Unsaturated Fatty Acid Composition Research Articles

Seasonal Changes of Fatty Acid Compositions in Overwintering Larvae of Rice Stem Borer, Chilo suppressalis (Lepidoptera: Pyralidae)

Cold acclimation and overwintering state can affect fatty acid compositions of insects. To determine compositional change of fatty acids during nondiapause and diapause stages, an experiment was conducted to investigate fatty acid constituents from whole body of C. suppressalis larvae. Five most abundant fatty acids were found to be palmitoleic (35–58%), palmitic (18–44%), oleic (14–23%), stearic (0.5–2.5%) and linoleic acid (0.4–2%). However, linolenic, erucic, lauric and myristic acid were found at lower level. Saturated fatty acids significantly decreased and conversely unsaturated fatty acids increased from August (pre-diapause) to October (initiation of diapause). The increase in seasonal cold hardiness during cold acclimation, exposed at −15°C for 24 h, was related to degree of fatty acid unsaturation. The elevation of palmitoleic acid content at low temperature resulted in an increase in the overall degree of unsaturation in the whole body. These results indicated the importance of unsaturated fatty acids composition to prepare larvae entering diapause phase.

The role of sterols in morphogenetic processes and dimorphism in fungi

The review considers the fundamental biological problem of fungal dimorphism as an adaptive reaction to adverse impacts. Primary attention is paid to sterols, phospholipids, storage lipids, and fatty acids. The structural and biological functions of sterols are considered, as well as their role in membrane stabilization under stress and their relation to morphogenetic processes in mycelial fungi, of which many are pathogenic. Data on the biosynthesis of the main fungal sterol, ergosterol, are presented, as well as data on the inhibitors of this process and on the mutants deficient in its particular stages. Ergosterol biosynthesis is also considered in terms of its relation to the composition of the fungal cell wall, which is the cell shape-determining structure, and to the intensity of chitin synthesis, a process in which azole derivatives play a role. Data obtained by the authors are presented that show the role of changes in the composition of sterols, phospholipids, storage lipids, and unsaturated fatty acids of resting cells in the induction of yeastlike growth in mucoraceous fungi.

Effect of magnesium on reactive oxygen species production in the thigh muscles of broiler chickens

1. The objective of the present study was to investigate the effect of magnesium (Mg) on reactive oxygen species (ROS) production in the thigh muscles of broiler chickens. A total of 96 1-d-old male Arbor Acre broiler chickens were randomly allocated into two groups, fed either on low-Mg or control diets containing about 1·2 g/kg or 2·4 g Mg/kg dry matter. 2. The low-Mg diet significantly increased malondialdehyde (MDA) concentration and decreased glutathione (GSH) in the thigh muscles of broiler chickens. ROS production in the thigh muscle homogenate was significantly higher in the low-Mg group than in the control group. Compared with the control, muscle Mg concentration of broiler chickens from the low-Mg group decreased by 9·5%. 3. Complex II and III activities of the mitochondrial electron transport chain in broilers on low-Mg diet increased by 23 and 35%, respectively. Significant negative correlations between ROS production and the activities of mitochondrial electron transport chain (ETC) complexes were observed. 4. The low-Mg diet did not influence contents of iron (Fe) or calcium (Ca) in the thigh muscles of broiler chickens and did not influence unsaturated fatty acid composition (except C18:2) in the thigh muscles. 5. A low-Mg diet decreased Mg concentration in the thigh muscles of broiler chickens and then induced higher activities of mitochondrial ETC, consequently increasing ROS production. These results suggest that Mg modulates the oxidation–anti-oxidation system of the thigh muscles at least partly through affecting ROS production.

