In vitro digestion of dairy and egg products enriched with grape extracts: Effect of the food matrix on polyphenol bioaccessibility and antioxidant activity

Abstract

The aim of this study was to evaluate the effect of the food matrix on polyphenol bioaccessibility and antioxidant activity during the in-vitro digestion of dairy and egg products enriched with grape extracts (GE). Four GE-enriched matrices produced under industrial conditions (custard dessert, milkshake, pancake and omelet) and the GE dissolved in water (control solution) were submitted to in vitro digestion and the bioaccessibility of the major classes of polyphenols as well as the evolution of the antioxidant activity of the matrices were monitored at oral, gastric and intestinal level. Apart from the digestion effect itself, the release, stability and solubility of polyphenols was governed by mainly two factors: 1-the composition and structure of the food matrices and 2-the class of polyphenol. Results showed that the inclusion of the GE extracts into the different egg and dairy food matrices greatly impacted the release and solubility of anthocyanins and proanthocyanidins during digestion, especially in the solid food matrices and during the oral and gastric phases of digestion. Also, the presence of the food matrices protected anthocyanin from degradation during the intestinal phase. However, if the total phenolic content is considered at the end of the whole digestion process, the proportion of soluble (bioaccessible) and insoluble phenolics delivered by the enriched-matrices was quite similar to that of the control solution. On the contrary, the food matrix effect did not affect the antioxidant activity of the matrices, which remained constant during the oral and gastric phases but greatly increased during the intestinal phase of digestion. Among the GEenriched matrices, omelet presented higher recoveries of total phenolics and antioxidant activity at the end of digestion.

Bioaccessibility of rutin, caffeic acid and rosmarinic acid: Influence of the in vitro gastrointestinal digestion models

“…Similar trend (loss in antioxidant capacity during intestinal digestion) was previously reported in the digestion of different foods (Carbonell-Capella et al, 2015;Celep et al, 2015;Rodríguez-Roque et al, 2013;Rodríguez-Roque et al, 2014). However, other studies have indicated a high antioxidant capacity of intestinal digested samples (Oliveira & Pintado, 2015;Pineda-Vadillo et al, 2016;Tagliazucchi et al, 2010), attributed to the deprotonation of the hydroxyl moieties present on the aromatic ring of the phenolic compounds due to the mild alkaline intestinal environment (Bouayed et al, 2011) or to the formation of derived products with a higher antioxidant capacity than that of their precursors (Pineda-Vadillo et al, 2016).…”

“…In fact, the oral step lasts a few minutes, and polyphenol degradation is usually a time-depending process. Moreover, it has also been described that acid pH during the gastric step protects polyphenols against degradation (Pineda-Vadillo et al, 2016).…”

“…filtration (Chen et al, 2016;Pinacho et al, 2015), dialysis membrane (Carbonell-Capella, Buniowska, Esteve, & Frígola, 2015;Mosele, Macià, Romero, & Motilva, 2016), and centrifugation (He et al, 2016;Pineda-Vadillo et al, 2016). These different methods gave rise to different conclusions about the bioaccessibility of phenolic compounds.…”

Valorisation of grape pomace: an approach that is increasingly reaching its maturity – a review

“…Their bioaccessibility must be considered first when evaluating the related nutritional efficacy, thus defining the term bioaccessibility as the fraction potentially available for absorption at the intestinal level. Recent studies have proved that this by‐product is an interesting source of bioactive compounds with applications in pharmacological, cosmetic and food industries, thanks to their bioactivity and technological characteristics (Pineda‐Vadillo et al ., ; Gil‐Sánchez et al ., ). For this reason, to deepen the knowledge about how these compounds may be efficiently absorbed into the circulation system appears sound.…”

Black carrot pomace as a source of polyphenols for enhancing the nutritional value of cake: An in vitro digestion study with a standardized static model

“…To overcome this issue, a standardized and practical static digestion model based on physiologically relevant conditions was proposed (Minekus et al, 2014). This model has already been used to study the bioaccessibility of certain polyphenols including anthocyanins (Pineda-Vadillo et al, 2016).…”