Capillary GLC Research Articles

Determination of methoxypyrazines in dry wines

The quality of wine depends not only on the balance of volatile and non-volatile macro-components, but also on the content of micro-components contained in ng, such as methoxypyrazines. They form shades of green vegetables – peas, asparagus, which are undesirable in excess for grape wines. Due to extremely low concentrations and serious interference from the complex wine matrix, their direct quantitative analysis is difficult. The general opinion of the researchers indicates that the direct determination of methoxypyrazines by available chromatography methods is practically impossible. Therefore, as a sample preparation, various types of extraction concentration are mainly offered, providing for subsequent concentrate purification. The possibilities of different variants of the QuEChERS technology are evaluated. The information analysis suggests that QuEChERS preparation will be the most accessible and effective, which can then be easily combined with analysis by gas-liquid chromatography methods. Due to the volatility of methoxypyrazines, capillary GLC with a highly sensitive detector is proposed as the main method of analysis. Some advantage is given to multidimensional analysis: the use of a mass spectrometer in combination with a flame ionization detector shows higher reliability of the results. The use of a fairly simple but reliable flame ionization detector, which is able to ensure the reliability of measurements, is evaluated. In general, the approaches proposed by the researchers make it possible to ensure the necessary accuracy and quality of the quantitative determination of methoxypyrazines in wine samples.

Trends in the development of analytical methods for determination of the quality and authenticity of foodstuffs

The review presents several results of investigations carried out at the Federal Research Centre for Nutrition, Biotechnology and Food Safety on the development and application of modern chemical-analytical methods for determining the quality indicators, nutritional and biological value of foodstuffs. Particular attention is paid to methodological approaches to the determination of biologically active substances of dietary supplements of plant origin, to the definition of criteria for authenticity and methods to disclose falsification of food and dietary supplements. The practical application of modern analytical techniques (capillary GLC, capillary electrophoresis, HPLC with a mass spectrometric detection, UV/VIS diode-array detection, etc.), combining high efficiency and selective separation and detection for identification and qualitative and quantitative determination of components in complex matrix of foodstuffs and dietary supplements is shown.

Sensitivity of fatty acid desaturation and elongation to plasma zinc concentration: a randomised controlled trial in Beninese children.

Zn status may affect fatty acid (FA) metabolism because it acts as a cofactor in FA desaturase and elongase enzymes. Zn supplementation affects the FA desaturases of Zn-deficient rats, but whether this occurs in humans is unclear. We evaluated the associations between baseline plasma Zn (PZn) concentration and plasma total phospholipid FA composition, as well as the effect of daily consumption of Zn-fortified water on FA status in Beninese children. A 20-week, double-blind randomised controlled trial was conducted in 186 school age children. The children were randomly assigned to receive a daily portion of Zn-fortified, filtered water delivering on average 2·8 mg Zn/d or non-fortified filtered water. Plasma total phospholipid FA composition was determined using capillary GLC and PZn concentrations by atomic absorption spectrometry. At baseline, PZn correlated positively with dihomo-γ-linolenic acid (DGLA, r 0·182; P=0·024) and the DGLA:linoleic acid (LA) ratio (r 0·293; P<0·000), and negatively with LA (r -0·211; P=0·009) and the arachidonic acid:DGLA ratio (r -0·170; P=0·036). With the intervention, Zn fortification increased nervonic acid (B: 0·109; 95 % CI 0·001, 0·218) in all children (n 186) and more so in children who were Zn-deficient (n 60) at baseline (B: 0·230; 95 % CI 0·023, 0·488). In conclusion, in this study, Zn-fortified filtered water prevented the reduction of nervonic acid composition in the plasma total phospholipids of children, and this effect was stronger in Zn-deficient children. Thus, Zn status may play an important role in FA desaturation and/or elongation.

Determination of Labeled Fatty Acids Content in Milk Products, Infant Formula, and Adult/Pediatric Nutritional Formula by Capillary Gas Chromatography: Collaborative Study, Final Action 2012.13.

