EFFECTS OF LINOLEIC ACID SUPPLEMENTS ON THE SYNTHESIS BY YEAST OF LIPIDS AND ACETATE ESTERS

The concentrations of acetate esters in beer were reduced by up to 85% by addition of linoleic acid to the fermentation or by pitching with yeast previously enriched with this unsaturated fatty acid. Linoleic acid was rapidly incorporated into yeast lipids and was effective in reducing the rate of ethyl acetate formation within 2 h. Addition of linoleic acid altered the pattern of synthesis of fatty acids by yeast, causing a shift from medium toward long chain acids. Secondly, the amount of squalene in yeast was reduced by up to 70% whereas that of lanosterol was increased threefold. Since total yeast lipid synthesis was reduced by up to 40%, we conclude that less acetylCoA is synthesized in the presence of linoleic acid. Further, high concentrations of linoleic acid decreased the proportion of acetylCoA consumed by the synthesis of acetate esters. Therefore linoleic acid may directly decrease acetate ester synthesis in addition to its effect via reduction of acetylCoA availability.     

Fatty acids and bioactive compounds of the pulps and kernels of Brazilian palm species,guariroba (Syagrus oleraces), jerivá (Syagrus romanzoffiana) and macaúba (Acrocomia aculeata)

BACKGROUND: Bioactive compounds are capable of providing health benefits, reducing disease incidence or favoring body functioning. There is a growing search for vegetable oils containing such compounds. This study aimed to characterize the pulp and kernel oils of the Brazilian palm species guariroba (Syagrus oleracea), jerivá (Syagrus romanzoffiana) and macaúba (Acrocomia aculeata), aiming at possible uses in several industries. RESULTS: Fatty acid composition, phenolic and carotenoid contents, tocopherol composition were evaluated. The majority of the fatty acids in pulps were oleic and linoleic; macaúba pulp contained 526 g kg^?1 of oleic acid. Lauric acid was detected in the kernels of all three species as the major saturated fatty acid, in amounts ranging from 325.8 to 424.3 g kg^?1. The jerivá pulp contained carotenoids and tocopherols on average of 1219 µg g^?1 and 323.50 mg kg^?1, respectively. CONCLUSION: The pulps contained more unsaturated fatty acids than the kernels, mainly oleic and linoleic. Moreover, the pulps showed higher carotenoid and tocopherol contents. The kernels showed a predominance of saturated fatty acids, especially lauric acid. The fatty acid profiles of the kernels suggest that these oils may be better suited for the cosmetic and pharmaceutical industries than for use in foods. Copyright © 2011 Society of Chemical Industry     

Variation in oil content and fatty acid composition of the seed oil of Acacia species collected from the northwest zone of India

BACKGROUND: The oil content and fatty acid composition of the mature seeds of Acacia species collected from natural habitat of the northwest zone of the Indian subcontinent (Rajasthan) were analyzed in order to determine their potential for human or animal consumption. RESULTS: Oil content varied between 40 and 102 g kg^?1. The highest oil content was obtained in Acacia bivenosa DC. (102 g kg^?1) among the nine Acacia species. The fatty acid composition showed higher levels of unsaturated fatty acids, especially linoleic acid (～757.7 g kg^?1 in A. bivenosa), oleic acid (～525.0 g kg^?1 in A. nubica) and dominant saturated fatty acids were found to be 192.5 g kg^?1 palmitic acid and 275.6 g kg^?1 stearic acid in A. leucophloea and A. nubica respectively. Seed oils of Acacia species can thus be classified in the linoleic–oleic acid group. Significant variations were observed in oil content and fatty acid composition of Acacia species. CONCLUSION: The present study revealed that the seed oil of Acacia species could be a new source of high linoleic–oleic acid‐rich edible oil and its full potential should be exploited. The use of oil from Acacia seed is of potential economic benefit to the poor native population of the areas where it is cultivated. The fatty acid composition of Acacia seed oils is very similar to that reported for commercially available edible vegetable oils like soybean, mustard, sunflower, groundnut and olive. Hence the seed oil of Acacia species could be a new source of edible vegetable oil after toxicological studies. Copyright © 2012 Society of Chemical Industry     

Assessment and profiling of the fatty acids in two ackee fruit (Blighia sapida Köenig) varieties during different ripening stages