The use of formaldehyde protected palm kernel meal and its effects on animal performance, nitrogen utilization and unsaturated fatty acid composition in Priangan sheep

An experiment was conducted to investigate the effect of formaldehyde-treated Palm Kernel Cake (BIS) in male Priangan sheep diet and its effect on animal performance, N utilization, and unsaturated fatty acids composition of musculus longisimus dorsal . The experiment was designed based on completly randomized design with four treatments and nine replications. The treatments consisted of four levels of formaldehyde treated BIS: R1 (0%), R2 (15%), R3 (30%) and R4 (45%). Results indicated that formaldehyde treated BIS up to 45% in diet did not negatively affect consumption, dry matter digestibility and daily live weight gain. Formaldehyde protection especially in R4 could significantly reduce ruminal N-NH 3 concentration, increased protein digestibility and nitrogen retention, but did not influence allantoin urine concentration. Unsaturated fatty acid composition of musculus longisimus dorsal was not affected by formaldehyde treated BIS in diet. It is concluded that the inclusion of 45% formaldehyde treated BIS in diet did not negatively affect animal performance, and R4 is the most effective in improving nitrogen utilization in male Priangan sheep, but unable to alter the unsaturated fatty acids composition of musculus longisimus dorsal . Key Words: Palm Kernel Cake, Formaldehyde, Performance, Nitrogen, Unsaturated Fatty Acids

OS3-5 バイオディーゼル燃焼に及ぼす不飽和脂肪酸組成の影響(OS3 バイオマス・新燃料・環境技術,循環型社会における動力エネルギー技術)

OS3-5 バイオディーゼル燃焼に及ぼす不飽和脂肪酸組成の影響(OS3 バイオマス・新燃料・環境技術,循環型社会における動力エネルギー技術)

옻나무 사료의 급여수준과 기간이 비육돈의 냉장중 육질에 미치는 영향

비육돈에게 옻나무 사료의 첨가수준과 급여기간이 도축 후 육질에 미치는 영향을 구명하기 위해 본 실험을 실시하였다. 생시체중이 80kg과 65kg인 미경산돈(Landrace×Yorkshire×Duroc)을 도축전 5주(비육후기)와 8주(비육전기:3주; 비육후기:5주)동안 옻나무 사료를 0%(대조구), 2% 및 4%로 처리구당 5두씩 급여하였다. 도축후 24시간동안 냉각시킨 다음 발골한 등심(M. longissimus)을 3±0.2℃에서 8일 동안 저장하면서 실험을 실시하였다. 일반성분 함량에서 옻나무 사료를 4% 급여한 돈육이 대조구에 비해 조지방 함량이 감소하였다(p<0.05). 보수력은 옻 급여육이 대조구보다 높았다(p<0.05). 표면육색에서 명도(L* 값)는 저장기간 동안 옻나무 사료를 5주간 급여육이 대조구보다 높았으나(p<0.05), 적색도(a* 값)와 황색도(b* 값)는 옻나무 급여수준과 기간에 따른 영향을 받지 않았다. TBARS는 저장기간중에 옻나무 급여육이 대조구보다 낮았으며(p<0.05), 옻나무 사료를 5주간 급여육이 가장 높은 항산화 효과를 보였다. 옻나무 사료를 급여하면 돈육 지방의 불포화지방산이 증가하고 상대적으로 포화지방산이 줄어드는 것으로 나타났다. 단가 불포화지방산(MUFA)의 경우 옻나무 사료 급여량이나 기간에 상관없이 모든 옻 급여육이 대조구에 비해 유의적으로 높았고, 다가 불포화지방산(PUFA)은 8주간 옻나무 사료를 급여한 돈육에서 유의적으로 높게 나타났다(p<0.05). 반면 포화지방산의 경우 옻나무 사료를 5주간 급여한 돈육이 대조구보다 유의적으로 낮았다(p<0.05). 등지방의 융점은 옻나무 사료의 급여수준과 기간이 증가함에 따라 감소하였다(p<0.05). 따라서 옻나무 사료를 비육돈에게 급여하면 돈육의 지방 함량이 줄어드나 보수력 및 불포화지방산이 증가되며, 냉장기간중 지방산화가 억제되었다. This study was carried out to investigate the effect of feeding levels and periods of Rhus verniciflua Stokes (RVS) on the quality of M. longissimus from gilts (Landrace×Yorkshire×Duroc) at finishing stage. The gilts were fed diets containing 0 (control), 2 and 4% RVS for 5 weeks (the latter feeding periods) and 8 weeks (the first feeding periods+the latter feeding periods) before slaughtering, respectively. Samples were stored at 3±0.2℃ for 8 days. Crude fat content was decreased by feeding diets of 4% RVS (p<0.05). Water-holding capacity (WHC) was higher in RVS treatments than in control during storage (p<0.05). L*(Lightness) value was higher in 5 weeks-RVS treatment than in control during storage (p<0.05). a*(Redness) and b*(yellowness) were not affected by the levels and periods of RVS supplementation. Thiobarbituric acid reactive substances (TBARS) value was lower in RVS treatment than in control (p<0.05), and the 5 weeks with 4% RVS treatment showed the highest antioxidative activity. Fatty acid compositions of pork were changed by RVS feeding levels and periods. The meat supplemented with RVS showed high levels of unsaturated fatty acid (UFA) composition and monounsaturated fatty acid (MUFA)/saturated fatty acid (SFA) ratio compared with control. The dietary 8 weeks-RVS treatments had lower stearic acid(18:0) and higher polyunsaturated fatty acid (PUFA) contents than in other treatments. Melting point of backfat also decreased by increasing the level and period of RVS supplementation (p<0.05). Therefore, RVS fed pork decreased fat content and melting point, increased WHC and UFA composition, and delayed lipid oxidation during storage.

