Effect of replacing beef fat and tail fat with interesterified plant oil on quality characteristics of Turkish semi-dry fermented sausages

Seven treatments of Turkish semi-dry fermented sausage were manufactured by replacing 0, 20, 60 and 100% of beef fat and tail fat by interesterified palm (IPaO) and cottonseed oils (ICO). pH, fat and moisture content, penetrometer value and fatty acid composition as well as sensory attributes were determined for each formulation. Addition of interesterified plant oils (IPOs) was found to significantly affect the miristic, palmitic, palmitoleic, stearic, oleic, linoleic acid content and also saturated to unsaturated (SFA/UFA), polyunsaturated to saturated (PUFA/SFA) ratios of treatments ( p<0.05), however no significant change in the miristoleic acid content was recorded ( p>0.05). Sensory evaluation indicated that control sausages had the highest sensory scores. However the sausages produced with IPOs were also acceptable. Therefore, further research is needed to improve the sensory attributes of these products, particularly their flavour.     

A study on monitoring of frying performance and oxidative stability of cottonseed and palm oil blends in comparison with original oils

Blending polyunsaturated oils with highly saturated or monounsaturated oils has been studied extensively; however, in literature there is negligible information available on the blending of refined cottonseed oil with palm olein oil. Blending could enhance the stability and quality of cottonseed oil during the frying process. In the present study, the effects of frying conditions on physicochemical properties of the palm olein-cottonseed oil blends (1:0, 3:2, 1:1, 2:3, and 0:1, w/w) were determined and compared to the pure oils. The frying process of frozen French fries was performed in duplicate at 170 ± 5°C for 10 h without interruption. The oil degradations were characterized during deep-frying applications; peroxide, free fatty acid, and iodine value by standardized methods, fatty acid profile by using a gas chromatography-flame ionization detector, polar and polymeric compounds by using the high-performance size exclusion chromatography/evaporative light scattering detector technique. The present study clearly indicated that the oxidative and frying performances of pure palm olein oil and cottonseed oil significantly improved by blending application. Results clearly indicated that the frying performance of cottonseed oil significantly improved by the blending with palm olein oil. Except that free fatty acid content, all the physicochemical variables were significantly influenced by type of pure and blend oils. By increasing the proportion of palm olein oil in cottonseed oil, the levels of polyunsaturated fatty acids decreased, while saturated fatty acid content increased. The progression of oxidation was basically followed by detecting polar and polymeric compounds. The fastest increments for polar and polymeric compounds were found as 6.30% level in pure cottonseed oil and as 7.07% level in 40% cottonseed oil:60% palm olein oil blend. The least increments were detected as 5.40% level in 40% cottonseed oil:60% palm olein oil blend and 2.27% level in 50% cottonseed oil:50% palm olein oil blend. These levels were considerably below the acceptable levels recommended by the official codex. Therefore, the present study suggested that blending of cottonseed oil with palm olein oil provided the oil blends (50% cottonseed oil:50% palm olein oil and 40% cottonseed oil:60% palm olein oil, w/w) with more desirable properties for human nutrition.     

Geographical origin classification of olive oils by PTR-MS

The volatile compositions of 192 olive oil samples from five different European countries were investigated by PTR-MS sample headspace analysis. The mass spectra of all samples showed many masses with high abundances, indicating the complex VOC composition of olive oil. Three different PLS-DA models were fitted to the data to classify samples into ‘country’, ‘region’ and ‘district’ of origin, respectively. Correct classification rates were assessed by cross-validation. The first fitted model produced an 86% success rate in classifying the samples into their country of origin. The second model, which was fitted to the Italian oils only, also demonstrated satisfactory results, with 74% of samples successfully classified into region of origin. The third model, classifying the Italian samples into district of origin, yielded a success rate of only 52%. This lower success rate might be due to either the small class set, or to genuine similarities between olive oil VOC compositions on this tight scale.     

