Exclusive quantification of methyl-branched fatty acids and minor 18:1-isomers in foodstuff by GC/MS in the SIM mode using 10,11-dichloroundecanoic acid and fatty acid ethyl esters as internal standards

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).

Potential Modulation of Inflammation and Physical Function by Combined Probiotics, Omega-3 Supplementation and Vitamin D Supplementation in Overweight/Obese Patients with Chronic Low-Grade Inflammation: A Randomized, Placebo-Controlled Trial

Obesity is characterized by low-grade inflammation and increased gut permeability. Here, we aim to evaluate the effect of a nutritional supplement on these parameters in subjects with overweight and obesity. A double-blinded, randomized clinical trial was conducted in 76 adults with overweight or obesity (BMI 28 to 40) and low-grade inflammation (high-sensitivity C-reactive protein (hs-CRP) between 2 and 10 mg/L). The intervention consisted of a daily intake of a multi-strain probiotic of Lactobacillus and Bifidobacterium, 640 mg of omega-3 fatty acids (n-3 FAs), and 200 IU of vitamin D (n = 37) or placebo (n = 39), administered for 8 weeks. hs-CRP levels did not change post-intervention, other than an unexpected slight increase observed in the treatment group. Interleukin (IL)-6 levels decreased in the treatment group (p = 0.018). The plasma fatty acid (FA) levels of the arachidonic acid (AA)/eicosapentaenoic acid (EPA) ratio and n-6/n-3 ratio (p < 0.001) decreased, and physical function and mobility improved in the treatment group (p = 0.006). The results suggest that hs-CRP may not be the most useful inflammatory marker, but probiotics, n-3 FAs, and vitamin D, as non-pharmaceutical supplements, may exert modest effects on inflammation, plasma FA levels, and physical function in patients with overweight and obesity and associated low-grade inflammation.

Furan Fatty Acids in Some 20 Fungi Species: Unique Profiles and Quantities

Furan fatty acids (FuFAs) are a group of excellent antioxidants in food. Since data in fungi were scarce, 37 commercial or collected edible and meadow fungi were analyzed on FuFA patterns and contents. FuFA amounts in fresh fungi ranged from not detectable (n = 2) to 40 mg/100 g fungi dry weight. Fresh samples of the popular edible fungi genera Agaricus and Pleurotus showed comparable FuFA contents of 9.0-33 mg/100 g fungi dry weight. The unique FuFA profile of the fungi was dominated by 9-(3,4-dimethyl-5-pentylfuran-2-yl)-nonanoic acid (9D5). In addition, the uncommon 9-(3,4-dimethyl-5-butylfuran-2-yl)-nonanoic acid (9D4) was present in 30% of the samples with contents of up to 0.2 mg/100 g fungi dry weight. Countercurrent separation techniques were used to isolate the main FuFA 9D5, to verify the presence of 9D4, and to determine ultra-traces of 11-(3,4-dimethyl-5-pentylfuran-2-yl)-undecanoic acid (11D5), which may have been assimilated by the fungi from the substrate.

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.

Optimizing accelerated solvent extraction combined with liquid chromatography-Orbitrap mass spectrometry for efficient lipid profile characterization of mozzarella cheese

In this study, a novel Accelerated Solvent Extraction (ASE) procedure combined with UHPLC-Q-Orbitrap-MS was developed for detailed untargeted lipid profile of mozzarella cheese. Response Surface Methodology and Pareto front, using a Central Composite Design (CCD), were employed to define the optimised combination of extraction temperature, number of extraction cycles and mix of solvents. LipidSearch™ software was used for a reliable and accurate lipid identification. A total of 13 subclasses, including ceramides, diacylglycerols, triacylglycerols, lysophosphatidylcholines, lysophosphatidylethanolamines, phosphatidylcholines, phosphatidylethanolamines, phosphatidylinositols, sphingomyelins, bismethyl phosphatidic acids, cholesterol ester, zymosterol ester, hexosyl ceramides were measured. The elaboration of the CCD showed that the solvents ratio was the main factor affecting the extraction efficiency. The optimised ASE method, together with the Folch extraction, synergistically contributed to a complete characterization of lipid profile of mozzarella cheese, confirming ASE technique, associated with high resolution mass spectrometry detection, as an efficient tool for Lipidomics in food science.