Nutritional Composition and Assessment of Gracilaria lemaneiformis Bory

AbstractThe chemical composition, mineral elements, vitamins, free fatty acids and amino acid content of the edible red alga Gracilaria lemaneiformis Bory, grown in the sea near Nan'ao island, Guangdong Province, were analyzed in the present study. Gracilaria lemaneiformis Bory showed a total sugar content of 14.65%. The protein content was 21%, of which approximately 41% was determined to be essential amino acids (EAA). The major amino acid components were glutamic acid, leucine, arginine, and alanine. Of the EAA assayed, methionine and cysteine appeared to be the most limiting amino acids compared with the EAA pattern provided by Food and Agricultural Organization of the United Nations. The total lipids content was 0.87% and comprised a high composition of unsaturated fatty acids (61%), mainly as linoleic acid and oleic acid, and a little amount of polyunsaturated fatty acid; palmitic acid was the main component (39%) of saturated acids. Relatively high levels of vitamin C, iodine, phosphorus, and zinc were also present in G. lemaneiformis. The nutritional composition between G. lemaneiformis and Nostoc flagelliforme, a rare alga that is widely eaten in Chinese society, was compared. The results suggest that N. flagelliforme can be substituted for by G. lemaneiformis, not only because of their similar shape, but also because of their approximate nutritional composition. Gracilaria lemaneiformis may possibly serve as a potential healthy food in human diets in the future.(Managing editor: Ping He)

산수유의 영양성분과 항균효과

산수유의 영양성분과 냉면육수 제조시 항균효과를 조사하여 식품소재로써 산수유의 이용성을 증대시키는 기초자료로 삼고자하였다. 산수유의 일반성분은 건량기준으로 탄수화물 87.7%, 조단백질 3.2%, 조지방 4.5%, 회분 4.6%이었다. 산수유의 총아미노산 함량은 2,470 ㎎%로 나타났다. 아미노산 조성으로는 산성아미노산인 aspartic acid가 523㎎%, glutamic acid가 347 ㎎%로 높게 나타났다. 지방산은 총 포화지방산 함량 30.8%, 총 불포화지방산 함량 69.2%로 다가불포화지방산의 함량이 높게 나타났다. 지방산 조성을 살펴보면 linoleic acid가 33.3%로 가장 높았고, 그 다음으로는 palmitic acid (25.1%), linolenic acid(21.6%), oleic acid(13.2%) 순이었다. 무기질 중 칼륨함량이 건물기준으로 2,067.5 ㎎%로 가장 높았고 그 다음으로는 Ca 372.9 ㎎%, Mg 98.4 ㎎% 순이었다. 산수유의 유기산 함량은 gallic acid가 19,478 ㎎%로 가장 그 함량이 높았으며, 그 다음으로는 succinic acid(18,167 ㎎%), malonic acid(14,487 ㎎%), malic acid(13,018 ㎎%) 순이었다. 산수유 3 g을 첨가하여 제조한 냉면육수는 살균효과를 향상시켜줄 뿐 아니라 저장기간에도 균의 생육을 충분히 억제시켰다. 관능검사 결과는산수유 1.5 g을 첨가하여 만든 육수가 색깔, 냄새, 맛 및 전체기호도에서 좋은 영향을 미치는 것으로 나타났다.

