Bioaccessibility and transepithelial transportation of cranberrybush (Viburnum opulus) phenolics: Effects of non-thermal processing and food matrix

Interactions between proteins and phenolics: effects of food processing on the content and digestibility of phenolic compounds

Phenolic compounds have recently become one of the most interesting topics in different research areas, especially in food science and nutrition due to their health-promoting effects. Phenolic compounds are found together with macronutrients and micronutrients in foods and within several food systems. The coexistence of phenolics and other food components can lead to their interaction resulting in complex formation. This review article aims to cover the effects of thermal and non-thermal processing techniques on the protein-phenolic interaction especially focusing on the content and digestibility of phenolics by discussing recently published research articles. It is clear that the processing conditions and individual properties of phenolics and proteins are the most effective factors in the final content and intestinal fates of phenolic compounds. Besides, thermal and non-thermal treatments, such as high-pressure processing, pulsed electric field, cold plasma, ultrasonication, and fermentation may induce alterations  in those interactions. Still, new investigations are required for different food processing treatments by using a wide range of food products to enlighten new functional and healthier food product design, to provide the optimized processing conditions of foods for obtaining better quality, higher nutritional properties, and health benefits. © 2024 Society of Chemical Industry.

Cellular assays combined with metabolomics highlight the dual face of phenolics: From high permeability to morphological cell damage

The Caco-2 cellular permeability of phenolic aqueous extracts from blackcurrant press cake (BC), Norway spruce bark (NS), scots pine bark (SP), and sea buckthorn leaves (SB) was evaluated by combining high-resolution mass spectrometry and atomic force microscopy. Besides, Caco-2 and HepG2 cells allowed the study of intracellular oxidative stress assessed in both apical and basolateral domains. Overall, BC and NS showed the highest total phenolic contents, 4.38 and 3.76 µg/mL, respectively. Multivariate statistics discriminated NS and BC from SP and SB extracts because of their phenolic profile. Polyphenols were classified as highly permeable, thus suggesting their potentially high bioavailability through the gastrointestinal tract. All the phenolic subclasses showed efflux ratio values < 1, except for BC flavonols, flavan-3-ols, and stilbenes. Regarding cellular damage, NS and BC extracts, when acting on the basolateral cellular side, caused epithelial leakage and morphological shape cell damage on Caco-2 cells associated with ROS production.

Effect of In Vitro Digestion on the Phenolic Content of Herbs Collected from Eastern Anatolia

Phenolic compounds in herbs have high antioxidant activities, and their consumption as functional foods may impact human health positively. The main objective of this study was to investigate the total phenolic (TPC) and total flavonoid (TFC) contents as well as total antioxidant capacities (TAC) of bioactive compounds in various infusions prepared by herbs collected from the Bingöl region of Turkey during in vitro gastrointestinal digestion. According to the results, while the highest TPC (5836 ± 373 mg GAE/100 g dw), TFC (2301 ± 158 CE/100 g, dw), and TAC (1347 mg TE/100 g dw) were obtained with Anchusa azurea Mill. species, Crataegus orientalis exhibited the lowest values (863 ± 24 mg GAE/100 g dw, 242 ± 23 CE/100 g dw, 735 ± 47 mg TE/100 g dw, respectively). Gallic acid and chlorogenic acid were the most common phenolic compounds in the infusions. In detail, the highest gallic acid was found in E. spectabilis M. Bieb (27.3 ± 0.9 mg/100 g of dw) and the highest chlorogenic acid was observed in F. elaeochytris (919.2 ± 35.7 mg/100 g of dw). After in vitro gastrointestinal digestion, the highest bioaccessibility values of TPC and TFC were determined as 0.6- and 3-fold of the values observed in undigested C. orientalis, respectively. Besides, C. orientalis Pall. had the highest bioaccessibility of TAC according to the DPPH (6.7-fold increase) and CUPRAC (9.7-fold increase) assays. It can be concluded that the use of these medicinal herbs in human dietary intake due to their high bioactive compounds even after digestion can improve nutritional value and contribute to human health.

Characterization of the flavor, sensory quality and in vitro bioaccessibility in cloudy pomegranate juice treated by high pressure and thermal processing

BACKGROUND

Recently, cloudy pomegranate juice (PJ) has become popular due to its rich phenolic and health-promoting effects. The aim of the present work was to evaluate the application of high hydrostatic pressure processing (HPP), pasteurization (PT) and high-temperature short-time sterilization (HTST) on physicochemical properties (color, flow behavior, turbidity, sugars, organic acids, aroma and sensory evaluation) and in vitro bioaccessibility of total phenolics content (TPC), total flavonoids content (TFC) and phenolics of cloudy PJ.

RESULTS

Compared to HPP, thermal sterilization significantly increased the brightness (L*), redness (a*), total color difference (ΔE) and turbidity, and decreased the TPC and TFC. HPP maintained the volatile profile of cloudy PJ better, while thermal sterilization significantly changed the profile by decreasing alcohols 23.8-32.7% and increasing acids by 33.6%-182.8%. The bioaccessibility of flavonoids, phenolic acids and tannins in the control cloudy PJ after in vitro oral-gastric-intestinal digestion were 1.5%, 4.9%, and 9.0%, respectively, which were not significantly changed by different treatments.