A collaborative study was conducted on AOAC First Action Method 2012.13 "Determination of Labeled Fatty Acids Content in Milk Products and Infant Formula by Capillary Gas Chromatography," which is based on an initial International Organization for Standardization (ISO)-International Dairy Federation (IDF) New Work Item that has been moved forward to ISO 16958:2015|IDF 231:2015 in November 2015. It was decided to merge the two activities after the agreement signed between ISO and AOAC in June 2012 to develop common standards and to avoid duplicate work. The collaborative study was performed after having provided highly satisfactory single-laboratory validation results [Golay, P.A., & Dong, Y. (2015) J. AOAC Int. 98, 1679-1696] that exceeded the performance criteria defined in AOAC Standard Method Performance Requirement (SMPR(®)) 2012.011 (September 29, 2012) on 12 products selected by the AOAC Stakeholder Panel on Infant Formula (SPIFAN). After a qualification period of 1 month, 18 laboratories participated in the fatty acids analysis of 12 different samples in duplicate. Six samples were selected to meet AOAC SPIFAN requirements (i.e., infant formula and adult nutritionals in powder and liquid formats), and the other Six samples were selected to meet ISO-IDF requirements (i.e., dairy products such as milk powder, liquid milk, cream, butter, infant formula with milk, and cheese). The fatty acids were analyzed directly in all samples without preliminary fat extraction, except in one sample (cheese). Powdered samples were analyzed after dissolution (i.e., reconstitution) in water, whereas liquid samples (or extracted fat) were analyzed directly. After addition of the internal standards solution [C11:0 fatty acid methyl ester (FAME) and C13:0 triacylglycerols (TAG)] to the samples, fatty acids attached to lipids were transformed into FAMEs by direct transesterification using methanolic sodium methoxide. FAMEs were separated using highly polar capillary GLC and were identified by comparison with the retention times of pure analytical standards. Quantification of fatty acids was done relative to C11:0 FAME as internal standard and to instrument response factors (determined separately using calibration standards mixture). The performance of the method (i.e., transesterification) was monitored in all samples using the second internal standard, C13:0 TAG. RSDR values were summarized separately for labeled fatty acids in SPIFAN materials and ISO-IDF materials due to different expression of results. This method was applied to representative dairy, infant formula, and adult/pediatric nutritional products and demonstrated global acceptable reproducibility precision for all fatty acids analyzed (i.e., 46 individuals and/or groups) for these categories of products.

Evaluation of the oil Produced from lettuce crop cultivated under three irrigation conditions

Three oil lettuce seed samples ( lactuca Sativa LS10, LS20, LS30) were cultivated under three irrigation conditions (well, normal and water deficient conditions, after 10, 20 and 30 days respectively) to evaluate their oils and to see to what extent the oil lettuce plant resists draught conditions. The oils extracted from the three seed samples were evaluated by determining eight lipid profiles using HPLC in conjunction with capillary GLC. Lettuce seed oils are characterized by high contents of linoleic and oleic acids. Of the triacyl glycerols determined, those containing linoleyl and oleyl acyles are the major ones. The whole sterol profiles include β-sitosterol (as major component) followed by 7-stigmasterol, campesterol and 5-stigmasterol, which were found in all the lettuce seed oil samples but with slight differences. Furthermore, sterol patterns of the free and acylated sterols, free and acylated sterylglycosides were determined. It was found that LS30 oil has the highest tocopherol content and α-tocopherol is the only constituent in all the lettuce seed oil samples. On the other hand, the 2-position in the lettuce seed oil samples is mainly acylated by unsaturated fatty acids (98.6%) namely, oleic and linoleic acids. According to these results, it can be concluded that irrigation conditions do not affect the lipid constituents of the oil and the oil lettuce plant resists draught and its lipid profiles are in agreement with those of conventional vegetable oils.

