain triacylglycerol in nutritional support: Current perspectives and future directions

As a unique structured lipid, medium- and long-chain triacylglycerol (MLCT) is characterized by the combination of medium- and long-chain fatty acids in a single triacylglycerol molecule. In recent years, MLCT, as a nutritional lipid, has gradually emerged as a research hot topic in the fields of food science and nutrition. This paper innovatively provides a comprehensive review of the current application status and development prospects of MLCT in nutritional support. First, the basic principles defining characteristics and selection basis of both enteral and parenteral nutrition are analyzed, elucidating the differences between the two modalities in terms of nutrient delivery pathway, absorption mechanisms, and physiological effects. Subsequently, the natural sources and artificial synthetic pathways of MLCT along with its metabolic behavior in vivo are elaborated. On this basis, the latest research advancements in the application of MLCT in both nutritional models are reviewed, with a particular emphasis on current research hotspots. Finally, the challenges encountered in the practical application of MLCT are discussed, and the future trajectory of MLCT as a functional lipid is predicted. In particular, the innovative potential of MLCT in functional foods, food for special medical purposes, personalized nutrition, and other aspects is emphasized, which provides beneficial ideas and directions for further research and industrial applications of MLCT.

Analysis of triacylglycerol regioisomers in plant oils using direct inlet negative ion chemical ionization tandem mass spectrometry

Triacylglycerols (TGs) are the primary lipids of plant oils and the positional distribution of fatty acids (FAs) is essential to physicochemical, functional, and nutritional qualities of oils. Most studies have reported TG species in plant oils. In some studies, FA combinations in each TG species have been reported still neglecting the regioisomer composition of TGs. In this study, a fast direct inlet negative ion chemical ionization tandem mass spectrometric (NICI-MS/MS) method and optimization algorithm were applied to study the regioisomerism of TGs in 18 different plant oils. According to FA composition results, oleic, FA 18:1(9); linoleic, FA 18:2(9,12); palmitic, FA 16:0 and stearic acid, FA 18:0 were the most abundant FAs, composing mainly TG species having acyl carbon numbers 50, 52 and 54 and 1-4 double bonds. Based on 35 detected TG species, oils were classified into five groups using clustering analysis. Each group had a different dominant TG species of which the most abundant were triunsaturated ones. In regioisomeric pairs or triplets, FA 16:0, FA 16:1(9), FA 18:0, and FA 18:2(9,12) were more commonly in the sn-1/3 position, while FA 18:1 slightly preferred sn-2. The most abundant TG regioisomers were: TG 16:0_18:1(sn-2)_18:1 (52:2, mainly 18:1 in sn-2) especially in avocado, macadamia nut, olive, and palm oils; TG 18:2_18:2(sn-2)_18:1 and TG 18:2_18:1(sn-2)_18:2 (TG 54:5, mainly 18:2 in sn-2) in corn, pumpkin seed, sesame, and sunflower oils. The use of high-throughput NICI-MS/MS method to study regioisomers in commercial plant oils contributes to further studies on profiling lipid structure and developing products with specific TG compositions to meet dietary needs. The regiospecific information of TGs in edible oils is crucial for understanding their health benefits and functional properties, which are in turn needed in selecting oils for various applications.

Novel PCR-Based Technology for the Detection of Sunflower in Edible and Used Cooking Oils

Reliable detection of sunflower (Helianthus annuus) in edible and used cooking oil (UCO) is crucial for the sustainable production of food and biodiesel. In this study, a variety of sunflower oils (crude, cold pressed, extra virgin, refined, and UCO) were examined using different methods of DNA extraction and PCR amplification to develop an efficient technology for the identification of sunflower in oils. DNA extraction kits such as NucleoSpin Food, DNeasy mericon Food, and Olive Oil DNA Isolation as well as modified CTAB method were found to be able to isolate amplifiable genomic DNA from highly processed oils. Novel uniplex, double, and nested PCR systems targeting the sunflower-specific helianthinin gene were developed for efficient identification of sunflower. New sunflower DNA markers were revealed by uniplex PCRs. The combination of modified CTAB and nested PCR was demonstrated as a reliable, rapid, and cost-effective technology for detecting traces of sunflower in 700 μL of highly processed oil, including refined and used cooking oil. The study will contribute to both the food industry and the energy sector as developed methods can be used for oil authenticity testing in food and biodiesel production.