Effect of interesterified fat mixtures on certain lipid indices in experimental fat metabolism disturbance

Groups of adult Wistar male and female rats were fed isoenergetically for a three and a six weeks period either with synthetic lipogenic diet containing 5% and 20% fat mixtures (in which sunflower oil and lard were blended according to the ratio of 35:65) or with the same synthetic diet containing the mixture of sunflower oil and interesterified lard in a similar ratio. A control group received a normal diet for 6 weeks, whereas one of the experimental groups (fed with the 20% fat mixture in the lipogenic diet for 6 weeks) was given the normal diet for an additional two weeks period. After the feeding periods had been completed serum HDL-C levels and the total lipid, triglyceride, total cholesterol, free fatty acid levels were determined in serum and liver. The distribution of fatty acids in liver and heart muscle was also evaluated. In comparison to the control values it has been found: 1. Consumption of the lipogenic diet which is known to increase the serum total lipid and total cholesterol content induced in male rats a smaller augmentation in these indices when consuming the 20% fat mixture with a P/S ratio approaching the ideal 1 values, than in case of a 5% fat mixture consumption. In case of female rats, considerable increases of the serum values, could be observed at both fat consumption levels. The serum triglyceride and HDL-C contents decreased for all experimental groups. 2. The total lipid and triglyceride content of the liver increased in a high degree, the fatty liver syndrome was developed--more rapidly in males than in females. The total lipid, triglyceride and total cholesterol contents of the liver of male rats exceeded those of females by 15-30%. 3. The interesterification of the lard component of fat mixture resulted in lipid indices similar to those without interesterification, or in certain cases, they were found to be even slightly more favourable, i.e. the biological effect of the technological change proved to be adequate. 4. After a two weeks regeneration period the serum values of the male rats approached closer the normal control values than those of the females which were decreasing from a very high level but the degree of decrease was greater for them than for the male rats. The lipid content of the liver showed similar values.(ABSTRACT TRUNCATED AT 400 WORDS)     

不同熔点棕榈油脂肪酸组成和SFC测定分析

分析七种不同棕榈油脂肪酸组成及在0℃~25℃(5℃间隔)温度下固体脂肪含量(SFC)及其变化规律。结果表明:随熔点降低,棕榈酸含量有逐渐降低趋势,而油酸和亚油酸含量则逐渐上升;饱和脂肪酸含量逐渐减少,而不饱和脂肪酸含量则逐渐升高;低熔点棕榈油营养价值要比高熔点棕榈油高;在不同温度段,SFC值增加幅度有所不同。该试验为棕榈油进一步深加工研究提供参考数据。     

Influence of olive crushing temperature on phenols in olive oils

An experimental investigation was carried out to evaluate the influence the different temperatures at which olives are hammer-crushed and paste kneaded had on the quality of oil and particularly on the phenolic components. The results obtained showed that temperature influenced the diffusion of phenolic compounds in oil. Greater amounts of hydroxytyrosol, tyrosol, caffeic acid, hydroxycaffeic acid and oleuropeine were measured in oils obtained from previously refrigerated olives. Kneading brought about a reduction of total phenols when it was performed on olives crushed at a higher temperature (18vv°C) while it led to a slight increase when it was executed on pastes of previously refrigerated olives (6vv°C).     

Saturated hydrocarbon content in olive fruits and crude olive pomace oils

Olive fruits contain an n-alkane series of saturated hydrocarbons mainly in the pulp. Lower amounts of a complex mixture of paraffins, unresolved by gas chromatography (UCM – unresolved complex mixture), have been found in cuticle, stone (woody shell and seed), olive leaves, and talc used as an aid to olive oil extraction. The amounts of both kinds of hydrocarbons are related to the olive cultivar and are transferred to oils in a proportion depending on the oil-obtaining process (centrifugation or solvent extraction). In olive oil obtained by centrifugation, only n-alkanes were detected. However, in olive oil extracted by second centrifugation, small amounts of UCM paraffins were detected together with the n-alkanes. Olive pomace oils showed a very variable content of both types of hydrocarbons according to the different obtaining process, such as double centrifugation, solvent extraction or centrifugation followed by solvent extraction. ‘White mineral oil’ used in oil extraction machinery is the source of the high concentrations of UCM paraffins found in some olive and olive pomace oils. In the case of second centrifugation olive oil, a maximum limit of 50 mg kg^?1 of UCM is suggested, whereas in the case of crude olive pomace oil, it amounts to 250 mg kg^?1 plus an additional minimum of 1.0 for the n-alkanes/UCM ratio.     

Utilization of interesterified fat in the production of Turkish white cheese

The chemical, physicochemical, proteolysis, sensory, and texture characteristics of white cheeses made from interesterified fat were examined throughout ripening for 90 days. The water-soluble nitrogen based ripening indexes of cheeses increased throughout the ripening period. However, there were not large quantitative differences between the peptide profiles of the all cheese samples. Cheeses produced by using fully interesterified fat had higher values for hardness, chewiness, and gumminess than that of control cheese (p<0.05). The polyunsaturated to saturated fatty acid ratios of cheeses were increased due to the presence of interesterified fat. The cholesterol values of cheeses decreased at the rate of between 58.83–89.04% depending on interesterified fat addition. In the sensory analysis, similar scores were obtained for both the control cheese and the other cheeses. The results showed that interesterified fat in cheese production could be used to fully or partially replace the milk fat in cheese.     