Effect of two postharvest technologies on the micronutrient profile of cashew kernels from Mozambique

The economics involved in processing cashew nuts (Anacardium occidentale) might alter micronutrient profiles and concentrations. We analyzed and evaluated carotenoids, tocopherols, tocotrienols, minerals, fatty acids, and amino acids in (1) cashew kernels with testa recovered from nuts dried with and without the apple, and (2) testa-free industrial grade baby butts, splits, and white whole kernels using HPLC, ICP-OES, and GC-MS techniques. The results indicated that drying cashews with the respective apple slightly decreased the concentration of some carotenoids and total fatty and amino acids, but increased the concentration of iron, magnesium, and total tocotrienols compared with the conventionally (sun-) dried kernels. We also found high concentrations of carotenoids in the testa-containing kernels. Among the industrially processed kernel, baby butt grade was associated with lower content of β-carotene, total tocopherols, and tocotrienols, but with significantly higher concentrations in minerals, fatty acids, and amino acids than in white wholes and split grades. Conventional sun drying of cashew nuts revealed results similar to drying with apples regarding micronutrient concentrations. The high micronutrient content of industrial grade BB is reflected in widespread human consumption and better market value.

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.

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.

Patterns and compound specific stable carbon isotope analysis (δ13 C) of capsaicinoids in Cayenne chilli fruits of different ripening stages

INTRODUCTION

Capsaicinoids are alkaloids of high pungency which are exclusively formed by fruits of the genus Capsicum. Capsaicinoid content and composition of Capsicum fruits are influenced by ripening.

OBJECTIVE

Determination of changes in content and pattern of individual capsaicinoids in chilli pods with fruit ripening. Compound specific stable carbon isotope analysis (δ¹³ C values (‰), CSIA) was used for a better understanding of capsaicinoid development during fruit ripening.

METHODOLOGY

Cayenne chillies (Capsicum annuum) were grown in a glasshouse and harvested from different plants at four ripening stages (unripe, semi-ripe, ripe, overripe). Nine capsaicinoids (one verified by synthesis) were quantified by gas chromatography with mass spectrometry (GC-MS). For CSIA, an acetylation method for derivatising capsaicinoids was developed.

RESULTS

Variations in the patterns of the nine capsaicinoids were not relatable to a distinct ripening stage and also total contents varied extensively from plant to plant. However, changes in total capsaicinoid concentrations were systematic. In almost all plants, maximum values were reached in unripe fruits, then decreased to semi-ripe samples and increased again in the following ripening process. Likewise, δ¹³ C values of individual capsaicinoids were always by ~2‰ heavier in unripe than in semi-ripe or ripe fruits. However, direction of changes in sum-δ¹³ C values (‰) (taking contributions of all capsaicinoids together) could not be explained by corresponding variations in capsaicinoid concentrations.

CONCLUSIONS

Both quantification and δ¹³ C values (‰) verified the presence of ripening-related changes in the capsaicinoid content which may be caused by simultaneously proceeding reactions like synthesis, storage and degradation of capsaicinoids.

Isolation of saturated alkylresorcinols from rye grains by countercurrent chromatography

Alkylresorcinols (5-alkyl-1,3-dihydroxybenzenes) are amphiphilic phenolic lipid compounds that are abundant in cereals with highest contents in rye. Alkylresorcinols are suspected to show a wide range of favourable biological activities. For such and further testing, highly pure alkylresorcinol standards are required. Especially, purities >> 98% were partly difficult to obtain in the past. Here, we aimed to isolate the most abundant (saturated) alkylresorcinols from rye using countercurrent chromatography. To achieve very high purity, alkylresorcinol-containing extract (∼7.14 g) of rye grains (cold extracts with cyclohexane/ethyl acetate (46/54, w/w)) were preparatively transesterified followed by a preparative hydrogenation. Countercurrent chromatography separation of ∼1 g hydrogenated and transesterified rye grain extract using the solvent system n-hexane-ethyl acetate-methanol-water (9:1:9:1, v/v/v/v) yielded 51.8 mg AR17:0, 77.4 mg AR19:0, 57.2 mg AR21:0, 28.8 mg AR23:0 and 11.5 mg AR25:0 with purities >99% in either case. The isolated alkylresorcinol homologues can be used for subsequent bioassays.

