A gas chromatography/electron ionization-mass spectrometry-selected ion monitoring method for determining the fatty acid pattern in food after formation of fatty acid methyl esters

Molecular decoding a meat-like aroma generated from Laetiporus sulphureus-mediated fermentation of onion (Allium cepa L.)

The organoleptic properties of plant-based meat alternatives do not meet consumer expectations due to the lack of characteristic flavors resembling meat. To address this challenge, a fermentation system utilizing Laetiporussulphureus was developed to generate a meat-like and fatty flavor from a vegetable source, onion. By means of multiple stir bar sorptive extraction and gas chromatography-mass spectrometry-olfactometry, an unsaturated aldehyde, (E,Z)-2,4-decadienal, which imparts a tallow-like and fatty odor, and a sulfurous compound benzothiazole, with a broth-like odor were identified, which well contributed to the characteristic odor of the supernatant. (E,Z)-2,4-Decadienal as the most important odorant (odor activity value = 206) was biosynthesized by transformation of linoleic acid with L.sulphureus, as revealed by isotopic tracing experiments. For the first time in Basidiomycota, the biogenetic pathway of (E,Z)-2,4-decadienal from linoleic acid was proposed.

Passive Wireless Porous Biopolymer Sensors for At-Home Monitoring of Oil and Fatty Acid Nutrition

Dietary oils─rich in omega-3, -6, and -9 fatty acids─exhibit critical impacts on health parameters such as cardiovascular function, bodily inflammation, and neurological development. There has emerged a need for low-cost, accessible method to assess dietary oil consumption and its health implications. Existing methods typically require specialized, complex equipment and extensive sample preparation steps, rendering them unsuitable for home use. Addressing this gap, herein, we study passive wireless, biocompatible biosensors that can be used to monitor dietary oils directly from foods either prepared or cooked in oil. This design uses broad-coupled split ring resonators interceded with porous silk fibroin biopolymer (requiring only food-safe materials, such as aluminum foil and biopolymer). These porous biopolymer films absorb oils at rates proportional to their viscosity/fatty acid composition and whose response can be measured wirelessly without any microelectronic components touching food. The engineering and mechanism of such sensors are explored, alongside their ability to measure the oil presence and fatty acid content directly from foods. Its simplicity, portability, and inexpensiveness are ideal for emerging needs in precision nutrition─such sensors may empower individuals to make informed dietary decisions based on direct-from-food measurements.

LC-MS/MS-based phospholipid profiling of plant-pathogenic bacteria with tailored separation of methyl-branched species

Plant-pathogenic bacteria are one of the major constraints on agricultural yield. In order to selectively treat these bacteria, it is essential to understand the molecular structure of their cell membrane. Previous studies have focused on analyzing hydrolyzed fatty acids (FA) due to the complexity of bacterial membrane lipids. These studies have highlighted the occurrence of branched-chain fatty acids (BCFA) alongside normal-chain fatty acids (NCFA) in many bacteria. As several FA are bound in the intact phospholipids of the bacterial membrane, the presence of isomeric FA complicates lipid analysis. Furthermore, commercially available reference standards do not fully cover potential lipid isomers. To address this issue, we have developed a reversed-phase high-performance liquid chromatography (RP-HPLC) method with tandem mass spectrometry (MS/MS) to analyze the phospholipids of various plant-pathogenic bacteria with a focus on BCFA containing phospholipids. The study revealed the separation of three isomeric phosphatidylethanolamines (PE) depending on the number of bound BCFA to NCFA. The validation of the retention order was based on available reference standards in combination with the analysis of hydrolyzed fatty acids through gas chromatography with mass spectrometry (GC/MS) after fractionation. Additionally, the transferability of the retention order to other major lipid classes, such as phosphatidylglycerols (PG) and cardiolipins (CL), was thoroughly examined. Using the information regarding the retention behavior, the phospholipid profile of six plant-pathogenic bacteria was structurally elucidated. Furthermore, the developed LC-MS/MS method was used to classify the plant-pathogenic bacteria based on the number of bound BCFA in the phospholipidome.

Omega-3 blood biomarkers relate to brain glucose uptake in individuals at risk of Alzheimer's disease dementia

INTRODUCTION

Brain glucose hypometabolism is a preclinical feature of Alzheimer's disease (AD). Dietary omega-3 fatty acids promote brain glucose metabolism, but clinical research is incipient. Circulating omega-3s objectively reflect their dietary intake.

METHODS

This was a cross-sectional study in 320 cognitively unimpaired participants at increased risk of AD dementia. Using lipidomics, we determined blood docosahexaenoic (DHA) and alpha-linolenic (ALA) acid levels (omega-3s from marine and plant origin, respectively). We assessed brain glucose metabolism using [18-F]-fluorodeoxyglucose (FDG) positron emission tomography (PET).

RESULTS

Blood ALA directly related to FDG uptake in brain areas known to be affected in AD. Stronger associations were observed in apolipoprotein E ε4 carriers and homozygotes. For DHA, significant direct associations were restricted to amyloid beta-positive tau-positive participants.

DISCUSSION

Blood omega-3 directly relate to preserved glucose metabolism in AD-vulnerable brain regions in individuals at increased risk of AD dementia. This adds to the benefits of omega-3 supplementation in the preclinical stage of AD dementia.

Highlights

Blood omega-3s were related to brain glucose uptake in participants at risk of Alzheimer's disease (AD) dementia.Complementary associations were observed for omega-3 from marine and plant sources.Foods rich in omega-3 might be useful in early features of AD.

Effects of fatty acid hydroperoxides produced by lipoxygenase in wheat cultivars during dough preparation on volatile compound formation

The formation of volatile compounds affects the flavor of processed wheat flour products. Herein, the effects of the composition of fatty acid hydroperoxides and the differences in the antioxidant contents among wheat cultivars on the flavor of wheat flour products were clarified. For this purpose, the volatile compounds in wheat flour doughs, LOX activity, fatty acid hydroperoxide composition from fractionated LOX, and antioxidant content were analyzed. Norin61 exhibited a high LOX activity and 9-fatty acid hydroperoxide production. Unsaturated aldehydes derived from 9-fatty acid hydroperoxides contributed significantly to the volatile compound profile of Norin61. Moreover, the lowest lutein content was observed in Norin61 among the analyzed cultivars. The LOX activity and composition of the fatty acid hydroperoxides produced by LOX affected the production of volatile compounds, whereas carotenoids had a suppressive effect. This study provides useful information for product design with the desired flavor for developing various processed wheat flour products.

Short-term effects of gastric bypass versus sleeve gastrectomy on high LDL cholesterol: The BASALTO randomized clinical trial

BACKGROUND

There has been a substantial increase in the use of laparoscopic sleeve gastrectomy (SG) to treat morbid obesity despite observational evidence demonstrating the superiority of Roux-en-Y gastric bypass (RYGB) for reducing low-density lipoprotein (LDL) cholesterol. The main aim was to ascertain whether high LDL cholesterol levels should be considered when selecting the most appropriate surgical procedure for each patient (RYGB or SG).

