Synthesis and Physical Properties of EOE and EEO,Triacylglycerols Containing Elaidic and Oleic Fatty Acids

Symmetrical and non-symmetrical triacylglycerols (TAG) containing oleic (O; 9c-18:1) and elaidic (E; 9t-18:1) acids were required as part of a study relating the physical characteristics and functionality of trans-containing TAG with the mouth feel, taste characteristics and related characteristics desired by consumers in frying oils and pastries. To replace the trans isomers in frying oils—a significant part of frying oils prepared by partial hydrogenation of vegetable oils—without loss of the sensory properties desired by consumers, required the initiation of a study relating the structure of trans-containing TAG with such characteristics as melting range, drop points, and other crystalline properties. Elaidic acid was esterified to trielaidin (EEE), and the EEE partially converted (glycerol/p-toluenesulfonic acid) to a mixture containing ca. 40% DAG (the 1,3- and 1,2-isomers). The DAG fraction was separated by silica gel chromatography, the 1,3-dielaidylglycerol (1,3EE-DAG) isomer isolated (structural purity >99%) by crystallization from acetone and esterified with oleic acid (O) to yield EOE. The 1(3)O-MAG was purchased commercially and esterified with E acid to prepare OEE. Both syntheses yielded multi-gram quantities of EOE and EEO, in 80–85% yields, and with structural purities >99%. Thus, by careful selection of the thermodynamically more-stable MAG or DAG precursors, the symmetrical EOE and non-symmetrical EEO isomers could be readily synthesized, and their drop point and melting point values determined. The 1- and 3- positions on the glycerol backbone of the MAG, DAG and TAG molecules are assumed to be equivalent.     

Palmitoleic Acid Enrichment of Seabuckthorn (Hippophaë rhamnoides L.) Pulp Oil by Crystallization Process

Abstract

Seabuckthorn pulp oil was fractionated using a crystallization process with acetone under controlled cooling rate of 0.25°C/min without agitation at different crystallization temperatures ranging from ? 15 to 15°C. The obtained liquid (LF) and solid (SF) fractions were analyzed for their fatty acid and triacylglycerol compositions and their melting profiles were characterized. Fractionation at ? 15°C yielded about 20% of LF where palmitoleic acid represented 53% of total lipids. The SF fraction was mainly rich in palmitic acid. LF were richer in triacylglycerol with acyl carbon numbers of 50 and 52 (C50 and C52) than SF, which contained a higher amount of C48. The melting curves of LF and SF showed multiple endothermic transitions.     

Effect of ingestion of dark chocolates with similar lipid composition and different cocoa content on antioxidant and lipid status in healthy humans

The association between in vitro antioxidant capacity of dark chocolates with different cocoa percentage and the in vivo response on antioxidant status was investigated. In a randomized crossover design, 15 healthy volunteer consumed 100 g of high antioxidants dark chocolate (HADC) or dark chocolate (DC). In vitro, HADC displayed a higher Total Antioxidant Capacity (TAC) than DC. In vivo, plasma TAC significantly peaked 2 h after ingestion of both chocolates. TAC levels went back to zero 5 h after DC ingestion whilst levels remained significantly higher for HADC. HADC induced a significantly higher urinary TAC in the 5-12 h interval time than DC. No change was detected in urinary excretion of F2-isoprostanes. Plasma thiols and triacylglycerol (TG) levels significantly increased for both chocolate with a peak at 2 h remaining significantly higher for DC after 5 h respect to HADC. Results provide evidence of a direct association between antioxidant content of chocolate and the extent of in vivo response on plasma antioxidant capacity.     

The Updated Bottom Up Solution Applied to Atmospheric Pressure Photoionization and Electrospray Ionization Mass Spectrometry

The Updated Bottom Up Solution (UBUS) was recently applied to atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) of triacylglycerols (TAG). This report demonstrates that the UBUS applies equally well to atmospheric pressure photoionization (APPI) MS and to electrospray ionization (ESI) MS. Critical Ratio 1 (CR1), the [MH]⁺/Σ[DAG]⁺ or [MNH₄]⁺/Σ[DAG]⁺ ratio, does not exhibit the same strongly sigmoidal shape as it does by APCI‐MS. CR1 varies more widely for APPI‐MS than by APCI‐MS, having a maximum value of 11.8, indicating a much greater effect of unsaturation on ion ratios in APPI‐MS than APCI‐MS. Critical Ratio 2, the [AA]⁺/[AB]⁺ ratio for Type II TAG or [AC]⁺/([AB]⁺+[BC]⁺) ratio for Type III TAG, allows quantification of regioisomers of TAG, and shows good agreement for APPI‐MS to regioisomer quantification determined by APCI‐MS. Critical Ratio 3, the [BC]⁺/[AB]⁺ ratio for Type III TAG, reveals new trends relating the degree of unsaturation by APPI‐MS, and shows that structural assignments made by ESI‐MS are in good agreement to APCI‐MS data. In addition to providing valuable structural information, the Critical Ratios also constitute a reduced data set that allows APPI‐MS or ESI‐MS mass spectra to be reconstructed when processed through the UBUS. Quantification by APPI‐MS of vitamin D in the gelcaps gave values of 42.90 ± 0.83 μg, or 1716 ± 33 international units, in good agreement with APCI‐MS.     