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.

Novel "Matrix-Corrected Calibration" study for the detection of polyunsaturated fatty acids (PUFAs) in plasma and erythrocytes by means of a gas chromatography-mass spectrometry approach optimized to follow up long-term parental patients

An accurate and specific gas chromatography-mass spectrometry (GC-MS) method was optimized to quantify specific polyunsaturated fatty acids (PUFAs) in plasma and in erythrocyte membranes for clinical purposes. The developed and fully-validated method showed optimal linearity in addition to adequate results in terms of accuracy, intra-day and inter-day precision. By adopting the Matrix-Corrected Calibration approach on all the biological matrices tested, both the constant and the proportional errors of the developed analytical methodology were considered to assure that the method was not affected by matrix bias. Moreover, a pilot study involving patients in parental nutrition with two different compositions of the administered fat emulsion was performed. The comparison of results obtained in these patients with a group of healthy subjects (i.e. control population) showed significant differences in the collected values of PUFAs in both plasma and erythrocyte membranes, thus providing evidence that the described GC-MS method could be employed as a simple tool for fast and accurate PUFAs analysis aimed at optimizing parenteral nutrition protocols.

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).

Validation of the German version of the Mediterranean Diet Adherence Screener (MEDAS) questionnaire

Background

Health benefits of the Mediterranean Diet (MD) have been shown in different at-risk populations. A German translation of the Mediterranean Diet Adherence Screener (MEDAS) from the PREvención con DIeta MEDiterránea (PREDIMED) consortium was used in the LIBRE study, investigating effects of lifestyle-intervention on women with BRCA1/2 mutations. The purpose of the present study is to validate the MEDAS German version.

Methods

LIBRE is a multicentre (three university hospitals during this pilot phase), unblinded, randomized, controlled clinical trial. Women with a BRCA1/2 mutation of age 18 or over who provided written consent were eligible for the trial. As part of the assessment, all were given a full-length Food Frequency Questionnaire (FFQ) and MEDAS at baseline and after 3 months. Data derived from FFQ was compared to MEDAS in order to evaluate agreement or concordance between the two questionnaires. Additionally, the association of dietary intake biomarkers in the blood (β-carotene, omega-3, omega-6 and omega-9 fatty acids and high-sensitivity C-reactive protein (hsCRP)) with some MEDAS items was analyzed using t-Tests and a multivariate regression.

Results

The participants of the LIBRE pilot study were 68 in total (33 Intervention, 35 Control). Only participants who completed both questionnaires were included in this analysis (baseline: 66, month three: 54). The concordance between these two questionnaires varied between the items (Intraclass correlation coefficient of 0.91 for pulses at the highest and −0.33 for sugar-sweetened drinks). Mean MEDAS scores (sum of all items) were 9% higher than their FFQ counter-parts at baseline and 15% after 3 months. Higher fish consumption (at least 3 portions) was associated with lower omega-6 fatty acid levels (p = 0.026) and higher omega-3 fatty acid levels (p = 0.037), both results being statistically significant.

Conclusions

We conclude that the German MEDAS in its current version could be a useful tool in clinical trials and in practice to assess adherence to MD.

Trial registration

ClinicalTrials.gov, registered on March 12, 2014, identifier: NCT02087592. World Health Organization Trial Registration, registered on 3 August 2015, identifier: NCT02087592.

