Tribological Properties of Physisorbed, Unsaturated Fatty Acids

2008 ◽  
Author(s):  
M. Ruths ◽  
S. Lundgren ◽  
K. Danerlo¨v ◽  
K. Persson
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Unsaturated Fatty Acids ◽  
Surface Forces ◽  
Surface Forces Apparatus ◽  
Friction Forces ◽  
Linear Friction ◽  
Very High ◽  
Lateral Friction

We have measured normal and lateral (friction) forces across films of saturated and unsaturated fatty acids with the Surface Forces Apparatus (SFA). When adsorbed onto mica from n-hexadecane, linoleic acid forms a dimer layer between monolayer-covered surfaces. This dimer layer, which is not observed in stearic or oleic acid, is removed at low loads. The remaining linoleic acid monolayers are thinner than the ones formed by stearic and oleic acid, and show a more complex friction response with two regimes of linear friction, higher stability at very high loads, and a dependence of the friction on sliding speed and adsorption time.

scholarly journals Inhibition of steroid 5α-reductase by specific aliphatic unsaturated fatty acids

1992 ◽  
Vol 285 (2) ◽  
pp. 557-562 ◽  
Author(s):  
T Liang ◽  
S Liao
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Unsaturated Fatty Acids ◽  
Binding Assay ◽  
Reductase Activity ◽  
Undecylenic Acid ◽  
Gamma Linolenic Acid ◽  
Enzymic Assay

Human or rat microsomal 5 alpha-reductase activity, as measured by enzymic conversion of testosterone into 5 alpha-dihydrotestosterone or by binding of a competitive inhibitor, [3H]17 beta-NN-diethulcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([3H]4-MA) to the reductase, is inhibited by low concentrations (less than 10 microM) of certain polyunsaturated fatty acids. The relative inhibitory potencies of unsaturated fatty acids are, in decreasing order: gamma-linolenic acid greater than cis-4,7,10,13,16,19-docosahexaenoic acid = cis-6,9,12,15-octatetraenoic acid = arachidonic acid = alpha-linolenic acid greater than linoleic acid greater than palmitoleic acid greater than oleic acid greater than myristoleic acid. Other unsaturated fatty acids such as undecylenic acid, erucic acid and nervonic acid, are inactive. The methyl esters and alcohol analogues of these compounds, glycerols, phospholipids, saturated fatty acids, retinoids and carotenes were inactive even at 0.2 mM. The results of the binding assay and the enzymic assay correlated well except for elaidic acid and linolelaidic acid, the trans isomers of oleic acid and linoleic acid respectively, which were much less active than their cis isomers in the binding assay but were as potent in the enzymic assay. gamma-Linolenic acid had no effect on the activities of two other rat liver microsomal enzymes: NADH:menadione reductase and glucuronosyl transferase. gamma-Linolenic acid, the most potent inhibitor tested, decreased the Vmax. and increased Km values of substrates, NADPH and testosterone, and promoted dissociation of [3H]4-MA from the microsomal reductase. gamma-Linolenic acid, but not the corresponding saturated fatty acid (stearic acid), inhibited the 5 alpha-reductase activity, but not the 17 beta-dehydrogenase activity, of human prostate cancer cells in culture. These results suggest that unsaturated fatty acids may play an important role in regulating androgen action in target cells.

scholarly journals A Research on Determination of Some Properties of Butter Made from Creams Extracted from Whey and Milk

2021 ◽  
Vol 3 (4) ◽  
pp. 19-24
Author(s):  
Asya Çetinkaya
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Unsaturated Fatty Acids ◽  
Raw Material ◽  
Milk Whey ◽  
Production Parameters ◽  
Butter Production

In this study, it was aimed to determine the effect of some production parameters on the characteristics of butters made from whey, which is an important dairy by-product, and creams obtained from milk. The acidity values of milk, whey, cream, and butter were respectively detected as 0.17±0.00%, 0.13±0.01%, 0.22±0.01%, 0.24±0.01%, 0.26±0.00%, 0.25±0.01%, fat values were respectively detected as; 3.50±0.14%, 0.60±0.19%, 39.0±0.34%, 43.0±0.35%, 80.0±0.46%, 84.0±0.42% and protein values were respectively detected as; 3.30±0.19%, 0.68±0.03%, 0.93±0.12%, 0.54±0.03%, 0.51±0.02%, 0.58±0.00%. 10 saturated and 7 unsaturated fatty acids were detected in cream and whey butter samples. It was seen that the most common fatty acids were palmitic, stearic, myristic and oleic acid, and the amount of oleic, stearic and linoleic acid was higher in whey butter. In conclusion, we can state that whey, which is an important dairy residue, can be used as an alternative raw material in butter production.

