Influence of Radiation Processing of Cooked Beef Sausage on Its Lipids

The effect of gamma irradiation on fatty acid composition and lipid oxidation in emulsion-type cooked beef sausages was investigated. Vacuum-packaged sausages were irradiated at 2, 4, 6 and 8 kGy and stored at 4 °C for 4 weeks. Samples were analyzed for fatty acid composition at 0 and 4 weeks and lipid oxidation after 0, 1, 2, 3 and 4 weeks of storage. Irradiation reduced the content of oleic acid and linoleic acid, and the effect was intensified during storage. Elaidic acid content increased at doses of 6 and 8 kGy. The results indicated that irradiation at 6 and 8 kGy increased lipid oxidation, measured as the thiobarbituric acid reactive substances value. Based on the results, cooked beef sausages could be irradiated at 2 and 4 kGy without affecting the molecular structure of lipids.     

Application of metal triflate catalysts for the trans-esterification of Jatropha curcas L. oil with methanol and higher alcohols

This paper describes an experimental study on the application of metal triflate salts for the (trans‐) esterification of fatty esters (triolein, methyl oleate, methyl linoleate), fatty acid (oleic acid), as well as Jatropha curcas L. oil with methanol and higher alcohols (ethanol, n‐propanol, iso‐propanol, iso‐butanol, tert‐butanol). The effect of the metal type (scandium, bismuth, aluminium, lanthanum, copper, zinc) and process conditions on reaction performance were evaluated. Highest conversions were obtained with Al(OTf)₃. Reaction of triolein with methanol gave 99 mol% conversion at 165 °C for 1 h and the main product was the methyl ester. In addition, partial methoxylation of the carbon–carbon double bonds in the fatty acid chains was observed, though their fraction in the mixture was less than 20 mol%. The trans‐esterification reaction was also successfully performed using higher alcohols, giving >95 % conversions for ethanol, n‐propanol, iso‐propanol and iso‐butanol, whereas tert‐butanol was not reactive. For the reaction of oleic acid with methanol, quantitative esterification, partial methoxylation of the carbon–carbon double bonds and the formation of small amounts of a lactone was observed. The methodology using Al(OTf)₃ was successfully performed on the trans‐esterification reaction of JO (FFA content of 2.1 wt%) with various alcohols. Key properties (viscosity, pour point and cloud points) of the (branched) Jatropha esters were determined. The best cold‐flow properties were obtained for the iso‐propyl esters of JO, with cloud point and pour point of ?3 and ?24 °C, respectively.     

Double Bond Position Plays an Important Role in Delta-9 Desaturation and Lipogenic Properties of Trans 18:1 Isomers in Mouse Adipocytes

The objective of this research was to study the delta‐9 desaturation of individual trans (t) fatty acids that can be found in ruminant fat or partially hydrogenated vegetable oils (PHVO) and determine their effects on lipogenic gene expression in adipocytes. It was hypothesized that delta‐9 desaturation and lipogenic properties of t‐18:1 isomers depend on the position of double bond. Differentiated 3T3‐L1 adipocytes were treated with 200 µM of t6–18:1, t9–18:1, t11–18:1, t13–18:1 or t16–18:1, cis (c)‐9 18:1 or bovine serum albumin (BSA) vehicle control for 48 h. Cells were then harvested for fatty acid and gene expression analyses using gas chromatography and quantitative PCR respectively. Among t‐18:1 isomers, t13–18:1 and t11–8:1 had the greatest percent delta‐9 desaturation (44 and 41 % respectively) followed by t16–18:1 and t6–18:1 (32 and 17 % respectively), while c9–18:1 and t9–18:1 did not undergo delta‐9 desaturation. Trans9–18:1 up‐regulated (P < 0.05) the expression of lipogenic genes including fatty acid synthase and stearoyl‐CoA desaturase‐1 (P < 0.05), whereas the expression of these genes were not affected with other t‐18:1 isomers (P > 0.05). Consistent with gene expression results, t9–18:1 increased the de novo lipogenic index (16:0/18:2n‐6) compared with control cells and increased delta‐9 desaturation index (c9–16:1/18:0) compared to other t‐18:1 isomers (P < 0.05). The current study provides further evidence that the predominant trans fatty acid in PHVO (t9–18:1) has isomer specific lipogenic properties.     