Unraveling the Metabolomics Mysteries in Camellia Oil: From Cognition to Application

Camellia oil is a high-value edible seed oil, recommended by the Food and Agriculture Organization (FAO). It is essential to develop accurate and rapid analytical methods to authenticate camellia oil due to its susceptibility to adulteration. Recently, hyphenated chromatography-mass spectrometry, especially high-resolution mass spectrometry using chemometrics, has become a promising platform for the identification of camellia oil. Based on the compositional analysis, the fatty acid, sterol, phenol, and tocopherol profiles (or fingerprints) were utilized as predictor variables for assessing authenticity. The review systematically summarizes the workflow of chromatography-mass spectrometry technologies and comprehensively investigates recent metabolomic applications combined with chemometrics for camellia oil authentication. Metabolomics has significantly improved our understanding of camellia oil composition at the molecular level, contributing to its identification and full characterization. Hence, its integration with standard analytical methods is essential to enhance the tools available for public and private laboratories to assess camellia oil authenticity. Integrating metabolomics with artificial intelligence is expected to accelerate drug discovery by identifying new metabolic pathways and biomarkers, promising to revolutionize medicine.

Streamlined enzymatic synthesis of human milk fat substitutes

The positional distribution of palmitic acid (PA) in human milk fat substitutes (HMFSs) plays a pivotal role in mimicking the nutritional profile of human milk fat for nourishing non-breastfed infants. This study innovatively introduced a streamlined enzymatic process for preparing HMFSs rich in sn-2 PA using palm stearin, a PA-rich source without the necessity for positional distribution of PA. The initial step involved enhancing the sn-2 PA concentration through enzymatic interesterification using Lipase UM1, which exhibited superior catalytic efficiency than Novozym 435. This process increased the sn-2 PA level from 40.98 % to 64.51 %. Subsequently, acidolysis was employed to reduce PA levels by replacing PA at sn-1,3 positions using sn-1,3-regioselective lipases. The PA content decreased from 60.64 % to 26.73 %, simultaneously raising the relative sn-2 PA concentration to 71.57 %, meeting the benchmarks for HMFSs. This study establishes a robust conceptual framework for the prospective industrial synthesis of HMFSs.

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

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

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

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

Looking into the lipid profile of avocado and byproducts: Using lipidomics to explore value-added compounds

Consumer priorities in healthy diets and lifestyle boosted the demand for nutritious and functional foods as well as plant-based ingredients. Avocado has become a food trend due to its nutritional and functional values, which in turn is increasing its consumption and production worldwide. Avocado edible portion has a high content of lipids, with the pulp and its oil being rich in monounsaturated fatty acids and essential omega - 3 and omega - 6 polyunsaturated fatty acids (PUFA). These fatty acids are mainly esterified in triacylglycerides, the major lipids in pulp, but also in minor components such as polar lipids (phospholipids and glycolipids). Polar lipids of avocado have been overlooked despite being recently highlighted with functional properties as well. The growth in the industry of avocado products is generating an increased amount of their byproducts, such as seed and peels (nonedible portions), still undervalued. The few studies on avocado byproducts pointed out that they also contain interesting lipids, with seeds particularly rich in polar lipids bearing PUFA, and thus can be reused as a source of add-value phytochemical. Mass spectrometry-based lipidomics approaches appear as an essential tool to unveil the complex lipid signature of avocado and its byproducts, contributing to the recognition of value-added lipids and opening new avenues for their use in novel biotechnological applications. The present review provides an up-to-date overview of the lipid signature from avocado pulp, peel, seed, and its oils.

