93 research outputs found
Physico-chemical stability of flaxseed oil with natural antioxidant mixtures during heating
An optimization study has been carried-out to evaluate synergistic effects of natural antioxidants on physico-chemical characteristics of flaxseed oil during heating. Results showed that the use of oleoresin rosemary extract, sage extract and citric acid improved the stability of the oil during 20 times of frying. This study also revealed that the addition of these antioxidants effectively retarded flaxseed oil deterioration after as early as 5 times of frying of potato chips. Analyses from Response Surface Methodology (RSM) indicated that for all physico-chemical characteristics of flaxseed oil evaluated, all mathematical models or equations could be developed with high confidence, where all R2 values greater than 0.87. From this study, the highest R2 (0.98) was shown by yellow colour, followed by absorbance at 268 nm (0.97), saturated /unsaturated fatty acid ratio (0.95), absorbance at 232 nm (0.93), and AnV (0.92). R2 values for four other parameters were 0.88 (PV and IV) and 0.87 (FFA and red colour). This meant that the R2 values obtained from this study were all satisfactory and considered accurate enough, not only for prediction purposes, but also for optimization purposes
Fatty acid, mineral and heavy metal contents of different Malaysia fish species
Fish are popularly recognized as an excellent source of lipids that are composed of a wide range of important fatty acids. Fish also contain good quality protein and are an adequate source of many vitamins (e.g. fat soluble A, D, E and the water soluble B-complex), in addition to important minerals such as calcium and phosphorous. We recently investigated the fatty acid (FA) profiles, mineral and heavy metal contents of 13 different species of commonly consumed, wild marine fin-fish found off Langkawi Island,
a popular Malaysian tourist destination. The fish species were ājenahakā (Lutjanus agentimaculatus), ākebasiā (Anadontostoma chacunda), āduriā (Arius umatranus), ātenggiri batangā (Scomberomorus
commersonii), ākembongā (Rastrelliger kanagurta), ākintanā (Psettodes crumei), ākerisiā (Pristipomoides typus), ākerapuā (Epinephelus sexfasciatus), āgelama kelingā (Sciaena dussumieri),āmalongā (Congresax talabon), ālabanā (Cynoglossus lingua), āyu 9ā (Scolidon sorrakowah) and ābagiā (Aacnthurs nigrosis). The overall findings reveal that all fish showed a considerable amount of unsaturated fatty acids particularly those with 4, 5 and 6 double bonds. Two physiologically important n-3
polyunsaturated fatty acids (PUFAs), i.e. eicosapentaenoic acid (EPA) and docasahaexaenoic acid (DHA), made up more than 50% of the total PUFAs. It can be concluded that fin fish found in Langkawi Island coastal areas are beneficial for human health as they have considerable amounts of PUFAs,
especially AA and DHA fatty acids. In the case of heavy metal analysis, the result reveals the safety of the
consumption of fish from the human health point of vie
Nutritional Status of Children with Attention Deficit Hyperactivity Disorder: A Pilot Study
Objectives. This is a pilot study of the dietary intake and nutrient status of children with Attention Deficit Hyperactivity Disorder (ADHD). Method. Nutritional assessment of 43 children aged 6ā12 with ADHD was performed using a 3-day food record, 24-hour recall, and serum assessors. Results. Macronutrient intake and consumption of Low-Nutrient Foods were comparable to population norms; however, 66% were found to be deficient in zinc and 23% in copper. Conclusions. This pilot study reports the food intake and nutrient status of children with ADHD and shows a predisposition for low zinc and copper status in ADHD
Synergistic effect of rosemary, sage and citric acid on fatty acid retention of heated flaxseed oil
A study to optimize the use of oleoresin rosemary extract (OR), sage extract (OS) and citric acid (CA) in flaxseed oil during heating was performed using response surface methodology (RSM). Results showed that the natural antioxidants used in this study retarded oil deterioration, as evidenced by retention of fatty acids profiles. Results from this study revealed that the addition of OR and OS effectively retarded flaxseed oil deterioration after 20 times of frying of potato chips. Five type of fatty acids, namely C16:0, C18:0, C18:1, C18:2 and C18:3 were found in the oil, with all fatty acids having very good correlations with addition of natural antioxidants used during the frying. Mathematical models to predict the fatty acid composition of flaxseed oil after the frying could be developed with high confidence for all types of fatty acids. Therefore, for optimization purposes, the use of the ratio of saturated to unsaturated fatty acids was chosen because it covers all individual fatty acids present in the oil. After 20 fryings, the ratio best predicted the efficacy of natural antioxidants in preserving flaxseed oil with R2 of 0.954. Further analysis showed that after 20 fryings, all three antioxidants had a significant effect on the ratio. Based on these results, a combination of 0.064% oleoresin rosemary extract, 0.061 sage extract and 0.041% citric acid can be recommended for use in flaxseed oil before deep-fat frying
