Use of GC and PDSC methods to characterize human milk fat substitutes obtained from lard and milk thistle oil mixtures

The aim of this study was the analytical evaluations of human milk fat substitutes (HMFS) synthesized via enzymatic interesterification of lard and milk thistle oil mixtures by a immobilized commercial sn-1,3-specific lipase, using calorimetric and chromatographic methods. The mixtures of lard and milk thistle oil at mass ratio 6: 4 and 8: 2 were interesterified for 2, 4 and 6 h at the temperature of 60 degrees C. The determination of fatty acid composition was carried out by gas chromatographic analysis of fatty acid methyl esters. The positional distribution of fatty acids in the sn-2 and sn-1,3 positions of triacylglycerols was based on the ability of the pancreatic lipase to selectively hydrolyze ester bonds in the sn-1,3 positions. Pressure differential scanning calorimetry (PDSC) method was used for the determination of the oxidative stability of HMFS. The oxidative induction time was obtained from the PDSC curves. Due to enzymatic interesterification of mixtures of lard and milk thistle oil, new HMFS that have a similar regiospecific structure of triacylglycerols to human milk fat can be produced. The induction time obtained from PDSC measurements can be used as a parameter for the assessment of the resistance of tested fats to their thermal-oxidative decomposition.info:eu-repo/semantics/publishedVersio

The Effect of Chia Seeds ( Salvia hispanica

The aim of the study was to analyze and characterize the influence of chia seeds (CS) addition (0, 2, 4, 6, and 8%) on wheat bread properties. Bread properties that underwent evaluation included chemical composition, fatty acid composition, total phenolics content, volume, baking losses, crumb texture, and color and sensory analysis. The addition of CS decreased baking losses and the volume of bread. The color of the crumb with CS was much darker as compared with the control sample. The texture analysis showed that the CS caused a decrease in the hardness of the crumb. Most importantly, the addition of CS increased the nutritional value of the bread. Bread with CS contained more dietary fiber and mineral components. Moreover, it has been observed that in comparison to the control product bread with CS was characterized by a rich fatty acids composition and higher level of phenolic compounds. Most importantly, the results showed that the substitution of wheat flour with chia seeds up to 6% did not negatively affect the final product acceptance

The Influence of Interesterification on the Thermal and Technological Properties of Milkfat-Rapeseed Oil Mixture and Its Potential Use in Incorporation of Model Meat Batters

Enzymatic interesterification gives the possibility to obtain a wide range of lipids with a modified structure. In the present study, model meat batters were produced from chicken breast muscles and enzymatically interesterified fats: milkfat:rapeseed oil (3:2 w/w). Fatty acids composition and their positional distribution in triacylglycerol, melting profile and oxidative stability have been determined in fats used for interesterification, after interesterification and extracted from meat batters. In meat batters, the physiochemical parameters were determined. Interesterified fats were characterized by significantly lower induction times than noninteresterified fat (85.29 and 18.21 min, respectively). Meat batters were also characterized by a lower oxidative stability of lipid fraction (24.90 and 13.67 min) than lipids used to their production. A higher content of unsaturated fatty acids was found in meat batters with noninteresterified and interesterified fats (69.40% and 70.03%, respectively) than in the control meat batter with a pork jowl (58.63%). In comparison to the control product, meat batter prepared with interesterified mixture was characterized by significantly lower apparent viscosity. In the analyzed meat batters, there were no differences in thermal drip and penetration force. The incorporation of interesterified milkfat with rapeseed oil in model meat batters can be a strategy to improve the nutritional quality without adversely affecting the quality characteristics

Application of Response Surface Methodology to Optimize the Extraction Process of Bioactive Compounds Obtained from Coffee Silverskin

The present research focused on the extraction optimization of bioactive compounds from coffee silverskin (CS), a by-product generated in large amounts worldwide during the coffee roasting process. The effect of the different extraction conditions has been investigated by the exploitation of the response surface methodology (RSM). The antioxidant activity assays, such as ABTS and FRAP, total phenolics content (TPC), browning index (BI), and chromatographic analysis of caffeine and chlorogenic acids contents have been performed to evaluate the CS extracts characteristics. The most favorable extraction conditions on the maximum recovery of antioxidant bioactive compounds were found to be as follows: 50% aqueous solution of ethanol (v/v) in solvent solid ratio of 45 mL/g CS, during 30 min at 60 °C. The CS extract prepared in this extraction variant reached the values for ABTS, FRAP, TPC, and BI approximately 101.6 µmol Trolox/g d.m. CS, 132.3 µmol Fe (II)/g d.m. CS, 52.3 µmol GAE (gallic acid equivalent) per g d.m. CS, and 0.3, respectively. Additionally, this extract is rich in caffeine (6 mg/g d.m. CS) and chlorogenic acids (0.22 mg/g d.m. CS). In conclusion, this research demonstrates that CS could be considered as a valuable by-product of bioactive compounds with potential applications in the food industry