Chemical Composition and Geographic Variation of Cold Pressed Balanites aegyptiaca Kernel Oil

With the increasing impacts of climate change, establishing more sustainable and robust plants such as desert dates (Balanites aegyptiaca) seems to be necessary. Known for its resilience in arid conditions, this tree has the potential to become a more important food source, particularly for its potential to yield edible oil. This study characterized Balanites kernel oil (BKO) as a promising oil source in arid regions, studying the influence of geographical origin and environmental factors. Moroccan and Sudanese BKO samples were analyzed and compared with Mauritanian BKO. In the fatty acid profile, unsaturated fatty acids constituted over 70% of the BKO profile, with a predominance of linoleic acid (Li), oleic acid (Ol), palmitic acid (Pa), and stearic acid (St). Consequently, the predominant triacylglycerols were PaLiLi, PaLiOl, LiLiOl, OlLiOl, and StLiOl. α-Tocopherol dominated the tocochromanol composition (324 to 607 mg/kg), followed by γ-tocopherol (120 to 226 mg/kg), constituting 90% of the total tocochromanols. The total phytosterol content in BKO ranged from 871 to 2218 mg/kg oil, with β-sitosterol dominating (58% to 74%). Principal Component Analysis revealed that the geographical origin significantly influences BKO composition, emphasizing environmental factors, particularly water deficit and/or temperatures. Notably, Moroccan BKO collected from an area characterized by high aridity and relatively low winter temperatures, showcased a unique profile in fatty acid, phytosterols, and tocochromanols. The valorization of BKO presents an opportunity for local agricultural development in arid regions and a role model for plant development and agricultural practices in other parts of the world.

Discrimination between the Triglyceride Form and the Ethyl Ester Form of Fish Oil Using Chromatography-Mass Spectrometry

Although the triglyceride form is the natural form of fish oil found in fish, the ethyl ester form of fish oil, which is used during processing to save costs, is also present on the market. In this study, fatty acids and lipids were determined using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-linear ion trap mass spectrometry (LC-LIT/MS), respectively, according to developed methods. The identification of fatty acids was based on the mass spectral characteristics and equivalent chain lengths. However, the fatty acid contents of both forms of fish oils are quite similar. The application of the LC-LIT/MS method for the structural characterization of triacylglycerols (TAGs) and the mechanism of LIT/MS fragmentation are also discussed. Neutral losses of CH2=CH2 (m/z 28) and CH3CH2OH (m/z 46), which are LIT/MS characteristics of ethyl ester from fish oil, were found for the first time. The triglyceride form of fish oils was easily and accurately identified using fingerprint chromatography. In conclusion, lipid analysis combined with LC-LIT/MS showed an improved capability to distinguish between types of fish oil.

Camellia oil exhibits anti-fatigue property by modulating antioxidant capacity, muscle fiber, and gut microbial composition in mice

Camellia seed oil (CO) has high nutritional value and multiple bioactivities. However, the specific anti-fatigue characteristics and the implied mechanism of CO have not yet been fully elucidated. Throughout this investigation, male C57BL/6J mice, aged 8 weeks, underwent exhaustive exercise with or without CO pretreatment (2, 4, and 6 mL/kg BW) for 28 days. CO could extend the rota-rod and running time, reduce blood urea nitrogen levels and serum lactic acid, and increase muscle and hepatic glycogen, adenosine triphosphate, and anti-oxidative indicators. Additionally, CO could upregulate the mRNA and Nrf2 protein expression levels, as well as enhance the levels of its downstream antioxidant enzymes and induce the myofiber-type transformation from fast to slow and attenuate the gut mechanical barrier. Moreover, CO could ameliorate gut dysbiosis by reducing Firmicutes to Bacteroidetes ratio at the phylum level, increasing the percentage of Alistipes, Alloprevotella, Lactobacillus, and Muribaculaceae, and decreasing the proportion of Dubosiella at the genus level. In addition, specific bacterial taxa, which were altered by CO, showed a significant correlation with partial fatigue-related parameters. These findings suggest that CO may alleviate fatigue by regulating antioxidant capacity, muscle fiber transformation, gut mechanical barrier, and gut microbial composition in mice. PRACTICAL APPLICATION: Our study revealed that camellia seed oil (CO) could ameliorate exercise-induced fatigue in mice by modulating antioxidant capacity, muscle fiber, and gut microbial composition in mice. Our results promote the application of CO as an anti-fatigue functional food that targets oxidative stress, myofiber-type transformation, and microbial community.

