Determination Of Total Fat Content Research Articles

Aktivitas Antioksidan Likopen Buah Tomat (Solanum lycopersicum L.) Terblending dalam Minyak Padat Ikan Lele (Clarias sp)

Research on the antioxidant lycopene of tomato fruit (Solanum lycopersicum L.) blended in frying fat from catfish (Clarias sp) oil has been done. The purpose of this research is to determine the antioxidant activity of tomato lycopene before and after being grounded into frying fat and determine the quality of frying fat after being grounded with tomato lycopene. The antioxidant activity of tomato lycopene is determined by the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. Analysis of frying fat quality includes determination of pH, determination of FFA (free fatty acid) levels, determination of total fat content, measurement of water content, peroxide number and organoleptic observation. Antioxidant activity of tomato lycopen was very high, namely with inhibition value of 89.79%; 90.34%; 91.49% and 92.10%. Frying fat analysis showed high antioxidant activity of lycopene tomatoes with 50.67% inhibition; 51.63%; 51.39% and 51.23%. The results of the analysis of the quality of frying fat are nearly same with SNI quality standards, except for peroxide numbers.
 Keywords: tomato, lycopene, antioxidants, frying fat, catfish, DPPH

Comparison of gravimetric, creamatocrit and esterified fatty acid methods for determination of total fat content in human milk

The gravimetric method is considered the gold standard for measuring the fat content of human milk. However, it is labor intensive and requires large volumes of human milk. Other methods, such as creamatocrit and esterified fatty acid assay (EFA), have also been used widely in fat analysis. However, these methods have not been compared concurrently with the gravimetric method. Comparison of the three methods was conducted with human milk of varying fat content. Correlations between these methods were high (r2=0.99). Statistical differences (P<0.001) were observed in the overall fat measurements and within each group (low, medium and high fat milk) using the three methods. Overall, stronger correlation with lower mean (4.73g/L) and percentage differences (5.16%) was observed with the creamatocrit than the EFA method when compared to the gravimetric method. Furthermore, the ease of operation and real-time analysis make the creamatocrit method preferable.

Forward-and-back dynamic ultrasound-assisted extraction of fat from bakery products

A dynamic ultrasound-assisted extraction method prior to the gravimetric determination of total fat content in bakery products is proposed. An open approach in which forward-and-back extractant steps and cycles of extract draining and filling of the sample chamber with fresh extractant was used, which provided the best results as compared with both an open system with forward-and-back of a single extractant volume and an one-direction open system. Recoveries from 99.7 to 100.7% compared with Sohxlet extraction were obtained. The repeatability and within laboratory reproducibility, expressed as relative standard deviation (R.S.D.), were 2.04 and 2.74%, respectively. As compared with conventional Soxhlet, the extraction time was shortened more than five times—from 16 to 3 h—in the case of cookies and more of eight times—from 8 to 1 h—in the case of snacks. Thirteen or 25 ml of hexane was required for total extraction in 10 or 20 cycles, depending on the sample.

Determination of Fat Content and Fatty Acid Composition in Meat and Meat Products after Supercritical Fluid Extraction

Two different relatively simple, commercially available supercritical fluid extractors (SFE), Leco and Foss-Tecator, were tested for the determination of total fat content in meat and meat products. The fatty acid composition in meat and meat products was also determined after the Foss-Tecator extraction in an aliquot of the extract. Total fat was determined by weighing after the different extraction procedures and the fatty acid composition by gas chromatography after hydrolysis and methylation of the extract. The results for total fat content agreed well with results from a standard method of Schmid, Bondzynski, and Ratzlaff, which uses conventional solvent extraction. Fatty acid composition was compared with the Bligh and Dyer extraction, and showed good agreement. The average relative difference between SFE and Bligh and Dyer of all fatty acids in the sample was <3% for acids exceeding 0.5% of total fatty acid amount. The advantages of SFE over traditional methods are a much lower consumption of hazardous organic solvents and shorter extraction times. To obtain quantitative recoveries by SFE, ethanol was added to the extraction cells before extraction.

A comparison of oil and fat content in oilseeds and ground beef—using supercritical fluid extraction and related analytical techniques

A supercritical fluid extraction (SFE) has been applied for the determination of total fat content of five different oilseed matrices (soybeans, sunflower, safflower, cottonseed and rapeseed) and ground beef samples containing approximately 10, 20 and 30% fat by weight. Lipid content was determined using both gravimetric analysis as well as the sum of all fatty acids, expressed as triglycerides, from the gas chromatography (GC) profiles of the fatty acid methyl esters (FAMEs). The latter analysis is required by the Nutritional Labeling and Education Act of 1990 which redefined the determination of fat for nutritional labeling purposes. The oilseed results are compared to data from a collaborative study by the American Oil Chemists Society (AOCS) and the Association of Official Analytical Chemists International (AOAC). The collaborative study data were determined by both AOCS Official Methods and by SFE. All of our data yielded higher oil recoveries than the collaborative study data obtained via AOCS official methods and SFE with neat carbon dioxide (CO 2). However, our results are in excellent agreement with the collaborative study data obtained by SFE with ethanol-modified CO 2 and the Federation of Oil, Seeds and Fats Association International method. The ground beef results are compared to previously published reports from our laboratory. They show that fat determination using GC–FAME analysis is equivalent to the gravimetric analysis results and has the additional benefit that different types of fat (i.e. saturated and monounsaturated) can also be determined in addition to total fat. Hence, the results from this study advocate the use of SFE as a suitable replacement for traditional organic solvent extraction in the determination of fat/oil content in agriculturally-derived products.

Development of a new SFE method for rapid determination of total fat content of food

The application of supercritical fluid extraction (SFE) for the determination of the total fat content of meat and cheese products as an alternative to the official German solvent extraction is described. Under optimised conditions (40°C, 410 bar, 750 ml min−1), quantitative lipid extraction could be performed in only 35 min (compared to 5–6 hours by the classicial method) with an average recovery better than 95%. To determine the total fat content of a food sample, it must be acid-treated before extraction, otherwise, like the solvent extraction, the “free accessible fat” content is determined and not the “total fat” content. A further advantage of the acid treatment is that the lipids are separated from the particular sample matrix, prior to extraction, and fixed onto a filter. Extraction is, therefore, independent of the sample matrix, which makes this method of interest for many different foods and other samples.