Study of Intermolecular Interactions Involved in Capillary GLC with Liquid Crystal Compounds as Stationary Phases

Abraham's equation was employed in order to investigate nonspecific intermolecular interactions involving liquid crystals. Several aromatic azo derivatives, proved to have liquid crystal behavior, were used as stationary phases in capillary gas chromatography. The polarizability, polarity, hydrophobicity and hydrogen-bond donor or acceptor characters were estimated using the Abraham solvation model. Calculations were based on the isothermal retention times for 25 compounds, in the temperature range between 70˚ and 170˚C, both in the heating and the cooling mode. The descriptors R, � , �� , �� , and logL 16 (Abraham parameters) were converted into orthogonal descriptors following Randi� 's procedure. The above-mentioned properties involve the r, s, a, b and l coefficients, respectively, which were determined by means of multilinear regression applied to the considered set. Following the orthogonalization procedure, the polarizability term (rR*) was found to be statistically insignificant in the case of the studied compounds. Plots of these coefficients vs temperature are discussed, in order to allow estimations regarding the retention mechanism and contributions of polar and Van der Waals interactions. The variation of properties (e.g. polarity, hydrogen-bond donor and hydrogen-bond acceptor character) with temperature was assigned to the changes in the molecular geometry of the compound used as stationary phase.

Efficient in vitro elicitation of β-carboline alkaloids in transformed root cultures of Peganum harmala

An efficient in vitro production of biomass hairy root cultures and elicitation of β-carboline alkaloids of Peganum harmala was established from P. harmala seedlings. Hairy root culture was arised by inoculation of the excised seedling with Agrobacterium rhizogenes. Analysis of rolC and virC genes by using polymerase chain reaction (PCR) has confirmed the transformation of the root culture. Hairy root cultures were employed to study the production of harmine as the main β-carboline alkaloids. The transformed cultures were incubated with potential elicitors, such as hydrogen peroxides (H2O2), or biosynthetic precursor as tryptophane in order to stimulate the biosynthesis of β-carboline alkaloids, mainly harmine as the major one. Profile and amounts of β-carboline alkaloids were analyzed using capillary GLC–MS.The results revealed that, treatment of the cultures with H2O2 (0.01%) induced the accumulation of harmine, as the major β-carboline alkaloids in root, by approximately sixfold as compared to the untreated control. The highest stimulation resulted in a harmine level of ca. 4.5mg/g DW after 24h of incubation. Concerning the biosynthetic precursor, tryptophane (2mM) enhanced the alkaloid production approximately fivefold (0.25–0.3mg/g DW) within 24h.

Dietary fatty acid determinants of human milk fatty acids.

Human milk provides fatty acids (FA) for energy and essential n‐6 and n‐3 FA to support infant growth and development. The n‐3 FA docosahexaenoic acid (DHA) particularly important because of its crucial role in neural development and function. Low milk DHA is associated with poor infant visual and neural development. Using a longitudinal blinded intervention with 400mg/d DHA or placebo in gestation, we addressed the relationship between maternal n‐6 and n‐3 fatty acid status in gestation and DHA secretion in milk, and dietary determinants fatty acid intake and milk fatty acids. Blood was collected at 16 and 36 wks gestation, then breast milk collected at 1 mth postpartum for 156 mothers who exclusively breast fed term infants. FA was determined using 100m capillary column GLC. Fatty acid methodology, recovering trans and medium chain FA, impacts the number and accuracy of FA quantization, and data interpretation. Milk DHA was positively correlated to maternal DHA in gestation, varied from 0.06 to 1.25% milk FA, and was inversely related to milk trans FA. Medium chain FA from mammary gland synthesis, varied 3 fold, and were inversely related to milk 18:2n‐6 and 18:3n‐3, but not DHA, 20:5n‐3 or 20:4n‐6. Milk FA vary widely; diets high in hydrogenated fats are associated with low milk DHA, while diets rich in unsaturated vegetable oils may lower MCFA secretion in human milk. Supported by CIHR.

Direct Diet Quantification Indicates Low Intakes of (n-3) Fatty Acids in Children 4 to 8 Years Old