Unexpected Formation of Low Amounts of (R)-Configurated anteiso-Fatty Acids in Rumen Fluid Experiments

Anteiso-fatty acids (aFA) with odd carbon number are a class of branched-chain fatty acids (BCFA) mainly produced by bacteria. Bacterial sources are also made responsible for their occurrence in the low percent-range in lipids of ruminants (meat and milk) and fish. aFAs are chiral molecules and typically occur predominantly in form of (S)-enantiomers, and their primary precursor has been noted to be isoleucine. Yet, low proportions of (R)-aFAs were also detected in fish and cheese samples. Here we investigated the potential formation of (R)-aFAs by means of incubation experiments with rumen fluid from fistulated cows. Supplementation of rumen fluid with both L- and DL-isoleucine, resulted in a significant (α <0.05) increase of the aFA concentrations but in both cases enantiopure (S)-aFAs were observed. By contrast, incubations without addition of any isoleucine lead to a significant (α <0.05) formation of small proportions of (R)-aFAs similarly to those previously observed in fish and cheese. These results were consistently reproduced in three different years with rumen fluid from different cows fed different diets. All findings point to the existence of a further biosynthesis pathway of aFAs with different stereospecificity than the classic one using isoleucine as primer.

A comprehensive study of serum odd- and branched-chain fatty acids in patients with excess weight

OBJECTIVE

While small amounts of odd-chain fatty acids (OCFAs) and branched-chain fatty acids (BCFAs) were known to be present in mammals, it was quite recently that they were shown to play an important role in human health. However, still little is known on OCFA and BCFA profiles in subjects who have obesity. The aim of this study was to verify whether obesity is associated with changes in serum OCFA and BCFA profiles.

METHODS

Serum content of fatty acids was determined by gas chromatography-mass spectroscopy in 23 patients with excess weight and 21 nonobese controls.

RESULTS

Six OCFAs and six BCFAs (three iso-BCFAs and three anteiso-BCFAs) were found in sera from the examined subjects. Patients with excess weight presented with significantly lower serum iso-BCFA levels than the controls. Total serum content of iso-BCFAs correlated inversely with serum insulin, triglycerides, and 18:1/18:0 desaturation index. Both OCFA and iso-BCFA levels correlated inversely with C-reactive protein concentration.

CONCLUSIONS

Lower iso-BCFA content in patients with excess weight may be involved in elevation of serum concentration of triglycerides and inflammation. Decreased contents of iso-BCFAs in subjects with have obesity, and established anti-inflammatory, antidiabetic, and anticancer properties of these fatty acids, point to potential beneficial effects of an iso-BCFA-rich diet.

anteiso-Fatty Acids in Brussels Sprouts (Brassica oleracea var. gemmifera L.): Quantities, Enantioselectivities, and Stable Carbon Isotope Ratios

anteiso-Fatty acids (aFAs) are a class of branched-chain fatty acids that are characterized by one methyl branch on the antepenultimate carbon of the straight acyl chain. aFAs are mainly produced by bacteria, and sources in vegetables are scarce. This study reports the concentrations of odd-numbered aFAs (a15:0-a21:0) in Brussels sprout buds. Selective enrichment followed by enantioselective gas chromatography with mass spectrometry in the selected ion monitoring mode revealed that both a15:0 and a17:0 were (S)-enantiopure in Brussels sprout samples. δ(13)C values (‰) of a17:0 in Brussels sprouts were comparable with those of palmitic acid, indicating no different source for both fatty acids.

Branched-chain fatty acid content of foods and estimated intake in the USA

Branched-chain fatty acids (BCFA) are bioactive food components that constitute about 2 % of fatty acids in cows' milk fat. There are few systematic data available on the BCFA content of other foods to estimate dietary intakes. In the present study, we report BCFA distribution and content of fresh and processed foods representing the major foods in the American diet and estimate BCFA intake. BCFA are primarily components of dairy and ruminant food products, and are absent from chicken, pork and salmon. The mean BCFA intake of 500 mg/d was delivered primarily from dairy and beef food products; by comparison, average intake of the widely studied long-chain PUFA EPA and DHA has been estimated to be 100 mg/d. Common adjustments in the diet could double the daily intake of BCFA. The fermented foods sauerkraut and miso had appreciable fractions of BCFA, but, overall, they are low-fat foods providing very small amounts of BCFA in the diet, and other fermented foods did not contain BCFA as might have been expected from the influence of microbial exposure. These data support the quantitative importance of BCFA delivered primarily from dairy and beef food products and highlight the need for research into their effects on health.

