In vitro gastrointestinal digestion of pomegranate peel (Punica granatum) flour obtained from co-products: Changes in the antioxidant potential and bioactive compounds stability

Amelioration activity of the high bioaccessible chrysanthemum (Gongju) phenolics on alcohol-induced oxidative injury in AML-12 cells

The main bioavailable phenolics from of Gongju (GJ) and their mechanism for hepato-protection remain unclear. To select the GJ phenolics with high bioavailability, chrysanthemum digestion and Caco-2 cells were used and their hepato-protective potential were examined by using AML-12 cells. The digestive recovery and small intestinal transit rate of the main phenolic compounds ranged from 28.52 to 69.53% and 6.57% ∼ 15.50%, respectively. Among them, chlorogenic acid, 3,5-dicaffeoylquinic acid, and 1,5-dicaffeoylquinic acid, showed higher small intestinal transit rates and digestive recoveries. Furthermore, we found that by increasing intracellular Catalase (CAT) and Superoxide dismutase (SOD) viability and lowering Malondialdehyde (MDA) level (P < 0.05), 3,5-dicaffeoylquinic acid significantly mitigated the oxidative damage of AML-12 liver cells more than the other two phenolics. Our results demonstrated that 3,5-dicaffeoylquninic acid was the primary phenolic compounds in GJ that effectively reduced liver damage, providing a theoretical basis for the development of GJ as a potentially useful resource for hepatoprotective diet.

Impact of rice variety, cooking equipment and pretreatment method on the quality of lightly milled rice

Lightly milled rice is a healthier choice compared to refined white rice. In this study, the effects of variety, cooking equipment and pretreatment method on the quality of six varieties of lightly milled rice from China after cooking was investigated through physics, chemistry and instrumental analysis method. Nanjing-No.5055 has the best eating quality, Xiadao-No.1 has higher appearance score, and Fengliangyouxiang-No.1 has the lowest glycemic index. Compared with microwave oven and electric cooker, steamer has a more significant positive impact on component retention, eating quality and sensory quality, but the former has lower cooking time and higher glycemic index. Soaking can effectively improve the water absorption rate, thus reducing hardness. Cleaning affects component retention but is beneficial for sensory quality. The most obvious variation in organizational structure can be observed in the steamer and soaking processes. These findings could serve as a valuable reference for the processing of lightly milled rice.

The use of an in vitro fecal fermentation model to uncover the beneficial role of omega-3 and punicic acid in gut microbiota alterations induced by a Western diet

The influence of gut microbiota in the onset and development of several metabolic diseases has gained attention over the last few years. Diet plays an essential role in gut microbiota modulation. Western diet (WD), characterized by high-sugar and high-fat consumption, alters gut microbiome composition, diversity index, microbial relative levels, and functional pathways. Despite the promising health effects demonstrated by polyunsaturated fatty acids, their impact on gut microbiota is still overlooked. The effect of Fish oil (omega-3 source) and Pomegranate oil (punicic acid source), and a mixture of both oils in gut microbiota modulation were determined by subjecting the oil samples to in vitro fecal fermentations. Cecal samples from rats from two different dietary groups: a control diet (CD) and a high-fat high-sugar diet (WD), were used as fecal inoculum. 16S amplicon metagenomics sequencing showed that Fish oil + Pomegranate oil from the WD group increased α-diversity. This sample can also increase the relative abundance of the Firmicutes and Bacteroidetes phylum as well as Akkermansia and Blautia, which were affected by the WD consumption. All samples were able to increase butyrate and acetate concentration in the WD group. Moreover, tyrosine concentrations, a precursor for dopamine and norepinephrine, increase in the Fish oil + Pomegranate oil WD sample. GABA, an important neurotransmitter, was also increased in WD samples. These results suggest a potential positive impact of these oils' mixture on gut-brain axis modulation. It was demonstrated, for the first time, the great potential of using a mixture of both Fish and Pomegranate oil to restore the gut microbiota changes associated with WD consumption.

Carotenoids and Intestinal Harmony: Exploring the Link for Health

Carotenoids, prominent lipid-soluble phytochemicals in the human diet, are responsible for vibrant colours in nature and play crucial roles in human health. While they are extensively studied for their antioxidant properties and contributions to vitamin A synthesis, their interactions with the intestinal microbiota (IM) remain poorly understood. In this study, beta (β)-carotene, lutein, lycopene, a mixture of these three pigments, and the alga Osmundea pinnatifida were submitted to simulated gastrointestinal digestion (GID) and evaluated on human faecal samples. The results showed varying effects on IM metabolic dynamics, organic acid production, and microbial composition. Carotenoid exposure influenced glucose metabolism and induced the production of organic acids, notably succinic and acetic acids, compared with the control. Microbial composition analysis revealed shifts in phyla abundance, particularly increased Pseudomonadota. The α-diversity indices demonstrated higher diversity in β-carotene and the pigments' mixture samples, while the β-diversity analysis indicated significant dissimilarity between the control and the carotenoid sample groups. UPLC-qTOF MS analysis suggested dynamic changes in carotenoid compounds during simulated fermentation, with lutein exhibiting distinct mass ion fragmentation patterns. This comprehensive research enhances our understanding of carotenoid-IM interactions, shedding light on potential health implications and the need for tailored interventions for optimal outcomes.

