Muscle tissue is known to contain plasmalogenic lipids. Traditional methodologies for the analysis of lipids in muscle consists of methanolysis followed by gas chromatography (GC). The resultant dimethylacetals (DMA) are difficult to resolve because of extensive overlap with fatty acid methyl esters. In this study a new two-step procedure was applied to isolate DMAs from FAMEs from methanolysed horse muscle lipids (n=48) after saponification and solvent partitioning. Both total and isolated DMAs were analysed by GC and the extent of overlap was evident. The total methylated mixture was also analyzed using GC with online reduction (GC-OR x GC) which confirmed the identity of the FAME, DMA and aldehyde products. The DMA content in horse muscle tissue was found to be 55.7 mg DMAs in 100 g of meat, or 3.10 % of total lipids. The saturates 16:0 and 18:0 were the predominant DMA isomers, and 18:3n-3 and 18:2n-6 DMA were identified in this tissue. Samples with a higher (> 3 g/100 g of meat) intramuscular fat (IM) content showed a lower (p <= 0.05) absolute content of the DMAs compared to samples with lower IM fat content (15.3 vs 29.3 mg/g of fat, respectively).

The present study aimed to thoroughly describe the profile of fatty acids in mare milk from farms with different management systems and changes during lactation. Eighteen mares belonging to three commercial farms (6 mares per farm) were milked during the complete lactation period (six months). Fat content was determined by infrared spectroscopy, while fatty acid methyl esters were analyzed using a GC-FID. Mare milk, in general, contained 47.5 % saturated, 25.3 % monounsaturated, and 26.5 % polyunsaturated fatty acids. A high proportion of 18:2n-6 and 18:3n-3 but a low concentration of their long-chain metabolites was observed, and seven branched-chain fatty acids were identified. Stage of lactation significantly influenced the content of most individual fatty acids, and in general, milk from mares managed under pasture-based feeding systems showed a higher content of n-3 polyunsaturated fatty acids. This study provides new insights into mare milk FA composition and into dynamics of mare milk nutritional quality as affected by lactation stage and grazing intensity.

The fatty acid composition of fats and oils is commonly determined by gas chromatography after preparing fatty acid methyl esters (FAME). Capillary columns coated with polyethylene glycol emerged as the preferred separation tool for the quantification of the polyunsaturated fatty acids contained primarily in marine oils. However, their selectivity is inadequate for measuring the trans fatty acids (TFA) contained in refined vegetable oils, dairy fats, and marine oils. Highly polar 100% poly(biscyanopropyl siloxane) capillary columns provide the necessary selectivity, but small differences in the phase polarity caused by column age, conditioning, or manufacturing variations affect the reproducibility of their separations of these complex samples. In this study, a simple procedure is described to compensate for small variations in column selectivity by adjusting the elution temperature. The balance between the dipole-induced dipole interactions and dispersive interactions was determined by measuring selectivity factors [SF(i)] corresponding to the elution of an unsaturated FAME such as 18:3n-3 relative to two saturated FAME such as 20:0 and 22:0. Knowing the SF(i) provided by the installed capillary column at a given elution temperature, and the SF(i) of the target separation, we propose a simple calculation to determine the necessary elution temperature adjustment to achieve (or restore) the desired separation. After determining the SF(i) which provides the optimal separation of TFA, the novel methodology was applied to the separation of refined vegetable oils, butter fats, and marine oils.

The Fourier transform near infrared (FT-NIR) spectrum of extra virgin olive oils (EVOO) shows two minor carbonyl absorptions at 5280 and 5180 cm(-1) that has been used to assess their authenticity. To establish components absorbing at 5280 cm(-1), volatile aldehydes and ketones, triacylglycerol (TAG), diacylglycerols (DAG), free fatty acids (FFA), phenolics, and water are investigated and sometimes added to refined olive oil (ROO). Except TAG, the remaining carbonyls contribute to 5280 cm(-1) by broadening peak. Water absorption is demonstrated by its removal using Na2SO4 or deuterium oxide addition; FT-NIR spectral changes are reconstituted by water addition. Water absorption depends on being free or complexed with polar compounds in oil. The size of absorption is not related to abundance, but on unique absorption specificity of components; water shows the strongest absorption. Heat removes water and volatiles, leaving behind DAG, FFA, and phenolics, and makes it possible to differentiate absorption of water, volatile and non-volatile carbonyls. Cloudy olive oils are analyzed using FT-NIR methodology after warming for 3 min at 50 degrees C. FT-NIR index values are replaced by a new calibration model based on correlating gravimetric mass loss of water plus volatiles with spectral changes. The FT-NIR methodology is expanded to include EVOOs with 15.5% to 21% linoleic acid. Practical Applications: Testing for authenticity of EVOOs remains a challenge because adulterations continue to be a problem due to economic gains. Spectroscopy methods, specifically FT-NIR, are much preferred to targeted chemical methods because they measure all constituents in products and are non-destructive and fast. The current universal FT-NIR methodology assesses 13 different parameters: five major FAs, and the DAG and FFA contents. The FT-NIR index value measuring the content of moisture plus volatiles is now replaced by a gravimetric determination. The methodology identifies four major types of adulterants, high in oleic acid, linoleic acid, palm olein or ROO. The composition of olive oils makes it necessary to develop five oil-specific groups, but cloudy samples still need to be clarified by slight warming before measuring. The value of this universal FT-NIR methodology will increase after being adopted by commercial and in regulatory settings.