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

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

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

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

Detection of walnut oil adulterated with high-linoleic acid vegetable oils using triacylglycerol pseudotargeted method based on SFC-QTOF-MS

Authentication of walnut oil (WO) is challenging due to the adulteration of high-linoleic acid vegetable oils (HLOs) with similar fatty acid composition. To allow the discrimination of WO adulteration, a rapid, sensitive and stable scanning method based on supercritical fluid chromatography quadrupole time-of-flight mass spectrometry (SFC-QTOF-MS) was established to profile 59 potential triacylglycerol (TAGs) in HLOs samples within 10 min. Limit of quantitation of the proposed method is 0.002 µg mL^-1 and the relative standard deviations range from 0.7% to 12.0%. TAGs profiles of WO samples from various varieties, geography origins, ripeness, and processing methods were used to construct orthogonal partial least squares-discriminant analysis (OPLS-DA) and OPLS models that were highly accurate in both qualitative and quantitative prediction at adulteration levels as low as 5% (w/w). This study advances the TAGs analysis to characterize vegetable oils and holds promise as an efficient method for oil authentication.

Lipidomic characteristics of three edible cold-pressed oils by LC/Q-TOF for simple quality and authenticity assurance

Distinguishing oil samples from each other is challenging but it is crucial for ensuring food quality, and for detecting and preventing the possible adulteration of these products. Lipidomic profiling is believed to provide sufficient information to get fit-to-purpose confidence of oil identification as well as to deliver oil-specific lipid features which could be used as targets for routine authenticity testing of camelina, flax, and hemp oil in food control laboratories. Conducted di- and triacylglycerol profiling by LC/Q-TOFMS yielded successful differentiation of the oils. A marker panel consisting of 27 lipids (both DAGs and TAGs) useful for quality verification and authenticity assurance of the oils was established. Moreover, sunflower, rapeseed, and soybean oils were analysed as potential adulterants. We identified 6 lipid markers (DAGs 34:6, 35:2, 40:1, 40:2, 42:2, and TAG 63:1) which can be used for revealing the adulteration of camelina, hemp, and flax seed oils with these oils.

LC-MS Metabolomic Profiling of Five Types of Unrefined, Cold-Pressed Seed Oils to Identify Markers to Determine Oil Authenticity and to Test for Oil Adulteration

The authenticity of food products marketed as health-promoting foods-especially unrefined, cold-pressed seed oils-should be controlled to ensure their quality and safeguard consumers and patients. Metabolomic profiling using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF) was employed to identify authenticity markers for five types of unrefined, cold-pressed seed oils: black seed oil (Nigella sativa L.), pumpkin seed oil (Cucurbita pepo L.), evening primrose oil (Oenothera biennis L.), hemp oil (Cannabis sativa L.) and milk thistle oil (Silybum marianum). Of the 36 oil-specific markers detected, 10 were established for black seed oil, 8 for evening primrose seed oil, 7 for hemp seed oil, 4 for milk thistle seed oil and 7 for pumpkin seed oil. In addition, the influence of matrix variability on the oil-specific metabolic markers was examined by studying binary oil mixtures containing varying volume percentages of each tested oil and each of three potential adulterants: sunflower, rapeseed and sesame oil. The presence of oil-specific markers was confirmed in 7 commercial oil mix products. The identified 36 oil-specific metabolic markers proved useful for confirming the authenticity of the five target seed oils. The ability to detect adulterations of these oils with sunflower, rapeseed and sesame oil was demonstrated.

