Bioaccessibility of Apple Polyphenols from Peel and Flesh during Oral Digestion

Abstract

Health benefits of apple polyphenols for different chronic diseases are postulated. To exert bioactive properties, absorption into the body is required (bioavailability), which is strongly influenced by matrix release (bioaccessibility). For seven apple varieties, in vitro experiments with simulated saliva fluid (SSF) and ex vivo digestion with centrifuged human saliva were conducted. Polyphenol characterization (high-performance liquid chromatography-tandem mass spectrometry) and quantification (high performance liquid chromatography-diode array detection) was related to an aqueous methanolic extraction. A polyphenol release of 63−82% from flesh and 42−58% from peel was estimated. While hydroxycinnamic acid derivatives were released in total, a significant retention was observed for flavanes and flavones. In particular, procyanidins were retained with increasing molecular weight. The data reveal a considerable polyphenol release during the oral digestion; however, differences among the varieties as well as flesh and peel were obvious. Due to negligible differences between both digestion media, the data supported the use of SSF instead of human saliva in further experiments.

Characterization and Quantification of Mal d 1 Isoallergen Profiles and Contents in Traditional and Commercial Apple Varieties by Mass Spectrometry

“…To obtain profounder knowledge on the isoallergen profile of Mal d 1 in apples, a method for an isoallergen-specific absolute quantification, based on isotope dilution analysis, was developed for freeze-dried apple samples using a mass spectrometric bottom-up approach . In this preliminary study, we investigated five traditional apple varieties from orchard meadows (Bohnapfel, Brettacher, Boskoop, Gewürzluiken, Ontario; harvest year 2020), characterized by a high phenolic content and a proposed low allergenic potential; , Santana, a proposed hypoallergenic commercial breed, but often evaluated only as a medium allergenic; , and three new breeds (Natyra, Magic Star, Sonnenglanz; harvest year 2021). For the latter three, less information about the allergenic potential is available, except for Sonnenglanz, for which Nothegger et al determined a high allergenic potential by skin prick tests .…”

Analyzing Bioaccessibility of Polyphenols in Six Commercial and Six Traditional Apples (Malus domestica Borkh.) during In Vitro and Ex Vivo Oral Digestion

“…Sample preparation was performed according to Kaeswurm et al. [ 28 ] The lyophilized and milled samples were stored under argon at room temperature in the dark until further use.…”

“…studied the release of phlorizin, quercetin‐rutinoside, and procyanidins (PC) from five apple cultivars during oral digestion. [ 27,28 ] Our previous study revealed, that the total release of PP differed between peel and flesh. Furthermore, these data indicated that the individual phenolic structure affects the release more than individual apple matrix characteristics.…”

Ursachenforschung – Warum sind Apfelsorten unterschiedlich allergen?

“…Um den postulierten Einfluss der Polyphenole auf die Allergenität einer Apfelsorte zu prüfen, wurden in neun traditionellen und zehn kommerziellen Apfelsorten (Handelsproben, Erntejahr 2019, Mischprobe aus je 8 bis 10 Äpfeln) der Polyphenolgehalt, das Polyphenolprofil sowie die Freisetzung der Polyphenole während der oralen Verdauphase ex vivo und in vitro bestimmt. [26,27] Letzteres ist für die Bewertung des Einflusses der Polyphenole auf die Apfelallergie von besonderem Interesse, da die Apfelallergie auf den Mund-Rachen-Raum beschränkt ist.…”

“…3a). [26,27] Generell war der Polyphenolgehalt in der Schale 4-7-mal höher als im Fruchtfleisch. Oft, aber nicht grundsätzlich, besaßen traditionelle Sorten höhere Gehalte als kommerzielle Züchtungen.…”