Comparison of the regiospecific distribution from triacylglycerols after chemical and enzymatic interesterification of high oleic sunflower oil and fully hydrogenated high oleic sunflower oil blend by carbon-13 nuclear magnetic resonance

Structuration of lipid bases zero-trans and palm oil-free for food applications

This work evaluated structured lipids (SLs) through chemical and enzymatic interesterification (CSLs and ESLs). Blends of soybean oil and peanut oil 1:1 wt% were used, with gradual addition of fully hydrogenated crambe to obtain a final behenic acid concentration of 6, 12, 18, and 24 %. Chemical catalysis used sodium methoxide (0.4 wt%) at 100 °C for 30 min, while enzymatic catalysis used Lipozyme TL IM (5 wt%) at 60 °C for 6 h. Major fatty acids identified were C16:0, C18:0, and C22:0. It was observed that with gradual increase of hard fat, the CSLs showed high concentrations of reaction intermediates, indicating further a steric hindrance, unlike ESLs. Increased hard fat also altered crystallization profile and triacylglycerols composition and ESLs showed lower solid fat, unlike CSLs. Both methods effectively produced SLs as an alternative to trans and palm fats, view to potential future applications in food products.

Synthesis of cocoa butter alternatives from palm kernel stearin, coconut oil and fully hydrogenated palm stearin blends by chemical interesterification

BACKGROUND

Chemical interesterification (CIE) is one of the important technological processes for the production of zero-trans fats. The aim of this study was to produce trans-free cocoa butter alternatives (CBAs) from palm kernel stearin (PKS), coconut oil (CNO) and fully-hydrogenated palm stearin (FHPS) blends via CIE using sodium methoxide as a catalyst. The physicochemical properties, crystallization and melting behavior, solid fat content (SFC), crystal morphology and polymorphism of the structured lipids (SLs) obtained and the corresponding physical blends (PBs) were characterized and compared with commercial CBAs.

RESULTS

After CIE, randomization of fatty acid distribution within and among triacylglycerol (TAG) molecules of PKS, CNO and FHPS resulted in a modification in TAG compositions of the PKS/CNO/FHPS blends and improved the properties and crystallization behavior of the blends. SFC and slip melting points of all SLs decreased from those of their respective PBs. In particular, SLs obtained from CIE of blends with 60-70% wt. PKS (blend ratios 60:10:30 and 70:10:20) exhibited the melting characteristic, SFC curves, crystal morphology and polymorphic form most similar to the commercial CBAs. In addition, these blends melted almost completely at body temperature, an improvement from that of the commercial CBAs.

CONCLUSION

SLs obtained from CIE of blends with 60-70% wt. PKS has high potential to be used commercially as trans-free CBAs for the confectionery industry. © 2021 Society of Chemical Industry.

The effects of interesterification on the physicochemical properties of Pangasius bocourti oil and its fractions

Soft and solid fats which were fractionated from Pangasius bocourti oil (PBO), namely, Pangasius bocourti olein (PBOL) and Pangasius bocourti stearin (PBST), respectively, were introduced as new base oils for plastic fats. The physicochemical properties of PBO and its fractions were modified after interesterification. Enzymatic interesterification (EIE) reduced the sn-2 palmitic acid content attributed to the occurrence of acyl migration. The PBO solid fat content (SFC) at 20-40 °C increased after chemical interesterification whereas under similar range of temperature, the SFC of PBST decreased after EIE and a steep melting curve was obtained. The effect of interesterification on the crystal polymorphisms was less prominent whereby the initial and interesterified samples exhibited similar crystal forms. The solid state of PBOL was improved after interesterification but post-hardening was observed. Free fatty acids were produced via partial hydrolysis during EIE which contributed to the reduced oxidative stability in the EIE fats.