Gene expression after dietary intervention with trans fatty acids (trans‐11/trans‐12 18:1) in humans

Gene‐by‐diet interactions play an important role in the prevention of several diseases. Conjugated linoleic acids (CLA) are ligands of gene regulators [e.g. peroxisome proliferator‐activated receptors (PPAR)] and have anti‐inflammatory properties. The aim of the study was to investigate the changes in gene expression in monocytes during the intervention with two trans fatty acids (trans‐11 18:1 and trans‐12 18:1) and endogenous CLA from trans‐11 18:1 as precursor in humans. Monocytes were isolated at baseline and after a 6‐week intervention period. The female and male test groups received Σ6.0 g trans‐11 and trans‐12 18:1/day (1 : 1). The control group received control oil. The expression of candidate genes was determined by quantitative RT‐PCR. Gender‐ and treatment‐related gene expression was found. Due to trans fatty acid intake in both gender subgroups, the relative PPARγ expression was up‐regulated. In the female test group, the expression of FAT, SCD, COX2 and BCL2 were induced, while in the male test group E‐FABP, CYP, GLUT4 and PBE were induced. In the male test group compared to controls, a clear increase in gene expression of PPARγ and GLUT4 was shown. The results reveal a gender‐ and treatment‐related gene expression. There is no clear indication as to what extent the supplemented trans fatty acids and the synthesized cis‐9,trans‐11 CLA were involved.     

GTEM cell facility use during project development phases for automotive

The purpose of this paper is to present the results obtained with a gigahertz transverse electromagnetic mode (GTEM) cell for each phase of the project development, which consists of measuring and quantifying the integrated circuit's emissions and immunity compliance with automotive standards. These standards are defined using half anechoic chambers (HAC). Studies have already been conducted to compare trans electromagnetic (TEM) cell and HAC, or far-field emissions, and the test results show a limited correlation between TEM cells and the free space field or HAC. In this paper, it is shown that the correlation between the measurements made in a GTEM cell and HAC can be good enough in allowing us to use the GTEM facility during the research and development (R&D) phase (considering the facts that the HAC facility is often quite overloaded and of a high cost), that knowledge of the electromagnetic compatibility behavior of the integrated circuit is important for predicting the whole system's results as well as how to use an integrated circuit electromagnetic model to make the prediction of emissions.     

A novel process for the synthesis of unsaturated polyester

Traditionally polyester production is done in a batch reactor equipped with a separation column for a batch distillation. A promising alternative for the intensification of this process is reactive distillation. The aim of this paper is to study the conceptual design of reactive distillation and to find out whether reactive distillation is potentially interesting compared to batch reactor process. Therefore, a reactive distillation model is developed and sensitivity analysis is used to obtain the design and operational parameters for the reactive distillation process. These parameters are the required number of stages, required residence time, feed ratio, reflux ratio and temperature of feed stream. The model predicts the polymer attribute, isomerization and saturation composition of the polymer in the range of industrial polyester production data. The simulation study shows that the total production time of polyester in a continuous reactive distillation system is reduced from 12 h to 1.5-2 h compared to the industrial batch reactor process. The equilibrium conversion is also raised by 7% compared to the conventional process. The model demonstrated that reactive distillation has the potential to intensify the process by factor of 6-8 in comparison to the batch reactor.     