Application of Chromatographic and Thermal Methods to Study Fatty Acids Composition and Positional Distribution, Oxidation Kinetic Parameters and Melting Profile as Important Factors Characterizing Amaranth and Quinoa Oils

Amaranth and quinoa are classed as pseudocereals that do not belong to the grass family, meaning they are not technically a grain. Both of them are seeds with tremendous nutritional value; compared to other cereals, they contain much more fat. The aim of the study was to present the parameters characterizing thermal properties of amaranth and quinoa oils, such as: oxidation induction time, oxidation kinetic parameters, and melting profile. In isolated oils, the peroxide value, oxidative stability by the Rancimat test (in 120 °C) and the pressure differential scanning calorimetry (PDSC) method (at 100, 110, 120, 130, 140 °C), fatty acids composition, and their distribution between the triacylglycerol positions were determined. The kinetic parameters of the oxidation process (activation energy, pre-exponential factor, and reaction rate constants) were calculated using the Ozawa–Flynn–Wall method and the Arrhenius equation. To measure the melting profile, the differential scanning calorimetry (DSC) method was used. Both types of seeds are a good source of unsaturated fatty acids. Induction time of oxidation suggests that amaranth oil may have better resistance to oxidation than quinoa oil. The melting characteristics of the oils show the presence of low-melting triacylglycerol fractions, mainly containing unsaturated fatty acids, which means that a small amount of energy is required to melt the fats

Application of Chromatographic and Thermal Methods to Study Fatty Acids Composition and Positional Distribution, Oxidation Kinetic Parameters and Melting Profile as Important Factors Characterizing Amaranth and Quinoa Oils

Amaranth and quinoa are classed as pseudocereals that do not belong to the grass family, meaning they are not technically a grain. Both of them are seeds with tremendous nutritional value; compared to other cereals, they contain much more fat. The aim of the study was to present the parameters characterizing thermal properties of amaranth and quinoa oils, such as: oxidation induction time, oxidation kinetic parameters, and melting profile. In isolated oils, the peroxide value, oxidative stability by the Rancimat test (in 120 °C) and the pressure differential scanning calorimetry (PDSC) method (at 100, 110, 120, 130, 140 °C), fatty acids composition, and their distribution between the triacylglycerol positions were determined. The kinetic parameters of the oxidation process (activation energy, pre-exponential factor, and reaction rate constants) were calculated using the Ozawa–Flynn–Wall method and the Arrhenius equation. To measure the melting profile, the differential scanning calorimetry (DSC) method was used. Both types of seeds are a good source of unsaturated fatty acids. Induction time of oxidation suggests that amaranth oil may have better resistance to oxidation than quinoa oil. The melting characteristics of the oils show the presence of low-melting triacylglycerol fractions, mainly containing unsaturated fatty acids, which means that a small amount of energy is required to melt the fats

The Influences of Agglomeration and Storage on the Thermal Properties and Stability of Fats in Infant Formulas

Agglomeration is a technological process that is widely applied to obtain powdered products with the appropriate shape and particle size and different physical characteristics and stabilities. The purpose of this research was to study the influences of the composition and storage of powdered infant formulas on their thermal behaviours, as analysed by differential scanning calorimetry (DSC); fatty acid compositions, as determined by gas chromatography; and water activity and water content. This study investigated the influence of the storage time (six months) at temperatures of 20–22 °C and air humidities of 42–45% on powder mixtures and agglomerates. The isotherms of the agglomerates presented a shape and course similar to those of the isotherms of the mixtures from which they were obtained. The agglomeration process affected the stability of the fatty acids in the stored powdered infant formulas. The composition of the fatty acids changed during the storage process. The thermal properties of the powdered infant formulas were not significantly influenced by agglomeration. The compositions of the mixtures and agglomerates influenced the shape and course of the DSC diagrams. Using the DSC method, it was determined whether the fat was a natural component of the powder or it was added in the form of fatty acid preparations. Differences were observed between the shape and course of the DSC curves (heating and cooling) obtained for fresh and 6-month-stored mixtures and agglomerates