Enzymatic Interesterification of Palm Stearin and Palm Olein Blend Catalyzed by sn-1,3-Specific Lipase: Interesterification Degree, Acyl Migration, and Physical Properties

Acyl migration of fatty acid at sn-2 is often observed alongside enzymatic interesterification (EIE), causing the loss of lipase selectivity toward the acyl group at sn-1,3. In this study, an oil blend consisting of palm stearin (PST) and palm olein (POL) was interesterified via a chemical interesterification (CIE) and enzymatic method using a packed bed reactor. Characterization in terms of the triacylglycerol (TAG) compositions, sn-2 fatty acid distributions, and solid fat content profiles was performed. In comparison to that of CIE fats, EIE fats showed different modification effects on the solid fat content. Under similar reaction conditions, different interesterification degrees (IDs) were obtained according to the various blend ratios. Using the same mass ratio of substrates (POL/PST of 9:1), the EIE reaction time and temperature affected the ID and the change in the fatty acyl group at the sn-2 position. Under the reaction time of 46 min, an ID of 94.41% was acquired, while at 80 °C, the degree of acyl migration at sn-2 was 92.87%. EIE with high acyl migration exhibited a lower crystallization rate than that of EIE with low acyl migration. However, the effect of acyl migration on crystal polymorphism and oxidative stability was insignificant. Outcomes from this study are meaningful for the establishment of a theoretical basis for a controlled positional-specific EIE that is catalyzed by sn-1,3-specific lipase.

Vegetable oils: Are they true? A point of view from ATR-FTIR, 1H NMR, and regiospecific analysis by 13C NMR

Problems related to oil authenticity make it difficult to obtain the benefits associated with each type of vegetable oil. Fraudulent practices have been revealed by several targeted and nontargeted methods. In this paper, spectroscopic techniques (FT-IR, ¹H NMR, and ¹³C NMR) were applied to determine the chemical profiles of 23 Brazilian commercial vegetable oils obtained from five different high-value aggregated matrices (andiroba, babassu, baru, castor, and sweet almond oils) and investigate their adulteration, by comparison with the corresponding reference samples. Each technique is useful for the particular information it provides: differences in free fatty acids by FT-IR; adulteration with omega-3-enriched oils by ¹H NMR, and adulteration of unsaturated-enriched oil with another unsaturated oil without linoleic acid by regiospecific analysis. Our findings highlight the importance of fusion-based methods in providing precise information for use in oil quality authentication.

Modification of palm-based oil blend via interesterification: Physicochemical properties, crystallization behaviors and oxidative stabilities

Interesterification is widely employed as an effective technique to modify oils and fats. This study utilizes palm-based oil (palm olein: palm kernel oil: palm stearin, 5:3:2, w/w/w) as the raw material for the interesterification process performed in a pilot-scale packed bed reactor. Enzymatic interesterification (EIE) was catalyzed by Lipozyme TL IM (813.0 g) at 60℃ with reaction flow rate of 100 mL/min. Chemical interesterification (CIE) was catalyzed using sodium methoxide (0.3 wt%) as catalyst at 105 °C for 30 min. The results showed that the EIE fats had lower solid fat content tendency compared to that of CIE fats. The crystallization onset temperature was higher in EIE fats (23.09℃) compared to that of CIE (19.08℃). The results were consistent with the crystallization kinetics whereby the Avrami K constants of EIE fats were higher than that of CIE fats at various temperatures, indicating rapid crystallization and instant nucleation. Linear growth mechanism was dominant and the crystals formed were smaller in size as observed using polarized light microscope. The interesterified fats exhibited the presence of β and β'-crystals. While most of the tocopherol content was retained after EIE (386.18 ug/g), the molecular distillation process reduced the tocopherol concentration (110.01 ug/g) which consequently affected the oxidative stability. The findings in this work contribute to the fundamental understanding on the differences between CIE and EIE fats and provides data to support the preparation of modified fats via EIE that shows great potential as a controllable technique for industrialization.

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.

