Effect of monoglyceride content on emulsion stability and rheology of mayonnaise.

The aim of the study was to determine the effects of monoglyceride content on emulsion stability and rheology of mayonnaise. For this purpose, mono (MG) and diglycerides (DG) were produced by transesterification of refined olive oil with elevating glycerol contents from 25 to 100 g and reaction times from 25 to 40 min. Maximum MG-DG yield was obtained when the reaction was performed for 40 min using 75 or 100 g of glycerol. Under these conditions, 90% of triglycerides (TG) were converted to 40% MG and 50% DG. Using a molecular distillation unit, MG was separated from the transesterification reaction mixture and purified up to 98%. Emulsifiers were then prepared by introducing distilled MG into the transesterification reaction mixture in order to increase the MG concentration from 40 to 98%, for enabling the utilization of them in mayonnaise production. The mayonnaise incorporated with 98% MG showed the highest stability and reduction in the MG concentration in the emulsifier mixture decreased the emulsion stability. Rheological measurements indicated that the control sample without emulsifier had the highest viscosity and shear stress values. The increment of the MG concentration in the emulsifier mixtures resulted in only small differences on the rheological properties of mayonnaise.

Utilization of molecular distillation for determining the effects of some minor compounds on the quality and frying stability of olive pomace oil.

The objective of this study was to determine the effects of some minor components such as squalene and mono- and diglycerides (MDG) on the frying stability of olive pomace oil. Refined olive pomace oil was distilled using a falling film type short-path distillation unit at 230 °C under a pressure of 0.02 mbar to remove minor components. Distilled olive pomace oil was introduced with approximately 10,000 mg/kg of squalene and 2.5% of MDG. Fryings were performed 8 times/day at 180 °C for 3 min. Whole frying procedure proceeded for 5 days. Total polar compounds, polymerized triglycerides (PTG), free fatty acids, viscosity, color index, p-anisidine value, smoke point, fatty acid composition and iodine values of the oils were monitored. Results indicated that all criteria except smoke point and iodine value increased in all fractions during fryings. The lowest total polar compound was obtained in distilled olive pomace oil while PTG was the lowest in the MDG added fraction. Lower increases in viscosity and color indexes were recorded in squalene incorporated samples. It was observed that squalene and MDG were not effective on the oxidation rate of unsaturated fatty acids during frying.

Different sized wheat bran fibers as fat mimetic in biscuits: its effects on dough rheology and biscuit quality.

The aim of this study is to investigate the effects of various particle sized and different amount of plant fibers as fat mimetic for biscuit formulations instead of biscuit fat. The fibers with different particle sizes were obtained from wheat bran and used instead of fat in biscuit formulations. The texture, rheology and quality analyses of low-fat biscuit (30, 20 and 10% fat) were performed and compared with those of the full-fat control sample (40% fat). Results showed that wheat bran fiber with bigger particle size (Long Fiber, LF) were more favorable in terms of textural properties of the dough and the quality parameters of biscuits while the fibers with smaller particle size (Medium Fiber, MF and Small Fiber, SF) improved viscoelastic properties of dough similar to the control. Although the use of these fibers in the production of low-fat biscuits were suitable in terms of workability of dough increasing fiber content and/or reducing fiber size resulted in harder biscuits with lower spread ratio. This study showed that the texture of biscuits was greatly dependent on the texture of the dough.

Effect of black cumin oil on the oxidative stability and sensory characteristics of mayonnaise.

Mayonnaise is one of the most commonly used sauces all over the world but it is vulnerable to oxidation because of its high oil content. Using natural antioxidants instead of synthetic ones is a popular and promising topic in the food industry. The aim of this study was to increase the oxidative stability of mayonnaise using cold-pressed black cumin oil (BCO), which has high antioxidant activity due to its phenolic content. Four different mayonnaise formulations were used: Mayo-Control, Mayo-5% BCO, Mayo-10% BCO, and Mayo-20% BCO, which refer to a 0 (control), 5, 10, and 20% BCO replacement of total sunflower oil content, respectively. Thymoquinone content of the mayonnaises including BCO increased with the increasing BCO ratios. At the end of the storage for 4 weeks at 20 °C, peroxide values of Mayo-Control, Mayo-5% BCO, Mayo-10% BCO, and Mayo-20% BCO samples were recorded as 36.07 ± 1.51, 26.76 ± 0.67, 25.60 ± 0.57, and 17.66 ± 1.93 meq O2/kg oil, respectively. The conjugated diene and triene values of the mayonnaises prepared by adding BCO were lower than those of the control group during storage. Overall acceptability of Mayo-5% BCO in sensory analysis was higher than that of Mayo-Control. Using BCO in mayonnaise improved its oxidative stability and flavor.