scholarly journals Quantitative Trait Loci and Candidate Genes Associated with Fatty Acid Content of Watermelon Seed

2014 ◽  
Vol 139 (4) ◽  
pp. 433-441 ◽  
Author(s):  
Geoffrey Meru ◽  
Cecilia McGregor
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Palmitic Acid ◽  
Acid Composition ◽  
Seed Oil ◽  
Unsaturated Fatty Acids ◽  
Watermelon Seed

Seed oil percentage (SOP) and fatty acid composition of watermelon (Citrullus lanatus) seeds are important traits in Africa, the Middle East, and Asia where the seeds provide a significant source of nutrition and income. Oil yield from watermelon seed exceeds 50% (w/w) and is high in unsaturated fatty acids, a profile comparable to that of sunflower (Helianthus annuus) and soybean (Glycine max) oil. As a result of novel non-food uses of plant-derived oils, there is an increasing need for more sources of vegetable oil. To improve the nutritive value of watermelon seed and position watermelon as a potential oil crop, it is critical to understand the genetic factors associated with SOP and fatty acid composition. Although the fatty acid composition of watermelon seed is well documented, the underlying genetic basis has not yet been studied. Therefore, the current study aimed to elucidate the quality of watermelon seed oil and identify genomic regions and candidate genes associated with fatty acid composition. Seed from an F2 population developed from a cross between an egusi type (PI 560023), known for its high SOP, and Strain II (PI 279261) was phenotyped for palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), and linoleic acid (18:2). Significant (P < 0.05) correlations were found between palmitic and oleic acid (0.24), palmitic and linoleic acid (–0.37), stearic and linoleic acid (–0.21), and oleic and linoleic acid (–0.92). A total of eight quantitative trait loci (QTL) were associated with fatty acid composition with a QTL for oleic and linoleic acid colocalizing on chromosome (Chr) 6. Eighty genes involved in fatty biosynthesis including those modulating the ratio of saturated and unsaturated fatty acids were identified from the functionally annotated genes on the watermelon draft genome. Several fatty acid biosynthesis genes were found within and in close proximity to the QTL identified in this study. A gene (Cla013264) homolog to fatty acid elongase (FAE) was found within the 1.5-likelihood-odds (LOD) interval of the QTL for palmitic acid (R2 = 7.6%) on Chr 2, whereas Cla008157, a homolog to omega-3-fatty acid desaturase and Cla008263, a homolog to FAE, were identified within the 1.5-LOD interval of the QTL for palmitic acid (R2 = 24.7%) on Chr 3. In addition, the QTL for palmitic acid on Chr 3 was located ≈0.60 Mbp from Cla002633, a gene homolog to fatty acyl- [acyl carrier protein (ACP)] thioesterase B. A gene (Cla009335) homolog to ACP was found within the flanking markers of the QTL for oleic acid (R2 = 17.9%) and linoleic acid (R2 = 21.5%) on Chr 6, whereas Cla010780, a gene homolog to acyl-ACP desaturase was located within the QTL for stearic acid (R2 = 10.2%) on Chr 7. On Chr 8, another gene (Cla013862) homolog to acyl-ACP desaturase was found within the 1.5-LOD interval of the QTL for oleic acid (R2 = 13.5%). The genes identified in this study are possible candidates for the development of functional markers for application in marker-assisted selection for fatty acid composition in watermelon seed. To the best of our knowledge, this is the first study that aimed to elucidate genetic control of the fatty acid composition of watermelon seed.

scholarly journals Comparison of Biochemical Properties of the Original and Newly Identified Oleate Hydratases from Stenotrophomonas maltophilia

2017 ◽  
Vol 83 (9) ◽  
Author(s):  
Woo-Ri Kang ◽  
Min-Ju Seo ◽  
Kyung-Chul Shin ◽  
Jin-Byung Park ◽  
Deok-Kun Oh
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Stenotrophomonas Maltophilia ◽  
Unsaturated Fatty Acids ◽  
Hydroxy Fatty Acids ◽  
Plant Oils ◽  
Content Type ◽  
Oleate Hydratase

