Occurrence of tocopheryl fatty acid esters in vegetables and their non-digestibility by artificial digestion juices

Abstract

Tocopheryl fatty acid esters (TFAE) consist of tocopherols esterified to fatty acids, but only little is known about this substance class. In this study, twelve vegetable groups were screened on TFAE and contents of (free) tocopherols and TFAE were determined in red bell pepper, red chili pepper, cucumber and walnut (n = 5, respectively). Intact TFAE were separated by solid phase extraction from free tocopherols and analyzed by GC/MS. Highest TFAE values were determined in chili pepper (4.0–16 mg/100 g fresh weight, FW) and walnut (4.1–12 mg/100 g FW), followed by bell pepper (1.3–1.5 mg/100 g FW) and cucumber (0.06–0.2 mg/100 g FW). Contribution of TFAE to the total tocopherol content ranged from 7–84%. Neither the treatment with artificial digestion juices nor exposure to sunlight showed degradation of TFAE. This substance class might represent a hitherto overlooked storage form for free tocopherols in plants as they occur to be more stable. But as the ester bond in medium chain TFAE seems not to be fissile in the human body, they might not contribute in the same way as free tocopherols to the vitamin E activity of vegetables and might have to be determined separately.

Heart‐Cut Two‐Dimensional Countercurrent Chromatography for the Isolation of a Furan Fatty Acid Triacylglycerol from Latex Gloves and Identification of Further Lipid Compounds

“…Amounts of γ‐T 3 ‐FA esters in latex gloves were estimated from a 9‐point calibration of γ‐tocopheryl‐14:0 (γ‐T‐14:0) and γ‐T‐18:0 (c = 0.4–40 μg/mL) according to Krauß et al (). Two γ‐T fatty acid esters were chemically synthesized according to Krauß et al () by esterification of the fatty acids 14:0 and 18:0 with γ‐T.…”

“…Amounts of γ‐T 3 ‐FA esters in latex gloves were estimated from a 9‐point calibration of γ‐tocopheryl‐14:0 (γ‐T‐14:0) and γ‐T‐18:0 (c = 0.4–40 μg/mL) according to Krauß et al (). Two γ‐T fatty acid esters were chemically synthesized according to Krauß et al () by esterification of the fatty acids 14:0 and 18:0 with γ‐T. After correcting the GC/MS peak areas of the quantification ion ( m/z 410 for γ‐T 3 and m/z 416 for γ‐T) by the individual selected ion monitoring (SIM)‐responses for γ‐T and γ‐T 3 , the estimated amount of the esters was determined (Krauß et al, ).…”

Fate of free and bound phytol and tocopherols during fruit ripening of two Capsicum cultivars

“…Operating parameters were as described by Weichbrodt et al 21 Solvent was removed by rotary evaporation and the residue was diluted in 4 mL of n-hexane. An aliquot of the lipid extract (1 mL) was used for solid phase extraction (SPE) which was carried out according to Krauß et al 10 Using this method, TFAE and PFAE (SPE fraction 2), free tocopherols and phytol (SPE fraction 3) and chlorophyll (SPE fraction 4) were eluted into three different fractions (Supporting Fig. S2).…”

“…The GC/MS setups used for the analysis of intact TFAE and PFAE (SPE fraction 2) as well as of free tocopherols and phytol (both trimethylsilyl (TMS) derivatives) were the same as described before. 10 In short, intact TFAE/PFAE were analyzed on GC/MS system I which was equipped with a cool-on-column inlet and a Rtx-1 GC column (Restek, Bellefonte, PA). The GC/MS-SIM method included m/z 123.2, 143.2, 209.2, 217.2, 223.2, 237.2, 357.2, 474.5, 488.5, and 502.5 (dwell time was 35 ms each).…”

Freies und verestertes Vitamin E und Phytol in Capsicum‐Früchten in Abhängigkeit vom Reifegrad

“…mehr Tocopherylfettsäureester als freie Tocopherole vor. Da Tocopherylfettsäureester im Magen nicht gespalten werden [1], wird in diesen Proben bioverfügbares Tocopherol (d.h. freies Tocopherol) nach Verseifung mit bis zu 50% überbestimmt.…”