The oxidation of methyl linoleate has been studied extensively, and many of the oxidative mechanisms have been demonstrated in great detail. The proposition that conjugated linoleic acid or other olefins or diene fatty acids are oxidized by atmospheric oxygen alone must be put in perspective because this is an unlikely outcome under normal conditions. We will demonstrate that glass autosampler vials are enhanced as activators in the presence of light, and that they are strong initiators of fatty acid methyl esters (FAME) "oxidation." For comparative purposes, we examined other fatty acid FAME held in glass vials under dark conditions. The whole experiment could be interpreted as a measure of the glass as an initiator for the oxidation of FAME under conditions of dark and ambient light. The same solutions that were used to oxidize FAME in glass vials were also evaporated into Polypropylene vials.

The complexity of determining the composition of animal tissue lipids is greatly increased by the presence of plasmalogens in which the alkyl chain is linked to glycerol by an enol ether bond instead of being esterified. Acidic methanolysis of animal tissue lipids provides the simultaneous scission of acyl and alkenyl ether moieties, but the complexity of the products of reaction poses a great challenge in their gas chromatographic analysis. Two-dimensional gas chromatography with online reduction (GC-OR x GC) provided the resolution of all components contained in acid methanolyzed animal lipids, taking advantage of the selective hydrogenation of alkenyl ether methanolysis products prior to the second-dimension separation (2D). In this study, we also studied the chemical transformations occurring during the acidic methanolysis of animal lipids and the subsequent gas chromatographic analysis. In particular, we observed that using methanolysis reagents contaminated with water resulted in the undesired formation of fatty aldehydes, and we made recommendations on how to avoid these side reactions using proper methanolysis conditions. Products of acidic methanolysis were studied by GC-OR x GC, GC-MS, NMR spectroscopy, and GC with flame ionization detection (GC-FID). We defined the GC-FID elution order of animal lipid acidic methanolysis products using 100 m x 0.25 mm 100% bis(cyanopropyl)siloxane columns and two different set of elution conditions: isothermal elution at 180 degrees C, and a temperature program optimized for dairy fats. A simple procedure for isolating dimethyl acetals (DMA) prior to GC analysis is also described. Published by Elsevier B.V.

Extra virgin olive oils (EVOO) command higher prices because they contain health-promoting nutrients and desirable sensory characteristics. Many targeted methods have limited success in determining olive oil authenticity. Therefore, attention has been paid to rapid spectroscopic methods that provide the composition of multiple components. A Fourier transform near infrared (FT-NIR) method was reported that identified five major fatty acids and volatiles in EVOO, plus four models that identify common adulterants and their content. However, it did not include diacylglycerol (DAG) and unesterified fatty acids (FFA) known to be associated with freshness of the oil. The newly improved FT-NIR method now includes 1,2-DAG and 1,3-DAG models based on the DAG isomer content in freshly prepared EVOO, and a FFA model based on quantitative addition of oleic acid. The new FT-NIR method was used to reassess previously used EVOO products to evaluate their freshness. Based on these results and review of the published data, we propose several revisions to the EVOO regulation: limit FFA to ≤0.5%, include 1,2-DAG and 1,3-DAG in standard, place no limit on 1,2-DAG because it characterizes the oils, set the 1,3-DAG content to ≤1.0%, and lower the content of 18:2n-6 to 1.5%.

The study was conducted under real grazing conditions and addressed the hypothesis that the fatty acid composition of milk from ewes reared in mountain farms is more beneficial from human health perspective compared to milk from valley farms. Bulk raw milk from six commercial flocks was sampled during the milking period from May to June. Flocks were managed under extensive grazing but, according to usual local practices in valley farms, sheep diet was supplemented with a small amount of concentrate in May. Botanical species from mountain and valley areas where commercial flocks grazed were also collected. Sheep milk from mountain farms showed higher fat content that was richer in α-linolenic acid and its biohydrogenation intermediates, long-chain saturated, branched-chain, and cis-monounsaturated fatty acids compared to milk from valley farms. Differences in fatty acid profile of botanical species plus the concentrate supplementation given to sheep in May were the factors that mostly influenced the fatty acid composition of milk from mountain compared to valley farms. Overall, this approach has evidenced that milk produced in mountain regions of northern Spain would add value to the ‘mountain product’ label, and would contribute to maintain a resilient and sustainable dairy production system in these areas.