Properties of high-oleic palm oils derived by fractional crystallization

ABSTRACT:  High-oleic palm oil (HOPO) with an oleic acid content of 59.0% and an iodine value (IV) of 78.2 was crystallized in a 200-kg De Smet crystallizer with a predetermined cooling program and appropriate agitation. The slurry was then fractionated by means of dry fractionation at 4, 8, 10, 12, and 15 °C. The oil and the fractionated products were subjected to physical and chemical analyses, including fatty acid composition, triacylglycerol and diacylglycerol composition, solid fat content, cloud point, slip melting point, and cold stability test. Fractionation at 15 °C resulted in the highest olein yield but with minimal oleic acid content. Due to the enhanced unsaturation of the oil, fractionation at relatively lower crystallization temperature showed a considerable effect on fatty acid composition as well as triacylglycerol and diacylglycerol composition of liquid fractions compared to higher crystallization temperature. The olein and stearin fractionated at 4 °C had the best cold stability at 0 °C and sharper melting profile, respectively.     

The interesterification-induced changes in olive and palm oil blends

Refined olive oil and partially hydrogenated palm oil (PHPO) blends of varying proportions were subjected to both chemical and enzymatic interesterifications. The rearranged fats were investigated for their melting points, solid fat contents at selected temperatures, fatty acid compositions and trans isomer contents, as well as evaluations, by an expert sensory panel, of their spreadibility and appearance characteristics. The analytical results were compared with those of commercial Turkish margarines. The 30:70 olive oil-PHPO blend after enzymatic interesterification was found to have properties very similar to those of Turkish package margarines, with the additional advantage of possessing higher amounts of monounsaturated fatty acids.     

Effects of interesterified vegetable oils and sugarbeet fiber on the quality of frankfurters

The effects of interesterified vegetable oils (IVOs) prepared from palm, cottonseed and olive oil, respectively, and sugarbeet fiber (SBF) on quality of frankfurters have been studied. Beef fat (10%) was replaced by one of the IVOs for 60% and 100%. Incorporation of IVOs in frankfurters improved the nutritional content of product due to altering the fatty acid composition. The oleic acid content of frankfurters increased from 28.76% to 45.57% and 47.15% as the interesterified palm oil (IPO) and interesterified olive oil (IOO) contents increased from 0% to 10% and 6%, respectively. The linoleic acid contents of 6% and 10% interesterified cottonseed oil (ICO) added frankfurters were, respectively, 10- and 19.6-fold higher than treatments without ICO. Addition of SBF (<425 μm size and 1% level) significantly increased (p<0.05) the total dietary fiber content and water-holding capacity (WHC) of frankfurters. Incorporation of IVOs and SBF did not lead to significant changes in appearance, colour, texture, flavour or sensory scores. It is concluded that IVOs and SBF may be successfully applied as beef fat substitute in frankfurters since this combination offset some of the changes brought about by beef fat replacement.     

Structured lipids obtained by chemical interesterification of olive oil and palm stearin

Interesterification of palm stearin (PS) with liquid vegetable oils could yield a good solid fat stock that may impart desirable physical properties, because PS is a useful source of vegetable hard fat, providing β′ stable solid fats. Dietary ingestion of olive oil (OO) has been reported to have physiological benefits such as lowering serum cholesterol levels. Fat blends, formulated by binary blends of palm stearin and olive oil in different ratios, were subjected to chemical interesterification with sodium methoxide. The original and interesterified blends were examined for fatty acid and triacylglycerol composition, melting point, solid fat content (SFC) and consistency. Interesterification caused rearrangement of triacylglycerol species, reduction of trisaturated and triunsaturated triacylglycerols content and increase in diunsaturated-monosaturated triacylglycerols of all blends, resulting in lowering of melting point and solid fat content. The incorporation of OO to PS reduced consistency, producing more plastic blends. The mixture and chemical interesterification allowed obtaining fats with various degrees of plasticity, increasing the possibilities for the commercial use of palm stearin and olive oil.     

Determination of double bonds in olive and sunflower oils by ozonize method

Kinetics of spending double bonds of tocotherol and accumulation of peroxides during oxidation of olive and sunflower oils were investigated. Date on spending double bonds during oxidation of commercial oils were measured for the first time.     