Whey protein gel composites of soybean and linseed oils as a dietary method to modify the unsaturated fatty acid composition of milk lipids

Dairy products are an important source of nutrients in diets of many persons in developed countries. One criticism of milk fat is its low content of polyunsaturated fatty acids (PUFA), in particular the omega-3 fatty acids (FA). Various methods to protect unsaturated FA from rumen biohydrogenation have been developed. The most promising method employs formaldehyde, a carcinogen, and thus of limited application in many parts of the world due to regulatory exclusion. A novel gel based on whey protein, water, and oil [US Patent Application 20040058003 A1 (Pending); US Patent Application 20050089550 A1 (Pending)] was developed at the University of California in Davis. The objective of this study was to determine the efficacy of this whey protein gel composite as a dietary delivery method to modify the FA composition of triacylglycerol (TG) and phospholipid (PL) fractions, as well as TG sn-2 composition of milk lipids, compared to feeding either unprotected or calcium salts of the oils. Four primiparous Holstein cows were used in a 4 × 4 Latin square design. The supplemental lipid was a 1:1 (w/w) mixture of soybean oil/linseed oil (S/L) added to a total mixed ration. Soybean oil was selected as a source of n6 and linseed as a source of n3 FA. The S/L supplement was fed in one of four physical forms including: (1) oil (Oil) where S/L was added directly to the diet unmodified, (2) calcium salts (CaS) of S/L, (3) whey protein concentrate (WPC) gel complex of S/L, and (4) whey protein isolate (WPI) gel complex of S/L. Each diet provided a similar amount of total FA. Dietary treatment had no effect on dry matter intake, milk yield, or milk fat proportion. Unsaturated FA composition of the TG and PL increased with WPI. Linoleic acid (C18:2) concentration in TG averaged 2.77, 3.53, 3.59 and 6.35 g/100 g FA and linolenic acid (C18:3) averaged 0.97, 1.33, 1.73 and 4.09 g/100 g FA for Oil, CaS, WPC and WPI, respectively. Total C18:1 trans FA decreased from 4.01 g/100 g FA for Oil to 2.50 g/100 g FA for WPI. Similar changes in PUFA content of PL and sn-2 of TG occurred. The lower trans FA, and higher PUFA, in milk fat are a result of reduced rumen biohydrogenation of PUFA in WPI. Feeding whey protein isolate gel complex successfully increased the PUFA of milk lipids without affecting productive performance. This protein gel offers a practical dietary method to modify the PUFA composition of milk lipids, by the type of FA protected, to allow changes in both the nutritional value of milk fat as well as potential changes in its manufacturing properties.

Genetic correlations among fatty acid compositions in different sites of fat tissues, meat production, and meat quality traits in Duroc pigs

This study estimated genetic parameters for fatty acids of different sites of fat tissue, meat production, and meat quality traits of Duroc pigs selected during 7 generations for ADG, LM area, backfat thickness (BF), and intramuscular fat (IMF). For this study, 394 barrows and 153 gilts were slaughtered at 105 kg of BW. High heritabilities for C18:0 of outer and inner subcutaneous fat tissue were estimated, respectively, as 0.54 and 0.51; those of intermuscular and intramuscular fat were 0.40 and 0.51, respectively. Genetic and phenotypic correlations of ADG and BF with saturated fatty acids of outer and inner subcutaneous fat were positive, but those with C16:1 and C18:2 were negative, and those with C18:1 were nearly zero. Genetic and phenotypic correlations between LM area and respective fatty acids showed opposite results. Respective genetic and phenotypic correlations of melting points with C18:0 and C18:1 were positive and high, and negative and high, respectively. Genetic correlations between cooking loss and SFA (C14:0, C16:0, and C18:0) of IMF were positive and moderate: 0.56, 0.47, and 0.47, respectively. On the other hand, monosaturated fatty acid of C18:1 was highly and negatively correlated with cooking loss (-0.61). Moreover, high genetic correlation between meat color (pork color standard and lightness) and fatty acid compositions of IMF suggest that the SFA (C14:0, C16:0, and C18:0) were correlated genetically with meat lightness and that unsaturated fatty acid compositions (C18:1 and C18:2) were correlated with meat darkness. Results of this study suggest that the fatty acid composition of adipose tissue is correlated genetically with meat production and meat quality traits.

