Proportions Of Major Fatty Acids Research Articles

A comparative study of seed reserve accumulation in five Styrax species with potential for biofuel production

Carbon competition between starch and oil biosynthesis during seed development of Styrax tonkinensis has been reported, but reserve dynamics indicate an absence of significant carbon competition in other Styrax species. The accumulation of different storage reserves during seed development can be competitive. Carbon competition (i.e., carbon flow into starch instead of oil) has been reported in Styrax tonkinensis (Pierre) Craib ex Hartwich. In this study, developmental patterns in morphology and the accumulation of major biochemical fractions of five other Styrax species (S. calvescens Perkins, S. dasyantha Perk., S. faberi Perk., S. japonicus Sieb. et Zucc., and S. odoratissimus Champ. ex Benth.) were analyzed over 50 days. In all species, kernel fresh matter and dry matter increased during development, while the percent water content trended downwards to lower than 40% at the last sampling date. The time to maturity varied with species, as did the evolution of oil, fatty acids composition, sugar, starch, and protein. Contents of these major reserve fractions per kernel increased with development and were strongly correlated with each other. Final oil concentration ranged from 489 to 548 mg g−1, and the proportions of major fatty acids (palmitic, oleic and linoleic acid) were similar across species (11–15%, 39–41% and 43–47%, respectively). In contrast, starch concentrations never exceeded 7–45 mg g−1, depending on species and developmental stage. Final protein concentration ranged from 165 to 237 mg g−1. A slowdown in the speed of oil accumulation midway during development may occur in S. faberi but was not present in the other species. None of the five Styrax species examined here presented evidence for significant carbon competition between starch and oil accumulation.

114 Effect of altering fatty acid profile on fresh meat palatability

Abstract Fatty acids in fresh meat contribute to palatability in many ways. However, fatty acids primarily influence flavor and juiciness. Perceived juiciness is impacted through lubrication by fatty acids and stimulation of saliva during mastication. Therefore, the content of fatty acids primarily impacts juiciness. However, for flavor, fatty acid content and composition are each important. Volatile flavor compounds have been demonstrated to have greater expression as overall fatty acid content increases. This may be through the retention of fat-soluble volatile compounds leading up to consumption. In addition to content, fatty acid composition may also be altered. Factors, such as, species, muscle, and diet dictate fatty acid composition. In general, these factors mediate proportions of major fatty acids and thus alter levels of fatty acid saturation. As fatty acid saturation is decreased, there is greater propensity towards oxidation. Greater fatty acid oxidation generally leads to negative off-flavors. During storage and handling there is opportunity for less saturated fresh meats to undergo oxidation, ultimately impacting flavor. To summarize, both fatty acid content and composition play roles in fresh meat palatability. Understanding the role of fatty acids in palatability helps equip processors and meat scientist to maintain or improve meat palatability.

Proportion of oleic acid in olive oil as influenced by the dimensions of the daily temperature oscillation

Abstract Olive fruit dry weight, oil concentration and the proportions of individual fatty acids in the oil are influenced by environmental variables, such as ambient temperatures, between flowering and harvest. An increase in mean daily temperature above 25 °C has been shown to have a negative effect on fruit dry weight, and to produce a linear decrease both in fruit oil concentration and oleic acid proportion in the oil over the range of 16–32 °C. Under natural conditions or in experiments in which mean daily temperatures are manipulated following the natural daily oscillation in temperature, mean daily maximum and minimum temperatures covary with mean daily temperature. However, variations in temperature associated with altitude, location and climate change can affect maximum and minimum temperatures differently and modify thermal amplitude. The objectives of the present study were to assess associations between changes in: i) yield variables (fruit dry weight and oil concentration) and ii) the proportions of major fatty acids in the oil, with the different dimensions of the daily temperature oscillation (mean daily minimum and maximum temperatures, mean daily thermal amplitude) experienced by the fruit during its growth from the pit-hardening stage to maturity. Five branch-level temperature treatments were applied: a control (T0) that followed the daily dynamics of ambient temperature, two levels of daytime (8–20 h) heating that increased temperature 5 and 10 °C relative to T0 during the day, and two levels of nighttime (20–8 h) heating to 5 and 10 °C more than T0. Treatments were applied for 76 days during the oil accumulation phase using transparent chambers with individualized temperature control to enclose fruiting branches of cultivar Arauco trees. The treatments successfully broke the natural covariance between the different dimensions of daily temperature variation, and achieved a broad range in mean daily temperature (∼6 °C) which covered the natural range of this variable for the region. Fruit dry weight showed a tendency to decrease with increasing mean temperature, while the proportion of oil in the fruit exhibited a significant relationship (R2 = 0.70) with mean daily thermal amplitude, and weaker −but significant- ones with mean daily maximum and minimum temperatures. The proportion of the main fatty acid in the oil, oleic acid, showed significant negative associations with mean daily minimum temperature (R2 = 0.45) and with mean daily temperature (R2 = 0.32), and a significant curvilinear relationship with mean daily thermal amplitude, but was not significantly associated with mean maximum temperature. Mean daily thermal amplitude in our experiment was determined mainly by mean daily minimum temperatures, a feature also found in an analysis of meteorological data for five sites and five years in the olive producing areas of La Rioja province, Argentina. Our results highlight the need to broaden studies on the temperature responses of olive fruit size, oil content and oleic acid content of the oil to include the effects of minimum temperature and thermal amplitude.

