Gislaine C. Nogueira

Lipid and Cholesterol Oxidation in Chicken Meat Are Inhibited by Sage but Not by Garlic

UNLABELLED The effects of the addition of sage and garlic in chicken meat on lipid and cholesterol oxidation, having as prooxidant factors the addition of salt, thermal treatment, and frozen storage, were evaluated. The content of unsaturated fatty acids did not change in the presence of sage; on the contrary, with garlic, the content of these fatty acids decreased after cooking and storage. Hexanal and pentanal contents were lower in patties containing sage, and higher in those with garlic. The 7-ketocholesterol was the cholesterol oxide found in higher amount in raw chicken on day 0, while the formation of 7β- and 7α-hydroxycholesterol was verified only from day 30 on. Cooking and storage resulted in increase of total cholesterol oxides and decrease of α- and γ-tocopherol. Sage was effective in controlling lipid and cholesterol oxidation, minimizing the prooxidant effects of salt, cooking, and storage. However, garlic presented no effect as antioxidant and accelerated lipid oxidation. PRACTICAL APPLICATION The addition of sage to chicken meat (0.1 g/100 g) is a good alternative to prevent and delay the formation of compounds derived from lipid oxidation that are responsible for off-flavors and loss of nutritional quality during long-term frozen storage. Care must be taken when using garlic to seasoning chicken meat products, such as hamburgers and meatballs, especially cooked or precooked due to its potential to promote lipid oxidation and consequently raising the risk of having the product rejected by the consumer.

Optimization and validation of analytical conditions for cholesterol and cholesterol oxides extraction in chicken meat using response surface methodology.

The analytical conditions for the extraction of cholesterol and cholesterol oxides in chicken meat were optimized by means of response surface methodology. The separation and identification were performed by normal phase HPLC using UV and refractive index (RI) detectors, and the confirmation of the 11 cholesterol oxides identities in the samples was verified by HPLC-APCI-MS. The developed methodology showed good analytical performance, presenting recovery levels from 84 to 103% and detection limits varying from 0.01 to 0.06 microg/g for UV detection and from 1.98 to 2.12 microg/g for RI detection. The present study demonstrated the presence of 22 R-hydroxycholesterol, 24 S-hydroxycholesterol, and 22 S-hydroxycholesterol for the first time in chicken meat.

Fast analysis of curcuminoids from turmeric (Curcuma longa L.) by high-performance liquid chromatography using a fused-core column.

The recent development of fused-core technology in HPLC columns is enabling faster and highly efficient separations. This technology was evaluated for the development of a fast method for the analysis of main curcuminoids (curcumin, demethoxycurcumin and bisdemethoxycurcumin) present in extracts of turmeric (Curcuma longa L.). A step-by-step strategy was used to optimize temperature (40-55 °C), flow rate (1.0-2.5 mL min(-1)), mobile phase composition and equilibration time (1-5 min). A gradient method was developed using acidified water and acetonitrile combined with high column temperature (55 °C) and flow rate (2.5 mL min(-1)). Optimized conditions provided a method for the separation of these three curcuminoids in approximately 1.3 min with a total analysis time (sample-to-sample) of 7 min, including the clean-up and the re-equilibration of the column. Evaluation of chromatographic performance revealed excellent intraday and interday reproducibility (>99%), resolution (>2.23), selectivity (>1.12), peak symmetry (1.24-1.42) while presenting low limits of detection (<0.40 mg L(-1)) and quantification (<1.34 mg L(-1)). The robustness of the method was calculated according to the concentration/dilution of the sample and the injection volume. Several combinations of methanol and ethanol with water as sample solvents were evaluated and the best chromatographic results and extraction rate were obtained using 100% methanol. Finally, the developed method was validated with different extracts of turmeric rhizome and products that use turmeric in their formulation.

Assessment of methodology for the enzymatic assay of cholesterol in egg noodles

Abstract Cholesterol content is generally used as a quality parameter for egg noodles, but some methods for its determination are not specific for cholesterol; moreover, they require numerous organic solvents and corrosive reagents, which have harmful affects on the environment. The present paper suggests an alternative technique for this determination using enzymes, which is cheaper, faster and environmentally safe. This enzymatic method was compared to the provenly reliable and accurate high pressure liquid chromatography (HPLC) method involving direct saponification. The results obtained by the former were significantly higher than those obtained by HPLC, but the correlation was high and a correlation factor was determined: F =0.7257×enzymatic values−5.1419. The values calculated using this correlation factor showed no significant difference from those measured by HPLC.

Fast analysis of β-ecdysone in Brazilian ginseng (Pfaffia glomerata) extracts by high-performance liquid chromatography using a fused-core column

The recent development of fused-core technology in HPLC columns is enabling faster and highly efficient separations. This technology was evaluated for the development of a fast analysis method for β-ecdysone in extracts of Pfaffia glomerata. A step-by-step strategy was used to optimize temperature (30–55 °C), flow rate (1.0–2.0 mL min−1), mobile phase composition (mixtures of water and methanol or acetonitrile) and equilibration time (1–5 min). A gradient method has been developed using two solvents: 0.1% acetic acid in water and 0.1% acetic acid in acetonitrile. Optimized conditions provided a method for the separation of β-ecdysone in approximately 2 min with a total analysis time (sample-to-sample) of 9 min, including the return to initial conditions and the re-equilibration of the column. Evaluation of chromatographic performance revealed excellent intraday and interday reproducibility (>99.5%), resolution (2.78), selectivity (1.13), and peak symmetry (1.09) while presenting low limits of detection (0.20 mg L−1) and quantitation (0.67 mg L−1). The robustness of the method has also been calculated according to the concentration/dilution of the sample. Several sample solvents were evaluated and the best chromatographic results were obtained using 80% methanol in water. Finally, the developed method was validated with different extracts of Pfaffia glomerata samples.