Estimates of essential fatty acid intakes, including (n-3) PUFA, are available in pediatric populations based on limited indirect approaches. Furthermore, recommended intakes for short- and long-chain (LC) (n-3) PUFA have emerged for this population. This study provides direct quantification of fatty acid intakes in children aged 4–8 y. Identical portions of all food and natural health products consumed over 3 d were collected. Duplicate samples were analyzed for energy, macronutrients, and fatty acids, including α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) by high performance capillary GLC. The results for 41 children [25 females, 16 males; 5.8 ± 0.2 y (mean age ± SEM)] showed daily energy intakes of 5879 ± 211 kJ (mean ± SEM) and (n-3) PUFA intakes in mg/d as follows: ALA, 1161 ± 108; EPA, 38.4 ± 9.3; DPA, 26.3 ± 3.9; and DHA, 54.1 ± 11.4. Based on the Dietary Reference Intakes from the Institute of Medicine, 61% of the children met the adequate intake for ALA and 22% met the suggested adequate intake for DHA+EPA (10% of the adequate intake for ALA). These intakes were also compared with the recent Australia/New Zealand recommendations for children, where only 51% met the recommended intake for EPA+DPA+DHA. These results demonstrate a moderate shortfall in ALA intake in Canadian children and a nutrient gap for the LC (n-3) PUFA, including DHA, when comparing intakes for this population to suggested and recommended intakes.

Fatty acid pattern in serum is associated with bone mineralisation in healthy 8-year-old children

Animal studies have shown that fatty acids (FA) are important for normal bone development. Human data are scanty and mostly related to diseases. We hypothesised that serum FA pattern might be related to bone mineralisation in healthy children. Serum phospholipid FA pattern was studied in relation to bone parameters in eighty-five healthy Caucasian 8-year-olds. Dual-energy X-ray absorptiometry and blood sampling for analysis of serum phospholipid FA by capillary GLC were performed on the same day. SFA concentrations were associated with bone mineral density (BMD) of the hip, lumbar spine and total body. There was a general trend that linoleic acid (LA; 18 : 2n-6) was negatively associated with BMD, since that was found both for the LA concentration, the total n-6 concentration and the ratio of n-6:n-3 FA. Arachidonic acid (AA; 20 : 4n-6) was positively correlated with bone mineral content (BMC) and BMD of total body, as was the corresponding z-score and the AA:LA ratio. Both saturated and polyunsaturated serum phospholipid FA were associated with BMC and BMD in healthy children. LA and AA were found to inversely influence bone mineralisation and the association with the n-6:n-3 ratio suggested that this balance might also be of importance. The general trend of a negative influence of high n-6 FA concentrations on bone mineralisation might be of concern in relation to the changes in the Western diet. Longitudinal studies are necessary to verify if different bone compartments and different grades of modelling are related to different FA patterns.

Investigation of Liquid Wax Components of Egyptian Jojoba Seeds

Egyptian jojoba seeds newly cultivated in Ismailia desert in Egypt promoted us to determine its lipid components. Fatty alcohols, fatty acids, wax esters and sterols patterns were determined by capillary GLC whereas, tocopherols profile, isopropenoid alcohols and sterylglycosides were determined by HPLC. The Egyptian seeds are rich in wax esters (55 %) with fatty alcohols C20:1 and C22:1 as major components and amounted to 43.0 % and 45.6 % respectively followed by C24:1 and C18:1(9.6 % and 1.3 % respectively). The fatty acids profile showed that C20:1 is the major constituent (60 %) followed by C18:1 and C22:1 (14.5 and 11.8 % respectively) whereas C24:1 was present at low concentration amounted to 1.6 %. In addition, the Egyptian jojoba wax contained C18:2 fatty acid at a level of 8.7 %. Wax esters composition showed that the local wax had C42 and C40 esters as major components amounted to 51.1 and 30.1 % respectively. Also, it had C44 and C38 at reasonable amounts (10.0 and 6.3 % respectively). Whereas C36 and C46 were present at lower concentrations amounted to 1.4 and 1.1 respectively. The sterols analysis showed the presence of campe-, stigma-, beta-sito-, and isofuco- sterol amounting to 18.4 %, 6.9 %, 68.7 %, and 6.0 % respectively. The tocopherols pattern revealed that the local seed wax contained gamma-tocopherol as major constituent (79.2 %) followed by alpha-tocopherol (20.3 %). beta-tocopherol as well as delta-tocopherol were found as minor constituents. The isopropenoid alcohols and the sterylglycosides (free and acylated) were not detected. The wax is proposed to be used in oleo chemistry and cosmetics.