Triacylglycerol Composition Profiling and Comparison of High‐Oleic and Normal Peanut Oils

Oilseed plants produce huge amounts of fatty acids (FA) stored as triacylglycerols (TAG) in seeds that give a great variation in their composition. The variety and content of TAG directly affect the nutrition and function of lipids. TAG composition of 12 high‐oleic and normal peanut oil samples were profiled by two‐dimensional liquid chromatography (2D LC) coupled with atmospheric pressure chemical ionization mass spectrometry (APCI‐MS). The statistical evaluation of the TAG profiles determined was conducted on the basis of multidimensional data matrix using Principal Component Analysis (PCA). The technique enabled the differentiation of high‐oleic oils from normal peanut oils—as results illustrated TAG of high‐oleic peanut oil were clearly different from those of normal peanut oils. High‐oleic and normal peanut oils had different profiles mainly in the contents of OOO, OPO and POL. This finding provided theoretical foundation for detecting the adulteration of edible oils and analyzing the nutrition and function of high‐oleic peanut oils.     

Critical Ratios for structural analysis of triacylglycerols using mass spectrometry

Recent developments have finally allowed fragment behaviors using APCI‐MS to be elucidated after twenty years of literature reports. Critical Ratios have been defined that correspond to various aspects of triacylglycerol (TAG) analysis, from overall degree of unsaturation to localization of fatty acids on the glycerol backbone (regioisomers), to grouping of unsaturated fatty acids. The same ratios also constitute a compact library of TAG mass spectra.     

Enzymatic Interesterification of High Oleic Sunflower Oil and Tripalmitin or Tristearin

The objective of this study was to produce low saturated, zero‐trans, interesterified fats with 20 or 30 % saturated fatty acids (SFA) such as C16:0 or C18:0. Tripalmitin (TP) or tristearin (TS) was blended with high oleic sunflower oil (HOSO) at different ratios (0.1:1, 0.3:1, and 0.5:1 [w/w]). Total C16:0 and C18:0 compositions of the resulting TP/HOSO and TS/HOSO blends, respectively, were plotted against blending ratios. Linear interpolation was used to estimate blending ratios that would yield physical blends (PB) with 20 or 30 % SFA. Interesterified blends (IB) were then synthesized from the customized PB using Lipozyme TL IM as the biocatalyst. Total and sn‐2 fatty acid compositions, triacylglycerol (TAG) molecular species, thermal behavior, and oxidative stability of PB and IB were compared. The total fatty acid compositions of PB and IB were similar but fatty acid positional distributions and TAG molecular species composition differed. IB contained 5–10 % more SFA at the sn‐2 position than corresponding PB. Furthermore, interesterification generated mono‐ and disaturated TAG species which resulted in broader melting profiles for IB. However, IB had lower oxidative stability than PB. The reformulation of food products with zero‐trans interesterified fats may be advantageous to the reduction of cardiovascular disease burden in the population.     

Chemical Composition and Physical Properties of High Oleic Safflower Oils (Carthamus tinctorius,Var. CW88-OL and CW99-OL)

Chemical composition and physical properties of CW88‐OL and CW99‐OL cultivars of high oleic safflower seeds and their hexane‐extracted oils were determined. Dry‐based seed composition of CW88‐OL and CW99‐OL was: moisture = 4.29 and 4.23 %, oil = 42.29 and 46.44 %, Crude protein = 20.94 and 16.41 %, neutral detergent fiber = 28.11 and 28.49 %, ash = 1.55 and 2.01 %, phosphorus content = 2033 and 3995 mg/kg, respectively. Major fatty acids in oils were ~78 % oleic (O), ~13 % linoleic (L), ~5 % palmitic (P) and ~2 % stearic (St) acids, for both cultivars. The main triacylglycerols were OOO (~50 %), OOL (~20 %), SOL + OPO (~10 %), and LLP (~5 %). The oil composition of CW88‐OL and CW99‐OL in main minor components was: α‐tocopherol = 582 and 551 mg/kg, total sterols = 3996 and 3362 mg/kg, phospholipids = 22 and 21 mg/kg and wax content = 70 and 74 mg/kg. For both cultivars, density and viscosity of the oils between 25 and 55 °C varied from 903.4 to 912.6 kg/m³ and 63 to 23 mPa.s showing linear and exponential behaviors, respectively. The refractive index was 1.4694. The CIELab color parameters were: 89.69 and 89.53 (L*), ?3.72 and ?3.07 (a*), and 47.28 and 47.78 (b*) (CW88‐OL and CW99‐OL, respectively). Thus, the high oil content of the seeds and nutritional quality of the oil accompanied by low levels of waxes and phospholipids makes the cultivars studied promising for producers and consumers.     

Separation of Enantiomeric Triacylglycerols by Chiral‐Phase HPLC

Liquid chromatography–atmospheric pressure chemical ionization mass spectrometry (LC–MS/APCI) with a chiral phase was used for separation of triacylglycerols (TAG) obtained either by organic synthesis or isolated from different algal species. We present chromatographic characteristics and tandem mass spectra of enantiomers and positional isomers (regioisomers) of C16, C18 and C20 polyunsaturated fatty acids. The retention time was found to depend on the structure of the given TAG, increasing with increasing number of double bonds and decreasing with increasing number of the carbons in TAG, with the exception of dieicosapentaenoyl‐palmitoyl‐glycerols.