L-5-methyltetrahydrofolate supplementation increases blood folate concentrations to a greater extent than folic acid supplementation in Malaysian women
Background: Folic acid fortification of grains is mandated in many countries to prevent neural tube defects. Concerns regarding excessive intakes of folic acid have been raised. A synthetic analog of the circulating form of folate, l-5-methyltetrahydrofolate (l-5-MTHF), may be a potential alternative. Objective: The objective of this study was to determine the effects of folic acid or l-5-MTHF supplementation on blood folate concentrations, methyl nutrient metabolites, and DNA methylation in women living in Malaysia, where there is no mandatory fortification policy. Methods: In a 12-wk, randomized, placebo-controlled intervention trial, healthy Malaysian women (n = 142, aged 20ā45 y) were randomly assigned to receive 1 of the following supplements daily: 1 mg (2.27 Ī¼mol) folic acid, 1.13 mg (2.27 Ī¼mol) l-5-MTHF, or a placebo. The primary outcomes were plasma and RBC folate and vitamin B-12 concentrations. Secondary outcomes included plasma total homocysteine, total cysteine, methionine, betaine, and choline concentrations and monocyte long interspersed nuclear element-1 (LINE-1) methylation. Results: The folic acid and l-5-MTHF groups had higher (P < 0.001) RBC folate (mean Ā± SD: 1498 Ā± 580 and 1951 Ā± 496 nmol/L, respectively) and plasma folate [median (25th, 75th percentiles): 40.1 nmol/L (24.9, 52.7 nmol/L) and 52.0 nmol/L (42.7, 73.1 nmol/L), respectively] concentrations compared with RBC folate (958 Ā± 345 nmol/L) and plasma folate [12.6 nmol/L (8.80, 17.0 nmol/L)] concentrations in the placebo group at 12 wk. The l-5-MTHF group had higher RBC folate (1951 Ā± 496 nmol/L; P = 0.003) and plasma folate [52.0 nmol/L (42.7, 73.1 nmol/L); P = 0.023] at 12 wk than did the folic acid group [RBC folate, 1498 Ā± 580 nmol/L; plasma folate, 40.1 nmol/L (24.9, 52.7 nmol/L)]. The folic acid and l-5-MTHF groups had 17% and 15%, respectively, lower (P < 0.001) plasma total homocysteine concentrations than did the placebo group at 12 wk; there were no differences between the folic acid and l-5-MTHF groups. No differences in plasma vitamin B-12, total cysteine, methionine, betaine, and choline and monocyte LINE-1 methylation were observed. Conclusion: These findings suggest differential effects of l-5-MTHF compared with folic acid supplementation on blood folate concentrations but no differences on plasma total homocysteine lowering in Malaysian women. This trial was registered at clinicaltrials.gov as NCT01584050
Cooperation, Norms, and Revolutions: A Unified Game-Theoretical Approach
Cooperation is of utmost importance to society as a whole, but is often
challenged by individual self-interests. While game theory has studied this
problem extensively, there is little work on interactions within and across
groups with different preferences or beliefs. Yet, people from different social
or cultural backgrounds often meet and interact. This can yield conflict, since
behavior that is considered cooperative by one population might be perceived as
non-cooperative from the viewpoint of another.
To understand the dynamics and outcome of the competitive interactions within
and between groups, we study game-dynamical replicator equations for multiple
populations with incompatible interests and different power (be this due to
different population sizes, material resources, social capital, or other
factors). These equations allow us to address various important questions: For
example, can cooperation in the prisoner's dilemma be promoted, when two
interacting groups have different preferences? Under what conditions can costly
punishment, or other mechanisms, foster the evolution of norms? When does
cooperation fail, leading to antagonistic behavior, conflict, or even
revolutions? And what incentives are needed to reach peaceful agreements
between groups with conflicting interests?
