The effect of different levels of sunflower head pith addition on the properties of model system emulsions prepared from fresh and frozen beef

The effect of sunflower head pith on the functional properties of emulsions was studied by using a model system. Oil/water (O/W) model emulsion systems were prepared from fresh and frozen beef by the addition of the pith at five concentrations. Emulsion capacity (EC), stability (ES), viscosity (EV), colour and flow properties of the prepared model system emulsions were analyzed. The pith addition increased the EC and ES and the highest EC and ES values were reached when 5% of pith added; however, further increase in the pith concentration caused an inverse trend in these values. Fresh beef emulsions had higher EC and ES values than did frozen beef emulsions. One percent pith concentration was the critic level for the EV values of fresh beef emulsions. EV values of the emulsions reached a maximum level at 5% pith level, followed by a decrease at 7% pit level.     

Composition and thermal properties of cattle fats

The physical‐chemical properties, fatty acid composition and thermal properties of cattle subcutaneous, tallow and intestinal fats were determined. Subcutaneous fat differed from the other fat types with respect to its lower melting point (29.0 °C) and higher saponification (211.4 mg KOH/g) and iodine (50.55) values. The cattle fat types contained palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1n‐9) and linoleic acid (18:2n‐6) as the major components of fatty acid composition (24.58–25.90%, 10.21–33.33%, 28.18–46.05%, 1.54–1.73%, respectively). A differential scanning calorimetry (DSC) study revealed that two characteristic peaks were detected in both crystallization and melting curves. Major peaks (T_peak) of tallow and intestinal fats were similar and determined as 24.10–27.71 °C and 2.16–4.75 °C, respectively, for crystallization peaks and 7.09–9.39 °C and 43.28–46.49 °C, respectively, for melting peaks in DSC curves; however, those of subcutaneous fat (12.48 °C and –6.79 °C for crystallization peaks and 3.56 °C and 23.55 °C for melting peaks) differed remarkably from those of the other fat types.     

Response surface methodology study on the optimisation of effects of fat, wheat bran and salt on chemical, textural and sensory properties of patties

A three-factor Box-Behnken design was adopted for studying the simultaneous effects of processing variables such as fat (10–30%), wheat bran (5–15%) and NaCl (0–2%) on physicochemical, textural and sensory properties of cooked beef patties. In addition, the ridge analysis was conducted to find the values of processing variables that maximise and minimise the texture profile analysis (TPA) parameters (hardness, chewiness, gumminess, adhesiveness, springiness, resilience and cohesiveness) and sensory ratings. Experimental design allowed for evaluation of potential interactive and quadratic effects between these variables; fat wheat bran and NaCl. It was found that protein and fat contents of patties was decreased and increased, respectively as the amount of wheat bran increased. NaCl increased the ash content of patties. Fat and wheat bran had a notable influence on textural properties, which improved the textural properties at certain levels. Lower addition of wheat bran and NaCl into patty resulted in higher acceptable product with respect to firmness, juiciness and overall quality properties.     

Mind the gap—deficits in our knowledge of aspects impacting the bioavailability of phytochemicals and their metabolites—a position paper focusing on carotenoids and polyphenols

Various secondary plant metabolites or phytochemicals, including polyphenols and carotenoids, have been associated with a variety of health benefits, such as reduced incidence of type 2 diabetes, cardiovascular diseases, and several types of cancer, most likely due to their involvement in ameliorating inflammation and oxidative stress. However, discrepancies exist between their putative effects when comparing observational and intervention studies, especially when using pure compounds. These discrepancies may in part be explained by differences in intake levels and their bioavailability. Prior to exerting their bioactivity, these compounds must be made bioavailable, and considerable differences may arise due to their matrix release, changes during digestion, uptake, metabolism, and biodistribution, even before considering dose‐ and host‐related factors. Though many insights have been gained on factors affecting secondary plant metabolite bioavailability, many gaps still exist in our knowledge. In this position paper, we highlight several major gaps in our understanding of phytochemical bioavailability, including effects of food processing, changes during digestion, involvement of cellular transporters in influx/efflux through the gastrointestinal epithelium, changes during colonic fermentation, and their phase I and phase II metabolism following absorption.     