Bioaccessibility of Phenolic Compounds, Resistant Starch, and Dietary Fibers from Australian Green Banana during In Vitro Digestion and Colonic Fermentation

Green bananas contain a substantial amount of resistant starch (RS), dietary fiber (DF), and phytochemicals, which exhibit potent antioxidant capabilities, primarily attributable to the abundance of polyphenols. The objective of this study was to assess the variations in the contents and bioaccessibility of RS, DF, and phenolic compounds in three types of Australian green bananas (Cavendish "Musa acuminata", Ladyfinger "Musa paradisiaca L.", and Ducasse "Musa balbisiana"), along with their antioxidant capacities, and the production of short-chain fatty acids (SCFAs) following in vitro simulated gastrointestinal digestion and colonic fermentation. The studied cultivars exhibited significant levels of RS, with Ladyfinger showing the greatest (49%). However, Ducasse bananas had the greatest DF concentration (38.73%). Greater TPC levels for Ladyfinger (2.32 mg GAE/g), as well as TFC and TTC (0.06 mg QE/g and 3.2 mg CE/g, respectively) in Cavendish, together with strong antioxidant capacities (DPPH, 0.89 mg TE/g in Cavendish), have been detected after both intestinal phase and colonic fermentation at 12 and 24 h. The bioaccessibility of most phenolic compounds from bananas was high after gastric and small intestinal digestion. Nevertheless, a significant proportion of kaempferol (31% in Cavendish) remained detectable in the residue after colonic fermentation. The greatest production of SCFAs in all banana cultivars was observed after 24 h of fermentation, except valeric acid, which exhibited the greatest output after 12 h of fermentation. In conclusion, the consumption of whole green bananas may have an advantageous effect on bowel health and offer antioxidant characteristics.

Food-grade hexosomes as efficient vehicles for delivery of fish-purified antioxidant peptide

Herein, we describe the potential use of food-grade hexosomes (HEXs) for delivering fish-purified antioxidant peptide (PF10). Using a binary lipid mixture of Dimodan U/citrem, the nanocarriers were produced with a size range of 202.7-569.8 nm and peptide encapsulation efficiency of 64.6-89.3%. These HEXs were also characterized by SAXS and cryo-TEM, and were able to sustain the release of PF10, where only 32.2% released in PBS after 24 h. SAXS findings verified that PF10 modulate the internal structure of HEXs in a pH-dependent manner. Antioxidant assays proved the efficacy of such nano-self-assemblies in maintaining the bioactivity of the loaded peptide. Moreover, the in vitro gastrointestinal stability test indicated that the antioxidant capacity of the free- and PF10-loaded HEXs decreased under SGF/SIF conditions with the reduction in activity being greater for the free PF10. The present findings may provide a useful basis for development of pH-responsive nano-self-assemblies for delivery of antioxidant peptides.

Wild and Micropropagated Artemisia eriantha Infusions: In Vitro Digestion Effects on Phenolic Pattern and Antioxidant Activity

This study investigated the in vitro simulated gastrointestinal digestion (GID) effects on wild and micropropagated Apennines Genepì infusions. Wild and micropropagated infusions were compared for their antioxidant activity, phenolic contents, and polyphenolic profiles before and after GID. Before digestion, the wild infusions had higher amounts of phenolic compounds and antioxidant activity than the micropropagated ones. Instead, after digestion, the differences in the total phenolic content (TPC) and antioxidant activity between wild and micropropagated infusions were less pronounced. The changes in the TPC and phenolic profiles revealed the presence of several chemical transformations and rearrangements that resulted in compounds with different reactivity and antioxidant potential. Without enzyme actions, the wild infusion digest undergoes higher modifications than those obtained from the micropropagated ones. The current study offers the first concrete proof of the impact of GID on the polyphenolic chemicals present in infusions of wild and micropropagated Apennines Genepì and their antioxidant properties. Our findings are essential for future in-depth analyses of Apennine Genepì infusions and their potential impacts on human health.

Indian Almond (Terminalia catappa Linn.) Leaf Extract Extends Lifespan by Improving Lipid Metabolism and Antioxidant Activity Dependent on AMPK Signaling Pathway in Caenorhabditis elegans under High-Glucose-Diet Conditions

This study aimed to evaluate the antioxidant and antiaging effects of Indian almond (Terminalia catappa Linn.) leaf extract (TCE) on high-glucose (GLU)-induced obese Caenorhabditis elegans. Since TCE contains high contents of flavonoids and phenolics, strong radical scavenging activity was confirmed in vitro. The stress-resistance effect of TCE was confirmed under thermal and oxidative stress conditions at nontoxic tested concentrations (6.25, 12.5, and 25 μg/mL). GLU at 2% caused lipid and reactive oxygen species (ROS) accumulation in C. elegans, and TCE inhibited lipid and ROS accumulation under both normal and 2% GLU conditions in a concentration-dependent manner. In addition, TCE proved to be effective in prolonging the lifespan of C. elegans under normal and 2% GLU conditions. The ROS reduction effect of TCE was abolished in mutants deficient in daf-16/FOXO and skn-1/Nrf-2. In addition, the lifespan-extending effect of TCE in these two mutants disappeared. The lifespan-extending effect was abolished even in atgl-1/ATGL-deficiency mutants. The TCE effect was reduced in aak-1/AMPK-deficient mutants and completely abolished under 2% GLU conditions. Therefore, the effect of prolonging lifespan by inhibiting lipid and ROS accumulation under the high GLU conditions of TCE is considered to be the result of atgl-1, daf-16, and skn-1 being downregulated by aak-1. These results suggest that the physiological potential of TCE contributes to antiaging under metabolic disorders.

Gastrointestinal digestion assays for evaluating the bioaccessibility of phenolic compounds in fruits and their derivates: an overview

Fruits and their derivatives are sources of phenolic compounds, which contribute to the maintenance of health benefits. In order to exert such properties, these compounds must be exposed to gastrointestinal conditions during digestion. In vitro methods of gastrointestinal digestion have been developed to simulate and evaluate the changes that compounds undergo after being exposed to various conditions. We present, in this review, the major in vitro methods for evaluating the effects of gastrointestinal digestion of phenolic compounds in fruits and their derivatives. We discuss the concept of bioaccessibility, bioactivity, and bioavailability, as well as the conceptual differences and calculations among studies. Finally, the main changes caused by in vitro gastrointestinal digestion in phenolic compounds are also discussed. The significant variation of parameters and concepts observed hinders a better evaluation of the real effects on the antioxidant activity of phenolic compounds, thus, the use of standardized methods in research would contribute for a better understanding of these changes.