Altered membrane free unsaturated fatty acid composition in human colorectal cancer tissue

Polyunsaturated free fatty acids (PUFAs) participate in normal functioning of the cell, particularly in control intracellular cell signalling. As nutritional components they compose a human diet with an indirect promoting influence on tumourogenesis. The PUFAs level depends on the functional state of the membrane. This work is focused on changes only of free unsaturated fatty acids amount (AA - arachidonic acid, LA - linoleic acid, ALA - alpha-linolenic acid, palmitoleic acid (PA) and oleic acid) in cell membranes of colorectal cancer of pT3 stage, G2 grade without metastasis. Qualitative and quantitative composition of free unsaturated fatty acids in the membrane was determined by high-performance liquid chromatography. It was shown that the malignant transformation was accompanied by a decrease in amount of LA and ALA while arachidonic and oleic acids increased. It is of interest that free AA levels are elevated in colon cancer, as AA is the precursor to biologically active eicosanoids.

Genetic Regulation of Unsaturated Fatty Acid Composition in C. elegans

Delta-9 desaturases, also known as stearoyl-CoA desaturases, are lipogenic enzymes responsible for the generation of vital components of membranes and energy storage molecules. We have identified a novel nuclear hormone receptor, NHR-80, that regulates delta-9 desaturase gene expression in Caenorhabditis elegans. Here we describe fatty acid compositions, lifespans, and gene expression studies of strains carrying mutations in nhr-80 and in the three genes encoding delta-9 desaturases, fat-5, fat-6, and fat-7. The delta-9 desaturase single mutants display only subtle changes in fatty acid composition and no other visible phenotypes, yet the fat-5;fat-6;fat-7 triple mutant is lethal, revealing that endogenous production of monounsaturated fatty acids is essential for survival. In the absence of FAT-6 or FAT-7, the expression of the remaining desaturases increases, and this ability to compensate depends on NHR-80. We conclude that, like mammals, C. elegans requires adequate synthesis of unsaturated fatty acids and maintains complex regulation of the delta-9 desaturases to achieve optimal fatty acid composition.

Effect of dietary conjugated linoleic acid (CLA) on lipid composition, metabolism and gene expression in Atlantic salmon ( Salmo salar) tissues

Dietary conjugated linoleic acid (CLA) affects fat deposition and lipid metabolism in mammals, including livestock. To determine CLA effects in Atlantic salmon ( Salmo salar), a major farmed fish species, fish were fed for 12 weeks on diets containing fish oil or fish oil with 2% and 4% CLA supplementation. Fatty acid composition of the tissues showed deposition of CLA with accumulation being 2 to 3 fold higher in muscle than in liver. CLA had no effect on feed conversion efficiency or growth of the fish but there was a decreased lipid content and increased protein content after 4% CLA feeding. Thus, the protein:lipid ratio in whole fish was increased in fish fed 4% CLA and triacylglycerol in liver was decreased. Liver β-oxidation was increased whilst both red muscle β-oxidation capacity and CPT1 activity was decreased by dietary CLA. Liver highly unsaturated fatty acid (HUFA) biosynthetic capacity was increased and the relative proportion of liver HUFA was marginally increased in salmon fed CLA. CLA had no effect on fatty acid Δ6 desaturase mRNA expression, but fatty acid elongase mRNA was increased in liver and intestine. In addition, the relative compositions of unsaturated and monounsaturated fatty acids changed after CLA feeding. CLA had no effect on PPARα or PPARγ expression in liver or intestine, although PPARβ2A expression was reduced in liver at 4% CLA feeding. CLA did not affect hepatic malic enzyme activity. Thus, overall, the effect of dietary CLA was to increase β-oxidation in liver, to reduce levels of total body lipid and liver triacylglycerol, and to affect liver fatty acid composition, with increased elongase expression and HUFA biosynthetic capacity.

