Tocochromanols

Siger, Aleksander; Dwiecki, Krzysztof; Bąkowska, Ewa

doi:10.1007/978-3-030-61879-7_6

Cited by 3 publications

(2 citation statements)

References 162 publications

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“…Remarkably, free tocochromanols (tocopherols, vitamin E) could also be detected at intensities comparable with free sterols by GC/MS in all sterol fractions of examined oils. This is important to note because standard sample processing protocols of tocopherols require the use of antioxidants for their protection during saponification [ 35 , 36 ] which was not necessary in the present case. Silylated β- and γ-tocopherol co-eluted in the applied GC/MS method but could be distinguished by means of the ratio of m/z 222 to m/z 223 [ 8 ].…”

Section: Resultsmentioning

confidence: 99%

Sample preparation of free sterols from vegetable oils by countercurrent chromatography in co-current mode

et al. 2023

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Countercurrent chromatography (CCC) is a preparative instrumental method where both the mobile and stationary phases are liquids and which are predominantly used for the isolation of natural products. In this study, we widened the scope of CCC by using it as an instrumental method for the direct enrichment of the free sterol fraction from plant oils to which they contribute with ~ 1%. For the enrichment of sterols in a narrow band, we employed the so-called co-current CCC (ccCCC) mode in which both liquid phases of the solvent system (here: n-hexane/ethanol/methanol/water (34:11:12:2, v/v/v/v)) are moved at different flow rates in the same direction. Different from previous applications of ccCCC, the lower and predominant “stationary” phase (LPs) was pumped twice as fast as the mobile upper phase (UPm). This novel reversed ccCCC mode improved the performance but also required a higher demand of LPs compared to UPm. Therefore, the exact phase composition of UPm and LPs was determined by gas chromatography and Karl Fischer titration. This step enabled the direct preparation of LPs which considerably reduced the waste of solvents. Internal standards (phenyl-substituted fatty acid alkyl esters) were synthesised and utilised to frame the free sterol fraction. This approach allowed a fractionation of free sterols based on the UV signal and compensated run-to-run variations. The reversed ccCCC method was then applied to the sample preparation of five vegetable oils. In addition to free sterols, free tocochromanols (tocopherols, vitamin E) were also eluted in the same fraction as free sterols. Graphical Abstract

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Section: Resultsmentioning

confidence: 99%

Sample preparation of free sterols from vegetable oils by countercurrent chromatography in co-current mode

et al. 2023

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“…Vitamin E is the umbrella term for all tocochromanols and tocols, which are isoprenoid chromanols of two homologous series, namely, tocopherols (2‐methyl‐2‐[4ʹ,8ʹ,12ʹ‐trimethyltridecyl]‐chroman‐6‐ol) with a saturated side chain and tocotrienols (2‐methyl‐2‐ [4ʹ,8ʹ,12ʹ‐trimethyltrideca‐3ʹ,7ʹ,11ʹ‐trienyl]chroman‐6‐ol) with an unsaturated side chain, as well as some compounds with low prevalence, including tocomonoenols (Fiorentino et al., 2009), tocodienols (Siger et al., 2021), desmethyltocotrienols, and didesmethyltocotrienol (Szymańska & Kruk, 2018) as shown in Figure 1. Tocopherols and tocotrienols (Eitenmiller & Lee, 2004) comprise a chromanol group attached to a saturated (tocopherol) or unsaturated (tocotrienol) phytyl side chain.…”

Section: Vitamin E Chemistry and Metabolismmentioning

confidence: 99%

Vitamin E in foodstuff: Nutritional, analytical, and food technology aspects

Zaaboul

Liu

2022

Comp Rev Food Sci Food Safe

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Vitamin E is a group of isoprenoid chromanols with different biological activities. It comprises eight oil‐soluble compounds: four tocopherols, namely, α‐, β‐, γ‐, and δ‐tocopherols; and four tocotrienols, namely, α‐, β‐, γ, and δ‐tocotrienols. Vitamin E isomers are well‐known for their antioxidant activity, gene‐regulation effects, and anti‐inflammatory and nephroprotective properties. Considering that vitamin E is exclusively synthesized by photosynthetic organisms, animals can only acquire it through their diet. Plant‐based food is the primary source of vitamin E; hence, oils, nuts, fruits, and vegetables with high contents of vitamin E are mostly consumed after processing, including industrial processes and home‐cooking, which involve vitamin E profile and content alteration during their preparation. Accordingly, it is essential to identify the vitamin E content and profile in foodstuff to match daily intake requirements. This review summarizes recent advances in vitamin E chemistry, metabolism and metabolites, current knowledge on their contents and profiles in raw and processed plant foods, and finally, their modern developments in analytical methods.

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The Effect of High-Temperature Heating on Amounts of Bioactive Compounds and Antiradical Properties of Refined Rapeseed Oil Blended with Rapeseed, Coriander and Apricot Cold-Pressed Oils

Fedko,

Siger,

Szydłowska-Czerniak

et al. 2024

Foods

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Cold-pressed oils are rich sources of bioactive substances, which may protect triacylglycerols from degradation during frying. Nevertheless, these substances may decompose under high temperature. This work considers the content of bioactive substances in blends and their changes during high-temperature heating. Blends of refined rapeseed oil with 5% or 25% in one of three cold-pressed oils (rapeseed, coriander and apricot) were heated at 170 or 200 °C in a thin layer on a pan. All non-heated blends and cold-pressed oils were tested for fatty acid profile, content and composition of phytosterols, tocochromanols, chlorophyll and radical scavenging activity (RSA) analyzed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. Moreover, the stability of phytosterols, tocochromanols, DPPH and ABTS values was determined in heated blends. All tocochromanols were lost during the heating process, in particular, at 200 °C. However, there were some differences between homologues. α-Tocopherol and δ-tocopherol were the most thermolabile and the most stable, respectively. Phytosterols were characterized by very high stability at both temperatures. We observed relationships between ABTS and DPPH values and contents of total tocochromanols and α-tocopherol. The obtained results may be useful in designing a new type of fried food with improved health properties and it may be the basis for further research on this topic.

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Tocochromanols

Cited by 3 publications

References 162 publications

Sample preparation of free sterols from vegetable oils by countercurrent chromatography in co-current mode

Sample preparation of free sterols from vegetable oils by countercurrent chromatography in co-current mode

Vitamin E in foodstuff: Nutritional, analytical, and food technology aspects

The Effect of High-Temperature Heating on Amounts of Bioactive Compounds and Antiradical Properties of Refined Rapeseed Oil Blended with Rapeseed, Coriander and Apricot Cold-Pressed Oils

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