Metabolomic Characterization of Phoradendron brachystachyum Mistletoe and In-Silico and In-Vitro Investigation of Its Therapeutic Potential in Metabolic Disorders

Plants of the Phoradendron genus have been traditionally used for their lipid- and glucose-lowering effects. However, the compounds responsible for these effects and the overall chemical profile of these plants have not been thoroughly investigated. We aimed to characterize the metabolome of leaves, stems, and aerial parts of the Phoradendron brachystachyum plant. We used mass spectrometry and colorimetric screening techniques (with various solvents) to identify and characterize the metabolites present. We also evaluated the antioxidant (FRAP, ORAC, TEAC, and DPPH assays) and inhibitory effects on pancreatic lipase and α-glucosidase enzymes of hydrophilic extracts. Furthermore, we compared the molecular fingerprints between the identified metabolites and FDA-approved drugs to gain insights into the metabolites that might be responsible for the observed effects on enzymes. Our findings revealed the presence of 59 putative metabolites, primarily flavonoids. However, we also hint at the presence of peptide and carbohydrate derivatives. The leaf extracts demonstrated the most promising metrics across all assays, exhibiting strong antioxidant and enzyme inhibitory effects as well as high levels of phenolic compounds, flavonoids, and tannins. Fingerprint analysis suggested potential peptide and carbohydrate metabolites as pancreatic lipase and α-glucosidase inhibitors. Overall, our study provides evidence on specific metabolites in Phoradendron brachystachyum that could be responsible for the therapeutic effects noted in obese and type 2 diabetes subjects.

Quality Characteristics of Fresh Date Palm Fruits of "Medjoul" and "Confitera" cv. from the Southeast of Spain (Elche Palm Grove)

The quality characteristics (physical, techno-functional, and chemical) of date fruits (at the tamar stage) of two cultivars ("Confitera", autochthonous and unknown vs. "Medjoul", widely distributed and well-known), grown in the Southeast of Spain (Elche palm grove) were evaluated in order to reinforce decisions aimed at organizing the production of fresh dates from Elche by selecting the most profitable cultivar. Morphologically, Confitera dates were longer and with higher pulp yield than Medjoul dates (4.58 cm vs. 3.88 cm, and 84% vs. 78%, respectively) (p < 0.05). Nutritionally, both dates are a good source of carbohydrates (total sugars (43-48%) and dietary fiber (20-22%)), with small amounts of fat and proteins. The main free sugars in dates from both cultivars were glucose and fructose (reducing sugars). The most abundant mineral found in both date fruits were K, followed by Ca or Mg (depending on the cultivar; Ca in Medjoul and Mg in Confitera). Confitera dates showed a higher total antioxidant activity than Medjoul, corresponding with their higher (p < 0.05) content in polyphenolic compounds, mainly flavonoids (catechin and epicatechin predominantly). Confitera dates should be promoted in this region not only for their contribution to sustainable agricultural development and biodiversity, but also for their higher overall quality.

The Impact of In Vitro Digestion on the Polyphenol Content and Antioxidant Activity of Spanish Ciders

Various factors can influence the polyphenol content and the antioxidant capacity of ciders, such as the apple variety, its degree of maturity, apple farming and storage conditions, and the cider-fermentation method, all of which explains why ciders of different origin present different values. In addition, digestive processes could have some effects on the properties of cider. Hence, the objective of this study is to characterize Spanish ciders in terms of their polyphenol content and antioxidant capacity and to ascertain whether those same properties differ in digested ciders. In total, 19 ciders were studied from three different zones within Spain: Asturias (A) (10), the Basque Country (BC) (6), and Castile-and-Leon (CL) (3). A range of assays was used to determine the total polyphenol content and the antioxidant capacity of the ciders. In addition, a digestive process was simulated in vitro, assessing whether the use of amylase might influence the recovery of bioactive compounds after digestion. The Basque Country ciders presented higher total polyphenol contents (830 ± 179 GAE/L) and higher antioxidant capacities (DPPH: 5.4 ± 1.6 mmol TE/L; ABTS: 6.5 ± 2.0 mmol TE/L; FRAP: 6.9 ± 1.6 mmol TE/L) than the other ciders that were studied. The in vitro digestion process, regardless of the use of amylase, implied a loss of phenolic compounds (598 ± 239 mg GAE/L undigested samples; 466 ± 146 mg GAE/L digested without amylase samples; 420 ± 115 mg GAE/L digested with amylase samples), although the variation in antioxidant activity depended on the assay chosen for its determination.

Biotransformation and bioaccessibility of active ingredients from Radix Astragali by Poria cocos during solid-state fermentation and in vitro digestion and antioxidant activity evaluation

Radix Astragali is one of the most famous and frequently used health food supplements and herbal medicines. Among more than 227 components of Radix Astragali, Astragaloside IV (AG IV) is famous functional compound and is commonly used as a quality marker for Radix Astragali. However, the relatively low content of AG IV in Radix Astragali (< 0.04%, w/w) severely limits its application. The purpose of this study is to improve the biotransformation of AG IV and its bioaccessibility during in vitro digestion by Poria cocos solid fermenting Radix Astragali. The optimum fermentation conditions were as follows: Inoculation amount 8 mL; fermentation time 10 d; fermentation humidity 90%. Through fermentation, the content of AG IV was increased from 384.73 to 1986.49 μg/g by 5.16-fold. After in vitro digestion, the contents of genistin, calycosin, formononetin, AG IV, Astragaloside II (AG II) and total flavonoids in fermented Radix Astragali (FRA) of enteric phase II (ENTII) were 34.52 μg/g, 207.32 μg/g, 56.76 μg/g, 2331.46 μg/g, 788.31 μg/g, 3.37 mg/g, which were 2.08-fold, 2.51-fold, 1.05-fold, 8.62-fold, 3.22-fold and 1.50-fold higher than those of control, respectively. The Scanning electron microscopy (SEM) of FRA showed rough surface and porous structure. The DPPH and ABTS radical scavenging rate of FRA were higher than those of control. These results showed that the Poria cocos solid fermentation could increase the content of the AG IV in Radix Astragali and improve the bioaccessibility and antioxidant activity of Radix Astragali, which is providing new ideas for future development and utilization of Radix Astragali.