METHODS

In this single-center, randomized clinical trial using intention-to-treat analysis, 38 patients with severe obesity and elevated levels of LDL cholesterol were randomly assigned to undergo RYGB or SG. The primary outcome was LDL cholesterol remission at 12 months, defined as LDL cholesterol < 3.36 nmol/l without lipid-lowering medications. Secondary outcomes included changes in weight, other comorbidities, qualitative lipoprotein traits, cholesterol esters, glycoproteins, cholesterol absorption and synthesis metabolites and complications.

RESULTS

Intention-to-treat analysis revealed that LDL cholesterol remission occurred in 66.6% of RYGB patients compared to 27.8% of SG patients (p = 0.019). Among patients completing follow-up, RYGB demonstrated superior remission (80.0% vs. 29.4%, p = 0.005). Exclusive benefits of RYGB included a reduction in large, medium, and small LDL particles. Cholesterol absorption markers showed differential behavior after both techniques: campesterol (Δ -15.2 µg/mg, 95% CI -30.2 to -0.1) decreased after RYGB, and sitosterol (Δ 21.1 µg/mg, 95% CI 0.9 to 41.2), cholestanol (Δ 30.6 µg/mg, 95% CI 14.8 to 57.9) and campesterol (Δ 18.4 µg/mg, 95% CI 4.4 to 32.3) increased after SG. No differences in weight loss, cholesterol esters, glycoproteins, cholesterol synthesis metabolites or postoperative complications were observed between techniques.

CONCLUSION

In conclusion, RYGB is superior to SG in terms of short-term of high LDL cholesterol remission. Furthermore, RYGB also led to a greater improvement in lipoprotein parameters that confer an atherogenic profile. Therefore, the presence of elevated levels of LDL cholesterol should be considered when determining the optimal bariatric surgery procedure for each patient.

TRIAL REGISTRATION

Clinicaltrials.gov number, NCT03975478).

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.

Temporally and spatially resolved molecular profiling in fingerprint analysis using indium vanadate nanosheets-assisted laser desorption ionization mass spectrometry

This study presents the first-ever synthesis of samarium-doped indium vanadate nanosheets (IVONSs:Sm) via microemulsion-mediated solvothermal method. The nanosheets were subsequently utilized as a nano-matrix in laser desorption/ionization mass spectrometry (LDI-MS). It was discovered that the as-synthesized IVONSs:Sm possessed the following advantages: improved mass spectrometry signal, minimal matrix-related background, and exceptional stability in negative-ion mode. These qualities overcame the limitations of conventional matrices and enabled the sensitive detection of small biomolecules such as fatty acids. The negative-ion LDI mechanism of IVONSs:Sm was examined through the implementation of density functional theory simulation. Using IVONSs:Sm-assisted LDI-MS, fingerprint recognitions based on morphology and chemical profiles of endogenous/exogenous compounds were also achieved. Notably, crucial characteristics such as the age of an individual's fingerprints and their physical state could be assessed through the longitudinal monitoring of particular biomolecules (e.g., ascorbic acid, fatty acid) or the specific biomarker bilirubin glucuronide. Critical information pertinent to the identification of an individual would thus be facilitated by the analysis of the compounds underlying the fingerprint patterns.

The Nature of the Spark Is a Pivotal Element in the Design of a Miller-Urey Experiment

Miller and Urey applied electric sparks to a reducive mixture of CH4, NH3, and water to obtain a complex organic mixture including biomolecules. In this study, we examined the impact of temperature, initial pressure, ammonia concentration, and the spark generator on the chemical profile of a Miller-Urey-type prebiotic broth. We analyzed the broth composition using Gas Chromatography combined with Mass Spectroscopy (GC/MS). The results point towards strong compositional changes with the nature of the spark. Ammonia exhibited catalytic properties even with non-nitrogen-containing compounds. A more elevated temperature led to a higher variety of substances. We conclude that to reproduce such a broth as well as possible, all the studied parameters need to be tightly controlled, the most difficult and important being spark generation.

Enrichment and structural assignment of geometric isomers of unsaturated furan fatty acids

Furan fatty acids (FuFAs) are valuable minor fatty acids, which are known for their excellent radical scavenging properties. Typically, the furan moiety is embedded in an otherwise saturated carboxyalkyl chain. Occasionally, these classic FuFAs are accompanied by low amounts of unsaturated furan fatty acids (uFuFAs), which additionally feature one double bond in conjugation with the furan moiety. A recent study produced evidence for the occurrence of two pairs of E-/Z-uFuFA isomers structurally related to saturated uFuFAs. Here, we present a strategy that allowed such trace compounds to be enriched to a level suited for structure determination by NMR. Given the low amounts and the varied abundance ratio of the four uFuFA isomers, the isolation of individual compounds was not pursued. Instead, the entire isomer mixture was enriched to an amount and purity suitable for structure investigation with contemporary NMR methods. Specifically, lipid extracted from 150 g latex, the richest known source of FuFAs, was subsequently fractionated by countercurrent chromatography (CCC), silver ion, and silica gel column chromatography. Analysis of the resulting mixture of four uFuFAs isomers (2.4 mg in an abundance ratio of 56:23:11:9) by different NMR techniques including PSYCHE verified that the structures of the two most abundant isomers were E-9-(3-methyl-5-pentylfuran-2-yl)non-8-enoic acid and E-9-(3-methyl-5-pent-1-enylfuran-2-yl)nonanoic acid. Additionally, we introduced a computer-based method to generate an averaged chromatogram from freely selectable GC/MS runs of CCC fractions without the necessity of pooling aliquots. This method was found to be suitable to simplify subsequent enrichment steps.

Omega-3 polyunsaturated fatty acids improve intestinal barrier integrity-albeit to a lesser degree than short-chain fatty acids: an exploratory analysis of the randomized controlled LIBRE trial

PURPOSE

Adherence to the Mediterranean diet is associated with beneficial health effects, including gastrointestinal disorders. Preclinical studies suggest that omega-3 polyunsaturated fatty acids (n-3 PUFAs), found in Mediterranean foods like nuts and fish, improve intestinal barrier integrity. Here, we assessed possible effects of n-3 PUFAs on barrier integrity in a randomized controlled trial.

METHODS

We studied 68 women from the open-label LIBRE trial (clinicaltrials.gov: NCT02087592) who followed either a Mediterranean diet (intervention group, IG) or a standard diet (control group, CG). Study visits comprised baseline, month 3, and month 12. Barrier integrity was assessed by plasma lipopolysaccharide binding protein (LBP) and fecal zonulin; fatty acids by gas chromatography with mass spectrometry. Median and interquartile ranges are shown.

