scholarly journals Determination of Total Fat in Foods and Feeds by the Caviezel Method, Based on a Gas Chromatographic Technique

1998 ◽  
Vol 81 (4) ◽  
pp. 907-917 ◽  
Author(s):  
Roger Pendl ◽  
Marcel Bauer ◽  
Rafael Caviezel ◽  
Peter Schulthess
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Fat Content ◽  
Standard Reference Materials ◽  
Phase System ◽  
Good Precision ◽  
Relative Standard ◽  
Total Fat

Abstract This peer-verified method specifies a fast, easy, and reliable quantitative method to determine total fat in foods and feeds in compliance with the new definition of fat from the U.S. Food and Drug Administration. The method takes into consideration all fatty acids, from C4 to C24, and when fat is present at 0.3-100%. The validation study included 9 matrixes, with fat levels ranging from 1 to 79%. Sample and internal standard (IS; tridecanoic acid) are added to solvent (n-butyl alcohol). Fat is extracted and simultaneously saponified by potassium hydroxide. The fatty acid potassium salts are converted to fatty acids by adding an acidic aqueous salt solution, which produces a 2-phase system. The upper phase, containing the fatty acids and IS, is injected into the fat determination system. After gas chromatographic separation, the fat content is calculated from IS and fatty acid peak areas. The fat content is automatically converted to triglyceride content with a predetermined factor. Ten replicates of 9 different food samples, which cover the whole range of different contents in fat, proteins, and carbohydrates, were analyzed by the submitting and the peer laboratories. Repeatability relative standard deviation (RSDr) values ranged from 0.47 to 4.62%. Reproducibility relative standard deviation (RSDR) values ranged from 0.85 to 9.52%. These estimates include between-run variability. The method shows good accuracy. Values for standard reference materials (SRMs) are in agreement with certified values. Regression analysis of the correlation between observed fat and certified value over all matrixes and fat levels indicated good precision and absence of method bias (5 SRMs; 1-30% fat; correlation coefficient, R2 = 99.98%)

scholarly journals Determination of Total, Saturated, Unsaturated, and Monounsaturated Fats in Cereal Products by Acid Hydrolysis and Capillary Gas Chromatography: Collaborative Study

1997 ◽  
Vol 80 (2) ◽  
pp. 359-372 ◽  
Author(s):  
Jerry Ngeh-Ngwainbi ◽  
James Lin ◽  
Anthony Chandler ◽  
C Bannon ◽  
K Carr ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Standard Deviation ◽  
Acid Hydrolysis ◽  
Relative Standard Deviation ◽  
Collaborative Study ◽  
Capillary Gc ◽  
Cereal Products ◽  
Relative Standard ◽  
Monounsaturated Fats ◽  
Total Fat

Abstract Fifteen laboratories participated in a collaborative study to determine total, saturated, unsaturated, and monounsaturated fats in cereal products by gas chromatographic (GC) analysis of fatty acid methyl esters (FAMEs). Cereal products, representing a wide range of cereal grains and processes, were hydrolyxed in 8N HCI and extracted with ethyl and petroleum ethers. FAMEs were produced by the reaction of the mixed ether extracts with sodium hydroxide in methanol (NaOH/MeOH) and then with boron trifluoride reagent (14% BF3 in MeOH). They were quantitatively determined by capillary GC. Total fat was calculated as the sum of individual fatty acids expressed as triglyceride equivalents in accordance with nutrition labeling guidelines. Saturated, unsaturated, and monounsaturated fats were calculated as sums of individual fatty acids. The total fat contents of samples ranged from 0.56 to 12.64%. A split design was used to determine performance parameters of results obtained by 15 laboratories on 24 samples. Of the 24 samples, 7 were blind duplicates and 5 were independent materials. Statistical analysis for total fat yielded a relative standard deviation for repeatability (RSDr) range of 1.32 to 13.30% and a relative standard deviation for reproducibility (RSDr) range of 4.42 to 22.82%. The goal of this study was to determine total fat, saturated fat, unsaturated, and monounsaturated fat in cereal-based products by complete extraction, methylation, and quantitation of total fatty acids. The acid hydrolysis-capillary GC method for determining total, saturated, unsaturated, and monosaturated fats in cereal products has been adopted by AOAC INTERNATIONAL.

scholarly journals The Dietary Total-Fat Content Affects the In Vivo Circulating C15:0 and C17:0 Fatty Acid Levels Independently

Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1646 ◽  
Author(s):  
Benjamin Jenkins ◽  
Manar Aoun ◽  
Christine Feillet-Coudray ◽  
Charles Coudray ◽  
Martin Ronis ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fat Content ◽  
Dietary Biomarkers ◽  
Dietary Fatty Acid Composition ◽  
Fat Consumption ◽  
Total Fat ◽  
Complex Influence ◽  
Fatty Acid Compositions