Synthesis of 7-Hydroperoxycholesterol and Its Separation, Identification, and Quantification in Cholesterol Heated Model Systems

7-Hydroperoxycholesterol is considered to be an intermediate compound of the cholesterol oxidation path as the first product formed when cholesterol is oxidized by triplet oxygen. However, there is a limitation on cholesterol mechanism studies because of the lack of 7-hydroperoxycholesterol analytical standard due to its low stability. To verify the formation of hydroperoxides in cholesterol model systems heated at 140, 180, and 220 °C, 7α-hydroperoxycholesterol was synthesized by cholesterol photooxidation followed by rearrangement at room temperature in chloroform. Its structure was confirmed on the basis of 13C NMR and mass spectra obtained by APCI-LC-MS. The synthesized compound was also used as standard for the quantification of 7-hydroperoxycholesterol as the sum of 7α- and 7β-hydroperoxycholesterol. The results demonstrated that 7-hydroperoxycholesterol is the first compound formed when the temperature is lower (140 °C). However, the concentration of the 7-hydroperoxycholesterol depends on the temperature and time of exposure: the higher the time, the higher the amount of 7-hydroperoxycholesterol at lower temperatures, and the lower the time, the lower the amount of 7-hydroperoxycholesterol at higher temperatures (180 and 220 °C). By the formation of 7-hydroperoxycholesterol, the known cholesterol oxidation mechanism in three phases (initiation, propagation, and termination) could be confirmed; once at lower temperatures, the stage of cholesterol oxidation is at initiation, at which hydroperoxide formation predominates.

Solid phase microextraction - gas chromatography for the evaluation of secondary lipid oxidation products in chicken patties during long-term storage

The formation of hexanal, pentanal and malonaldehyde from raw and grilled chicken patties during storage at -18 oC for 90 days was evaluated by SPME using a DVB/CAR/PDMS fiber. The extraction conditions were optimized to provide reproducible results and avoided fiber saturation even for more oxidised samples. The performance of different DVB/CAR/PDMS fibers was verified during the entire storage period and seven separate fibers were used to assay the extent of lipid oxidation. The relative standard deviation (RSD) was calculated for 60 duplicate analysis and no differences were observed (p > 0.05) among the fibers RSD despite the number of times they were used. The relationship between the different parameters were also established and compared to the results obtained by the traditional TBARS test. Raw patties showed significant (p < 0.05) Pearsons correlations between all parameters, varying from 0.93 to 0.99. However, grilled patties presented a correlation of 0.98 only between hexanal and pentanal.

Phenolic Compounds in Coffee Compared to Other Beverages

Abstract Coffee is the most important product obtained from roasted coffee beans and one of the most consumed beverages in the world. Although coffee is known for its stimulating properties attributed mainly to caffeine, it also contains other biologically active compounds, including phenolic compounds, with chlorogenic acids being the most abundant. The critical factor that affects these compounds in green coffee is the roasting time–temperature profile. Another beverage that contains a great amount of phenolic compounds is “tea” (Camellia sinensis L.), in which the flavonoids are the most abundant, particularly the catechins. Wine and fruit juices have also phenolic compounds, but in lower concentrations, such as phenolic acids, flavonoids, anthocyanins, stilbenes, and tannins, with different biological activities and intensities.

Process Engineering Applying Supercritical Technology for Obtaining Functional and Therapeutic Products

Abstract The incorporation of bioactive compounds with functional and therapeutic properties in food-related products is at the forefront of innovation in their life cycle. Modern consumers are demanding functional products because they are increasingly aware of the physiological, nutritional, and therapeutic benefits of consuming products that contain bioactive compounds. To keep up with developments in the society, investors from the private sector have been investing on modern, green, and promising technologies to obtain extracts, mostly from vegetal sources, which meet integrally the expectations of the consumers. Extracts also need to attend the trends of the global market regarding safe products that promote healthiness. In this context, extracts obtained after applying supercritical technology present great quality and they are free of organic solvents because “eco-friendly” solvents as carbon dioxide and water might be used in the processes. Extracts are rich of heat-sensitive bioactive compounds as a consequence of the mild conditions of temperature set in supercritical technology when carbon dioxide is used as solvent. Therefore, this chapter presents a critical review of obtaining bioactive compounds applying supercritical fluid extraction, as well as the potentialities of such target compounds in formulating functional products are overviewed along the chapter. The main purpose is to present a detailed assessment of such technology and the range of bioactive compounds produced, aiming to present a protocol of experimental activities on the field of food processing for increased consumption.

Application of cholesterol determination method to indirectly detect meat and bone meals in ruminant feeds

The aim of this study was to verify the presence of meat and bone meal (MBM) in ruminant feed, by identifying the cholesterol using gas chromatography with a flame ionization detector. The proposed method demonstrated precision, trueness, and capability to detect MBM in the ruminant feed.