RESULTS

Adherence to the Mediterranean diet increased the proportion of the n-3 docosahexaenoic acid (DHA) (IG + 1.5% [0.9;2.5, p < 0.001]/ + 0.3% [- 0.1;0.9, p < 0.050] after 3/12 months; CG + 0.9% [0.5;1.6, p < 0.001]/ ± 0%) and decreased plasma LBP (IG - 0.3 µg/ml [- 0.6;0.1, p < 0.010]/ - 0.3 µg/ml [- 1.1; - 0.1, p < 0.001]; CG - 0.2 µg/ml [- 0.8; - 0.1, p < 0.001]/ ± 0 µg/ml) and fecal zonulin levels (IG - 76 ng/mg [- 164; - 12, p < 0.010]/ - 74 ng/mg [- 197;15, p < 0.001]; CG - 59 ng/mg [- 186;15, p < 0.050]/ + 10 ng/mg [- 117;24, p > 0.050]). Plasma DHA and LBP (R2: 0.14-0.42; all p < 0.070), as well as plasma DHA and fecal zonulin (R2: 0.18-0.48; all p < 0.050) were found to be inversely associated in bi- and multivariate analyses. Further multivariate analyses showed that the effect of DHA on barrier integrity was less pronounced than the effect of fecal short-chain fatty acids on barrier integrity.

CONCLUSIONS

Our data show that n-3 PUFAs can improve intestinal barrier integrity.

TRIAL REGISTRATION NUMBER

The trial was registered prospectively at ClinicalTrials.gov (reference: NCT02087592).

Intravascular hemolysis triggers NAFLD characterized by a deregulation of lipid metabolism and lipophagy blockade

Intravascular hemolysis is a common feature of different clinical entities, including sickle cell disease and malaria. Chronic hemolytic disorders are associated with hepatic damage; however, it is unknown whether heme disturbs lipid metabolism and promotes liver steatosis, thereby favoring the progression to nonalcoholic fatty liver disease (NAFLD). Using an experimental model of acute intravascular hemolysis, we report here the presence of liver injury in association with microvesicular lipid droplet deposition. Hemolysis promoted serum hyperlipidemia and altered intrahepatic triglyceride fatty acid composition, with increments in oleic, palmitoleic, and palmitic acids. These findings were related to augmented expression of transporters involved in fatty acid uptake (CD36 and MSR1) and deregulation of LDL transport, as demonstrated by decreased levels of LDL receptor and increased PCSK9 expression. Hemolysis also upregulated hepatic enzymes associated with cholesterol biosynthesis (SREBP2, HMGC1, LCAT, SOAT1) and transcription factors regulating lipid metabolism (SREBP1). Increased LC3II/LC3I ratio and p62/SQSTM1 protein levels were reported in mice with intravascular hemolysis and hepatocytes stimulated with heme, indicating a blockade of lipophagy. In cultured hepatocytes, cell pretreatment with the autophagy inductor rapamycin diminished heme-mediated toxicity and accumulation of lipid droplets. In conclusion, intravascular hemolysis enhances liver damage by exacerbating lipid accumulation and blocking the lipophagy pathway, thereby promoting NAFLD. These new findings have a high translational potential as a novel NAFLD-promoting mechanism in individuals suffering from severe hemolysis episodes. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Egg yolk phospholipids as an ideal precursor of fatty note odorants for chicken meat and fried foods: A review

Egg yolk phospholipids (PLs) have been demonstrated to generate large quantities of lipid-derived odorants, especially the fatty note odorants. Recently, egg yolk PLs have been successfully used in chicken meat and fried foods to improve aroma. This review comprehensively summarizes the properties of egg yolk PLs as precursors of fatty note odorants, including their classes, extraction, identification, oxidation, decomposition and odorant formation, applications, considerations and future prospects in the food industry. Most likely, phosphatidylcholine (PC) is the most abundant class in egg yolk PLs, and PC is more efficient than phosphatidylethanolamine in generating fatty note odorants; moreover, the predominant polyunsaturated fatty acid is linoleic acid, and its corresponding predominant hydroperoxide is 9-hydroperoxy-10,12-octadecadienoic acid during autoxidation, which is the precursor of 2,4-decadienals and 2,4-nonadienals, the key fatty note odorants. Therefore, egg yolk PLs could be an ideal precursor of fatty note odorants for chicken meat and fried foods.

Causal effects of fatty acids on atopic dermatitis: A Mendelian randomization study

Background

Some evidence suggests abnormalities in fatty acids in patients with atopic dermatitis (AD), and benefits of supplementation with these fatty acids have been reported. However, there is still substantial controversy on the correlation between fatty acids and AD. Therefore, the aim of this study was to determine whether fatty acid levels are causally related to AD using a Mendelian randomization approach.

Methods

We evaluated the data about the fatty acids levels and AD with various methods from Genome-Wide Association Study (GWAS). GWAS results were available both from European ancestry. Mendelian randomization methods were used to analysis the casual inference of fatty acids on AD. MR Egger and MR-PRESSO were used to determine pleiotropy and heterogeneity. Further analysis was conducted using instruments associated with the FADS genes to address mechanisms involved. We also used Multivariate MR (MVMR) to show the independent casual inference of omega-3 (n-3) fatty acids on AD.

Results

Mendelian randomization (MR) analysis suggests that n-3 fatty acid levels are associated with a lower risk of AD (n-3 OR_IVW: 0.92, 95% confidence interval [CI]: 0.87-0.98; p = 0.01). Moreover, docosahexaenoic acids (DHA) levels, which is a kind of long-chain, highly unsaturated omega-3 (n-3) fatty acid, and its higher level was associated with a lower risk of AD (DHA ORIVW: 0.91, 95% CI: 0.84-0.98; p = 0.02). We ran multivariable MR analysis while controlling for variables within the other types of fatty acids. The effect estimates agreed with the preliminary MR analysis indicating the effect of n-3 fatty acids levels on AD was robust. MR-egger suggest no significant pleiotropy and heterogeneity on genetic instrumental variants. Outliers-corrected MR analyses after controlling horizontal pleiotropy were still robust. The single-SNP analyses revealed that n-3 fatty acids are likely linked to a decreased risk of AD through FADS cluster, highlighting the significance of the FADS gene in the fatty acids synthesis pathway in the development of AD.

Conclusion

Our studies suggest that n-3 fatty acids may reduce the risk of AD. Risk prediction tools based on n-3 fatty acid levels may be valuable methods for improving AD screening and primary prevention. To reduce the risk of AD, individuals could enhance n-3 fatty acids intake through supplement or diet.

Nutritional lipidomics for the characterization of lipids in food

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

Sex differences in endocannabinoids during 3 years of Mediterranean diet intervention: Association with insulin resistance and weight loss in a population with metabolic syndrome

Background

Excess circulating endocannabinoids (eCBs) and imbalanced N-acylethanolamines (NAEs) related eCBs abundance could influence dietary weight loss success. We aimed to examine sex differences in the impact of a 3-years Mediterranean diet (MedDiet) intervention on circulating eCBs, NAEs and their precursor fatty acids, and to analyze the interplay between changes in eCBs or NAEs ratios, insulin resistance and the achievement of clinically meaningful weight reductions.