Various concentrations of erucic acid in mustard oil and mustard

Erucic acid is a typical constituent of mustard or rape. Foodstuff with a high content of erucic acid is considered undesirable for human consumption because it has been linked to myocardial lipidosis and heart lesions in laboratory rats. As a result, several countries have restricted its presence in oils and fats. In this study, the erucic acid content in several mustard oils and prepared mustard samples from Germany and Australia was determined. Seven of nine mustard oil samples exceeded the permitted maximum levels established for erucic acid (range: 0.3-50.8%, limit: 5%). The erucic acid content in mustard samples (n=15) varied from 14% to 33% in the lipids. Two servings (i.e. 20 g) of the mustards with the highest erucic acid content already surpassed the tolerable daily intake established by Food Standards Australia New Zealand. However, a careful selection of mustard cultivars could lower the nutritional intake of erucic acid.

Two-dimensional ³¹P,¹H NMR spectroscopic profiling of phospholipids in cheese and fish

Phospholipids (PLs) comprise an important lipid class in food because of their technological use as emulsifiers and their nutritional value. This study used one-dimensional (31)P NMR and two-dimensional (2D) (31)P,(1)H COSY NMR spectroscopy for the determination of the PL composition of cheese and fish after liquid-liquid enrichment. This extraction step enabled the identification of 10 PLs in cheese and 9 PLs in fish by 2D (31)P,(1)H NMR. Variations in the (31)P shifts indicated differences in the fatty acids attached to the individual PLs. The total PL content in cheese fat and fish oil ranged from 0.3 to 0.4% and from 5 to 12%, respectively. Phosphatidylcholine was the most prominent PL in both matrices (up to 65%). Minor PLs (limit of detection = 4 nmol, i.e. 500 μL of an 8 μM solution) were identified in forms of phosphatidic acid, lysophosphatidic acid, and phosphatidylglycerol. Specific cross couplings and (1)H fine structures in the 2D (31)P,(1)H NMR spectra proved to be valuable for the assignment and verification of known and uncommon PLs in the samples.

Synthesis and tandem mass spectrometry of chlorinated triacylglycerols

The incorporation of 9,10-dichlorooctadecanoyl groups using enzyme-catalyzed acylation and protecting group strategies yielded specific regioisomers of di- and tetrachlorinated triacylglycerols. Hexachloro- and hexabromotriacylglycerols were synthesized by addition of chlorine or bromine to tri-(cis-9-octadecenoyl)glycerol. Upon electrospray ionization and tandem mass spectrometry, the sodium adduct ions of all compounds containing a 9,10-dichlorooctadecanoyl group readily lost two molecules of HCl when subjected to collision-induced dissociation. A mechanism describing sequential HCl losses and the formation of a conjugated diene is proposed for the loss of both vicinal chlorine atoms from an alkyl chain. This characteristic fragmentation behavior and the availability of characterized standards will facilitate the development of quantitative analytical methods for the determination of chlorinated triacylglycerols in lipid mixtures isolated from marine and other biological sources.