Pentadecanoic acid (C15:0) and heptadecanoic acid (C17:0) have been described as dietary biomarkers of dairy-fat consumption, with varying degrees of reliability between studies. It remains unclear how the total amount of dietary fat, representing one of the main confounding factors in these biomarker investigations, affects C15:0 and C17:0 circulating concentrations independent of their relative intake. Additionally, it is not clear how changes in the dietary total-fat affects other fatty acids in circulation. Through two dietary studies with different total-fat levels but maintaining identical fatty acid compositions, we were able to see how the dietary total-fat affects the fatty acids in circulation. We saw that there was a statistically significant, proportionate, and robust decrease in the endogenous C15:0 levels with an increase in dietary total-fat. However, there was no significant change in the circulating C17:0 concentrations as the total-fat increased. To conclude, the dietary total-fat content and fat-type have a very complex influence on the relative compositions of circulating fatty acids, which are independent of the actual dietary fatty acid composition. Knowing how to manipulate circulating C15:0 and C17:0 concentrations is far-reaching in nutritional/pathological research as they highlight a dietary route to attenuate the development of metabolic disease (both by reducing risk and improving prognosis).

scholarly journals The content of fat and fatty acids composition in chicken liver

2011 ◽  
Vol 27 (4) ◽  
pp. 1855-1856 ◽  
Author(s):  
E. Cieślik ◽  
I. Cieślik ◽  
J.M. Molina-Ruiz ◽  
I. Walkowska ◽  
W. Migdal
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Rhode Island ◽  
Fatty Acid Content ◽  
Fat Content ◽  
Chicken Liver ◽  
Fatty Acids Composition ◽  
Chromatography Method ◽  
Fatty Acids Profile ◽  
Total Fat

Liver is recognized as a valuable source of nutrients in human nutrition but there are a few reports of the lipid profile of chicken liver. The aim of work was to determine fat content as well as fatty acids composition of raw chicken liver. The study was carried out on three chicken breeds (New Hampshire, Plymouth Rock, Rhode Island) obtained from National Research Institute of Animal Production in Balice. Total fat was determined by Soxhlet method and the fatty acids profile was performed with gas chromatography method on a Varian 3400. Fat content of chicken liver ranged from 2.65 to 10.07 g/100g depended on the breed. The predominant saturated acid (SFA) in all samples was palmitate (C16:0), followed by stearate (C18:0). Oleate (C18:1) was the major monounsaturated fatty acid (MUFA) in all samples, followed by palmitooleate (16:1). n-3 fatty acids in chicken liver were comparatively lower than SFA and MUFA. The predominant polyunsaturated acid (PUFA) was linoleate (C18:2). Arachidonate (C20:4) was the second most important n-6 fatty acid. Fatty acid content also varied between breeds of chicken. It has been demonstrated that conjugated linoleic acids (CLA) is found in chicken liver.

Voltammetric Determination of Metals in Copper Alloys at Trace and Ultratrace Concentrations

2003 ◽  
Vol 68 (8) ◽  
pp. 1437-1448 ◽  
Author(s):  
Clinio Locatelli ◽  
Giancarlo Torsi
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Relative Error ◽  
Analytical Procedure ◽  
Copper Alloys ◽  
Voltammetric Determination ◽  
Standard Reference Materials ◽  
Relative Standard ◽  
Precision And Accuracy

The present work describes the analytical procedures for the voltammetric determination of Cu, Pb, Cd, Zn, Fe, Mn, Co, Ni, Sn, Sb and Bi in copper alloys. The possibility of determining simultaneously metal concentrations in the case of interference of the voltammetric signals due to the peak overlapping is also highlighted and discussed. The analytical procedure was verified by the analysis of the standard reference materials: commercial bronze A NIST-SRM 1115, gunmetal BCS-CRM 207/2, high tensile brass BCS-CRM 390. Precision and accuracy, expressed as relative standard deviation and relative error, respectively, were in all cases lower than 6%. The limits of detection for each element were also reported.

scholarly journals The Dietary Total-Fat Content Affects the In Vivo Circulating C15:0 and C17:0 Fatty Acid Concentrations Independently to the Dietary Fatty Acid Compositions; Highlighting Dietary Routes that may Attenuate the Development of Metabolic Disease

2018 ◽  
Author(s):  
Benjamin Jenkins ◽  
Manar Aoun ◽  
Christine Feillet-Coudray ◽  
Charles Coudray ◽  
Martin Ronis ◽  
...  
Keyword(s):  
Metabolic Disease ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Fat Content ◽  
Dietary Fatty Acid ◽  
Dietary Biomarkers ◽  
Fat Consumption ◽  
Total Fat ◽  
Fatty Acid Compositions