A novel mutation of ABCG5 gene in a Turkish boy with phytosterolemia presenting with macrotrombocytopenia and stomatocytosis.

Phytosterolemia is a rare autosomal recessive sterol storage disease caused by mutations in ABCG5 and ABCG8 genes. A 9-year-old Turkish boy who was presented with exclusively hematologic abnormalities had elevated plant sterol levels. Sequencing of ABCG5 and ABCG8 genes revealed a novel homozygous IVS10-1 G>T mutation in ABCG5 gene. Four of the 13 family members had xanthoma but they had neither hematologic abnormalities nor IVS10-1 G>T mutation. Ezetimibe therapy reduced plant sterol levels in association with marked clinical improvement. Plant sterol levels and ABCG5/ABCG8 genes should be analysed in patients with unexplained hemolytic anemia and macrothrombocytopenia.

Utilization of zero-trans non-interesterified and interesterified shortenings in cookie production.

The effects of zero-trans chemically interesterified (in-es) and non-interesterified (non-in-es) cottonseed (CO), hazelnut (HO) and olive oil (OO) and their blends (25, 50 and 75%) with palm oil (PO) were studied in the production of cookies. All the experimental shortenings had zero-trans fatty acids (TFA) while the shortening contained 14.20% TFA. Incorporation of CO in PO considerably increased the linoleic acid content whereas the raising of HO and OO ratio in the blend increased the oleic acid content. Zero-TFA and lower saturated /unsaturated fatty acid ratio (SFA/UFA) of some of the experimental shortenings indicated an important in nutritional properties of cookies produced from these experimental shortenings. Cookies with in-es shortenings showed significantly higher (p < 0.05) spread ratios and L Hunter color than their non-in-es shortenings added counterparts. It can be concluded that chemical interesterification is a promising method to produce cookie shortenings with zero-TFA.

Furan formation in some vegetable oils during heat treatments.

Furan formations were monitored in commercially refined sunflower, soybean and olive oils during heat treatments at 170, 180 and 190 °C for 0, 2, 4, 6 and 8 h. The lowest furan concentrations were detected in sunflower oil at all temperatures, while soybean oil generated the highest furan concentration at 190 °C at the end of 8th hour. Furan contents were higher in olive oil at 170 and 180 °C, which might be due to its high diglyceride content. Furan formation linearly increased with time. Zero-order kinetic equations were used to determine kinetic parameters. Temperature was found effective on the furan formation because increases in reaction rate constants were observed by increasing the temperature. Using Arrhenius equation, activation energies of sunflower, soybean and olive oils were calculated as 45.08, 100.24 and 22.41 J/mol, respectively.

Formation kinetics of polycyclic aromatic hydrocarbons (PAHs) during drying process of olive pomace.

The objective of this study was to evaluate the formation kinetics of polycyclic aromatic hydrocarbons (PAHs) during drying of olive pomace. It was dried at 170, 200 and 230 °C until the final moisture of 5%. PAH analyses were realized after certain drying times and moisture contents. Kinetics of the total PAH formation was comprised with the formation of PAH compounds through the drying process. The highest formation (2224 µg/kg) was observed at 200 °C and 5% moisture after 40 min. This also indicated the significance of drying time and evolution of temperature on the formation of PAH compounds. First order kinetic was applied to determine the kinetic constants as a function of temperature. Total PAH fomration rate constants (k) increased with the drying temperature. Activation energy (Ea) and frequency factor (k0) values were determined to be 45.9 × 103 kJ/kg-mol and 18125.95 min-1, respectively using the Arrhenius equation.

Genetic basis and hematologic manifestations of sitosterolemia in a group of Turkish patients.