Methods

Prospective cohort study in a subsample of N = 105 participants (54.3% women; 65.6 ± 4.6 years) with overweight or obesity and metabolic syndrome that underwent a 3-years MedDiet intervention (PREDIMED-Plus study). Plasma eCBs and NAEs, including 2-arachidonoylglycerol (2-AG), anandamide (AEA), oleoylethanolamide (OEA) and palmitoylethanolamide (PEA), fatty acids, diet, glycemic homeostasis (including the assessment of insulin resistance-HOMA-IR), and cardiovascular risk markers were monitored (at 0-6-12-36 months).

Results

Mediterranean diet adherence increased in both sexes and remained high during the 3 years of follow-up. Reductions in body weight, glycemic and cardiovascular parameters were larger in men than in women. Women presented higher concentrations of NAEs than men throughout the study. In both sexes, AEA and other NAEs (including OEA, and PEA) decreased after 6 months (for AEA: −4.9%), whereas the ratio OEA/AEA increased after 1 year (+5.8%). Changes in 2-AG (−3.9%) and the ratio OEA/PEA (+8.2%) persisted over the 3 years of follow-up. In women, 6-months changes in AEA (OR = 0.65) and the ratio OEA/AEA (OR = 3.28) were associated with the achievement of 8% weight reductions and correlated with HOMA-IR changes (r = 0.29 and r = −0.34). In men, OEA/PEA changes were associated with 8% weight reductions (OR = 2.62) and correlated with HOMA-IR changes (r = −0.32).

Conclusion

A 3-years MedDiet intervention modulated plasma concentrations of eCBs and NAEs. Changes in AEA and in the relative abundance of NAEs were associated with clinically meaningful weight reductions. However, marked sex differences were identified in eCBs and NAEs, as well as in the efficacy of the intervention in terms of glycemic and cardiovascular parameters, which could be related to post-menopause alterations in glucose metabolism. These findings support a sex-balanced research strategy for a better understanding of the mechanisms underlying the regulation of body weight loss.

Potentially Beneficial Effects on Healthy Aging by Supplementation of the EPA-Rich Microalgae Phaeodactylum tricornutum or Its Supernatant-A Randomized Controlled Pilot Trial in Elderly Individuals

Dietary supplements that promote healthy aging are mostly warranted in an aging society. Because of age-related risks, anti-inflammatory and anti-oxidative agents such as microalgae are potential candidates for intervention. In a randomized controlled trial, we tested Phaeodactylum tricornutum (PT), a microalgae rich in eicosapentaenoic acid (EPA), carotenoids, vitamins, and β-glucans, cultured in bioreactors. In this pilot trial, 19 healthy elderly received supplements for two weeks based on either the whole PT (A), the β-1,3-glucan-rich PT supernatant (SupB), the combination thereof (A+SupB), or a Comparator product (Comp). The primary outcome variable plasma interleukin-6 was reduced after treatment with A+SupB compared to the Comp group (p = 0.04). The mobility parameters 5 s sit-to-stand test (p = 0.04 in the A group) and by trend gait speed (p = 0.08 in the A+SupB diet) were improved compared to Comp. No treatment effects were observed for fatty acids, compared to Comp but omega-6 to -3 fatty acid ratio (p = 0.006) and arachidonic acid/EPA ratio (p = 0.006) were reduced within group A+SupB. Further, the SupB study product reduced faecal zonulin (p = 0.03) compared to the Comp. The data revealed an anti-inflammatory and potentially anti-oxidative effect of particular PT preparations, suggesting that they might be suitable for effects in healthy elderly.

Relationship of Circulating Vegetable Omega-3 to Prognosis in Patients With Heart Failure

BACKGROUND

There is an urgent need for cost-effective strategies to promote quality of life in patients with heart failure (HF). Several studies reported benefits in HF prognosis for marine omega-3 fatty acids and plant-based dietary patterns.

OBJECTIVES

The aim of this study was to explore whether dietary alpha-linolenic acid (ALA), the main plant omega-3, relates to a better HF prognosis.

METHODS

ALA was determined in serum phospholipids (which reflect long-term dietary ALA intake and metabolism) by gas chromatography in 905 ambulatory patients with HF caused by different etiologies.

RESULTS

After a median follow-up of 2.4 years (range: 0.02-3 years), 140 all-cause deaths, 85 cardiovascular (CV) deaths, and 141 first HF hospitalizations (composite of all-cause death and first HF hospitalization, n = 238) were documented. Using Cox regression analyses, we observed that, compared with patients at the lowest quartile of ALA in serum phospholipids (Q1), those at the 3 upper quartiles (Q2-Q4) exhibited a reduction in the risk of composite of all-cause death and first HF hospitalization (HR: 0.61; 95% CI: 0.46-0.81). Statistically significant reductions were observed for all-cause death (HR: 0.58; 95% CI: 0.41-0.82), CV death (HR: 0.51; 95% CI: 0.32-0.80), first HF hospitalization (HR: 0.58; 95% CI: 0.40-0.84), and the composite of CV death and HF hospitalization (HR: 0.58; 95% CI: 0.42-0.79).

CONCLUSIONS

HF patients with bottom 25% ALA levels in serum phospholipids had a worse prognosis during a mid-term follow-up compared with those with the highest levels. This might be a target population in whom to test dietary ALA-rich interventions to promote quality of life.

Microbial incubations of 8-phenyloctanoic acid and furan fatty acids in rumen fluid

AIMS

The digestive tract of ruminants is specialised in the digestion of various plant components. One of the largest parts of the stomach is the so-called rumen, which contains a large number of microorganisms that may degrade or modify fatty acids e.g. by β-oxidation, chain elongation and/or hydrogenation.

METHODS AND RESULTS

Here we performed incubation experiments with less common fatty acids by in vitro incubations with rumen fluid of fistulated cows for 24 h. Sample extracts were analysed by gas chromatography with mass spectrometry. As substrates, we selected one phenyl fatty acid and four furan fatty acids (FuFAs). All studied fatty acids were degraded by β-oxidation (two or three chain-shortening steps) while chain elongation or saturation of the aromatic part (terminal phenyl or central furan moiety) was not observed in any case.

CONCLUSIONS

The percentage of β-oxidation products was low, especially in the case of the FuFAs. This could be due to the rather long carbon number of FuFAs (19-22 carbon atoms). In addition, compound-specific differences in the degradation rates were observed in our experiments.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results produce evidence that FuFAs, which are valuable antioxidants that are known to be present in various feed items of the cow, can be effectively passed on the rumen into the milk.