Evaluation of enzymatic interesterification in structured triacylglycerols preparation: a concise review and prospect

Enzymatic interesterification (EIE) is one of the emerging technologies in the specialty fats industry. EIE has several advantages over the conventional chemical interesterification method, such that the process has higher flexibility and efficiency, is environmentally friendly and the immobilized enzyme can be recycled besides of the lower requirement for substrate's acid value. The physical properties and nutritional qualities of the fats and oils are modified after EIE, depending on the change in the position of fatty acids on the triacylglycerol (TAG) molecules. Evaluation of the interesterification reaction are important and useful in terms of its technological applications. This paper summarizes the conventional methods and the advancement for evaluating EIE processes, e.g., determination of the change in slip melting points, solid fat contents, TAG with equivalent carbon numbers, and sn-2 fatty acid compositions of the end product. Nonetheless, these methods are not comprehensive because during the EIE process, acyl migration occurs. A novel and convenient evaluation model which is based on the fatty acid distribution on the glycerol-backbone is proposed as a perspective. This model can be employed to monitor the interesterification degree and acyl migration during a regiospecific EIE process, which serves as a reaction rule that can be employed to control and optimize the EIE process, thereby producing structured TAG with desired properties.

Safety Factors of Oils Marketed in Iran and Applicable Strategies in Control of Food Derived Cardiovascular Diseases

Background:

The proposed criteria for a healthy daily diet play a drastic role in the prevention of non-communicable disease. Several cases of acute and chronic diseases occurred due to the presence of toxic and unsafe agents in the body. Trans and some saturated fatty acids as an example of these unfavorable components, could pose some dangerous effects on human health such as cardiovascular disease.

Objective:

In the current study, health criteria were undertaken to evaluate the safety of collected edible oils samples from Iranian market, and then some of the approaches for elimination and control of arisen health concerns were discussed.

Methods:

Totally 18 edible oil samples including cooking oil (n=5), frying oil (n=9) and table margarine (n=4) were collected from Tehran local market and were analyzed in 2016. The fatty acid profile was determined by using gas chromatography equipped with a flame ionization detector. Furthermore, the stability of frying oil was also measured by the Rancimat method.

Results:

All samples contained the trans and saturated fats in concentrations lower than the maximum recommended values (1%, 2% and 4% of trans for cooking oils, frying oils and table margarines, and 30% and 48% of saturation in frying oils and table margarines, respectively). The frying oils demonstrated the desired stability against high temperatures. Optimization of stability was done mainly by the addition of palm oil to the formula in the past. However, based on the fact of the high saturation of palm oil and its carcinogenicity under uncontrolled consumption, a risk assessment conducted in Iran led to the limited import of palm oil. This approach resulted in the production of healthier alternatives in the country.

Conclusion:

The usage of applicable approaches such as inter-esterification, fractionation and blending by more stable oils fractions is suggested to achieve healthier products.

Immobilization of zirconium-glycerolate nanowires on magnetic nanoparticles for extraction of urinary ribonucleosides

The authors have immobilized nanowires made from zirconium glycerolate (ZrGly) on magnetite (Fe₃O₄) nanoparticles by applying a solvothermal growth process using metal-glycerolate as a precursor. The structure and the dissolution-recrystallization mechanism of the resulting Fe₃O₄@ZrGly composite were investigated by attenuated total reflection-FTIR, energy-dispersive X-ray analysis, thermogravimetric analysis and solid-state cross polarization/magic angle spinning ¹³C NMR spectroscopy. The interaction between the zirconium glycerolate in Fe₃O₄@ZrGly and cis-diols leads to efficient adsorption of riboncleosides which then can be quantified by HPLC with UV detection. The sorbent was successfully applied to the selective enrichment of adenosine, cytidine, uridine and guanosine from spiked human urine samples. The detection limit of the method is in the range from 1.7 to 19 ng·mL^-1 of nucleosides in spiked human urine, with relative standard deviations of lower than 12.4% and recoveries ranging from 90.6 to 113%. Graphical abstract Fe₃O₄@ZrGly with high selectivity towards ribonucleosides was designed and applied for quantitation of urinary ribonucleosides.