Exploring the Potential of Pomegranate Peel Extract as a Natural Food Additive: A Review

PURPOSE OF THE REVIEW

Pomegranate is one of the super fruit and a storehouse of several antioxidants and health-promoting compounds which can act as a natural food additive. The pomegranate processing industry generates huge quantities of by-products, particularly peels (50% of fresh fruit weight), that cause environmental pollution due to improper disposal. In this perspective, the present review article focuses on the chemical composition of pomegranate peel and its application as a natural food additive in different food products such as bakery, dairy, meat/meat products, fish/fish products, edible oils, and packaging materials.

RECENT FINDINGS

There is a continuous demand for processed foods exhibiting natural food additives over foods containing synthetic additives/colorants, which can cause serious health implications such as cancer with regular consumption. The food industry is looking for an alternative to synthetic/artificial food additives. To overcome these problems, pomegranate peel or its extract can be used as a natural biopreservative in food products that are prone to fat oxidation and microbial growth. Pomegranate peel contains bioactive compounds, especially tannins, phenolic acids, and flavonoids, which have nutraceutical value and possess higher antioxidant activity and antimicrobial properties. Due to these properties, pomegranate peel prevents lipid oxidation in fatty foods and can also retard the microbial growth.

Assessment of the Bioaccessibility of Elaeagnus angustifolia L. Flour and Its Use in Cracker Formulation

In this study, in vitro digestion of polyphenols of oleaster (Elaeagnus angustifolia L.) flour (OF) and the potential use of OF in cracker production were studied. The results showed that 21.90 mg gallic acid equivalent (GAE)/g dry matter (DM) of total polyphenol (TP), 28.15 mg rutin equivalent (RE)/g DM of total flavonoid (TF) and 7709.13 mmol ascorbic acid equivalent (AAE)/100 g DM of antioxidant capacity (AC) were found in OF. The bioaccessibility and content of the OF polyphenols and their AC during in vitro digestion varied depending on the digestion stage. The stability of the OF polyphenols was higher in gastric stage (41.92%) than intestinal one (34.01%). OF was used to replace flour in the cracker formulation at the levels of 5, 10 and 15% (w/w) and increased the TP contents and AC of the crackers compared to the sample without OF (control). The addition of OF to the cracker dough increased the bioaccessibility of the cracker polyphenols. After digestion, bioaccessibilities of enriched crackers (107.90-126.81%) were found higher than that of control sample (93.73%). However, as the level of OF in cracker increased, bioaccessibility of polyphenols decreased. The results generally indicated that oleaster has a good potential for the enrichment of foods.

Assessment of Polyphenols Bioaccessibility, Stability, and Antioxidant Activity of White Mugwort (Artemisia lactiflora Wall.) during Static In Vitro Gastrointestinal Digestion

White mugwort (Artemisia lactiflora Wall.), a traditional Chinese medicine, has been widely consumed in different forms for health care purposes. In this study, the in vitro digestion model of INFOGEST was used to investigate the bioaccessibility, stability, and antioxidant activity of polyphenols from two different forms of white mugwort, including dried powder (P 50, 100, and 150 mg/mL) and fresh extract (FE 5, 15, and 30 mg/mL). During digestion, the bioaccessibility of TPC and antioxidant activity were influenced by the form and ingested concentration of white mugwort. The highest bioaccessibility of the total phenolic content (TPC) and relative antioxidant activity were found at the lowest P and FE concentrations, as calculated relative to the TPC and antioxidant activity of P-MetOH and FE-MetOH based on the dry weight of the sample. Post-digestion, in comparison to P, FE had higher bioaccessibility (FE = 287.7% and P = 130.7%), relative DPPH radical scavenging activity (FE = 104.2% and P = 47.3%), and relative FRAP (FE = 673.5% and P = 66.5%). Nine compounds, 3-caffeoylquinic acid, 5-caffeoylquinic acid, 3,5-di-caffeoylquinic acid, sinapolymalate, isovitexin, kaempferol, morin, rutin, and quercetin, identified in both samples were modified during digestion, yet still provided strong antioxidant activity. These findings suggest that white mugwort extract possesses a higher polyphenol bioaccessibility, showing great potential as a functional ingredient.