BACKGROUND: The ripening of fruits is characterized by physical, chemical and biochemical compositional changes such as color, sugars and phenolic compounds. Ackee fruit is famous in Jamaica and the Caribbean. This study aimed to assess the variation of fatty acids in two varieties (cheese and butter) ackee (Blighia sapida) fruits during five different ripening stages. RESULTS: The total fatty acid content of ackee fruit was much higher in arils and ranged from 283.4 to 465.1 g kg^?1 dry weight (DW), while in husk they ranged from 235.2 to 465.1 g kg^?1 DW in both varieties. Total fatty acid content declined in the arils and the husks as the fruit ripened. Five major fatty acids were found: palmitic acid (C16:0) and stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2) and linolenic acid (C18:3). In the arils, oleic acid was found at the highest concentration, followed by palmitic, stearic, linoleic and last linolenic acid. The unsaturated:saturated ratio of fatty acids varied from 1.23 to 3.26 in the arils of both varieties, and from 1.03 to 5.05 in the husk. Monounsaturated:polyunsaturated fatty acids ranged from 8.56 to 25.19 in the arils and from 0.62 to 2.33 in the husk. CONCLUSION: The results show that ackee arils contain much higher levels of fats than the husk and the major fatty acid in the arils was oleic acid (Δ9‐cis‐oleic acid, an omega n‐9), while in the husk unsaturated fatty acids were higher than the saturated ones. Oleic acid was the major fatty acid in both varieties, and aril fatty acid content was 10–20 times higher than in the husk. In both varieties, unsaturated fatty acids were relatively higher than saturated ones; however, total fatty acids showed a decline with ripening for arils and husk tissues. © 2012 Society of Chemical Industry     

Oil Content and Fatty Acid Composition of Seeds of Guizotia Cass (Compositae)

Seeds of Guizotia abyssinica and wild Guizotia were analysed for oil content and fatty acid composition by multisequential and gas chromatographic methods, respectively. The oil content of G abyssinica ranged from 416 to 436 g kg^-1 (weight per kg dry matter of seeds) and that of the wild Guizotia taxa from 214 to 328 g kg^-1. Two unsaturated fatty acids (linoleic (54·3–72·8, weight percent of total oil) and oleic (5·4–26·8% of oil by wt) and two saturated fatty acids (palmitic (7·8–10%) and stearic (5·5–8·1%)) were about 91–97% of the fatty acids present. Palmitoleic, linolenic, arachidic, eicosenoic, behenic, erucic and lignoceric acids constituted about 2–3%. An unidentified fatty acid, probably an epoxy form of C: 20 or C: 22, has been found in all the materials and it was 1·1–6·6%. Total saturated and unsaturated fatty acids were about 74–84% and 15–20%, respectively. Differentiation in fatty acid composition between the taxa is too small to be of taxonomic use. It is inferred that when gene transfer is desired hybridisation between the wild and cultivated taxa may not affect the oil quality of the latter and the oils of the wild taxa are possibly safe for human consumption. © 1997 SCI.     

PRODUCTION OF ESTERS BY DIFFERENT YEAST STRAINS IN SUGAR FERMENTATIONS

The production of the acetates of isoamyl alcohol and phenethyl alcohol and the ethyl esters of the C₆-C₁₀ fatty acids was investigated in semiaerobic sugar fermentations by 56 strains of Saccharomyces cerevisiae and 3 strains of S. uvarum. The S. cerevisiae yeasts generally produced more esters than the S. uvarum yeasts. Isoamyl acetate was the main component in the ester fractions examined and others in decreasing order, were ethyl caprylate, ethyl caproate, ethyl caprate and phenethyl acetate.     

Resistance of fatty acyl amides to degradation and hydrogenation by ruminal microorganisms.

Two in vitro trials were conducted to determine whether fatty acyl amides are degraded and hydrogenated by ruminal microorganisms. The treatments consisted of ground hay supplemented with either no lipid, linoleoyl Met ethyl ester, or free linoleic acid plus Met ethyl ester. Incubations were carried out in Erlenmeyer flasks at 39 degrees C under CO2. Cultures were sampled at predetermined times and analyzed for long-chain fatty acids, Met, and VFA. In trial 1, the rate of disappearance of linoleic acid was lower for the amide than for the FFA (.004 and -.047/h, respectively). In trial 2, there were no differences in the rate of disappearance of linoleic acid from 0 to 6 h (-.237 and -.357/h for amide and FFA, respectively), but the rates from 6 to 48 h (-.003 and -.027/h for amide and FFA, respectively) were different. Linoleoyl Met cultures also had higher acetate to propionate ratio and lower loss of Met compared with free linoleic acid cultures. There was no loss of radioactivity from [14C]stearoyl Met after 24 h of incubation, indicating its resistance to bacterial breakdown. The results showed that fatty acyl amides resist bacterial breakdown and prevent loss of double bonds by microbial biohydrogenation.     