Comprehensive Evaluation of Quality Characteristics of Four Oil-Tea Camellia Species with Red Flowers and Large Fruit

Red-flowered oil-tea camellia (ROC) is an important woody oil species growing in the south, and its oil has high nutritional value. There are four main species of ROC in China, namely, Camellia chekiangoleosa (CCH), Camellia polyodonta (CPO), Camellia semiserrata (CSE) and Camellia reticulata (CRE). Reports on the comprehensive comparative analysis of ROC are limited. This study investigated the fruit characteristics and nutritional components of four ROC fruits, and the results showed that ROC had high oil content with levels of 39.13%-58.84%, especially the CCH fruit, which reached 53.6-58.84%. The contents of lipid concomitants of ROC oil were also substantial, including β-amyrin (0.87 mg/g-1.41 mg/g), squalene (0.43 mg/g-0.69 mg/g), β-sitosterin (0.47 mg/g-0.63 mg/g) and α-tocopherol (177.52 μg/g-352.27 μg/g). Moreover, the transverse diameter(TD)/longitudinal diameter (LD) of fruits showed a significant positive correlation with the oil content, and ROC fruits with thinner peels seemed to have better oil quality, which is similar to the result of the oil quality evaluation obtained by the gray correlation coefficient evaluation method. Four ROC oils were evaluated using the gray correlation coefficient method based on 11 indicators related to the nutritional value of ROC. CCH oil had the highest score of 0.8365, and YS-2 (a clone of CCH) was further evaluated as the best CCH oil. Finally, the results of heatmap analysis showed that triglycerides could be used as a characteristic substance to distinguish CCH oil from the other three ROC oils. The PLSDA (Partial least squares regression analysis) model and VIP (Variable important in projection) values further showed that P/S/O, P/O/O, P/L/L, P/L/Ln, S/S/O, S/O/O and P/S/S (these all represent abbreviations for fatty acids) could be used as characteristic differential triglycerides among the four ROC oils. This study provides a convenient way for planters to assess the nutritional quality of seed oil depending on fruit morphology and a potential way to distinguish between various ROC oils.

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.

Triacylglycerol fingerprint of sow milks during different lactation stages and from different breeds

Sow milk fats not only provide energy but also essential nutrients for piglets. Thus, feeding strategies must be aligned with fat composition, especially triacylglycerols (TAGs) and their isomers. The triacylglycerol (TAG) profiles of sow milk fats from five typical breeds (Landrace × Large White, Landrace, Large White, Duroc, Pietrain) and two lactation stages (colostrum and milk) were systematically studied. A total of 45 major TAG species were identified using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The most abundant TAG was oleic acid-palmitic acid-linoleic acid (O-P-L) (13.92% and 12.03% in colostrum and milk, respectively), which was not significantly different in colostrum among all breeds. TAG composition of sow milk was affected mainly by the lactation stage rather than sow breed. Furthermore, TAG compositions of sow milk fats were similar to those of human milk fats, but significant differences were observed between commercial piglet formulas and sow milk. Therefore, the results will contribute to the optimization of piglet formulas to improve the growth and wellness of piglets, as well as potentially providing a basis for food usage as a new source of nutrients for human infants in future.

Integration of lipidomics and metabolomics for the authentication of camellia oil by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry coupled with chemometrics

The integration of lipidomics and metabolomics approaches, based on UPLC-QTOF-MS technology coupled with chemometrics, was established to authenticate camellia oil adulterated with rapeseed oil, peanut oil, and soybean oil. Lipidomics revealed that the glyceride profile provides a prospective authentication of camellia oil, but no characteristic markers were available. Sixteen characteristic markers were identified by metabolomics. For camellia oil, all six markers were sapogenins of oleanane-type triterpene saponins. Lariciresinol, sinapic acid, doxercalciferol, and an unknown compound were identified as markers for rapeseed oil. Characteristic markers in peanut oil were formononetin, sativanone, and medicarpin. In the case of soybean oil, the characteristic markers were dimethoxyflavone, daidzein, and genistein. The established OPLS-DA and OPLS prediction models were highly accurate in the qualitative and quantitative analyses of camellia oil adulterated with 5% other oils. These results indicate that the integration of lipidomics and metabolomics approaches has great potential for the authentication of edible oils.