Lipidomic analysis of Toxoplasma gondii tachyzoites rhoptries: further insights into the role of cholesterol

Rhoptries are secretory organelles involved in the virulence of the human pathogen Toxoplasma gondii. In the present study we have used HPLC and capillary GLC to isolate and quantify lipids from whole Toxoplasma cells and their purified rhoptries. This comparative lipidomic analysis revealed an enrichment of cholesterol, sphingomyelin and, most of all, saturated fatty acids in the rhoptries. These lipids are known, when present in membranes, to contribute to their rigidity and, interestingly, fluorescence anisotropy measurements confirmed that rhoptry-derived membranes have a lower fluidity than membranes from whole T. gondii cells. Moreover, although rhoptries were initially thought to be highly enriched in cholesterol, we demonstrated that cholesterol is present in lower proportions, and we have provided additional evidence towards a lack of involvement of rhoptry cholesterol in the process of host-cell invasion by the parasite. Indeed, depleting the cholesterol content of the parasites did not prevent the secretion of protein-containing rhoptry-derived vesicles and the parasites could still establish a structure called the moving junction, which is necessary for invasion. Instead, the crucial role of host cholesterol for invasion, which has already been demonstrated [Coppens and Joiner (2003) Mol. Biol. Cell 14, 3804-3820], might be explained by the need of a cholesterol-rich region of the host cell we could visualize at the point of contact with the attached parasite, in conditions where parasite motility was blocked.

Docosahexaenoic acid is associated with endosteal circumference in long bones in young males with cystic fibrosis

In children, but not adults with cystic fibrosis (CF), associations between essential fatty acids (FA) and bone mass have been reported. Low bone mineral density (BMD) is common in these patients. Previously we found a normal annual increase of BMD, suggesting a potential for attaining normal bone mass. The aim of the present study was to investigate phospholipid FA pattern in relation to bone in young adult men with CF compared with healthy controls. Fourteen male patients with CF were compared with forty-two healthy controls, using dual-energy X-ray absorptiometry for total bone, lumbar spine and femur and peripheral quantitative computerised tomography for tibia and radius. A questionnaire concerning physical activity and nutrition was used. FA in serum phospholipids were measured using capillary GLC. CF patients did not differ in physical activity and anthropometry from controls. There were no differences in bone parameters between the two groups, but patients chronically colonised with Pseudomonas aeruginosa had lower BMD than non-colonised patients. The trabecular BMD in the tibia differed between patients and controls, but not after adjustment for age and weight. The endosteal circumference of the radius was significantly associated with serum phospholipid concentration of DHA and inversely with the n-6:n-3 FA ratio in CF patients but not in controls. The present study showed that young physically active adult males with classical CF obtained similar bone mass as controls, although influenced by pseudomonas colonisation. The association between DHA and long bone endosteal circumference suggested a later peak bone mass in those with CF compared with controls.

Association ofn-3 andn-6 long-chain polyunsaturated fatty acids in plasma lipid classes with inflammatory bowel diseases

In order to establish the biochemical basis for dietary interventions, we investigated the fatty acid composition of plasma lipid classes in patients with inactive inflammatory bowel disease. In this cross-sectional study thirty patients with ulcerative colitis (UC), twenty-one with Crohn disease (CD) and twenty-four controls were investigated (mean age: UC, 40.8 (sd 12.1); CD, 37.6 (sd 11.0); control, 31.5 (sd 8.4) years). Fatty acid composition of plasma lipids was determined by high-resolution capillary GLC. In plasma phospholipids, significantly higher values of eicosapentaenoic (20 : 5n-3), docosapentaenoic (22 : 5n-3) and gamma-linolenic (18 : 3n-6) acids were found in control patients and patients with UC as compared to patients with CD [median % (weight by weight), control v. UC v. CD : 20 : 5n-3, 0.09 (interquartile range (IQR) 0.05) v. 0.14 (IQR 0.10) v. 0.16 (IQR 0.10), P < 0.05; 22 : 5n-3, 0.14 (IQR 0.10) v. 0.27 (IQR 0.16) v. 0.31 (IQR 0.10), P < 0.001; 18 : 3n-6, 0.02 (IQR 0.02) v. 0.03 (IQR 0.02) v. 0.05 (IQR 0.03), P < 0.05]. When compared to the control, values of the principal n-3 and n-6 long-chain PUFA, arachidonic acid (20 : 4n-6) and DHA (22 : 6n-3) were significantly higher in patients with UC but not in patients with CD [median % (w/w), UC v. control: 20 : 4n-6, 8.43 (IQR 3.23) v. 6.92 (IQR 2.96), P < 0.05; 22 : 6n-3, 1.22 (IQR 0.56) v. 0.73 (IQR 0.39), P < 0.05]. As seen there are considerable differences between the long-chain PUFA status of patients suffering from UC or CD. The data obtained in the present study do not support the concept of eicosapentaenoic acid or DHA deficiency in patients with either UC or CD.