Stable isotope analysis confirms substantial changes in the fatty acid composition of bacteria treated with antimicrobial random peptide mixtures (RPMs)

Resistance of plant-pathogenic bacteria to classic antibiotics has prompted the search for suitable alternative antimicrobial substances. One promising strategy could be the use of purposely synthesized random peptide mixtures (RPMs). Six plant-pathogenic bacteria were cultivated and treated with two RPMs previously found to show antimicrobial activity mainly by bacterial membrane disruption. Here, we show that bacteria treated with RPMs showed partly remarkable changes in the fatty acid pattern while those unaffected did not. Quantitative changes could be verified by compound specific isotope analysis of δ¹³C values (‰). This technique was employed due to the characteristic feature of stronger bonds between heavier isotopes in (bio)chemical reactions. As a proof of concept, the increase in abundance of a fatty acid group after RPM treatment was accompanied with a decrease in the ¹³C content and vice versa. We propose that our findings will help designing and synthesizing more selective antimicrobial peptides.

Meta-Inflammation and De Novo Lipogenesis Markers Are Involved in Metabolic Associated Fatty Liver Disease Progression in BTBR ob/ob Mice

Metabolic associated fatty liver disease (MAFLD) is a hepatic manifestation of metabolic syndrome and usually associated with obesity and diabetes. Our aim is to characterize the pathophysiological mechanism involved in MAFLD development in Black Tan and brachyuric (BTBR) insulin-resistant mice in combination with leptin deficiency (ob/ob). We studied liver morphology and biochemistry on our diabetic and obese mice model (BTBR ob/ob) as well as a diabetic non-obese control (BTBR + streptozotocin) and non-diabetic control mice (BTBR wild type) from 4–22 weeks. Lipid composition was assessed, and lipid related pathways were studied at transcriptional and protein level. Microvesicular steatosis was evident in BTBR ob/ob from week 6, progressing to macrovesicular in the following weeks. At 12th week, inflammatory clusters, activation of STAT3 and Nrf2 signaling pathways, and hepatocellular ballooning. At 22 weeks, the histopathological features previously observed were maintained and no signs of fibrosis were detected. Lipidomic analysis showed profiles associated with de novo lipogenesis (DNL). BTBR ob/ob mice develop MAFLD profile that resemble pathological features observed in humans, with overactivation of inflammatory response, oxidative stress and DNL signaling pathways. Therefore, BTBR ob/ob mouse is an excellent model for the study of the steatosis to steatohepatitis transition.

Tocochromanol Profiles in Chlorella sorokiniana, Nannochloropsis limnetica and Tetraselmis suecica Confirm the Presence of 11'-α-Tocomonoenol in Cultured Microalgae Independently of Species and Origin

11'-α-Tocomonoenol (11'-αT1) is structurally related to vitamin E and has been quantified in the microalgae Tetraselmis sp. and Nannochloropsis oceanica. However, it is not known whether 11'-αT1 is present in other microalgae independent of species and origin. The aim of this study was to analyze the tocochromanol profiles of Chlorella sorokiniana, Nannochloropsis limnetica, and Tetraselmis suecica and to determine if 11'-αT1 is present in these microalgae. Cultured microalgae were freeze-dried and the presence and identity of α-tocomonoenols were confirmed by LC-MSn (liquid chromatography coupled to mass spectroscopy) and GC-MS (gas chromatography coupled to mass spectroscopy). Tocochromanol profiles were determined by HPLC-FLD (liquid chromatography with fluorescence detection) and fatty acid profiles (as fatty acid methyl esters; FAME) by GC-MS. As confirmed by LC-MSn and GC-MS, 11'-αT1 was the dominant αT1 isomer in cultured microalgae instead of 12'-αT1, the isomer also known as marine-derived tocopherol. αT1 represented less than 1% of total tocochromanols in all analyzed samples and tended to be more abundant in microalgae with higher proportions of polyunsaturated fatty acids. In conclusion, our findings confirm that αT1 is not restricted to terrestrial photosynthetic organisms, but can also accumulate in microalgae of different species, with 11'-αT1-and not the marine-derived tocopherol (12'-αT1)-as the predominant αT1 isomer.

Oxidative stability of tocochromanols, carotenoids, and fatty acids in maize (Zea mays L.) porridges with varying phytate concentrations during cooking and in vitro digestion

Phytic acid, the main storage form of phosphate in maize (Zea mays L.) grains, is known as antinutrient due to its chelating properties but may also prevent oxidation. Thus, the impact of phytic acid on the degradation of tocochromanols, carotenoids, fatty acids, and oxidation products in maize during cooking and subsequent in vitro digestion was examined. Maize porridges from low phytic acid maize flour with or without admixed phytate, or from high phytic acid maize flour were prepared, and digestion experiments conducted. HPLC-(MS) or GC-MS analyses revealed a significant decrease in tocochromanols, carotenoids, and unsaturated fatty acids in the digesta compared to the maize porridges while α-tocopherylquinone and malondialdehyde concentrations increased. The addition of phytic acid did not affect the digestive stabilities of total tocochromanols and carotenoids, but increased micellarisation efficiencies of carotenoids. In conclusion, phytate did not exert antioxidant effects in maize porridge during cooking or simulated digestion.

A new synthesis approach for the generation of single chain CP mixtures composed of a few major compounds

Chlorinated paraffins (CPs) are complex mixtures, which consist of thousands of individual compounds with no dominant representative. Consequently, knowledge on structure and environmental relevance of individual CP congeners is poor. Similarly to the synthesis of individual CPs, the generation of less complex CP mixtures that can be thoroughly analyzed may be used to overcome some drawbacks of the highly complex technical CP mixtures. Here, we present a new synthesis approach to generate such simple CP mixtures by decarboxylation of polyunsaturated fatty acids followed by saturation of the double bonds by chlorination. Specifically, α-linolenic acid (18:3Δ9,12,15) was decarboxylated to heptadecatriene. The resulting raw product was chlorinated with SO₂Cl₂. Purification by column chromatography led to a main fraction consisting of four major peaks originating from hexachloroheptadecane (C₁₇H₃₀Cl₆) isomers (∼80% of the total peak area) along with ∼20 low abundant by-products, according to gas chromatography with electron capture negative ion mass spectrometry. In the same way, decarboxylation and subsequent chlorination of other polyunsaturated fatty acids may lead to further simple CP mixtures with other chain lengths. Although these simple CP mixtures cannot fully reflect the various structural features present in technical mixtures they could be beneficial for transformation studies because changes in the CP pattern can easily be noted which is in contrast to technical CP mixtures. Such simple CP mixtures could also be used in toxicity tests which are difficult to perform with technical CP mixtures because of their high complexity.