Hemp Seeds, Flaxseed, and Açaí Berries: Health Benefits and Nutritional Importance with Emphasis on the Lipid Content

Abstract:

Some plant seeds and berries have gained increased recognition due to their wide variety of bioactive compounds. Many of these foods are rich in lipids with high nutritional value, of which n-3 and n-6 essential fatty acids stand out. However, knowledge of the chemical composition and biological activity of these compounds and their value as a source of healthy lipids is far from being fully explored. The benefits of the intake of hemp seeds, flaxseed, and açaí berries, considered functional foods, have been compiled in this review. Likewise, their general chemical composition will be described to evaluate their relevance in a healthy diet, highlighting their lipid components and health lipid indices. The fibres and essential fatty acids of hemp seeds and flaxseed and the antioxidant properties of açaí berries provide them protective roles against several chronic non-communicable diseases and represent significant beneficial effects that add value to these healthy natural products. More research is needed to deepen the knowledge on their lipids’ molecular composition and bioactivity.

Fingerprinting triacylglycerols and aldehydes as identity and thermal stability indicators of camellia oil through chemometric comparison with olive oil

Camellia oil is widely recognized as a high-quality culinary oil in East Asia for its organoleptic and health-promoting properties, but its chemical composition and thermal stability have not been comprehensively defined by comparisons with other oils. In this study, the triacylglycerols (TAGs) in camellia, olive, and six other edible oils were profiled by the liquid chromatography-mass spectrometry (LC-MS)-based chemometric analysis. Besides observing the similarity between camellia oil and olive oil, TAG profiling showed that OOO, POO, and OOG (O: oleic acid, P: palmitic acid, and G: gadoleic acid) can jointly serve as the identity markers of camellia oil. Thermal stability of virgin camellia oil (VCO) was further evaluated by extensive comparisons with virgin olive oil (VOO) in common lipid oxidation indicators, aldehyde production, and antioxidant and pro-oxidant contents. The results showed that p-anisidine value (AnV) was the sensitive lipid oxidation indicator, and C9-C11 aldehydes, including nonanal, 2-decenal, 2,4-decadienal, and 2-undecenal, were the most abundant aldehydes in heated VCO and VOO. Under the frying temperature, heated VCO had lower AnV and less aldehydes than heated VOO. Interestedly, the VCO had lower levels of pro-oxidant components, including α-linolenic acid, free fatty acids, and transition metals, as well as lower levels of antioxidants, including α-tocopherol and phenolics, than the VOO. Overall, great similarities and subtle differences in TAG and aldehyde profiles were observed between camellia and olive oils, and the thermal stability of camellia oil might be more dependent on the balance among its unsaturation level, pro-oxidant, and antioxidant components than a single factor.

Determination of Triacylglycerols by HTGC-FID as a Sensitive Tool for the Identification of Rapeseed and Olive Oil Adulteration

Triacylglycerols (TGs) are the most common compounds in food lipids, accounting for 95% of the weight of edible oils. The aim of this study was to scrutinize a procedure for quantitatively assessing possible adulteration of olive and rapeseed oil through GC-FID analysis of TGs. The recovery of TG standards ranged from 21% to 148%, and the relative response factor (RRF) ranged from 0.42 to 2.28. The limits of detection were in the range of 0.001 to 0.330 µg/mL, and the limits of quantitation from 0.001 to 1.000 µg/mL. The validated method was used to determine the TGs in olive oil (OO), refined rapeseed oil (RRO), and their blends. Eight TGs were detected in refined rapeseed oil, and 10 in olive oil. The addition of 1% of olive oil to rapeseed oil or vice versa can be detected using this method. Three triacylglycerols were pinpointed as indicators of adulteration of rapeseed oil with olive oil (PPO, PPL, PSO). The method described here can be used for controlling the quality of these oils.