小米中脂肪酸的GC-MS法测定及营养价值分析

为了研究小米所含有的不饱和脂肪酸及其营养价值,采用超临界萃取法对小米分离提取,用GC-MS分析其化学组成。在小米萃取物中共检测出26种化合物。其中,检测到7种不饱和脂肪酸(64.54%)、7种饱和脂肪酸(22.92%)、7种酯(7.30%)、3种醇(1.95%);新检测出9-十六烯酸、顺式-10-十七烯酸、8,9-亚甲基8-十七烯酸、蓖麻油酸4种不饱和脂肪酸。亚油酸(36.65%)、油酸(26.06%)、棕榈酸(16.33%)、亚油酸乙酯(1.33%)含量较高。     

QUANTITATIVE ASPECTS OF THE CONTROL BY OXYGENATION OF ACETATE ESTER CONCENTRATION IN BEER OBTAINED FROM HIGH-GRAVITY WORT

A single oxygenation of fermenting wort controls the otherwise excessive synthesis of ethyl acetate and iso-amyl acetate which may occur during the fermentation of wort of high specific gravity; ethyl acetate levels are more easily reduced than those of iso-amyl acetate. The effect of oxygen on acetate ester levels can be attributed to (a) the virtual suppression of ester synthesis during treatment and (b) the reduced rate of synthesis in the period following treatment. The latter effect is of greater mangitude if oxygenation is timed correctly. For an initial specific gravity of 1.080, acceptable levels of the acetate esters may be obtained by oxygenating for two hours whilst the specific gravity of the fermenting wort is in the range 1.063–1.044. The quantity of oxygen which must be supplied during this time has been defined in relation to the extent of attenuation which is desired and the effect of changing the rate of oxygen supply has been assessed. The rate of fermentation is greatly increased by oxygenation.     

Mode of action of the drying emulsion used in dried vine fruit production.: I. The effect of inorganic ions and fatty acid esters

Drying of Sultana grapes (Vitis vinifera L.) in Australia is enhanced by the berries being dipped in or sprayed with an alkaline oil-in-water drying emulsion consisting of K₂CO₃ and a mixture of ethyl esters of fatty acids. The relative importance of the nature of the cation and anion of the alkali salts of the drying emulsion and the relative effectiveness of the different fatty acid esters on the drying rate was investigated. When salt solutions used as dip were applied with commercial drying oil, water loss increased with decreasing hydrated ionic radius of the alkali cation and followed the lyotropic series Cs+ > Rb+ > K+ > Na+= Li+, with Ca²⁺= Li+. Carbonate was the most effective anion, while S₂O₅²-^-, HP₂O₅-_-, OH-, I-and Cl- gave responses which were similar to or less than the water control, depending on the presence or absence of drying oil. The interaction between cation and commercial drying oil seemed to be additive or synergistic. Without commercial drying oil, the CO₃^2– salts of Cs+, Rb+, K+ and Na+ all produced higher drying rates than those of Li+ and Ca²⁺, with the Cs+ and Rb+ salts having the greatest effect. When emulsified with 2% ethyl oleate instead of commercial drying oil, all salts with CO₃^2– as anion produced faster drying, and their ranking was the same with both emulsifiers. However, when the Cl“salts were used with 2% ethyl oleate, all cations produced similar and fast drying. The saturated fatty acid esters, caprylic acid ethyl ester and stearic acid ethyl ester, had little effect on drying rates whereas the unsaturated fatty acid esters, ethyl oleate, butyl oleate and ethyl linoleate, increased water loss two-fold compared with H₂O treatment. The results are discussed with particular emphasis on the role of the molecular structure of the cuticle in regulating water loss from grape berries.     

An improved gas chromatography-based approach for characterisation of fatty acids in fresh basil seed oil

An improved gas chromatography-based analytical method for the simultaneous separation of seventy-two fatty acids was developed. Twenty-six types of trans fatty acids and conjugated linoleic acids were separated and identified with this method, especially trans C18 isomers. This method was confirmed to be high throughput and have high sensitivity and a low detection limit. It was successfully applied to separate and identify fatty acids in fresh basil seed oil. The linolenic acid content (51.67 g/100 g) was highest in basil seed oil, followed by linoleic acid (20.16 g/100 g) and oleic acid (12.70 g/100 g). These unsaturated fatty acids in fresh basil seed oil were transformed into trans fatty acids, conjugated linoleic acids and saturated fatty acids after heating to a certain temperature for an adequate duration, and the formation mechanisms were characterised.     