Oral Bioavailability of Omega-3 Fatty Acids and Carotenoids from the Microalgae Phaeodactylum tricornutum in Healthy Young Adults

The microalgae Phaeodactylum tricornutum (PT) contains valuable nutrients such as proteins, polyunsaturated omega-3 fatty acids (n-3 PUFA), particularly eicosapentaenoic acid (EPA) and some docosahexaenoic acid (DHA), carotenoids such as fucoxanthin (FX), and beta-glucans, which may confer health benefits. In a randomized intervention trial involving 22 healthy individuals, we administered for two weeks in a crossover manner the whole biomass of PT (5.3 g/day), or fish oil (FO) containing equal amounts of EPA and DHA (together 300 mg/day). In an additional experiment, sea fish at 185 g/week resulting in a similar EPA and DHA intake was administered in nine individuals. We determined the bioavailability of fatty acids and carotenoids and assessed safety parameters. The intake of PT resulted in a similar increase in the n-3 PUFA and EPA content and a decrease in the PUFA n-6:n-3 ratio in plasma. PT intake caused an uptake of FX that is metabolized to fucoxanthinol (FXOH) and amarouciaxanthin A (AxA). No relevant adverse effects occurred following PT consumption. The study shows that PT is a safe and effective source of EPA and FX-and likely other nutrients-and therefore should be considered as a future sustainable food item.

Fatty acid profiles of milk from Holstein cows, Jersey cows, buffalos, yaks, humans, goats, camels, and donkeys based on gas chromatography-mass spectrometry

Due to the diversity and limitation of determination methods, published data on the fatty acid (FA) compositions of different milk samples have contributed to inaccurate comparisons. In this study, we developed a high-throughput gas chromatography-mass spectrometry method to determinate milk FA, and the proposed method had satisfactory linearity, sensitivity, accuracy, and precision. We also analyzed the FA compositions of 237 milk samples from Holstein cows, Jersey cows, buffalos, yaks, humans, goats, donkeys, and camels. Holstein, Jersey, goat, and buffalo milks contained high content of even-chain saturated FA, whereas goat milk had higher content of medium- and short-chain FA (MSCFA). Yak and camel milk are potential functional foods due to their high levels of odd- and branched-chain FA and low ratios of n-6 to n-3 polyunsaturated FA (PUFA). Human milk contained lower levels of saturated FA, MSCFA, and conjugated linoleic acid, and higher levels of monounsaturated FA and PUFA. As a special nonruminant milk, donkey milk contained low levels of monounsaturated FA and high levels of PUFA and MSCFA. Based on the FA profiles of 8 types of milk, nonruminant milk was distinct from ruminant milk, whereas camel and yak milk were different from other ruminant milks and considered as potential functional foods for balanced human diet.

Rapid quantification of fatty acids in plant oils and biological samples by LC-MS

Analysis of fatty acids (FA) in food and biological samples such as blood is indispensable in modern life sciences. We developed a rapid, sensitive and comprehensive method for the quantification of 41 saturated and unsaturated fatty acids by means of LC-MS. Optimized chromatographic separation of isobaric analytes was carried out on a C8 reversed phase analytical column (100 × 2.1 mm, 2.6 μm core–shell particle) with a total run time of 15 min with back pressure lower than 300 bar. On an old triple quadrupole instrument (3200, AB Sciex), pseudo selected reaction monitoring mode was used for quantification of the poorly fragmenting FA, yielding limits of detection of 5–100 nM. Sample preparation was carried out by removal of phospholipids and triglycerides by solid-phase extraction (non-esterified fatty acids in oils) or saponification in iso-propanol (fatty acyls). This is not only a rapid strategy for quantification of fatty acyls, but allows the direct combination with the LC-MS-based analysis of fatty acid oxidation products (eicosanoids and other oxylipins) from the same sample. The concentrations of fatty acyls determined by means of LC-MS were consistent with those from GC-FID analysis demonstrating the accuracy of the developed method. Moreover, the method shows high precisions with a low intra-day (≤ 10% for almost all fatty acids in plasma and ≤ 15% in oils) and inter-day as well as inter-operator variability (< 20%). The method was successfully applied on human plasma and edible oils. The possibility to quantify non-esterified fatty acids in samples containing an excess of triacylglycerols and phospholipids is a major strength of the described approach allowing to gain new insights in the composition of biological samples.

Identification and quantification of dicarboxylic fatty acids in head tissue of farmed Nile tilapia (Oreochromis niloticus)

Nile tilapia (Oreochromis niloticus) was grown in Bangladesh with four different feeding treatments as part of a project that aims to produce fish in a cost-effective way for low-income consumers in developing countries. Fillet and head tissue was analysed because both tissues were destined for human consumption. Gas chromatography with mass spectrometry (GC/MS) analyses of transesterified fatty acid methyl ester extracts indicated the presence of ~ 50 fatty acids. Major fatty acids in fillet and head tissue were palmitic acid and oleic acid. Both linoleic acid and polyunsaturated fatty acids with three or more double bonds were presented in quantities > 10% of total fatty acids in fillet, but lower in head tissue. Erucic acid levels were below the newly proposed tolerable daily intake in the European Union, based on the consumption of 200 g fillet per day. Moreover, further analysis produced evidence for the presence of the dicarboxylic fatty acid azelaic acid (nonanedioic acid, Di9:0) in head tissue. To verify this uncommon finding, countercurrent chromatography was used to isolate Di9:0 and other dicarboxylic acids from a technical standard followed by its quantification. Di9:0 contributed to 0.4–1.3% of the fatty acid profile in head tissue, but was not detected in fillet. Fish fed with increasing quantities of flaxseed indicated that linoleic acid was the likely precursor of Di9:0 in the head tissue samples.

A Gas Chromatography-Mass Spectrometry Method for the Determination of Fatty Acids and Sterols in Yeast and Grape Juice

Lipids are essential components of all living cells. In an oenological context, the supply of unsaturated lipids in grape juice allows the yeasts to grow and ferment, despite very low levels of oxygen. The current study proposes a systematic optimization procedure for the analysis of fatty acids and sterols relevant to the grape fermentation process, including both extracellular and intracellular (i.e., yeast cells) lipids. Even though it was extensive, the sample preparation yielded reproducible results for all compounds of interest. The stability of the analyzed compounds was also tested to offer some implementation flexibility for the extensive procedure. The performance parameters (i.e., selectivity, linearity, limit of detection and quantitation, accuracy, and precision) indicated that the method was suitable for future practical implementation. The proof of concept also suggests that the list of compounds of interest can be expanded if additional peaks are identified. Given the large variation in concentrations, the dilution of the matrix needs to be carefully considered in order to ensure that the lipids of interest are still within the dynamic range and not below the limit of detection and/or quantification.