The Effects of Adding Lactic Acid Bacteria and Cellulase in Oil Palm (Elais Guineensis Jacq.) Frond Silages on Fermentation Quality, Chemical Composition and in Vitro Digestibility

The main objective of the current study was to evaluate whether oil palm frond (OPF) can be successfully ensiled without or with the additives cellulase or lactic acid bacteria (LAB). Thus, fresh OPF was ensiled either without additives or with cellulase or LAB or their combination. Ensiling was carried out by storing 2 kg samples in airtight glass jars at 25-30°C for 12 weeks. Thereafter, the silage samples were subjected to proximate analyses, an in vitro digestibility assay and measures on selected indices of fermentation. Fermentation of OPF without additives appeared to be unsuccessful as both pH and ammonia content were too high (4.9 and 9.9%, respectively). In contrast, the use of cellulase or LAB resulted in silages with a pH<4.5 and ammonia fractions <8.4%, but the lowest values were found when both cellulase and LAB were used, i.e. pH=4.1 and ammonia fraction=6.7%. In vitro digestibility of dry matter was significantly higher in the cellulase treated silages. The process of ensiling was associated with both a significant decrease of the fat content of OPF and a significant change of the fatty acid profile. However, the proportions of major fatty acids (C16:0 and C18:2n-6) were not affected by the process of ensiling. In conclusion, the use of cellulase additive appears a practical tool to safeguard the process of fermentation. Using a cellulase enzyme or its combination with LAB improves the fermentation profile and increases the nutritional value of the OPF silage.

Variation in lipid profiles within semen compartments—the bovine model of aging

Semen lipid composition was examined in young and mature bulls. Given the specific roles of various semen compartments (i.e., seminal fluid, sperm head, and sperm tail) during fertilization, we hypothesized that altered fatty acid and cholesterol composition of a specific compartment might impair semen quality and sperm function. Semen samples were collected from five mature and five young Holstein Friesian bulls during the winter (December–January). Semen was evaluated by computerized sperm-quality analyzer for bulls and was centrifuged to separate the sperm from the seminal fluid. The sperm fraction was sonicated to separate its head and tail compartments. Cold extraction of lipids was performed, and fatty acids and cholesterol were identified and quantified by gas chromatography. Semen physiological features (concentration, motility, and progressive motility) did not differ between mature and young bulls. However, lipid composition within fractions varied between groups, with prominent impairments in the head compartment. In particular, the proportions of polyunsaturated fatty acids, omega-3 fatty acids, and docosahexaenoic acid in the intact sperm; seminal fluid; and sperm head were lower in semen collected from mature bulls than in that from young bulls. The finding suggests an age-differential absorption and/or metabolism through spermatogenesis. Reduced proportions of major fatty acids in mature bulls might reduce membrane fluidity, which in turn might affect the ability to undergo cryopreservation and/or oocyte-sperm fusion through fertilization.

Water-Deficit Impact on Fatty Acid and Essential Oil Composition and Antioxidant Activities of Cumin (Cuminum cyminum L.) Aerial Parts

This study is designed to examine the effect of water deficit on growth, fatty acid and essential oil composition, and antioxidant activities of Cuminum cyminum aerial part extracts. Plants were treated with different levels of water deficit: control (C), moderate water deficit (MWD), and severe water deficit (SWD). Plant growth (height, fresh and dry matter weights) as well as yield components were significantly increased under moderate water deficit and conversely reduced at severe level. Total fatty acid content decreased significantly with severity of constraint. Drought reduced considerably the proportions of major fatty acids and the unsaturated to saturated fatty acid ratio. The essential oil yield was 0.14% (based on the dry weight); it increased by 2.21-fold at MWD but decreased by 42.8% under SWD in comparison to the control. Drought results in the modification of the essential oil chemotype from 1-phenyl-1-butanol to 1-phenyl-1,2-ethanediol. Antioxidant activities of the acetone extracts were determined by two complementary test systems, namely, DPPH and β-carotene/linoleic acid. The highest activity was exhibited by moderately stressed plants and was reduced significantly under SWD. In control plants, the total phenolic amount was 10.23 mg GAE/g DW, which increased by 1.5-fold under MWD and decreased by 42% under SWD.