The "secret" in secretions: methodological considerations in deciphering primate olfactory communication

Olfactory communication in primates is gaining recognition; however, studies on the production and perception of primate scent signals are still scant. In general, there are five tasks to be accomplished when deciphering the chemical signals contained in excretions and secretions: (1) obtaining the appropriate samples; (2) extracting the target organic compounds from the biological matrix; (3) separating the extracted compounds from one another (by gas chromatography, GC or liquid chromatography, LC); (4) identifying the compounds (by mass spectrometry, MS and associated procedures); and (5) revealing biologically meaningful patterns in the data. Ultimately, because some of the compounds identified in odorants may not be relevant, associated steps in understanding signal function involve verifying the perception or biological activity of putative semiochemicals via (6) behavioral bioassays or (7) receptor response studies. This review will focus on the chemical analyses and behavioral bioassays of volatile, primate scent signals. Throughout, we highlight the potential pitfalls of working with highly complex, chemical matrices and suggest ways for minimizing problems. A recurring theme in this review is that multiple approaches and instrumentation are required to characterize the full range of information contained in the complex mixtures that typify primate or, indeed, many vertebrate olfactory cues. Only by integrating studies of signal production with those verifying signal perception will we better understand the function of olfactory communication.

Development, acceptability, and nutritional characteristics of a low-cost, shelf-stable supplementary food product for vulnerable groups in Kenya

BACKGROUND

Food-based approaches have been advocated as the best strategies to curb hunger and malnutrition in developing countries. The use of low-cost, locally available, nutritious foods in the development of supplementary foods has been recommended.

OBJECTIVE

To develop low-cost food supplements using different traditionally processed local foods, consisting of cereals, legumes, nuts, fish, and vegetables, to meet the nutrient requirements for vulnerable groups in Kenya.

METHODS

Four food supplements were developed and evaluated by taste panel procedures. The product containing amaranth grain, pigeon pea, sweet potato, groundnuts, and brown sugar was found to be the most acceptable supplement. Evaluation of nutritional composition, shelf-life, and cost analysis of the acceptable supplement was carried out to assess if it could satisfactorily provide more than 50% of the Recommended Dietary Allowances (RDAs) of the basic nutrients for vulnerable groups.

RESULTS

The acceptable supplement contained 453.2 kcal energy, 12.7 g crude protein, 54.3 g soluble carbohydrates, 20.8 g crude fat, and 10.1 g crude fiber per 110 g. The micronutrient contents were 93.0 mg calcium, 172.4 mg magnesium, 2.7 mg zinc, 5.7 mg iron, 0.8 mg vitamin B₁, 0.2 mg vitamin B₂, 7.9 mg niacin, 100 microg folic acid, and 140 microg retinol equivalent per 110 g. The supplement also contained 21% total essential amino acid in addition to appreciable levels of palmitic, stearic, oleic, linoleic, and alpha-linolenic fatty acids. The shelf-life study showed that it could be stored in different packaging materials (polythene bags, gunny bags, and kraft paper) at 26°C without deleterious effects on its chemical composition for up to 4 months. Cost analysis of the supplement indicated that the product could be competitively sold at US$0.812/kg (KES 65.50/kg).

CONCLUSIONS

Locally available indigenous foods can be used in the formulation of acceptable, low-cost, shelf-stable, nutritious supplementary foods for vulnerable groups.

Bioactive compounds in cashew nut (Anacardium occidentale L.) kernels: effect of different shelling methods

In the present study, the effects of various conventional shelling methods (oil-bath roasting, direct steam roasting, drying, and open pan roasting) as well as a novel "Flores" hand-cracking method on the levels of bioactive compounds of cashew nut kernels were investigated. The raw cashew nut kernels were found to possess appreciable levels of certain bioactive compounds such as beta-carotene (9.57 microg/100 g of DM), lutein (30.29 microg/100 g of DM), zeaxanthin (0.56 microg/100 g of DM), alpha-tocopherol (0.29 mg/100 g of DM), gamma-tocopherol (1.10 mg/100 g of DM), thiamin (1.08 mg/100 g of DM), stearic acid (4.96 g/100 g of DM), oleic acid (21.87 g/100 g of DM), and linoleic acid (5.55 g/100 g of DM). All of the conventional shelling methods including oil-bath roasting, steam roasting, drying, and open pan roasting revealed a significant reduction, whereas the Flores hand-cracking method exhibited similar levels of carotenoids, thiamin, and unsaturated fatty acids in cashew nuts when compared to raw unprocessed samples.