Thermal oxidative process in extra-virgin olive oils studied by FTIR,rheology and time-resolved luminescence

With the aim to characterise the antioxidant properties of different extra-virgin olive oils and to understand in more detail the mechanisms of oil degradation, we have made an experimental study on thermal induced oxidative processes of extra-virgin olive oils by using different techniques: Fourier Transform Infrared (FTIR) spectroscopy, rheology and time-resolved luminescence. The oxidation process was followed at three different heating temperatures (30, 60 and 90 °C) as a function of time up to 35 days. Thermal treatment induced changes in the FTIR spectra in the wavenumbers region 3100–3600 cm⁻¹: in particular, the absorption profiles show an initial formation of hydroperoxides and a subsequent increase of alcohols and secondary oxidation products. In agreement with the FTIR data, rheology measurements show that after thermal treatment all examined samples exhibit an increase in the viscosity values with respect to pristine ones, indicating that the heat treatment induces the formation of polar molecules with propensity to form hydrogen bonds, which has as a consequence a viscosity increase. Finally, a lifetime increase of luminescence of chlorophyll is observed in agreement with the viscosity rise. Indeed, the viscosity increase reduces the frequency of collisions between the chromophore and its environment, consequently lowering the non-radiative contribution to the luminescence decay.     

Role of vitamin E and phenolic compounds in the antioxidant capacity,measured by ESR,of virgin olive,olive and sunflower oils after frying

The effect of lipid profile, vitamin E and total phenolic content was studied in relation to the antioxidant capacity (measured by ESR) of three edible oils (virgin olive, sunflower and olive oils), using short-time deep fat frying as a model. Physico-chemical changes in the oils were also studied. Samples were analysed before and after 15, 30, 45 and 60 min fryings. Determination of free radicals, by electron spin resonance spectroscopy, revealed the highest antioxidant capacity in virgin olive oil and sunflower oil. This parameter was mainly influenced by vitamin E content, followed by lipid profile and phenolic content. The frying procedure decreased the antioxidant capacity in all tested oils. Sunflower oil underwent more chemical changes by frying than did olive and virgin olive oils. Antioxidant capacity of the edible oils was correlated with polar components and ultraviolet indices but not with peroxide index or acidity value. The use of ESR, as a rapid and very sensitive method for determining antioxidant capacity of edible oils, is suggested.     

Classification of different quality virgin olive oils by metal-oxide sensors

The European Union classifies virgin olive oils into three categories, extra virgin, virgin and lampante; lampante being the only oil that cannot be consumed before undergoing a refining process. A mathematical model based on two metal-oxide sensors has been designed and checked in order to detect on-line lampante oils inside the production systems. The model was developed using 114 samples and was successfully tested with an external test set of 55 samples taken from different single varietal olive oils and geographical origins. The model was able to detect 100% of non-lampante virgin olive oils and 89.5% of lampante virgin olive oils.     

Authentication of extra virgin olive oils by Fourier-transform infrared spectroscopy

Fourier-transform infrared spectroscopy (FTIR), followed by multivariate treatment of the spectral data, was used to classify vegetable oils according to their botanical origin, and also to establish the composition of binary mixtures of extra virgin olive oil (EVOO) with other low cost edible oils. Oil samples corresponding to five different botanical origins (EVOO, sunflower, corn, soybean and hazelnut) were used. The wavelength scale of the FTIR spectra of the oils was divided in 26 regions. The normalized absorbance peak areas within these regions were used as predictors. Classification of the oil samples according to their botanical origin was achieved by linear discriminant analysis (LDA). An excellent resolution among all categories was achieved using an LDA model constructed with eight predictors. In addition, multiple linear regression models were used to predict the composition of binary mixtures of EVOO with sunflower, corn, soybean and hazelnut oils. For all the binary mixtures, models capable of detecting a low cost oil content in EVOO as low as 5% were obtained.     

Study of oils from Calabrian olive cultivars by chemometric methods

A study of characterisation of a typical Italian food is performed by chemometrics. The olive oils from some cultivars of Calabria have been characterised according to their origin and olive genotype using the chemical information mainly provided by 14 chemical parameters of virgin olive oils. In particular, the models of three cultivars of Calabria (Carolea, Cassanese, Dolce di Rossano) were deeply studied. The microclimate of this region has a lower influence on fatty acid composition than the genotype. Using simple and relatively inexpensive analytical parameters as fatty acids and chemometric techniques it has been possible to characterise and classify the olive oils (60–94% prediction rate).