Fatty acid composition in some wild edible mushrooms growing in the middle Black Sea region of Turkey

The fatty acids in Agaricus bisporus, Agaricus campestris, Boletus edulis, Coprinus comatus, Pleurotus ostreatus, Oudemansiella radicata and Armillaria mellea species were obtained by a Soxtec system extracted with chloroform/methanol (2:1) and derivation of their methyl ester forms. The fatty acids were identified and quantified by gas chromatography. The fatty acid compositions mushrooms were studied using fruit body and stems. Fatty acid composition varied among species. The dominant fatty acid in fruit body and stem of all mushroom species was linoleic acid (18:2). Percentage of linoleic acid in species varied from 13% to 59%. Linoleic acid levels were higher in the stem of O. radicata than in the stems of other mushroom species. The other major fatty acids were, respectively, palmitic, oleic, stearic and arachidic acids. Linolenic acid levels were low in all species. Fatty acids analysis of the mushrooms showed that the unsaturated fatty acids were at higher concentrations than saturated fatty acids.     

Camelina sativa cake improved unsaturated fatty acids in ewe's milk

BACKGROUND: Camelina sativa cake (CSC), a rich source of unsaturated fatty acids, in the case of ruminants, may improve the energy value of a diet and also increase the unsaturated fatty acid content in milk. Effects of basal diet (control), basal diet plus 30 g kg⁻¹ of CSC in dietary dry matter (DM), basal diet plus 60 g kg⁻¹ of CSC in dietary dry matter on milk production and the fatty acid composition of ewe's milk with particular emphasis on the monoenes and conjugated isomers of linoleic acid content were examined. RESULTS: Elevated concentration of total monounsaturated fatty acids, the effect of an increase in monounsaturated fatty acids in the trans configuration, as well as the increased content of total polyunsaturated fatty acids, resulted from CSC supplementation. Total saturated fatty acid concentration was decreased. CONCLUSION: Milk from CSC‐supplemented ewes was characterized by increased levels of beneficial nutritional factors, including mono‐ and n‐3 polyunsaturated fatty acids, and was also by lower atherogenic and thrombogenic indices. Taking into consideration all the obtained results and recommended fat concentrations in a daily ruminant ration, we recommend supplementing a dairy ewe's diet with 30 g kg⁻¹ DM of CSC cake in practice. Copyright © 2011 Society of Chemical Industry     

光皮树籽抽出物的成分分析

为了分析光皮树籽抽提物的化学成分,采用无水乙醇、丙酮、正己烷、石油醚和乙酸乙酯分别抽提光皮树籽,抽出物经活性炭脱色后进行GC-MS 分析。结果发现,无水乙醇和丙酮抽出物中主要含有游离的棕榈酸、油酸和亚油酸,其中亚油酸相对含量最高,达到52% 以上,油酸相对含量最低,不超过8.2%。正己烷、石油醚和乙酸乙酯抽出物中甘三酯的脂肪酸组成主要是棕榈酸、硬脂酸、油酸和亚油酸,其中油酸相对含量最高,达到42% 以上,其次是亚油酸,总不饱和脂肪酸相对含量超过70%。抽出物中未发现三不饱和脂肪酸。     

Fatty acids in different pulses produced and consumed in Bangladesh

Five pulse samples, Musuri (Lens esculenta), Orhor (Cajnus indicus), Motor (Pisum sativum), Kheshari (Lathyrus sativus) and Mash-kalai (Phaseolus Munqo), produced and consumed in Bangladesh, were extracted with ether (Soxhlet). Total fat, estimated by gravimetry, ranged from 1 to 1.7 % of dry weights. Four saturated and 4 unsaturated fatty acids were detected in all in these fat extracts by g.l.c. The fat from Musuri, Orhor, Motor and Kheshari had 18 to 28 % palmitic acid and 54 to 67 % linoleic acid. Musuri fat also had oleic (17 %) and linolenic (10 %) acids as major components. Fat from Mash-kalai had an unusual pattern of fatty acids and contained linolenic (70 %) and behenic (10 %) acids as major components. The unsaturated by saturated fatty acid ratios in the fat extracts ranged between 2.3 for Orhor to 4.4 for Musuri.     