Chlorogenic Acid of Cirsium japonicum Resists Oxidative Stress Caused by Aging and Prolongs Healthspan via SKN-1/Nrf2 and DAF-16/FOXO in Caenorhabditis elegans

To evaluate the value of Cirsium japonicum (CJ; thistle) as a material for functional foods, we studied the functional composition of cultivated CJ and the in vitro and in vivo antioxidant activity of the functional substance. The detected phenolics in farmed CJ were chlorogenic acid (CA), linarin (LIN), and pectolinarin (PLIN) by HPLC analysis. As a result of the antioxidant activity of CJ and its phenolics by DPPH and ABTS method, CA had shown the greatest antioxidant activity. We employed Caenorhabditis elegans to validate that in vitro effects of CA are shown in vivo. CA delayed reduction in pumping rate and progeny production during aging of C. elegans. Under both normal and oxidative stress conditions, CA reduced the production of reactive oxygen species (ROS) in worms and increased their lifespan. In particular, CA showed the reducing effect of ROS accumulation due to aging in aged worms (8 days old). To gain insight into the mechanism, we used skn-1/Nrf2 and daf-16/FOXO transformed worms. The CA effects (on catalase activity and lifespan extension) in the wild-type (WT) decreased in skn-1 and daf-16 mutants. In particular, CA strongly relied on daf-16 under mild oxidative condition and skn-1 under overall (from mild to strong) oxidative stress to reduce ROS and extend healthspan. Thus, we conclude that CA, a key bioactive phenolic of CJ, reduces ROS production and ultimately extends healthspan, and this effect is the result of actions of daf-16 or skn-1 at different stages depending on the degree of oxidation or aging. Our results suggest that CJ containing CA can be used as an antiaging material due to its antioxidant properties.

Effect of Gastrointestinal Digestion on the Bioaccessibility of Phenolic Compounds and Antioxidant Activity of Fermented Aloe vera Juices

Plant-based beverages are enriched by the fermentation process. However, their biocompounds are transformed during gastrointestinal digestion, improving their bioaccessibility, which is of primary importance when considering the associated health benefits. This study aimed to evaluate the effect of in vitro gastrointestinal digestion on phenolic compound bioaccessibility and antioxidant activity of novel Aloe vera juices fermented by probiotic Enterococcus faecium and Lactococcus lactis. Aloe vera juices were digested using the standardized static INFOGEST protocol. During digestion, phenolic compounds and antioxidant activity (DPPH, ABTS, and FRAP) were accessed. The digestion process was seen to significantly increase the total phenolic content of the fermented Aloe vera juices. The fermentation of Aloe vera increased the bioaccessibility of juice biocompounds, particularly for kaempferol, ellagic acid, resveratrol, hesperidin, ferulic acid, and aloin. The phenolics released during digestion were able to reduce the oxidative radicals assessed by ABTS and FRAP tests, increasing the antioxidant action in the intestine, where they are absorbed. The fermentation of Aloe vera by probiotics is an excellent process to increase the bioavailability of beverages, resulting in natural added-value functional products.

Effects of simulated in vitro gastrointestinal digestion on antioxidant activities and potential bioaccessibility of phenolic compounds from K. coccinea fruits

The changes of bioactive substances in peels and sarcocarps of three different varieties of Kadsura coccinea (Dahong, Fenhong, and Zihei) were evaluated by an in vitro simulation model. In this study, three varieties of K. coccinea fruits were digested in vitro to compare the changes and differences in antioxidant activity (DPPH, ABTS, FRAP) and bioaccessibility. The results showed that before digestion the highest content of total phenolics (TPC) (2.265 ± 0.127 mg GAE/g DW) and the highest content of flavonoids contents (TFC) (10.379 ± 0.093 mg GAE/g DW) were found in Fenhong fruit. The highest release of TPC and TFC after simulated gastric digestion was observed in the Dahong and Zihei sarcocarp, which increased by 98.7 and 20%, respectively. During oral and intestinal digestion, the content of bioactive compounds showed a decreasing trend. The radical scavenging ability of 1, 1-diphenyl-2-picrylhydrazyl (DPPH), [2,2-azino-bis(3-ethylbenzothiazoline) (ABTS)] sulfonic acid free radical scavenging ability, and ferric ion reducing antioxidant power (FRAP) results showed that the antioxidant capacity of K. coccinea fruits increased most significantly (26.9∼181%) in gastric digestion stage and then decreased after intestinal digestion stage. The recoveries of TPC and TFC were all increased after whole simulated digestion, as well as their bioaccessibility in sarcocarps was higher than those in peels, especially for the bioaccessibility of TPC and TFC in Dahong reached 50.53 and 48.19%, respectively. These results indicated that the peel and sarcocarp of K. coccinea had good antioxidant activity, with high bioaccessibility of phenolics could be a promising antioxidant source for the food industry.

Simulated Gastrointestinal Digestion of Bioprocessed Spelt Seeds: Bioaccessibility and Bioactivity of Phenolics

The goal of this research was to evaluate the impact of different bioprocessing techniques on improved bioaccessibility of phenolics from spelt seeds. Despite the negative influence of gastrointestinal digestion, fermentation of germinated seeds significantly increased the bioaccessibility of total phenolics and their antioxidant activity compared to digested raw seeds. Enzymatic treated fermented seeds showed the highest relative bioaccessibility of p-coumaric and trans-ferulic acids, while their absolute contents were significantly higher in “germinated + fermented” seeds. Our research suggests that pretreatment of spelt seeds with hydrolytic enzymes improves access of fermenting microorganisms to structural elements, resulting in an increased content of extractable and bound trans-ferulic acid. Significantly higher biostability of phenolics was observed in raw seeds. Some major quality changes in the composition of extracts were observed under simulated in vitro digestion, since antioxidants of the same extract showed a different relative decrease in DPPH• and ABTS•+ scavenging activities compared to the raw seeds or their corresponding undigested counterparts. It is therefore important to increase the content of extractable antioxidants in seeds by bioprocessing, since they are strongly diminished during digestion.