CONCLUSION

These results contributed to promoting the color quality and health benefits of cloudy PJ rich in phenolics by optimizing the processing conditions in the food industry. © 2022 Society of Chemical Industry.

Formulation of Functional Drink with Milk Fortification: Effects on the Bioaccessibility and Intestinal Absorption of Phenolics

Due to a turn toward to functional foods with improved nutritional value, rosehip could be an appropriate candidate to create formulations using a milk matrix. In the present study, the influence of bovine or almond milk fortification on the bioaccessibility and intestinal absorption of rosehip infusion phenolics, mainly catechin, were investigated by a combined method of an in vitro gastrointestinal digestion/Caco-2 cell culture model. The results indicated that bovine (IB) or almond milk (IA) fortification enhanced the retention of total phenolics (TPC; increase of 8.1% and 20.3% for IB and IA, respectively), while there was a decline in the total flavonoids (TFC; decrease of 64% and 17% for IB and IA, respectively) and antioxidant capacity measured by CUPRAC assay (decrease of 15% and 4% for IB and IA, respectively) throughout the gastrointestinal tract in comparison with the control sample (IC). Then, based on the cytotoxicity (SRB) assay, 1/5 times diluted digests were subjected to transepithelial transportation of Caco-2 cells. According to the results, the bovine milk matrix positively affected the transportation of phenolics across the epithelial cell layer. It could be concluded that it is possible to produce functional infusion drinks with improved stability, bioaccessibility, and absorption efficiency of rosehip phenolics in the formulations containing milk matrix.

Entrapment of Black Carrot Anthocyanins by Ionic Gelation: Preparation, Characterization, and Application as a Natural Colorant in Yoghurt

Black carrot (BC) with its potential health benefits due to the greater amount of anthocyanins and the potent antioxidant activity could be utilized as a natural colorant. The objective of this study was the entrapment of BC anthocyanins by external ionic gelation technique within the biopolymer matrix including pectin, alginate, and the mixture of both. Beads were characterized in terms of entrapment efficiency (EE), morphology, total anthocyanin content, and antioxidant capacity measured by the 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid assay. Furthermore, the color of the beads as well as yoghurt samples fortified with BC-containing beads were evaluated during storage at 4 °C for 4 weeks. While the EE for anthocyanins ranged between 47.3 and 96.6%, the antioxidant capacity changed from 50.4 to 97.7%. The maximum anthocyanin retention was found as 91.7% for 1% BC containing 1% pectin (P) + 1% alginate (A)-based beads after 4 weeks of storage. In addition, anthocyanin protection reached up to 62% and antioxidant capacity up to 55.6% in the fortified yoghurt samples containing A-based beads during storage. It is concluded that external ionic gelation could be a feasible method for BC anthocyanins due to its protective effect against acidic environment.

Bioavailability of Rosehip (Rosa canina L.) Infusion Phenolics Prepared by Thermal, Pulsed Electric Field and High Pressure Processing

In this study, the in vitro bioavailability of rosehip infusion phenolics, mainly catechin, as a response to conventional and non-thermal treatments by combining gastrointestinal digestion and a Caco-2 cell culture model, was investigated. After application of thermal treatment (TT, 85 °C/10 min), high pressure (HPP, 600 MPa/5 min) or pulsed electric field (PEF, 15 kJ/kg) processing, all samples were subjected to simulated gastrointestinal digestion. Then, the amount of maximum non-toxic digest ratio was determined by the cytotoxicity sulforhodamine B (SRB) assay. Next, Caco-2 cells were exposed to 1:5 (v/v) times diluted digests in order to simulate the transepithelial transportation of catechin. Results showed that non-thermally processed samples (5.19 and 4.62% for HPP and PEF, respectively) exhibited greater transportation across the epithelial cell layer compared to than that of the TT-treated sample (3.42%). The present study highlighted that HPP and PEF, as non-thermal treatments at optimized conditions for infusions or beverages, can be utilized in order to enhance the nutritional quality of the final products.

Investigating the effects of supercritical antisolvent process and food models on antioxidant capacity, bioaccessibility and transepithelial transport of quercetin and rutin

In the present study, the effects of the Supercritical Anti-Solvent (SAS) process and food models on the antioxidant capacity, bioaccessibility and transport dynamics of flavonol-loaded polyvinylpyrrolidone (PVP) based microparticles were investigated using a combined in vitro gastrointestinal digestion/Caco-2 cell culture model. SAS-processed and unprocessed flavonols were supplied in two different food models: 10% ethanol for an aqueous hydrophilic food simulant and 3% acetic acid for an acidic food simulant. The SAS processing of quercetin and rutin resulted in a much higher recovery of these bioactives as well as greater retention of antioxidant capacity after gastrointestinal digestion in both hydrophilic and acidic food models. The present study also demonstrates that SAS coprecipitation has a positive effect on the stability and transport of bioactives across the epithelial cell layer. It can be deduced from the results that the SAS process can be a useful method in pharmaceutical and nutraceutical applications with high stability, bioaccessibility, bioavailability and thus enhanced nutritional value.