Incubation of DHA with sheep rumen fluid resulted in 80% disappearance in 6 h. The products were analyzed as their fatty acid (FA) methyl esters by GC-FID on SP-2560 and SLB-IL111 columns. The GC-online reduction × GC and GC-MS techniques demonstrated that all DHA metabolites retained the C22 structure (no evidence of chain-shortening). Two new transient DHA products were identified: mono-trans methylene interrupted-DHA and monoconjugated DHA (MC-DHA) isomers. Identification of MC-DHA was confirmed by their predicted elution using equivalent chain length differences from C18 FA, their molecular ions, and the 22:5 products formed which were the most abundant at 6 h. The 22:5 structures were established by fragmentation of their 4,4-dimethyloxazoline derivatives, and all 22:5 products contained an isolated double bond, suggesting formation via MC-DHA. The most abundant c4,c7,c10,t14,c19-22:5 appeared to be formed by unknown isomerases. Results suggest that the initial biohydrogenation of DHA was analogous to that of C18 FA.

Fourier transform near infrared spectroscopy was recently demonstrated to be an excellent method to evaluate the authenticity and adulteration of extra virgin olive oil. Since this method is matrix dependent, it takes a chemical fingerprint of all the components which sets it apart from the targeted methods. Careful examinations of the Fourier transform near infrared spectra lead to the identification of a minor carbonyl overtone absorption at 5269 cm−1 associated with the volatile fraction in extra virgin olive oil that appears to be a reliable indicator of authenticity. The same spectra were used to identify the fatty acids present in the oil using models based on comparison to accurate GC data. Gravimetric mixtures of extra virgin olive oil with refined edible oils were then prepared to develop PLS1 calibration models to identify possible adulterants and by how much. The great varietal difference in olive oils made it necessary to develop four unique sets of PLS1 calibration models for each extra virgin olive oil variety. As a result, an extra virgin olive oil acceptance specification was established.

This study was undertaken to provide a thorough analysis of the neutral lipid (NL) and polar lipid (PL) fractions of horse meat that included the content and distribution of acyl and alkenyl moieties in foals under different rearing conditions. Two groups of crossbred horses were studied; the first group was selected from suckling foals produced under grazing conditions and slaughtered at 4 months of age (n=8), and the second group was selected from concentrate-finished foals and slaughtered at 12 months of age (n=7). There were significant differences related to the age and feeding practices of foals which affected the intramuscular (IM) fat content and the fatty acid (FA) composition of NL and PL fractions. Samples from suckling foals were leaner and provided the highest content of methylation products from the plasmalogenic lipids, and total and n-3 polyunsaturated fatty acid (PUFA). By contrast, the meat from concentrate-finished foals had a higher IM fat level resulting in a greater accumulation of 16:0 and total monounsaturated FAs in the NL fraction, whereas the muscle PL fraction retained a similar FA composition between both groups. Linolenic acid was preferentially deposited in the NL fraction, but linoleic acid and the long-chain n-3 and n-6 PUFAs were incorporated into the PL fraction where they served as cell membrane constituents and in eicosanoid formation.

Custom made silver ion solid‐phase extraction (Ag+‐SPE) cartridges with glass housing were evaluated to see whether they could be used to analyze the trans fatty acids (TFA) in animal products when present at low concentration. Previous attempts were not successful to identify and characterize the TFA using commercial Ag+‐SPE cartridges, because of the coelution of artifacts from these cartridges. The glass cartridges proved successful to identify the low levels of TFA present in horse and wild boar meat. It is recommended that the supplier make available Ag+‐SPE cartridges in glass housing to avoid the problem of interferences.Practical applications: It was previously shown that commercially available silver ion solid‐phase extraction (Ag+‐SPE) cartridges could not be used to analyze biological samples with low levels of TFAs, because of interfering contaminants that eluted from the polypropylene housing. Custom made glass cartridges were generously provided by the supplier, and they proved successful to fractionate the geometric isomers of horse and wild boar lipids both of which are known to contain low levels of TFAs. Subsequent gas chromatographic analysis made it possible to identify the trans and cis isomers without interference of contaminants. The unsaturated fatty acid fractions from these glass cartridges were also free of contaminants.Ag+‐SPE cartridges in glass housing are recommended to resolve and identify the trans isomers when present at low concentrations in biological samples.