Biochemical composition influenced by different locations in Uzun pistachio cv. ( Pistacia vera L.) grown in Turkey

Uzun is one of the major pistachio varieties of Turkey. In this study conducted in seven different locations of the Buyuk Menderes River Basin of western Anatolia (Turkey), some biochemical and fruit quality traits were assessed. Biochemical contents such as protein, fat, dry matter and ash contents, unsaturated and saturated fatty acid compositions in this variety were determined based on locations over a period of 2 years. Biochemical composition such as protein, fat, dry matter and ash contents differed significantly by locations ( P < 0.05 ). The mean protein content ranged from 23.2%–31.7%. The mean fat content varied from 46.8%–66.5%. The unsaturated fatty acid composition as percent showed averagely a range of 72.2–75.0 for oleic acid, 11.2–13.1 for linoleic acid, 0.27–0.34 for linolenic acid, 0.21–0.28 for arachidic acid, 0.40–0.43 for gadoleic acid and 0.11–0.14 for behenic acid depending on locations. The saturated fatty acids as percent composed a range of 0.06–0.08 in myristic acid, 8.25–9.52 in palmitic acid, 0.59–0.76 in palmitoleic acid, 0.05–0.07 in heptadecanoic acid and 2.36–3.71 in stearic acid. The contents of saturated fatty acids (palmitic, palmitoleic and stearic) except for myrictic and heptadecanoic acid, and all unsaturated fatty acids (oleic, linoleic, linolenic, arachidic and behenic) except for gadoleic acid also differed significantly by locations ( P < 0.05 ). Consequently, the biochemical composition was significantly affected by different growing areas.

Highly Unsaturated Fatty Acid Composition of Rotifers (Brachionus plicatilis) and Artemia Fed Various Enrichments

Highly Unsaturated Fatty Acid Composition of Rotifers (<i>Brachionus plicatilis</i>) and <i>Artemia</i> Fed Various Enrichments

Efficacy of a Novel Whey Protein Gel Complex to Increase the Unsaturated Fatty Acid Composition of Bovine Milk Fat

A novel whey protein emulsion gel (WPEG) complex was developed to protect dietary unsaturated fatty acids from rumen biohydrogenation with the goal of modifying the fatty acid composition of milk fat. Three experiments were conducted with WPEG complexes made from either whey protein concentrate containing 80% crude protein, whey protein isolate, or whey protein concentrate high-gel capacity. Each experiment lasted 3 wk. All cows received a basal total mixed ration (TMR). During wk 1 and 3, all cows received only the TMR. During wk 2, 3 control cows received 330g/d of soybean oil added to the TMR, and the other 3 cows received 330g/d of soybean oil in one of the WPEG complexes. During wk 2, C18:2 increased from 3.29 to 5.88g/100g of fat in Experiment 1, 2.91 to 7.42g/100g of fat in Experiment 2, and 3.57 to 6.56g/100g of fat in Experiment 3 for WPEG cows. Fatty acid C18:3 increased from 0.51 to 0.84, 0.52 to 1.15, and 0.51 to 0.97g/100g of fat for Experiments 1, 2, and 3, respectively, for WPEG cows. Higher proportions of C18:1 trans-9 in milk fat of control cows compared with WPEG cows were seen in all experiments. The proportion of C18:1 trans-11 was also higher in control cows in Experiments 1 and 2, but not in Experiment 3. The WPEG complexes successfully protected unsaturated fatty acids from rumen biohydrogenation and resulted in an increase in the unsaturated fatty acid composition of milk fat produced by Holstein cows without increasing the trans 18-carbon monoenes.

Quantitative determination of saturated and unsaturated fatty acids in edible oils by infrared spectroscopy and chemometrics

The fatty acids of eight edible oil samples with varying composition were saponified, esterified into methyl esters and analysed by gas chromatography. These composition values were used in calculating the composition of 25 syntheic edible oil mixtures containing a wide range of saturation and unsaturation. All these 33 oils were then analysed by infrared spectroscopy using single reflectance technique. The reflectance infrared profiles in 1/R format were calibrated against their saturated, unsaturated, 18:1 and 18:2 fatty acids composition using regions and the whole spectral profiles. Second derivated spectral profiles were also used in the calibration. The results show that the cross-validated calibration model established with second derivated data of the infrared spectral profiles in the 4000–2700 cm − 1 region against the GC evaluated unsaturated fatty acid composition predicted 5 unknown oil samples within an error limit of ± 2.5%. The same was the case with the unsaturated fatty acid composition against second derivated infrared profiles in the region 4000–2700 cm − 1 . Oleic acid and linoleic acid composition in the calibration oil samples were calibrated against the second derivated profiles of the infrared spectra in the region 4000–600 cm − 1 . The prediction values of the cross-validated calibration model for the unknown oil samples give oleic acid and linoleic acid composition in the oils with an error margin ± 3.1% and ± 4.1%, respectively. The calibration and prediction error includes the error in the quantitative determination of the fatty acids by gas chromatography.