A Validated Method for Quantification of Fatty Acids Incorporated in Human Plasma Phospholipids by Gas Chromatography-Triple Quadrupole Mass Spectrometry

Fatty acids (FA) are important mediators of health maintenance and disease risk. Optimal quantification assays of FA in high and low abundance as well the identification of 13C-labeled tracers to monitor FA metabolism are of major interest. The article on hand reports about the development and validation of a gas chromatography (GC)-triple quadrupole mass selective detection (GC-TQMS) method for absolute quantification of FA in human plasma phospholipids (hpPL). The quantification of the calibration solution by GC-flame ionization detection (GC-FID), with the introduction of a correction factor, allows the direct comparison of individual FA concentrations in hpPL by GC-TQMS. Specificity, sensitivity, and reproducibility are achieved by optimized chromatographic separation and employment of GC-TQMS. The inter-method comparison between GC-FID and GC-TQMS concentrations revealed good comparability for 27 FA. A full validation has been performed with linearity over 4 magnitudes, a limit of detection of 0.18-38.3 fmol on column, a recovery of 83.6-109.6%, and intraday and interday precision data meeting the criteria of EMA and FDA guidelines. The method includes the absolute quantification of 58 positional and geometrical (cis/trans) isomeric FA in hpPL in the concentration range of 1-3000 nmol/mL, covering also low abundant positional cis/trans isomers. Results obtained from both methods are highly comparable, and selectivity and sensitivity are improved by using GC-TQMS. Additionally, we show here that calculation of 13C-labeled C16:0 tracer/tracee ratios in hpPL in human isotope enrichment studies is possible.

Detailed analysis of the fatty acid composition of six plant-pathogenic bacteria

Bacteria show distinct and characteristic fatty acid (FA) patterns which can be modified by environmental conditions. In this study, we cultivated six plant-pathogenic bacteria of agricultural concern and performed a detailed analysis of the fatty acid composition. The study covered four strains of the gram-negative Xanthomonas campestris pathovar (pv) campestris (Xcc), Xanthomonas perforans (Xp), Acidovorax citrulli (Ac) and Pseudomonas syringae pv. tomato (Pst), and two strains of the gram-positive Clavibacter michiganensis subsp. michiganensis (Cmm) and Streptomyces scabies (Ssc). After cultivation, freeze-dried bacteria samples were transesterified and analysed by gas chromatography with mass spectrometry in full scan and selected ion monitoring (SIM) modes. Altogether, 44 different FAs were detected in the six strains with individual contributions of 0.01-43.8% to the total FAs. The variety in the six strains ranged between 12 and 31 individual FAs. The FA composition of Xcc, Xp, Cmm and Ssc were dominated by iso- and anteiso-fatty acids (especially i15:0, a15:0, i16:0), which is typical for most bacteria. In contrast to this, Ac and Pst showed only saturated and monounsaturated FAs. Four of the six bacteria showed similar FA patterns as reported before in the literature. Differences were observed in the case of Cmm where many more FAs were detected in the present study. In addition, to the best of our knowledge, the FA pattern of Xp was presented for the first time.

Fatty acid profiles in erythrocyte membranes following the Mediterranean diet - data from a multicenter lifestyle intervention study in women with hereditary breast cancer (LIBRE)

BACKGROUND & AIMS

Evidence-based concepts to prevent breast cancer in women with BRCA1/2 mutations are limited. Adherence to a Mediterranean diet (MedD) has been associated with a lower risk for breast cancer, possibly due to a favorable fatty acid (FA) intake. Here, we studied in an at-risk population the effect of a lifestyle intervention that included the MedD on FA composition in red blood cell membranes (RBCM).

METHODS

Data derived from the German multicenter trial LIBRE, from which 68 women were randomized into an intervention group (IG) trained for MedD and increased physical activity for 12 months, and a usual care control group (CG). Adherence to the diet was assessed after 3 and 12 months using the validated Mediterranean Diet Adherence Screener (MEDAS) and a food frequency questionnaire. RBCM FA were analyzed by gas chromatography with mass spectrometry.

RESULTS

The MEDAS was increased in both groups after 3 months (IG: P < 0.001; CG: P = 0.004), and remained increased only in the IG after 12 months (P < 0.001). The food frequency questionnaire revealed an increased intake of omega-3 (n-3) FA at month 3 and month 12 in the IG (both P < 0.01), but not in the CG, in which intake of energy, protein and saturated FA decreased. In both groups n-6 FA in the RBCM decreased (P < 0.001), while n-9 FA increased (P < 0.001) and n-3 FA were unchanged. Women with higher consumption of fish had higher amounts of n-3 fatty acids in the RBCM. The MEDAS was inversely correlated with n-6 fatty acids.

CONCLUSIONS

The RBCM FA composition was associated with dietetic parameters related to the MedD. Adherence to the MedD resulted in an altered, likely favorable FA composition. Our data suggest selected FA as biomarkers to monitor compliance to a dietetic intervention such as the MedD.

CLINICAL TRIAL REGISTRY

The trial is registered at ClinicalTrials.gov (reference: NCT02087592).

Cloned pig fetuses exhibit fatty acid deficiency from impaired placental transport

Cloned pig fetuses produced by somatic cell nuclear transfer show a high incidence of erroneous development in the uteri of surrogate mothers. The mechanisms underlying the abnormal intrauterine development of cloned pig fetuses are poorly understood. This study aimed to explore the potential causes of the aberrant development of cloned pig fetuses. The levels of numerous fatty acids in allantoic fluid and muscle tissue were lower in cloned pig fetuses than in artificial insemination-generated pig fetuses, thereby suggesting that cloned pig fetuses underwent fatty acid deficiency. Cloned pig fetuses also displayed trophoblast hypoplasia and a reduced expression of placental fatty acid transport protein 4 (FATP4), which is the predominant FATP family member expressed in porcine placentas. This result suggested that the placental fatty acid transport functions were impaired in cloned pig fetuses, possibly causing fatty acid deficiency in cloned pig fetuses. The present study provides useful information in elucidating the mechanisms underlying the abnormal development of cloned pig fetuses.

Stable Carbon and Nitrogen Isotope Ratios of Red Bell Pepper Samples from Germany, The Netherlands, and Spain

Bell pepper is one of the most cultivated crops in the world. By means of δ¹³C and δ¹⁵N values (‰), red bell peppers from Germany, The Netherlands, and Spain could be distinguished from each other. German fruits cultivated under greenhouse conditions were extremely depleted in ¹³C with δ¹³C values for fatty acids of partly less than -50‰. The strong depletion in ¹³C was in accordance with the use of biomethane-derived CO₂ as growth regulator in the greenhouses. Seasonal variations in the δ¹³C values (‰) of German samples were tentatively assigned to varying CO₂ enrichment during the annual production cycle. δ¹³C values (‰) of Dutch samples also correlated with greenhouse production, whereas Spanish samples most likely originated from open field cultivation. Additionally, the use of color measurement as a tool for presorting the samples was investigated in order to slim the scattering ranges of δ¹³C and δ¹⁵N values (‰) for clearer differentiation.