Serum phospholipid fatty acid pattern is associated with bone mineral density in children, but not adults, with cystic fibrosis

Essential fatty acids (EFA) have proved to be important for normal bone mineral density (BMD) and bone growth in animal studies. Patients with cystic fibrosis often have low serum EFA levels, and low BMD has also been reported in patients with normal anthropometry. The aim of the present study was to analyse if BMD during a 2-year period was related to fatty acid status in patients with cystic fibrosis. Fifty-four patients, aged 6-33 years, were studied prospectively. BMD was measured with dual X-ray absorptiometry, and fatty acid concentrations in serum phospholipids were determined with capillary GLC. The cystic fibrosis patients showed low linoleic acid concentration and a high arachidonic acid (AA):DHA ratio in serum. The high eicosatrienoic acid:AA ratio, an indicator of EFA deficiency, increased further over 2 years, as did the total concentration of saturated fatty acids. In the adults there were no significant changes in fatty acids during the study. In the children, positive correlations were found between palmitic acid and bone mineral content in the lumbar spine and femoral neck. The lumbar spine BMD Z score correlated negatively with the AA:DHA ratio. No correlation was seen in adults except for a positive correlation between EFA deficiency index and the areas of lumbar spine and femoral neck. The present results imply that fatty-acid status influenced BMD in cystic fibrosis children, but not in adults, indicating that fatty-acid status would be important for bone growth.

Evaluation of the CP‐Sil 88 and SP‐2560 GC columns used in the recently approved AOCS official method Ce 1h‐05: Determination of cis‐, trans‐, saturated, monounsaturated, and polyunsaturated fatty acids in vegetable or non‐ruminant animal oils and fats by capillary GLC method

AbstractThe AOCS Official Method Ce 1h‐05 was recently approved at the 96th AOCS Annual Meeting (2005) by the Uniform Methods Committee as the official method for determining cis and trans FA in vegetable or non‐ruminant fats and oils. A series of experiments was undertaken using a margarine (hydrogenated soybean oil) sample containing approximately 34% total trans FA (28% 18∶1 trans, 6% 18∶2 trans, and 0.2% 18∶3 trans), a low‐trans oil (ca. 7% total trans FA), and a proposed system suitability mixture (12∶0, 9c−18∶1, 11c−18;1, 9c,12c,15c−18∶3, 11c−20∶1, and 21∶0) in an effort to evaluate and optimize the separation on the 100‐m SP‐2560 and CP‐Sil 88 flexible fused‐silica capillary GC columns recommended for the analysis. Different carrier gases and flow rates were used during the evaluation, which eventually lead to the final conditions to be used for AOCS Official Method Ce 1h‐05.

β-Carboline and Quinoline Alkaloids in Root Cultures and Intact Plants of Peganum harmala

Alkaloid profiles of root and shoot cultures, seedlings and mature plants were analysed by capillary GLC and GLC-MS. beta-Carboline alkaloids, such as harmine, harmaline dominate in normal and root cultures transformed by Agrobacterium rhizogenes, as well as in roots and fruits of the plant. In shoots, flowers and shoot cultures quinoline alkaloids such as peganine, deoxypeganine, vasicinone and deoxyvasicinone widely replace the beta-carboline alkaloids. In root cultures, the formation of beta-carboline alkaloids can be induced by methyljasmonate and several other elicitors indicating that these alkaloids are part of the reactive chemical defence system of Peganum harmala.