Our detailed quantitative analysis reveals a large variety of interesting
results, which are relevant for society, law and economics, and have
implications for the evolution of language and culture as well
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ā¼99% of the euchromatic genome and is accurate to an error rate of ā¼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Antioxidant and Functional Activities of MRPs Derived from Different SugarāAmino Acid Combinations and Reaction Conditions
The Maillard reaction (MR), or non-enzymatic browning, involves reducing sugars reacting with amino acids, peptides, or proteins when heated to produce an abundance of products that contribute to sensory, nutritional, and functional qualities of the food system. One example of an important functional quality of MR relates to antioxidant capacity, which has relevance to preserve food quality and also to extend a potential role that may promote gastrointestinal health. The addition of Alphacel (10%), a non-reactive polysaccharide, to MR reactants produced small significant (p < 0.05) reductions in yield of soluble Maillard reaction products (MRPs), sugar loss, and color change of products formed respectively, for reducing sugars. A similar effect was also noticed for different free-radical scavenging capacity (p < 0.05), using chemical (e.g., 2,2-diphenyl-1-picrylhydrazyl (DPPH)), Trolox equivalent antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays. An inflamed Caco-2 cell model revealed nitric oxide (NO) inhibitory activity for Glu-amino acid MRPs, which contrasted the NO stimulatory activity obtained with Fru-amino acid MRPs, especially when glycine was used as the amino acid. Pre-treating Caco-2 cells with Fru-glycine MRPs protected against loss in trans-epithelial resistance (TEER) (p < 0.05) and reduced (p < 0.05) disruption of Caco-2 intestinal epithelial tight-junction (TJ) protein cells when exposed to 7.5% ethanol. A low molecular weight Fru-glycine (e.g.,Land and Food Systems, Faculty ofReviewedFacult
Substrate utilization in the ovine fetus in utero
The turnover, interconversion and oxidation of substrates in the ovine conceptus in utero were studied making use of isotope dilution techniques. In Experiment 1, surgical techniques were standardized for the introduction of vascular catheters into the fetuses at approximately 120-130 days of gestation. Based on maternal and fetal blood acid base parameters and metabolite and hormone levels it was possible to obtain chronic fetal preparations which were physiologically stable.
In Experiment II, radioactive labelled substrates were injected introvenausly into the fetus and the disappearance of the label from the fetal circulation was monitored against time. Kinetic parameters of substrate metabolism were calculated by graphic analysis of the specific radioactivity-time curves. The pool size, irreversible rate of disposal and volume of distribution of glucose, lactate, and amino acids were estimated. The single injection technique employed in this study facilitated the calculation of 2 additional kinetic parameters not reported hitherto in the literature. These include the mean total residence time and number of cycles the labelled substrates made before being irreversibly lost from the fetal circulation. The finding that lactate and amino acids make more number of cycles into and out of the fetal circulation than glucose provides support to the concept that the placenta on the fetal side is relatively impermeable to the former two substrates. Though the rapid disappearance of isotopes administered into the fetus was recognized by earlier workers, the results of this study have brought to light the significance of recylcing of substrates. It is suggested that this unique dynamic feature serves as a physiological control mechanism to modulate fuel consumption according to nutrient and
oxygen availability. On the other hand, there was very little difference in
the irreversible rate of disposal when [2-Ā³H] or [U-Ā¹ā“C] glucose was injected
indicating that there is only approximately 12.5% of recirculation of glucose
within the fetal tissues.
The appearance in maternal circulation of only labelled glucose
injected into the fetus, but not lactate indicates the inability of lactate
to cross the placenta from the fetal side. Though 36% of the administered
glucose label appeared in lactate, the methodology used in this study does
not differentiate whether the conversion of glucose into lactate occurred
in the fetus itself or in the placenta. The recovery of 8.8% of alanine C
into glucose, though suggestive of gluconeogenic potential, may have occurred
by isotopic cross over rather than true metabolic conversion.
In experiment III, the COā production rates were estimated from
the plateau specific activity of blood Ā¹ā“CO2 after the continuous infusion
of [Ā¹ā“C] NaHCOā. The most important findings in this study pertains to
the contribution of substrates to oxidative metabolism in the fetus.
Contrary to the conclusions based on the Fick principle, the recovery of
administered label into Ā¹ā“COā indicates that glucose, lactate, alanine, acetate and amino acids contribute 15.2, 14.0, 6.8, 1.7 and 8.2% respectively to fetal oxidative metabolism. Though the metabolism of placental tissues may have influenced the above values, the results suggest that the metabolic fuel requirements of the fetus warrant reassessment.
The results of these experiments are discussed with reference to the metabolism of the fetus during a period of gestation where the greatest increment in fetal growth occurs.Land and Food Systems, Faculty ofGraduat
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