Pentadecanoic acid (C15:0) and heptadecanoic acid (C17:0) have been described as dietary biomarkers of dairy-fat consumption with varying degrees of reliability between studies. It remains unclear how the total amount of dietary fat; one of the main confounding factors in these biomarker investigations, affects C15:0 and C17:0 circulating compositions independently to their relative intake. Additionally, it is unknown how changes in the dietary total-fat affects other fatty acids in circulation. Through two dietary studies with different total-fat levels but maintaining individual fatty acid compositions we were able to see how the dietary total-fat affects the fatty acids in circulation. We saw that there was a significant, proportionate, and robust decrease in the endogenous C15:0 levels with an increase in dietary total-fat. However, there was an increase in the circulating C17:0 compositions as the total-fat increased. To conclude, the dietary total-fat content and fat-type have a very complex influence on the relative compositions of circulating fatty acids, which are independent to the actual dietary fatty acid composition. Knowing how to manipulate circulating C15:0 and C17:0 composition is far-reaching in nutritional/pathological research as they highlight a dietary route to attenuate the development of metabolic disease (both by reducing risk and improving prognosis).

Determination Of Total Fat In Meat And Meat Products By Solvent Extraction After Hydrochloric Acid Hydrolysis: NmkL Interlaboratory Study

1992 ◽  
Vol 75 (6) ◽  
pp. 1011-1015 ◽  
Author(s):  
Lars-Börje Croon ◽  
Harriet C Wallin
Keyword(s):  
Standard Deviation ◽  
Solvent Extraction ◽  
Acid Hydrolysis ◽  
Relative Standard Deviation ◽  
Meat Products ◽  
Gravimetric Method ◽  
Relative Standard ◽  
Significant Difference ◽  
Total Fat

Abstract A gravimetric method including acid hydrolysis and solvent extraction according to SBR (Schmid, Bondzynski, and Ratzlaff) for the determination of total fat in meat and meat products was collaboratively studied in 12 laboratories. The study aimed at investigating whether an older SBR method for the determination of fat in meat and meat products, published by the Nordic Committee on Food Analysis in 1974, could be simplified without significant losses in precision. The study samples consisted of 12 materials in the form of 6 matched pairs of meat types: ham, beef trimmings, pork loin, black pudding, sausage, and liver pate. The fat contents of the samples varied between 2.6 and 44.4 g fat per 100 g. The participating laboratories were asked to analyze the samples by both the old and the new methods. The results indicated that there was no significant difference between the results obtained by the 2 methods. The precision of the revised method in most respects meets the U.S. Department of Agriculture, Food Safety and Inspection Service requirements on methods for the analysis of meat and meat products. The relative standard deviation for repeatability of the method varied from 0.93% for the 44.5 g/100 g level of fat to 4.5% for the 2.5 g/100 g level. The relative standard deviation for reproducibility varied correspondingly between 1.2 and 6.1%. For samples with a fat content <5 g/100 g, the revised method gave somewhat lower fat concentrations than the older method. However, the mean differences were small and did not exceed the precision (repeatability and reproducibility) of the method. Ten of the 12 participating laboratories found the revised method easier to work with than the original method

scholarly journals The effect of maternal dietary fat content and n-6:n-3 ratio on offspring growth and hepatic gene expression in the rat

2020 ◽  
Vol 123 (11) ◽  
pp. 1227-1238
Author(s):  
Sally A. V. Draycott ◽  
Grace George ◽  
Matthew J. Elmes ◽  
Beverly S. Muhlhausler ◽  
Simon C. Langley-Evans
Keyword(s):  
Gene Expression ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Maternal Diet ◽  
Liver Weight ◽  
Fat Content ◽  
Sexually Dimorphic ◽  
Offspring Growth ◽  
Total Fat