Effect of dietary conjugated linoleic acid (CLA) supplementation on CLA isomers content and fatty acid composition of dry-cured Parma ham

To evaluate the effects of dietary conjugated linoleic acid (CLA) supplementation on cis-9, trans-11 and trans-10, cis-12 isomer content and on the fatty acid composition of subcutaneous adipose tissue and intramuscular lipids of biceps femoris, the lipids of 24 dry cured Parma hams, obtained from Large White pigs fed isoenergetic diets supplemented with either 0 (CON) or 0.25% (T1) CLA from 97 to 172 kg live weight, were analysed by Ag +-HPLC and capillary GLC. The dietary treatment had no influence on lipid content of BF and subcutaneous adipose tissue but increased ( P < 0.01) the content of both isomers, more markedly in the latter tissue. CLA supplementation increased ( P < 0.01) myristic, palmitic, palmitoleic and total saturated fatty acids, and decreased oleic and eicosenoic acids in both tissues. In adipose tissue, an increase ( P < 0.05) in stearic acid content was observed. Supplementing the finishing diet of heavy pigs with CLA has thus shown to be an effective tool for increasing the CLA content in cured ham and, also, the saturated:unsaturated ratio of the lipids, a positive effect from a technological point of view. From a human nutritional standpoint, the changes occurring in fatty acid composition negatively affect the atherogenic and thrombogenic indexes, but probably these changes are of no particular concern, as they would only partly offset the progressive increase in the degree of unsaturation of heavy pig lipids that has occurred in recent years, as a consequence of reduced adipose depots in carcasses.

Patterns of pyrrolizidine alkaloids in 12 Ethiopian Crotalaria species

Thirty-three alkaloidal extracts prepared from different parts of 12 Ethiopian Crotalaria species have been analysed for their alkaloid profiles using GLC–MS. Eleven of the species investigated namely, C. agatiflora Schweinf. subsp. erlangeri Bak. f., C. albicaulis Franch., C. axillaris Ait., C. emarginella Vatke, C. fascicularis Polhill, C. gillettii Polhill, C. incana L. subsp. purpurascens (Lam.) Milne-Redh., C. laburnifolia L. subsp. tenuicarpa Polhill, C. mildabraedi Bak. f., C. phillipsiae Bak. and C. pycnostachya Benth. contain pyrrolizidine alkaloids (PAs). No pyrrolizidine alkaloid could be detected in C. spinosa Hochst. ex Benth. Alkaloid contents ranged between 0.02% dry weight (for the twigs of C. pycnostachya) and 2.88% (for the seeds of C. axillaris). The alkaloidal patterns of the various organs of the plants have been determined by capillary GLC and GLC–MS. In addition to the commonly found PAs (simple esters and macrocyclic diesters), C. laburnifolia subsp. tenuicarpa and C. phillipsiae were shown to be adept in the biosynthetic elaboration of seco-pyrrolizidine alkaloids. The simple indolizidine alkaloid tashiromine, figured as a major compound in C. emarginella, C. phillipsiae and C. spinosa. It was also detected as a minor component of C. fascicularis. Altogether 37 alkaloids have been identified by GLC–MS. Most of these alkaloids were detected in the respective plants for the first time. Prior to our work, some of the alkaloids were not reported in the genus Crotalaria. The majority of the alkaloids identified were the potentially toxic macrocyclic diesters with a double bond at 1:2 position.

Geranium sanguineum (Geraniaceae) seed oil: A new source of petroselinic and vernolic acid

The occurrence of petroselinic acid (18:1delta6cis) in seed oils was believed to be limited to the Umbelliferae or Apiaceae, and a few other members of the Umbelliflorae. A major occurrence of petroselinic acid outside the Umbelliflorae must therefore be regarded as highly unusual and surprising. The seed oil of Geranium sanguineum, a member of the family Geraniaceae, has now been found to contain petroselinic and vernolic acids as major FA in its seed oil TAG. These unusual FA have not been reported previously as constituents of Geraniaceae seed oils. The structure and composition of the seed oil FA from G. sanguineum were determined by combined use of chromatographic (TLC, capillary GLC) and spectroscopic (IR, GC-MS) techniques. The double-bond position in petroselinic acid was located unambiguously by the characteristic mass fragmentation of its dimethyldisulfide (DMDS) adduct. The epoxy FA was identified as vernolic acid by co-chromatography and by the mass fragments formed during GC-MS of the products of the epoxy ring-opening reaction with BF3 in methanol.