Margarine from Organogels of Plant Wax and Soybean Oil

Organogels obtained from plant wax and soybean oil were tested for their suitability for incorporation into margarine. Sunflower wax, rice bran wax and candelilla wax were evaluated. Candelilla wax showed phase separation after making the emulsion with the formulation used in this study. Rice bran wax showed relatively good firmness with the organogel, but dramatically lowered firmness for a margarine sample. Sunflower wax showed the greatest firmness for organogel and the margarine samples among the three plant waxes tested in this study. Firmness of the margarine containing 2–6 % sunflower wax in soybean oil was similar to that of margarine containing 18–30 % hydrogenated soybean oil in soybean oil. The firmness of commercial spread could be achieved with about 2 % sunflower wax and that of commercial margarine could be achieved with about 10 % of sunflower wax in the margarine formulation. Dropping point, DSC and solid fat content of the new margarine containing 2–6 % sunflower wax showed a higher melting point than commercial margarine and spreads.     

A rapid method for monitoring total trans fatty acids (TTFA) during industrial manufacturing of Brazilian spreadable processed cheese by capillary zone electrophoresis

An alternative method for monitoring total trans fatty acids (TTFA) in hydrogenated vegetable fat (HVF) and spreadable processed cheese (SPC) using capillary zone electrophoresis (CZE) and indirect UV detection is proposed. This method is a simple, efficient and rapid way to monitor both raw materials and the final SPC product. The importance of printing nutritional tables on product labels, to provide more accurate information to consumers, and incorporation of stricter quality controls during food processing is emphasised. Following calculation of the response factor (R_f), the CE method was applied to TTFA analysis in SPC samples, and compared with the accepted AOCS gas chromatography (GC) method. According to a paired sample t test, no significant difference was found between the CE and GC methods within the 95% confidence interval for five different brands analysed in genuine duplicate (p-value > 0.05). The optimised CE method was applied to analyse the TTFA content of the hydrogenated vegetable fat raw material and the SPC final product. Based on our results, this optimised CE method can be successfully used for routine analysis of TTFA in SPC samples with a run time of 7.5 min.     

Influence of natural antioxidants on the formation of trans‐fatty‐acid isomers during heat treatment of sunflower oil

The intake of foods containing trans fatty acids (TFAs) can have deleterious effects on human health, mainly on the cardiovascular system. Thus, it is important to consider the processes that form TFAs in foods, and the alternatives to minimise their formation. The influence of two added natural antioxidants on TFA formation during heat treatment (120 h at 180°C) of sunflower vegetable oil were examined: rosemary extract (Rosmarinus officinalis L.) (1 g per kg oil) and lutein (0.1 g per kg oil). Changes in FA composition were determined using Ag‐ion SPE and gas–liquid chromatography, with total polar compounds determined using dielectric constant measurements and the index of atherogenicity was calculated. Total TFAs with ≥1 trans double bond increased from 0.91 to 1.71% in control samples; this increase was significantly less with both rosemary extract (1.55%) and lutein (1.43%) additions. Among the individual TFAs, significant increases were seen for C18:1,t‐9, C18:2,t‐9,t‐12 and C18:2,c‐9,t‐12/9‐t,12‐c. Polar compounds also increased, with the highest concentrations in control samples, and significantly less with both rosemary extract and lutein additions. According to results of our study, we can summarize that addition of lutein have greater effect on reduction of TFA formation than rosemary extract. Practical applications: Antioxidants, particularly from plants, are widely used in the food industry. They can provide benefits in food preparation, including improving colour, odour and stability, acting as acid regulators and natural preservatives. They have also become accepted by customers and consumers, and so indirectly they have had effects on consumer perception. Addition of natural antioxidants such as rosemary extract is usually limited by the sensory characteristics of the food, with one study showing that addition of rosemary extract at 1–3 g per kg vegetable oil is recommended. The effects of antioxidants on the formation of TFAs in vegetable oils has not been well studied in the literature. Among the already known benefits, the use of such antioxidants as functional ingredients in lipid technologies might reduce the formation of TFAs during thermal treatment.