Plasma fatty acids, prostaglandin F2alpha metabolite, and reproductive response in postpartum heifers fed rumen bypass fat.

An experiment was conducted to determine whether feeding rumen-protected fatty acids (FA) to postpartum heifers would increase plasma concentrations of linoleic acid and PGF2, metabolite (PGFM), shorten the interval from calving to first increase in plasma concentrations of progesterone (P4), and increase pregnancy rate relative to controls. Hereford x Angus heifers (346 kg) were assigned randomly to treatments containing either lipid or barley supplemented diets for the first 30 d postpartum. Lipid was .23 kg.heifer(-1).d(-1) of calcium salts of FA (CSFA; n = 20), and an isocaloric amount of barley served as the control (n = 19). Supplements, with .23 kg of barley as a vehicle, and a basal diet of meadow and alfalfa hays were pen fed to heifers (5/pen). Heifers were bled on alternate days (d1 to 30) and twice weekly (d 30 to 2 wk after first estrus) for RIA of plasma PGFM and P4, respectively. Weight percentage of major FA in plasma on d1 and 7 was determined with gas chromatography. First behavioral estrus was detected by use of intact bulls and confirmed by an increase in plasma P4. On d 7, but not d 1, plasma from heifers fed CSFA had altered proportions of major FA (P < .01), including an increase in linoleic acid compared with those of controls (29.1 vs 25.6% of total FA; SE = .75; P < .01). Analysis of variance of contrast variables revealed an effect of treatment on direction of change in PGFM from d 3 to 5 (P < .01). By d 7 and on d 9, plasma concentrations of PGFM were greater in heifers fed CSFA than in controls (P = .02 and P = .06, respectively). There was no difference in plasma concentration of PGFM between treatments on d 1, 3, 5, 11, 13, and 15 postpartum (P = .80, .17, .52, .82, .46, and .77, respectively). Days to first estrus with ovulation, pregnancy rate, and calving interval were not affected by treatments (P = .58, .52, and .24, respectively). Although supplemental lipid fed to primiparous beef heifers increased plasma levels of linoleic acid and production of PGFM in the early postpartum period, it did not improve the fertility of these heifers in the subsequent breeding season.

Black currant seeds as a nutrient source in breakfast cereals produced by extrusion cooking

Press residue from black currant juice production was used for the development of a nutritious breakfast cereal manufactured using an extrusion process at high temperatures. The milled residual fraction with crushed seeds contained significant amounts of essential fatty acids, minerals and dietary fibre. The maximal useful amount of this ingredient, about 30%, was reached in a mix containing 30% oat flour and oat bran, 30% potato starch, 7.5% sugar, 1.5% malt extract and 1% salt. In a model product the total fat content was 3%, with the proportions of major fatty acids as follows: linoleic acid 43 mol-%, oleic acid 20 mol-%, α-linolenic acid 12 mol-%, γ-linolenic acid 9 mol-% and stearidonic acid 2 mol-%. During the extrusion process the unsaturated fatty acids were not lost in quantifiable amounts. The product also contained approximately 20% total dietary fibre and plenty of Ca (1.9 g/kg), Mg (1 g/kg) and Fe (59 mg/kg).

Lipid Composition and Metabolism in Liver Mitochondria and Microsomes of Rats Fed a Low Protein Diet

Male, Wistar rats were fed a diet low in protein (4% casein) or a control diet high in protein (25% casein) for 6 weeks. The effect of these diets on the incorporation of 32P into liver mitochondrial and microsomal fractions and on the fatty acid and phospholipid composition of these tissue components was then investigated. In rats fed the low casein diet, the specific activity (cpm/µg P) of mitochondrial and microsomal phosphatidylcholine and phosphatidylethanolamine was increased at 1.5 and 4 hours after 32P injection, with the largest increase in phosphatidylcholine at the earlier time interval. Phosphatidylcholine had a lower specific activity than phosphatidylethanolamine, a difference which was most evident in the microsomal fraction. The specific activity values of these major phospholipids were similarly reduced in mitochondrial and microsomal fractions when rats were fed the 25% casein diet. The ratio of the relative specific activity of phosphatidylethanolamine in mitochondria to that in microsomes was uniformly lower than that of phophatidylcholine and this difference was unaffected by diet. The proportions of major fatty acids of the mitochondrial and microsomal fractions resembled one another and were similarly altered in rats fed the low casein diet. These changes included a decrease in the proportions of arachidonic and stearic acids, and an increase in palmitic, oleic, and docosapentaenoic acids. A low intake of dietary protein also affected the proportions of mitochondrial and microsomal phospholipids. The principal changes in each organelle were an increase in the concentration of phosphatidylethanolamine and a decrease in that of phosphatidylcholine.