Rahman, L. 1978. Indian J. Agric. Sci. 48(7): 401–406. Pleines et al. 1989. Theor. Appl. Genet, 78: 793–797. “The Development of Improved Rapeseed Cultivars”. B.R. Stefansson from High and Low Erucic Acid Rapeseed Oils, Chapter 6, edited by John K.G. Kramer, Frank D. Sauer, and Wallace J. Pigden, pp. 143-159, Academic Press Canada T5 Inventors: Ian Grant; David G. Charne, both of (1983). Guelph, Canada (List continued on next page.) 73) Assignee: Pioneer Hi-Bred International, Inc., Des Moines, Iowa Primary Examiner-David T. Fox Attorney, Agent, or Firm-Burns, Doane, Swecker & 21 Appl. No.: 399,926 Mathis, L.L.P.

Economically motivated adulteration (EMA) of extra virgin olive oils (EVOO) has been a worldwide problem and a concern for government regulators for a long time. The US Food and Drug Administration (FDA) is mandated to protect the US public against intentional adulteration of foods and has jurisdiction over deceptive label declarations. To detect EMA of olive oil and address food safety vulnerabilities, we used a previously developed rapid screening methodology to authenticate EVOO. For the first time, a recently developed FT-NIR spectroscopic methodology in conjunction with partial least squares analysis was applied to commercial products labeled EVOO purchased in College Park, MD, USA to rapidly predict whether they are authentic, potentially mixed with refined olive oil (RO) or other vegetable oil(s), or are of lower quality. Of the 88 commercial products labeled EVOO that were assessed according to published specified ranges, 33 (37.5%) satisfied the three published FT-NIR requirements identified for authentic EVOO products which included the purity test. This test was based on limits established for the contents of three potential adulterants, oils high in linoleic acid (OH-LNA), oils high in oleic acid (OH-OLA), palm olein (PO), and/or RO. The remaining 55 samples (62.5%) did not meet one or more of the criteria established for authentic EVOO. The breakdown of the 55 products was EVOO potentially mixed with OH-LNA (25.5%), OH-OLA (10.9%), PO (5.4%), RO (25.5%), or a combination of any of these four (32.7%). If assessments had been based strictly on whether the fatty acid composition was within the established ranges set by the International Olive Council (IOC), less than 10% would have been identified as non-EVOO. These findings are significant not only because they were consistent with previously published data based on the results of two sensory panels that were accredited by IOC but more importantly each measurement/analysis was accomplished in less than 5 min.

Fourier transform near infrared spectroscopy was recently demonstrated to be an excellent method to evaluate the authenticity and adulteration of extra virgin olive oil. Since this method is matrix dependent, it takes a chemical fingerprint of all the components which sets it apart from the targeted methods. Careful examinations of the Fourier transform near infrared spectra lead to the identification of a minor carbonyl overtone absorption at 5269 cm−1 associated with the volatile fraction in extra virgin olive oil that appears to be a reliable indicator of authenticity. The same spectra were used to identify the fatty acids present in the oil using models based on comparison to accurate GC data. Gravimetric mixtures of extra virgin olive oil with refined edible oils were then prepared to develop PLS1 calibration models to identify possible adulterants and by how much. The great varietal difference in olive oils made it necessary to develop four unique sets of PLS1 calibration models for each extra virgin olive oil variety. As a result, an extra virgin olive oil acceptance specification was established.

The objective of the present study was to assess the fatty acid composition of horse-meat available at the retail market in northern Spain. Horse steaks (Longissimus thoracis et lumborum muscle; n=82) were purchased from butcher-shops and large grocery stores throughout six northern regions of Spain in two different seasons. Fat content differed significantly among regions (1.12 to 2.77%). Samples with higher intramuscular fat content presented the highest percentages of total monounsaturated fatty acids and the lowest contents of dimethylacetal and polyunsaturated fatty acids (PUFA), while the opposite was found in the leanest samples. A high variability was observed in the muscle and subcutaneous n-3 PUFA content. Overall, total n-3 PUFA content ranged between 1.17% and 18.9% in muscle fat and between 1.52% and 27.9% in backfat. Interestingly, almost 5% of surveyed loins from horse carcasses (4 out of 82) contained over 300mg of linolenic acid per 100g of meat which could have been marketed as a "source" of n-3 FAs according to Commission Regulation (EU) No 116/2010.

Fatty acids are preferentially analyzed by gas chromatography in the form of methyl ester derivatives and employing polar or highly polar capillary columns. This module describes the separations provided by the three most currently used capillary columns for fatty acid methyl ester analysis: a polar poly(ethylene glycol) capillary column, a highly polar 100% poly(biscyanopropyl siloxane) column, and the extremely polar SLB-IL111. The elution profiles provided by each capillary column are established by analyzing FAMEs prepared from a bovine butter high in vaccenic acid and menhaden oil.