From Function to Metabolome: Metabolomic Analysis Reveals the Effect of Probiotic Fermentation on the Chemical Compositions and Biological Activities of Perilla frutescens Leaves

This study aimed to investigate the impact of probiotic fermentation on the active components and functions of Perilla frutescens leaves (PFL). PFL was fermented for 7 days using six probiotics (Lactobacillus Plantarum SWFU D16, Lactobacillus Plantarum ATCC 8014, Lactobacillus Rhamnosus ATCC 53013, Streptococcus Thermophilus CICC 6038, Lactobacillus Casei ATCC 334, and Lactobacillus Bulgaricus CICC 6045). The total phenol and flavonoid contents, antioxidant abilities, as well as α-glucosidase and acetylcholinesterase inhibition abilities of PFL during the fermentation process were evaluated, and its bioactive compounds were further quantified by high-performance liquid chromatography (HPLC). Finally, non-targeted ultra-HPLC-tandem mass spectroscopy was used to identify the metabolites affected by fermentation and explore the possible mechanisms of the action of fermentation. The results showed that most of the active component contents and functional activities of PFL exhibited that it first increased and then decreased, and different probiotics had clearly distinguishable effects from each other, of which fermentation with ATCC 53013 for 1 day showed the highest enhancement effect. The same trend was also confirmed by the result of the changes in the contents of 12 phenolic acids and flavonoids by HPLC analysis. Further metabolomic analysis revealed significant metabolite changes under the best fermentation condition, which involved primarily the generation of fatty acids and their conjugates, flavonoids. A total of 574 and 387 metabolites were identified in positive ion and negative ion modes, respectively. Results of Spearman's analysis indicated that some primary metabolites and secondary metabolites such as flavonoids, phenols, and fatty acids might play an important role in the functional activity of PFL. Differential metabolites were subjected to the KEGG database and 97 metabolites pathways were obtained, of which biosyntheses of unsaturated fatty acids, flavonoid, and isoflavonoid were the most enriched pathways. The above results revealed the potential reason for the differences in metabolic and functional levels of PFL after fermentation. This study could provide a scientific basis for the further study of PFL, as well as novel insights into the action mechanism of probiotic fermentation on the chemical composition and biological activity of food/drug.

Phenolic Compounds and Antioxidant Activity of Rice–Tartary Buckwheat Composite as Affected by In Vitro Digestion

The present study aimed to evaluate the phenolic compounds and antioxidant activity of rice–tartary buckwheat composite (RTBC) as affected by in vitro digestion to explore the structure-activity relationship of the release of total phenolic content (TPC) and total flavonoid content (TFC) with the antioxidant activity of RTBC during in vitro oral, gastric, and intestinal digestion stages. The release of TPC and TFC from RTBC increased significantly after in vitro digestion ( $P<0.05$ ), and the change of antioxidant activity was consistent with that of TPC and TFC. Compared with the initial stage of digestion, the antioxidant activity of RTBC was increased after digestion ( $P<0.05$ ), and there was a strong correlation between antioxidant activity and the release of TPC and TFC (0.954 < R < 0.997; $P<0.05$ ). The phenolic compounds released in the oral, gastric, and intestinal digestion stages varied, and eight phenolic compounds were identified by UPLC-Triple-TOF/MS, namely, quercetin-3-O-robinoside-7-O-sophoroside, quercetin-3-O-neohesperidoside-7-O-glucoside, forsythobiflavone A, forsythobiflavone B, quercetin-3-O-rutinoside-7-O-glucoside, rutin, isoquercetin, and ferulic acid. These results indicated that in vitro digestion significantly increases the release of phenolic compounds and flavonoids from RTBC and there is a higher antioxidant activity after digestion than before digestion. The phenolic compounds released after digestion of RTBC are beneficial to health protection.

Sambucus nigra flower and berry extracts for food and therapeutic applications: effect of gastrointestinal digestion on in vitro and in vivo bioactivity and toxicity

The bioavailability of natural compounds should be assessed through different perspectives. Studying the behaviour of the extracts after digestion is often overlooked but is crucial for success in the development of active food ingredients. Thus, the bioaccessibility of S. nigra (flower and berry) extracts after in vitro gastrointestinal digestion and their effect on toxicity and bioactive potential were studied. The flower extract had a higher content of phenolic compounds, like rutin, chlorogenic acid and rosmarinic acid, while in the berry extract, rutin, resveratrol, ferulic acid and chlorogenic acid were the main phenolic compounds. The effect of the non-digested and digested extracts was significantly different on different cell lines. The IC₅₀ of the normal cell line (L929) was the highest, indicating low toxicity. The IC₅₀ of the cancerous cell lines (HeLa and HT29) was lower, particularly the extract obtained from the flower upon digestion. In the presence of an oxidant agent - tbHP, only the berry extract was able to significantly reduce the formation of ROS in the L929 cell line, while in the HeLa cells, all the extracts were able to reduce ROS formation. The in vivo Artemia salina lethality bioassay demonstrated a dose-dependent effect of extracts, and the berry digested extract induced the lowest mortality rate. The promising results obtained on the chemical and biological evaluation of the extracts indicate that the natural compounds isolated from S. nigra by-products can be used as potential ingredients for functional food formulations and/or as bio-therapeutic agents.

The Effect of In Vitro Gastrointestinal Digestion on the Antioxidants, Antioxidant Activity, and Hypolipidemic Activity of Green Jujube Vinegar

Healthy fruit vinegar has been extensively favored in China in recent years. As a new type of fruit vinegar developed by our laboratory, green jujube vinegar has the characteristics of good taste and rich nutrition. To study the effect of in vitro gastrointestinal digestion on the antioxidant and hypolipidemic activity of green jujube vinegar, so as to provide basic data for research and the development of healthy food antioxidants, including the total phenolic content (TPC), total flavonoid content (TFC), total acid content, and volatile acid content, were measured. The antioxidant activity was measured by using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical scavenging methods and the ferric reducing antioxidant power assay (FRAP), and the hypolipidemic activity was measured by cholesterol adsorption and the sodium cholate adsorption capacities. The results show that gastric digestion significantly (p < 0.05) decreased the TPC, TFC, total acid content, and volatile acid content, for which the highest reductions were up to 54.17%, 72%, 88.83% and 82.35%, respectively. During intestinal digestion, the TFC remained at a high level and unchanged, and the TFC and volatile acid content significantly (p < 0.05) decreased by 72.66% and 89.05%, respectively. The volatile acid content did not significantly (p > 0.05) change within 2 h. The ABTS free radical scavenging ability and the reducing power free radical scavenging rate were correlated with the TPC, TFC, and total acid contents, and the DPPH free radical scavenging ability and cholesterol adsorption capacity were not. These findings suggest that green jujube vinegar can be a potential functional food for people’s use.