Yield and Quality Characteristics of Different Quinoa (Chenopodium quinoa Willd.) Cultivars Grown under Field Conditions in Southwestern Germany

Due to its highly nutritive compounds, the demand for quinoa, a small grain originating from the Andean region of South America, increased rapidly over the last years. However, the main producing countries Bolivia and Peru cannot cover the growing demand. Therefore, the interest of European farmers in cultivating quinoa as a profitable source of income rose very fast. Thanks to a broad genetic diversity an adaption to various climatic conditions is possible. The objective of this study was to evaluate the stability of agronomic performance in two consecutive growing periods (2015 and 2016) of four European quinoa cultivars (Puno, Titicaca, Jessie, Zeno), originating from different genepools to identify a suitable cultivar to grow in southwestern Germany. Measurements included grain yield, thousand kernel weight (TKW), saponin content, protein content, crude fat content, amino acid profile and fatty acid profile. This study demonstrated the possibility of an economic production of quinoa under the environmental conditions in southwestern Germany, combining competitive yields (1.73–2.43 Mg ha−1) with a high grain quality regarding protein content (11.9–16.1%), essential amino acid content (20.35–30.02 g 100 g−1 crude protein), fat content (5.5–7.5%) and fatty acid profile (consists of 60% linoleic acid). Depending on cultivar, the investigated yield (TKW and protein content)-and quality ((semi-)essential amino acids)-traits varied more or less sensitive, which was attributed to lower precipitation and higher temperatures in 2015. Furthermore, best yield- and quality-characteristics were not combined in one cultivar, wherefore the selection of a specific quinoa cultivar has to be aligned with the production aim.

Multivariate optimization of a method for the determination of fatty acids in dental biofilm by GC-MS

AIM

Phospholipid fatty acid methyl ester (FAME) analysis offers a simple option additionally to 16S rRNA sequencing to characterize microbial communities and to monitor changes. A method was established for the characterization of dental plaque via FAME profiles.

METHODOLOGY

Fatty acids were determined as FAMEs (direct, acidic transesterification) and analyzed by GC-MS using an optimized temperature gradient. The transesterification reaction was optimized using a fractional factorial central composite face-centered design.

RESULTS

Optimal conditions for the transesterification in methanol/toluene: hydrochloric acid concentration 2% (w/v), reaction time 40 min, temperature 110 °C. Method validation showed satisfactory accuracy, precision and linearity.

CONCLUSION

The method provides a useful tool to characterize plaque via FAME profiles and was successfully applied to samples from ten subjects demonstrating its applicability.

Fatty Acid 13C Isotopologue Profiling Provides Insight into Trophic Carbon Transfer and Lipid Metabolism of Invertebrate Consumers

Fatty acids (FAs) are useful biomarkers in food web ecology because they are typically assimilated as a complete molecule and transferred into consumer tissue with minor or no modification, allowing the dietary routing between different trophic levels. However, the FA trophic marker approach is still hampered by the limited knowledge in lipid metabolism of the soil fauna. This study used entirely labelled palmitic acid (¹³C16:0, 99 atom%) as a tracer in fatty acid metabolism pathways of two widespread soil Collembola, Protaphorura fimata and Heteromurus nitidus. In order to investigate the fate and metabolic modifications of this precursor, a method of isotopologue profiling is presented, performed by mass spectrometry using single ion monitoring. Moreover, the upstream laboratory feeding experiment is described, as well as the extraction and methylation of dominant lipid fractions (neutral lipids, phospholipids) and the related formula and calculations. Isotopologue profiling does not only yield the overall ¹³C enrichment in fatty acids derived from the ¹³C labeled precursor but also produces the pattern of isotopologues exceeding the mass of the parent ion (i.e., the FA molecular ion M⁺) of each labeled FA by one or more mass units (M⁺¹, M⁺², M⁺³, etc.). This knowledge allows conclusions on the ratio of dietary routing of an entirely consumed FA in comparison to de novo biosynthesis. The isotopologue profiling is suggested as a useful tool for evaluation of fatty acid metabolism in soil animals to disentangle trophic interactions.

Effects of simple rain-shelter cultivation on fatty acid and amino acid accumulation in 'Chardonnay' grape berries

BACKGROUND

Fatty acids and amino acids are the precursors of aliphatic and aromatic volatile compounds, higher alcohols and esters. They are also nutrition for yeast metabolism during fermentation. However, few reports have been concerned about the effect of viticulture practices on the accumulation of fatty acids and amino acids in wine grapes. This study aimed to explore the accumulation of these compounds in developing Vitis vinifera L. cv. Chardonnay grape berries under two vintages, and compare the influences of the rain-shelter cultivation and open-field cultivation.

RESULTS

Fifteen fatty acids and 21 amino acids were detected in total. The rain-shelter cultivation led to an increase in the total concentration of fatty acids, and a decrease in the total concentration of amino acids compared with the open-field cultivation in 2012, while no significant difference was observed between two cultivation modes in 2013 vintage. Concentrations of palmitoleic acid, isoleucine and cysteine were significantly promoted in the rain-shelter grape berries, whereas those of tyrosine and ornithine were markedly reduced in both vintages.

CONCLUSION

The rain-shelter cultivation of wine grapes in the rainy region is beneficial for improving grape quality and fermentation activity by influence on the concentration of fatty acids and amino acids. © 2017 Society of Chemical Industry.

Synthesis, structure elucidation, and determination of polyhalogenated N-methylpyrroles (PMPs) in blue mussels

Polyhalogenated N-methylpyrroles (PMPs) are halogenated natural products (HNPs) recently detected in seagrass, blue mussels, and other marine organisms. In this study, we synthesized 2,3,4,5-tetrachloro-N-methylpyrrole (Cl₄-MP), 2,3,4,5-tetrabrominated-N-methylpyrrole (Br₄-MP, aka TBMP), and mixed tetrahalogenated (Cl and Br) N-methylpyrrole congeners. Use of one- and two-dimensional ¹H and ¹³C NMR verified the structures of isolated/enriched 3,4-dibromo-2,5-dichloro-N-methylpyrrole (3,4-Br₂-2,5-Cl₂-MP), 2,3,4-tribromo-5-chloro-N-methylpyrrole (2,3,4-Br₃-5-Cl-MP), and 3-bromo-2,4,5-trichloro-N-methylpyrrole (3-Br-2,4,5-Cl₃-MP). GC/EI-MS and GC/ECNI-MS mass spectra of the five PMPs were studied with regard to fragmentation pattern and individual responses which were strongly affected by the presence (or absence) of Br in α-position(s). Quantitative solutions of the synthesized standards were used to determine the elution order of isomers and to quantify PMPs in selected blue mussel samples (Mytilus sp.) from the European Atlantic coast (Spain, France), the North Sea (the Netherlands, Germany) and Baltic Sea (Germany). PMPs were detected in all samples and the concentrations ranged between 0.6 and 52 μg/kg lipids with Br₄-MP being the most abundant representative of this substance class.