ABSTRACT Oleate hydratases (OhyAs) catalyze the conversion of unsaturated fatty acids to 10-hydroxy fatty acids, which are used as precursors of important industrial compounds, including lactones and ω-hydroxycarboxylic and α,ω-dicarboxylic acids. The genes encoding OhyA and a putative fatty acid hydratase in Stenotrophomonas maltophilia were identified by genomic analysis. The putative fatty acid hydratase was purified and identified as an oleate hydratase (OhyA2) based on its substrate specificity. The activity of OhyA2 as a holoenzyme was not affected by adding cofactors, whereas the activity of the original oleate hydratase (OhyA1) showed an increase. Thus, all characterized OhyAs were categorized as either OhyA1 or OhyA2 based on the activities of holoenzymes upon adding cofactors, which were determined by the type of the fourth conserved amino acid of flavin adenine dinucleotide (FAD)-binding motif. The hydration activities of S. maltophilia OhyA2 toward unsaturated fatty acids, including oleic acid, palmitoleic acid, linoleic acid, α-linolenic acid, and γ-linolenic acid, were greater than those of OhyA1. Moreover, the specific activity of S. maltophilia OhyA2 toward unsaturated fatty acids, with the exception of γ-linolenic acid, was the highest among all reported OhyAs. IMPORTANCE All characterized OhyAs were categorized as OhyA1s or OhyA2s based on the different properties of the reported and newly identified holo-OhyAs in S. maltophilia upon the addition of cofactors. OhyA2s showed higher activities toward polyunsaturated fatty acids (PUFAs), including linoleic acid, α-linolenic acid, and γ-linolenic acid, than those of OhyA1s. This suggests that OhyA2s can be used more effectively to convert plant oils to 10-hydroxy fatty acids because plant oils contain not only oleic acid but also PUFAs. The hydration activity of the newly identified OhyA2 from S. maltophilia toward oleic acid was the highest among the activity levels reported so far. Therefore, this enzyme is an efficient biocatalyst for the conversion of plant oils to 10-hydroxy fatty acids, which can be further converted to important industrial materials.

scholarly journals Studying the Physicochemical Properties and Isolation of Unsaturated Fatty Acids from Edible Oils by GC-MS and Argentated Silica Gel Chromatography

2021 ◽  
pp. 346-362
Author(s):  
Salim Najmaldain Saber ◽  
Hikmat Ali Mohamad ◽  
Madzlan Aziz
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Methyl Ester ◽  
Physicochemical Properties ◽  
Olive Oil ◽  
Unsaturated Fatty Acids ◽  
Acid Methyl Ester ◽  
Acid Methyl

The core objective of this study was to investigate the physicochemical characteristics and fatty acid composition of the oils of sunflower, olive, virgin coconut and ginger oils, as well as the separation of their unsaturated fatty acids. The data indicated a significant variation in physicochemical properties (acid, saponification, ester, and iodine values) among oils. Transesterification process was carried out at a molar ratio of 1:7:0.1 of oil: methanol: KOH. Fatty acid methyl esters of oils were analyzed by infrared (IR) and gas chromatography–mass (GC-MS) spectrometry. Twelve fatty acids were identified, where the major fatty acid of  olive oil was found to be  oleic acid (89%), whereas those of sunflower and ginger oils were linoleic acid (80.9 %) and (79.3 %), respectively. Sunflower and olive oils were fractionated by 25% silver nitrate-impregnated silica gel column chromatography. By this method, linoleic acid methyl ester from sunflower and oleic acid methyl ester from olive oil were isolated with high purity percentages and yields. This study is significant for the development of food and pharmaceutical products.

DEVELOPMENT OF OIL IN THE SEED OF HELIANTHUS ANNUUS L.

1961 ◽  
Vol 39 (10) ◽  
pp. 1481-1487 ◽  
Author(s):  
C. Y. Hopkins ◽  
Mary J. Chisholm
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Helianthus Annuus ◽  
Unsaturated Fatty Acids ◽  
Marked Change ◽  
Helianthus Annuus L ◽  
Stage Of Development ◽  
Steady Rate ◽  
Subsequent Conversion

Sunflower seed (Helianthus annuus L.) was collected from growing plants at weekly intervals. Analyses of the seed, the oil, and the fatty acids were made, the latter by gas chromatography. Oil formation began about 10 days after flowering and continued at a steady rate for 7 weeks. There was no evidence that any intermediate substance accumulated in the seed for subsequent conversion to oil.The weight of individual fatty acids per 100 seeds was determined at each stage of development. Except for one sample, the amount of each acid increased to maturity. Oleic acid accumulated most rapidly at first but at the mid-point of oil development it was overtaken by linoleic acid, which became the major component. The possibility that some oleic acid was converted to linoleic acid is discussed. The absence of any marked change in amounts of long-chain saturated acids suggests that they were not involved in the synthesis of the unsaturated fatty acids.

scholarly journals MACROALGAE Fucus vesiculosus OIL: BIODIESEL PRODUCTION USING ALKALINE TRANSESTERIFICATION

Química Nova ◽  
2021 ◽  
Author(s):  
Bruno Petry ◽  
Rafael Rial ◽  
Osmar Freitas ◽  
Joyce Barbosa ◽  
Leandro Cavalheiro ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Soybean Oil ◽  
Oxidative Stability ◽  
Unsaturated Fatty Acids ◽  
Fucus Vesiculosus ◽  
Raw Material ◽  
Biodiesel Production ◽  
Alkaline Catalyst