Fatty acid composition of the tropical lichen Teloschistes flavicans and its cultivated symbionts

Fatty acid components, in both the free and combined form of the intact tropical lichen Teloschistes flavicans, and its isolated photobiont and mycobiont, were analyzed by GC-MS of derived methyl esters. Its rDNA analysis confirmed that the isolated cultured symbionts belong to the genera Trebouxia and Teloschistes, respectively. The fatty acid composition of the lichen did not correspond to those found in the isolated symbionts, suggesting that the fatty acid metabolism is markedly influenced by the symbiosis. Differences in the fatty acid composition in the lichen were observed during the summer (27 °C), when the main fatty acids were saturated and in the winter (22 °C) when an increase of unsaturated fatty acids occurred. Similar differences of composition were also observed for the cultured mycobiont at different temperatures. The increase in the unsaturation level at low temperatures would maintain the membrane fluidity. Our results are the first on the fatty acids of a tropical lichen and suggest that it is sensitive to small temperature variations, which influences its saturated and unsaturated fatty acid composition.

Developmental Relationship of Unsaturated Fatty Acid Composition and Stearoyl-CoA Desaturase mRNA Level in Hanwoo Steers` Muscle

This study was conducted to investigate the developmental relationship between fatty acid composition in different lipid fractions and stearoyl-CoA desaturase (SCD) gene expression in steer muscles during growth. Twenty Hanwoo steers were used at 6, 12, 18, 24 and 30 months of age. Fatty acid composition and SCD mRNA level were analyzed. In the total lipid fraction, developmental profiles of C18:1, as the product of SCD enzyme, and SCD mRNA level were significantly increased between 6 months and 12 months of age. During this period, the percentage of C18:1 increased from 31.9% to 49.5% in the total lipid. The increased C18:1 level was maintained until 30 months of age within the range of 44.8- 49.9%. In contrast, the C18:0 composition decreased with age and this decrease was compensated by the increase of the C18:1. However, the sum of C18:0 and C18:1 was changed before and after 12- month old by a 20% increase. Unlike the C18 fatty acids, the C16 fatty acids such as C16:0 and C16:1 did not show a consistent change with age in steers' muscle. On the other hand, C18:2 proportion as a major polyunsaturated fatty acid in muscle was significantly reduced from 21.1% at 6 months of age to 4.4% at 12-months old and then this reduced level was maintained until 30 months within the range of 7.4-11.4%. As in the C18:1 composition during early stages, a 2-fold significant increase was observed in the ∆ 9 -desaturase index of C18 fatty acid as a measure of SCD activity , but not in that of C16 fatty acid. Also, the steady-state level of SCD mRNA reached a peak at 12 months of age. Thus, the positive relationship between the C18:1 composition and the ∆ 9 -desaturase (SCD enzyme) index of C18 fatty acid or SCD mRNA level was demonstrated during growth, but the negative relationship between the C18:2 composition and the above three indices was demonstrated at the same time, indicating that the sharp induction of SCD mRNA may be closely related to the dramatic reduction of C18:2, which is known as a suppressor of SCD gene expression during growth. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 4 : 562-566)

Physical, chemical and fuel related properties of tomato seed oil for evaluating its direct use in diesel engines

Oil was extracted from tomato seeds, tested for several important alternative fuel properties and compared with other vegetable oils. The oil yield of tomato seeds is about 35% on a dry weight basis. This vegetable oil has low volatility, low sulphur, low ash content, and high viscosity. Cetane number, density as well as the cold flow properties are similar to those of other vegetable oils. The fatty acid profile of tomato seed oil shows that there is a predominance of compounds containing an even number of carbon atoms, especially C 16 and C 18. The total saturated and unsaturated fatty acid composition is 18.28% and 81.72%, respectively, and the most abundant fatty acid is linoleic acid (56.12%). This study indicates that tomato seed oil is a renewable energy source and a promising fuel substitute which could be used in the diesel engine to bring down the consumption of the conventional petroleum products.