BACKGROUND: Sitosterolemia is a rare lipid disorder caused by mutations in adenosine triphosphate-binding cassette genes (ABCG) 5 and 8. OBJECTIVE: To evaluate the phenotypic/genotypic features of sitosterolemia in a group of Turkish patients. METHODS: Seven probands with unexplained hematologic abnormalities and their 13 relatives were enrolled. Sterol levels were measured by gas chromatography and genetic studies were performed using Sanger sequencing. Individuals were diagnosed with sitosterolemia if they were found to have frankly elevated sitosterol level >15 µg/mL and/or pathogenic variants of the ABCG5/ABCG8. RESULTS: The seven probands and their six relatives  were diagnosed with frank sitosterolemia, and all these patients had hematologic abnormalities. The remaining seven relatives were asymptomatic heterozygous carriers. Three novel variants in the ABCG5 gene (c.161G>A, c.1375C>T, IVS10-1G>T), one novel variant in the ABCG8 gene (c.1762G>C) and one known variant in the ABCG5 gene (c.1336 C>T) were identified. No variant was identified in one case. The mean sitosterol level was significantly higher and mean platelet count was significantly lower in patients with homozygous variants compared to heterozygous variants (p<0.05, for all). Diets low in plant sterols were recommended for 13 symptomatic cases. Four homozygotes received ezetimibe, and their splenomegaly, anemia, and thrombocytopenia completely resolved except one. CONCLUSION: The five pathogenic variants identified in this study indicate the genetic heterogeneity of sitosterolemia in Turkish population. Patients with unexplained hematologic abnormalities (specifically macrothrombocytopenia) should have their sterol level measured as initial testing. Ezetimibe can be a good choice for sitosterolemia.

Reducing polycyclic aromatic hydrocarbons (PAHs) in olive pomace oil using short-path molecular distillation.

Bleached olive pomace oil (BOPO) was distilled using a short-path molecular distillation unit to determine the impacts of distillation conditions on the removal of 15 PAHs from the list of 16 EPA-priority pollutant PAHs. The removal of PAHs was achieved at elevated temperatures (110-230°C) and pressures (0.05, 0.5, 5 mbar). The oil was also deodorised at 230°C under 0.5, 1 and 5 mbar pressures to determine the effect of pressure during deodorisation on the removal of PAHs. High-performance liquid chromatography (HPLC) with fluorescence detector (HPLC-FLD) was used for quantifying PAH concentrations in oil samples. PAH concentrations in BOPO were considerably reduced after molecular distillation and both temperature increment and pressure decrease were effective for the removal of PAHs from olive pomace oil. When above 190°C, BaP could be reduced to <2 µg/kg at all pressures. Distillation at 230°C under 0.05 mbar absolute pressure reduced the sum of four PAHs (BaP, Chr, BaA, BbF) to 7 µg/kg, which meets the acceptable levels established by the European Union (10 µg/kg). Deodorisation effectiveness was increased by decreasing absolute pressure, particularly for light PAHs.

Multi-objective Optimization of Molecular Distillation Conditions for Oleic Acid from a Rich-in-Fatty Acid Model Mixture.

Oleic acid is a commercially valuable compound and has many positive health effects. Determining optimum conditions in a physical separation process is an industrially significant point due to environmental and health related concerns. Molecular distillation avoids the use of chemicals and adverse effects of high temperature application. The objective of this study was to determine the molecular distillation conditions for oleic acid to increase its purity and distillation yield in a model fatty acid mixture. For this purpose, a short-path evaporator column was used. Evaporation temperature ranged from 110 to 190℃, while absolute pressure was from 0.05 to 5 mmHg. Results showed that elevating temperature generally increased distillation yield until a maximum evaporation temperature. Vacuum application also affected the yield at a given temperature, and amount of distillate increased at higher vacuums except the case applied at 190℃. A multi-objective optimization procedure was then used for maximizing both yield and oleic acid amounts in distillate simultaneously, and an optimum point of 177.36℃ and 0.051 mmHg was determined for this purpose. Results also demonstrated that evaporation of oleic acid was also suppressed by a secondary dominant fatty acid of olive oil - palmitic acid, which tended to evaporate easier than oleic acid at lower evaporation temperatures, and increasing temperature achieved to transfer more oleic acid to distillate. At 110℃ and 0.05 mmHg, oleic and palmitic acid concentrations in distillate were 63.67% and 24.32%, respectively. Outcomes of this study are expected to be useful for industrial process conditions.