Effects of occupational lead and cadmium exposure on some immunoregulatory cytokine levels in man

The levels of serum interleukin-1beta (IL-1beta), interleukin-2 (IL-2), tumor necrosis factor alpha (TNF-alpha) and gamma-interferon (gamma-IFN) were assessed in the workers who were occupationally exposed to lead and cadmium. The values were compared with the age-matched control group. Blood lead and cadmium levels were significantly raised. Our findings suggest that chronic lead and cadmium exposure in humans resulted in significant suppression of the serum IL-1beta level, but did not alter IL-2 and TNF-alpha levels. The gamma-IFN level was also reduced in lead workers. In contrast, a significant enhancement was observed in the cadmium-exposed group. We conclude from these results that lead and cadmium exposure at chronically high level may affect some cytokine levels in humans.     

Formation of polycyclic aromatic hydrocarbons in beef and lamb kokorec: Effects of different animal fats

Traditional kokorec, which is one of the products of offal (edible by-products) and consumed enthusiastically in Turkey, is produced from fresh and washed lamb and calf small intestines. Some health risks can occur unless hygiene and sanitation rules are followed and proper cooking procedures are applied during the production process of kokorec. One of the most important among these risks is the microbial origin hazard and another is the formation of polycyclic aromatic hydrocarbons. In this study, the aim was to determine the concentrations of eight polycyclic aromatic hydrocarbons formed during the cooking of kokorec produced from beef and lamb small intestines by adding various animal fats. Polycyclic aromatic hydrocarbonformation was specified in ready-to-consume kokorec samples in which eight polycyclic aromatic hydrocarbon concentrations varied between 3.07 and 40.11 µg/kg. The consumption of lamb kokorec could be recommended to consumers because its average total eight polycyclic aromatic hydrocarbon concentration was lower than that of beef kokorec.     

Microchannel reactor modeling for combustion driven reforming of iso-octane

Coupling of exothermic and endothermic reactions in parallel microchannels is investigated through parametric variation of geometric and material properties in the context of hydrogen production by steam reforming of iso-octane, the surrogate for gasoline. Heat required for the endothermic reforming reaction is provided by the catalytic combustion of methane, the model compound for natural gas. The combination of steam reforming and combustion is modeled for a microchannel reactor configuration in which reactions and heat transfer take place in parallel, micro-sized, square-shaped flow paths with wall-coated catalysts. Thickness of the wall between microchannels, side-length of the microchannels and channel texture (straight-through vs. micro-baffled) are the geometric parameters being studied, while the use of different materials of construction - α-alumina, AISI-steel and iron - is also investigated. Instead of a fully-fledged 3-D mathematical model, the parametric runs are performed on a 2-D unit cell model which is justified to give results close to that of the former. When the wall thickness is increased from 1 × 10⁻⁴ to 4 × 10⁻⁴ m, the hydrogen yield, defined as moles of hydrogen produced per mole of iso-octane fed, increases by 42% because axial heat conduction in the wall becomes more pronounced and spreads the energy released by combustion into the reforming channel more effectively. Increase in the yield is more remarkable (110%) when the channel side-length is doubled from 2.8 × 10⁻⁴ to 5.6 × 10⁻⁴ m. Use of micro-baffles also enhances the hydrogen yield: in the 1-4 × 10⁻⁴ m wall thickness range, the average increase is 16.5%, which is attributed both to the enhancement in heat transfer coefficients and axial conduction in the wall. As for the material property parameter, due to having the highest thermal conductivity, hence the ability of conducting heat axially, iron serves as the best wall material on the basis of highest hydrogen yield, compared with alumina and steel.     

Interactive approaches for biobjective problems with progressively changing solution sets

In this study, we develop interactive approaches to find a satisfactory alternative of a decision maker (DM) having a quasiconvex preference function where the alternative set changes progressively. In this environment, we keep searching the available set of alternatives and estimating the preference function of the DM. As new alternatives emerge, we make better use of the available preference information and eventually converge to a preferred alternative of the DM. We test our approaches on biobjective, multi‐item, multi‐round auction problems. The results show that our approaches work well in terms of both the preference function value of the obtained solution and the amount of preference information required.