This work studied the obtaining of methyl biodiesel and ethyl biodiesel using alkaline transesterification from macroalgae Fucus vesiculosos oil (FVO). FVO has 86.59% of its composition in unsaturated fatty acids, with a greater quantity of linoleic acid and oleic acid, a chemical composition near the soybean oil, the most used raw material for the production of biodiesel. Linoleic acid (47.88%), and oleic acid (34.66%) are the fatty acids present in the greatest amount in FVO, and unsaturated fatty acids correspond to 86.59% the composition of FVO, a composition of fatty acids close to that of soybean oil, which is the oil most produced and used for the production of biodiesel. To obtain methyl biodiesel (MBFVO) and ethyl biodiesel (EBFVO) the molar ratio oil: alcohol 1: 3 and 1% alkaline catalyst, NaOH, was used. The yield of the transesterification reaction was evaluated by varying the reaction time between 30 and 60 minutes and the highest yields were obtained after 60 minutes of reaction. In order to check the quality of the obtained biodiesel, the properties acidity index, iodine value, water content, specific mass at 20 o C, oxidative stability, cold filter lugging point and kinematic viscosity were evaluated. The oxidative stability had an induction period below the recommended, but it can be corrected with the addition of antioxidants to the biodiesel. All other physical and chemical properties had values within the stipulated by the regulatory agencies, indicating that the macroalgae Fucus vesiculosus can be a raw material in potential for production of biodiesel

scholarly journals Changes in Soybean (Glycine max L.) Flour Fatty-Acid Content Based on Storage Temperature and Duration

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2713 ◽  
Author(s):  
Mayakrishnan Prabakaran ◽  
Kyoung-Jin Lee ◽  
Yeonju An ◽  
Chang Kwon ◽  
Soyeon Kim ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Linolenic Acid ◽  
Acid Content ◽  
Unsaturated Fatty Acids ◽  
Storage Temperature ◽  
Fatty Acid Content ◽  
Soybean Flour

Soybeans are low in saturated fat and a rich source of protein, dietary fiber, and isoflavone; however, their nutritional shelf life is yet to be established. This study evaluated the change in the stability and quality of fatty acids in raw and roasted soybean flour under different storage temperatures and durations. In both types of soybean flour, the fatty-acid content was the highest in the order of linoleic acid (18-carbon chain with two double bonds; C18:2), oleic acid (C18:1), palmitic acid (C16:0), linolenic acid (18:3), and stearic acid (C18:0), which represented 47%, 26%, 12%, 9%, and 4% of the total fatty-acid content, respectively. The major unsaturated fatty acids of raw soybean flour—oleic acid, linoleic acid, and linolenic acid—decreased by 30.0%, 94.4%, and 97.7%, and 38.0%, 94.8%, and 98.0% when stored in polyethylene and polypropylene film, respectively, after 48 weeks of storage under high-temperature conditions. These values were later increased due to hydrolysis. This study presents the changes in composition and content of two soybean flour types and the changes in quality and stability of fatty acids in response to storage temperature and duration. This study shows the influence of storage conditions and temperature on the nutritional quality which is least affected by packing material.

scholarly journals CHEMICAL COMPOSITIONS OF PASSIFLORA EDULIS SEEDS OIL COLLECTED IN VIETNAM

2019 ◽  
Vol 57 (5) ◽  
pp. 551
Author(s):  
To Dao Cuong ◽  
Doan Lan Phuong ◽  
Nguyen Van Tuyen Anh ◽  
Pham Ngoc Khanh ◽  
Tran Thu Huong ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Linoleic Acid ◽  
Unsaturated Fatty Acids ◽  
Chemical Compositions ◽  
Fatty Acid Profiles ◽  
Main Ingredient ◽  
Passiflora Edulis ◽  
Soxhlet Method

The present research was aimed to study the chemical compositions of Passiflora edulis Sims seeds oil, including the fatty acid profiles, contents of tocopherols, sterols, and triglycerides. The seeds oil yield is 24.88% by using Soxhlet method. Passiflora edulis seeds oil showed high levels of unsaturated fatty acids (89.25%) with main ingredient linoleic acid (w-6, 66.94%) and oleic acid (w-6, 18.86%). Tocopherols (18.04 mg/kg), sterols (2935.35 mg/kg) and triglycerides (monomere TAG, 74.11%) are also determined by using IOC and ISO methods, respectively. The findings demonstrate that P. edulis seeds oil could be used beneficially in the food and cosmetic industries.

Sign in / Sign up

Export Citation Format

Share Document