Pomegranate peel polyphenols interaction with intestinal flora and its metabolic transformation

1. Pomegranate peel polyphenols (PPPs) have anti-oxidation, anti-atherosclerosis, anti-obesity effect, and so on. However, few studies have been conducted on the absorption and transformation of pomegranate polyphenols in the gut and the biologically active forms that ultimately work in the body.2. In this study, PPPs (300 mg/kg/day) were given to normal rats and relatively sterile rats by gavage respectively. The relatively sterile rats were obtained by neomycin sulfate (250 mg/kg/day) gavage to rats. The purpose of this study is to elaborate the relationship between intestinal flora and polyphenol metabolism of pomegranate peel, and to quantitatively analyze the transformation process of its metabolite urolithin in rats.3. The results showed that decreased bacterial diversity could significantly reduce the abundance of PPPs metabolites in feces and urine in relatively sterile rats. PPPs can regulate intestinal flora structure, significantly enhance the content of Clostrida Firmicutes (P < 0.05), and effectively promote acetic acid, propionic acid, butyric acid, iso-butyric acid and valeric acid production in rat (P < 0.05 or P < 0.01 or P< 0.001). PPPs can significantly elevate the relative proportion of Ruminococcaceae (P < 0.05). Ruminococcaceae_NK4A214_group, Ruminococcaceae_UCG-014 and Ruminococcaceae_UCG-005 can promote the metabolic transformation of PPPs and make the utilization of Urolithin A more effective.

Digestive recovery of polyphenols, antioxidant activity, and anti-inflammatory activity of selected edible flowers from the family Fabaceae

Edible flowers are regaining popularity as therapeutic agents, due to their phytochemical composition. The present study assessed the recovery of phenolics along with the antioxidant and anti-inflammatory properties of seven edible flowers of the Fabaceae family after being subjected to simulated gastrointestinal conditions and dialysis. The total phenolic content of all the flowers decreased after the gastric phase, whereas the total flavonoid content increased. The total anthocyanin content of four flower species decreased after the intestinal phase of digestion. Cassia auriculata expressed the highest hydrogen peroxide and nitric oxide scavenging activities in the dialyzed fraction. Bauhinia racemose had the highest activity in the inhibition of heat-induced hemolysis of red blood cells after dialysis (4.43 ± 01.5%). In general, the results suggest a reduction in the phenolic contents after gastrointestinal digestion and dialysis; however, phenolics, flavonoids and anthocyanins were sufficiently available to be absorbed with the dialysis to exert antioxidant and anti-inflammatory activities. PRACTICAL APPLICATION: The presence of various phenolic compounds in edible flowers has attracted the attention of consumers as well as the food industry, due to their potential to be incorporated in functional foods and drugs. However, the availability of phenolics after digestion is an important measure to get a realistic view of the health effects exerted upon the consumption of these edible flowers. The present study provides new information on the antioxidant and anti-inflammatory potential of selected edible flowers before and after in vitro digestion. This would be more useful for nutritionists, policymakers and consumers to effectively utilize edible flowers by understanding the changes undergone by the phenolic compounds upon digestion.

α-Amylase inhibition, cytotoxicity and influence of the in vitro gastrointestinal digestion on the bioaccessibility of phenolic compounds in the peel and seed of Theobroma grandiflorum

The aim of this work was to evaluate the bioaccessibility, cytotoxicity, antioxidant and antidiabetic potential of peel and seeds of cupuassu (Theobroma grandiflorum). Thus, the extracts of cupuassu were evaluated for inhibition of α-amylase, cytotoxicity, and bioaccessibility after gastrointestinal digestion and probiotic fermentation (Lactobacillus delbrueckii, Lactobacillus jhonsoni, Lactobacillus rhamus and Bifidobacterium longum). Digestion increased concentrations of phenolics, showing bioaccessibility of up to 274.13% (total phenolics) and 1105.15% (ORAC). β-carotene, quinic, tartaric, malic, citric, epicatechin, ethyl gallate, epigallocatechin gallate, gallic acid, pyrocatechol, vanillin, ramnetine were the main compounds while the epicatechin, ethyl gallate, gallic acid and pyrocatechol were the major effective phenolic compounds. The extracts did not show toxic effects and the cupuassu seeds showed 97% inhibition of α-amylase and 47.91% bioaccessibility of pyrocatechol. This study suggests that cupuassu extracts are sources of natural antioxidants with promising antidiabetic potential, and probiotics are able to increase phenolic compounds, responsible for health benefits.

Advances in static in vitro digestion models after the COST action Infogest consensus protocol

In vitro digestion models are essential to predictively evaluate the bioaccessibility and bioactivity of food molecules or natural products. Dynamic models better simulate the gastrointestinal conditions as they reproduce similar physiological environments. Despite this, static methods, also known as biochemical methods, represent a simple and useful approach for the study of different types of molecules, with a broad applicability in the nutritional, pharmaceutical, and toxicological fields. In addition, static models can be validated, avoiding the disadvantage of a difficult reproducibility of dynamic in vitro systems and inter-individual variations of in vivo experiments. A crucial point in the standardization of static models was the COST Action Infogest in 2014, which elaborated an international consensus static digestion method to harmonize experimental conditions and has general guidelines, thus allowing the comparison of studies and data. The aim of our review is to underline the impact of the Infogest consensus method and the development and evolution of in vitro static methods in the following years, with a focus on food applications.