Abstractn-6 Fatty acids have been shown to exert pro-adipogenic effects, whereas n-3 fatty acids work in opposition. Increasing intakes of linoleic acid (LA; n-6) v. α-linolenic acid (ALA; n-3) in Western diets has led to the hypothesis that consumption of this diet during pregnancy may be contributing to adverse offspring health. This study investigated the effects of feeding a maternal dietary LA:ALA ratio similar to that of the Western diet (9:1) compared with a proposed ‘ideal’ ratio (about 1:1·5), at two total fat levels (18 v. 36 % fat, w/w), on growth and lipogenic gene expression in the offspring. Female Wistar rats were assigned to one of the four experimental groups throughout gestation and lactation. Offspring were culled at 1 and 2 weeks of age for sample collection. Offspring of dams consuming a 36 % fat diet were approximately 20 % lighter than those exposed to an 18 % fat diet (P < 0·001). Male, but not female, liver weight at 1 week was approximately 13 % heavier and had increased glycogen (P < 0·05), in offspring exposed to high LA (P < 0·01). Hepatic expression of lipogenic genes suggested an increase in lipogenesis in male offspring exposed to a 36 % fat maternal diet and in female offspring exposed to a low-LA diet, via increases in the expression of fatty acid synthase and sterol regulatory element-binding protein. Sexually dimorphic responses to altered maternal diet appeared to persist until 2 weeks of age. In conclusion, whilst maternal total fat content predominantly affected offspring growth, fatty acid ratio and total fat content had sexually dimorphic effects on offspring liver weight and composition.

An Automated Procedure for the Determination of Ammonia in Tobacco

1972 ◽  
Vol 6 (4) ◽  
Author(s):  
P.F. Collins ◽  
W.W. Lawrence ◽  
J.F. Williams
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Distillation Method ◽  
Relative Standard ◽  
Tobacco Sample ◽  
Automated Determination

AbstractA procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate

How Certain Are the Reported Ionic Conductivities of Thiophosphate-Based Solid Electrolytes? an Interlaboratory Study

2020 ◽  
Author(s):  
Saneyuki Ohno ◽  
Tim Bernges ◽  
Johannes Buchheim ◽  
Marc Duchardt ◽  
Anna-Katharina Hatz ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Ionic Conductivity ◽  
Relative Standard Deviation ◽  
Solid Electrolytes ◽  
Ionic Conductivities ◽  
Ionic Conductors ◽  
Energy Storage Devices ◽  
Activation Barriers ◽  
Storage Devices ◽  
Relative Standard

<p>Owing to highly conductive solid ionic conductors, all-solid-state batteries attract significant attention as promising next-generation energy storage devices. A lot of research is invested in the search and optimization of solid electrolytes with higher ionic conductivity. However, a systematic study of an <i>interlaboratory reproducibility</i> of measured ionic conductivities and activation energies is missing, making the comparison of absolute values in literature challenging. In this study, we perform an uncertainty evaluation via a Round Robin approach using different Li-argyrodites exhibiting orders of magnitude different ionic conductivities as reference materials. Identical samples are distributed to different research laboratories and the conductivities and activation barriers are measured by impedance spectroscopy. The results show large ranges of up to 4.5 mScm<sup>-1</sup> in the measured total ionic conductivity (1.3 – 5.8 mScm<sup>-1</sup> for the highest conducting sample, relative standard deviation 35 – 50% across all samples) and up to 128 meV for the activation barriers (198 – 326 meV, relative standard deviation 5 – 15%, across all samples), presenting the necessity of a more rigorous methodology including further collaborations within the community and multiplicate measurements.</p>

scholarly journals Salmonids as Natural Functional Food Rich in Omega-3 PUFA

2021 ◽  
Vol 11 (5) ◽  
pp. 2409
Author(s):  
Wojciech Kolanowski
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Functional Food ◽  
Fat Content ◽  
Salmonid Fish ◽  
Omega 3 ◽  
Pufa Content ◽  
Human Diet ◽  
Fish Fillets ◽  
Food Market

Salmonids are valuable fish in the human diet due to their high content of bioactive omega-3 very long-chain polyunsaturated fatty acid (VLC PUFA). The aim of this study was to assess the omega-3 VLC PUFA content in selected salmonid fish present on the food market regarding whether they were farm-raised or wild. It was assumed that farm-raised fish, by eating well-balanced feed enriched with omega-3 PUFA, might contain omega-3 VLC PUFA in levels similar to that of wild fish. Fat content, fatty acid composition and omega-3 VLC PUFA content in fish fillets were measured. Farm-raised salmon from Norway, wild Baltic salmon, farm-raised rainbow trout and brown trout were bought from a food market whereas wild trout (rainbow and brown) were caught alive. The fat content in fish ranged from 3.3 to 8.0 g/100 g of fillet. It was confirmed that although wild salmonid fish contain 10–25% more omega-3 VLC PUFA in lipid fraction, the farm-raised ones, due to the 60–100% higher fat content, are an equally rich source of these desirable fatty acids in the human diet. One serving (130 g) of salmonid fish fillets might provide a significant dose of omega-3 VLC PUFA, from 1.2 to 2.5 g. Thus, due to very high content of bioactive fatty acids eicosapentaenoic (EPA), docosapentaenoic (DPA) and docosahexaenoic (DHA) in their meat, salmonid fish currently present on the food market, both sea and freshwater as well as wild and farm-raised, should be considered as natural functional food.

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