Monitoring of fatty acid composition in virgin olive oil by Fourier transformed infrared spectroscopy coupled with partial least squares

A rapid Fourier transformed infrared (FTIR) attenuated total reflectance (ATR) spectroscopic method was applied to the determination of fatty acid (FA) profile and peroxide value (PV) of virgin olive oil. Calibration models were constructed using partial least squares (PLS) regression. A FA calibration model was constructed in the spectral range from 3033 to 700 cm⁻¹. Oleic acid (62.0–80.0%), linoleic acid (5.3–15.0%), saturated fatty acids (SFA, 12.6–19.7%), mono-unsaturated fatty acids (MUFA, 64.4–81.0%) and poly-unsaturated fatty acids (PUFA, 6.0–15.9%) were considered for chemometric analysis. PV (5.7–15.7 meq O₂ kg⁻¹) was calibrated using the signal of the full spectral range 4000–700 cm⁻¹ with first derivative pre-treatment. The LODs of the FTIR-chemometric methods were: 3.0% for oleic acid, 0.5% for linoleic acid, 1.3% for SFA, 3.0% for MUFA, 0.3% for PUFA and 1.0 meq O₂ kg⁻¹ for PV. Analytical methods were evaluated by use of validation samples (n = 25 for all the FA related parameters and n = 10 for PV) with nearly quantitative recovery rates (98–103%). The proposed method provided results comparable to official procedures, with the advantages of being less expensive and more rapid.     

Enrichment of ω‐3 fatty acids in flax seed oil by alkaline lipase of Aspergillus fumigatus MTCC 9657

Flax seed oil obtained from the seeds of flax plant (Linum usitatissimum, L.) is an unexploited source which contains ω‐3 and ω‐6 fatty acids. Flax seed oil is hydrolysed with a novel alkaline lipase from Aspergillus fumigatus MTCC 9657 for the removal of unwanted fatty acids and enrichment of ω‐3 fatty acids. An appropriate balance of ω‐3 and ω‐6 polyunsaturated fatty acids and enzymatic enrichment of polyunsaturated fatty acids in diet promote nutrition and health. Fatty acid composition shows that flax seed oil contains about 26.80%, 13.5% and 25.45% of ω‐3 and ω‐6 fatty acids in triglyceride (TG), diglyceride (DG) and monoglyceride (MG), respectively. After 8 h of hydrolysis, ω‐3 content was increased to 39% in TG, showing that unwanted saturated fatty acids are removed. ω‐6 content of triglycerides in flax seed oil also showed 54.76% increase after 8 h of hydrolysis. An enzymatic method of hydrolysis by fungal lipase was developed by this study and achieved to concentrate the essential fatty acids linoleic acid (LA) and α‐linoleic acids (ALA).     

Isolation of Anticomplementary Substances from Cucurbita Moschata Duch

Chloroform and ethyl acetate extracts of the edible part of Cucurbita moschata Duch, which is commonly used as an oriental medicine as well as a popular food source, showed significant anticomplementary activities on the classical pathway of the complement system. Bioassay‐guided chromatographic separation using silica gel, Sephadex LH‐20, octadecyl silica gel, thin layer chromatography, and high performance liquid chromatography was performed to isolate the anticomplementary substances. Among the isolated substances, apigenin, phytosterols, and mixture of fatty acids, which were identified by nuclear magnetic resonance and gas chromatography‐mass spectrometry, presented the strongest activities. Especially, phytosterols and mixture of saturated fatty acids isolated from the ethyl acetate extracts had 0.74 and 0.67 mg/ml as IC₅₀, respectively, indicating that the ethyl acetate extraction is the best way to isolate the anticomplementary substances from Cucurbita moschata Duch.     

Fatty acids distribution in different tissues of wild and reared Seriola dumerili

In this study, we compared the lipid and fatty acids content, between cultured and wild Seriola dumerili, in different edible portions. Results showed that cultured fish contained a higher level of lipids than wild fish. The fatty acids profiles revealed that, among all the split‐fish side, palmitic (C16:0) and oleic (C18:1n‐9) acid were the principal saturated and monounsaturated fatty acids, in cultured and wild S. dumerili. On the other hand, wild S. dumerili contained a higher level of saturated (38.12 ± 0.54% vs. 33.66 ± 0.15% in cultured fish), monounsaturated (33.13 ± 1.07% vs. 26.49 ± 0.17%), n‐3 polyunsaturated fatty acids (PUFA) (23.90 ± 1.02% vs. 19.77 ± 0.51%) particularly docosahexaenoic acid (DHA) (18.83 ± 0.48% vs. 11.77 ± 0.42%). However, the cultured fish showed a higher level of n‐6 PUFA due principally to the higher value of linoleic acid (C18:2n‐6). In fact, changes in fatty acids content between anatomical areas marked differences in the muscle quality of wild and cultured S. dumerili. According to this study, both groups of wild and farmed S. dumerili have nutritional benefits for human health. Cultured fish were characterised by higher hypocholesterolaemic and hypercholesterolaemic fatty acids ratio for all samples studied and a lower n‐3/n‐6 ratio due to the abundance of n‐3 PUFA particularly DHA in wild fish.