Quantitation of cis- and trans-monounsaturated fatty acids in dairy products and cod liver oil by mass spectrometry in the selected ion monitoring mode

Monounsaturated fatty acids (MUFAs) are important constituents of dietary fats. While cis-configurated isomers belong to the classic fatty acids of food, trans-fatty acids are suspected to pose a risk to human health. In either case, a thorough assessment of both positional and geometrical isomers of MUFAs is an important task in food and life sciences. For this purpose, a method suitable for routine analysis was developed. After lipid extraction and conversion of fatty acids into corresponding fatty acid methyl esters, cis and trans isomers of MUFAs were separated on silver-ion-impregnated cartridges. Fractions containing either cis- or trans-MUFAs were determined by gas chromatography-electron ionization mass spectrometry in the selected ion monitoring (GC/EI-MS-SIM) mode using [M-32](+) as quantification ions and [M-74](+) as well as M(+) as qualifier ions. A total of 14 MUFAs were available as reference standards, but a total of 40 MUFAs (22 cis and 18 trans isomers) were identified with high selectivity in samples of cheese, goat fat, human milk, and cod liver oil. The 18:1 and 16:1 isomers contributed most to both the cis- and trans-MUFAs. Application of internal standards allowed for the quantification of MUFAs only in the food samples. The amount of trans-fatty acids was determined to be 0.9- 4.3 g/100 g, with the lowest levels in human milk fat and the highest levels in Roquefort cheese. After exclusion of oleic acid, the concentrations of trans- and cis-MUFAs were at the same level in samples from ruminants and human milk fat.

Undecylenic acid: a valuable and physiologically active renewable building block from castor oil

A lot of attention is currently being paid to the transition to a biobased economy. In this movement, most efforts concentrate on the development of bioenergy applications including bioethanol, biodiesel, thermochemical conversion of biomass, and others. However, in the energy sector other nonbiomass alternatives are known, whereas no valuable alternatives are available when thinking about chemical building blocks. Therefore, it is also essential to develop new routes for the synthesis of bio-based chemicals and materials derived thereof. Such intermediates can originate either from plants or from animals. Castor oil is a non-edible oil extracted from the seeds of the castor bean plant Ricinus communis (Euphorbiaceae), which grows in tropical and subtropical areas. Globally, around one million tons of castor seeds are produced every year, the leading producing areas being India, PR China, and Brazil.2 10-Undecenoic acid or undecylenic acid is a fatty acid derived from castor oil that, owing to its bifunctional nature, has many possibilities to develop sustainable applications.

Stable carbon isotope ratios of methyl-branched fatty acids are different to those of straight-chain fatty acids in dairy products

Methyl-branched fatty acids (MBFAs) are the dominant form of fatty acid found in many bacteria. They are also found at low levels in a range of foodstuffs, where their presence has been linked to bacterial sources. In this study we evaluated the potential of compound-specific isotope analysis to obtain insights into the stable carbon isotope ratios (delta(13)C values in per thousand) of individual MBFAs and to compare them to the stable carbon isotope ratios of straight-chain fatty acids in food. Due to their low abundance in foodstuffs, the MBFAs were enriched prior to gas chromatography coupled to isotope ratio mass spectrometric (GC-IRMS) analysis. After transesterification, urea complexation was used to suppress the 16:0 and 18:0 methyl esters that were dominant in the samples. Following that, silver-ion high performance liquid chromatography was used to separate the saturated from the unsaturated fatty acids. The resulting solutions of saturated fatty acids obtained from suet, goat's milk, butter, and human milk were studied by GC-IRMS. The delta(13)C values of fatty acids with 12-17 carbons ranged from -25.4 per thousand to -37.6 per thousand. In all samples, MBFAs were most depleted in carbon-13, followed by the odd-chain fatty acids 15:0 and 17:0. 14:0 and 16:0 contained the highest proportions of carbon-13. The results from this study illustrate that MBFAs have distinctive delta(13)C values and must originate from other sources and/or from very different substrates. These measurements support the initial hypothesis that delta(13)C values can be used to attribute MBFAs to particular sources.