A Comparative Analysis of Different Varietal of Fresh and Dried Figs by In Vitro Bioaccessibility of Phenolic Compounds and Antioxidant Activities

Varietal and sun-drying effects on phenolic compounds and their antioxidant activity were investigated during the in vitro gastrointestinal digestion of fresh and dried figs. The total phenolic compounds (phenolic, flavonoids, and proanthocyanidin) and their antioxidant activity (ferric reducing power; free radical scavenging activity DPPH, and phosphomolybdenum test) were evaluated before and after digestion. The total phenolic compounds and the antioxidant capacities of fresh and dried figs obtained before digestion were significantly (p < 0.05) higher than those obtained after digestion. A significant decrease (p < 0.05) of phenolic compounds and their antioxidant activity was observed during different digestion phases (oral phase > gastric phase > intestinal phase). A positive correlation was found between the total phenolic compounds and the antioxidant activity tested for both fresh and dried figs. Furthermore, the results showed that the digestion has no effect on the total phenolic compounds; however, a negative influence of the pH and the enzymes was observed on these compounds and their antioxidant activity. During in vitro gastrointestinal digestion, the varietal and the sun-drying has no significant effect on the phenolic compounds and their antioxidant activity. Likewise, the fresh or dry variety kept a high content before and after the digestion.

Impact of tea leaves types on antioxidant properties and bioaccessibility of kombucha

Five different tea varieties (white, green, oolong, black and pu-erh) were infused, drained and used for kombucha production. Antioxidant capacity, total phenolic content and bioaccessibility values were determined. Extractable, hydrolysable and bioaccessible fractions were used for antioxidant capacity and total phenolic content (TPC) and expressed as µmole TEAC/mL and mg GAE/100 mL, respectively. Antioxidant capacity and TPC were determined by Folin Ciocalteu's, ABTS and CUPRAC methods. In vitro digestion enzymatic extraction was used to determine bioaccessible fractions. It has found that kombucha fermentation with the tea extracts caused to elevate antioxidant capacity, TPC, and bioaccessibility. The green tea kombucha had the highest antioxidant capacity (4153.23 μmole TEAC/mL) and bioaccessibility (50.18%). Therefore, it can be suggested as a good supplement with high nutritional value in kombucha production. In general, TPC content increased significantly. The extractable fractions and bioaccessibility values of the kombucha tea varieties increased due to the fermentation, while the hydrolysable fractions decreased. Antioxidant capacity in the extractable fractions of the green tea kombucha samples was measured to increase by ABTS and CUPRAC methods. Bioaccessibility values of pu-erh tea by ABTS and white tea by CUPRAC were found to increase by the kombucha production.

Effect of digestion on bound phenolic content, antioxidant activity and hypoglycemic ability of insoluble dietary fibre from four Triticeae crops

To assess the physiological functions of bound phenols in insoluble dietary fiber (IDF) from different Triticeae crops, bound phenols in IDF were extracted from wheat, triticale, barley and quinoa. In addition, model in vitro was established and used in evaluating the release of bound phenols and changes in their physiological functions after simulated digestion. Results showed that bound phenol content in IDF from Triticeae crops before digestion was higher than which during digestion, and its physiological functions were also better (p < .05). Moreover, barley extracted before digestion, its bound phenolic content in IDF was higher than those in other three Triticeae crops, besides,its bound phenol also showed better antioxidant ability. Before digestion, bound phenols in IDF from triticale showed the best hypoglycemic ability (the inhibition rate of α-glucosidase was 95%; the inhibition rate of α-amylase was 97%). In the simulated digestion model, the bound phenols were mainly released during the intestinal digestion stage, they showed better physiological functions than which released at the gastric digestion stage. The bound phenol content in triticale was higher and its physiological functions was better than those in the other crops. PRACTICAL APPLICATIONS: The results of this experiment showed that the release of bound phenols measured by chemical extraction (i.e., before digestion) was higher than that by simulated gastrointestinal digestion. Compared with the chemical extraction method, in vitro gastro-intestinal digestion simulates the pH value and enzyme environment of food in the human body gastrointestinal digestion process more effectively. This study can provide reference for selecting Triticeae crops feeding in the future. To be more precise, bound phenol content in the insoluble dietary fiber of barley was the highest before digestion. The bound phenol in the insoluble dietary fiber of triticale had the best hypoglycemic ability. The bound phenolic compounds are mainly released during intestinal digestion, and their physiological functions are better than that in gastric digestion.

Valorisation of Olea europaea L. Olive Leaves through the Evaluation of Their Extracts: Antioxidant and Antimicrobial Activity

Olea europaea L. leaves constitute a source of bioactive compounds with recognized benefits for both human health and technological purposes. In the present work, different extracts from olive leaves were obtained by the application of two extraction methods, Soxhlet and microwave-assisted extraction (MAE), and six solvents (distilled water, ethanolic and glycerol mixtures solvents). MAE was applied under 40, 60 and 80 °C for 3, 6.5 and 10 min. The effect of the extraction method, solvent and treatment factors (the latter in MAE) on the total phenol content (TPC), the antioxidant activity (AA) and the phenolic profile of the extracts were all evaluated. The extracts showed high values of TPC (up to 76.1 mg GAE/g DW) and AA (up to 78 mg TE/g DW), with oleuropein being the most predominant compound in all extracts. The Soxhlet extraction method exhibited better yields in TPC than in MAE, although both methods presented comparable AA values. The water MAE extract presented the strongest antimicrobial activity against five foodborne pathogens, with minimum inhibitory concentration (MIC) values ranging from 2.5 to 60 mg/mL. MAE water extract is proposed to be exploited in the food and nutraceutical industry in the frame of a sustainable economy.

Pork Liver Pâté Enriched with Persimmon Coproducts: Effect of In Vitro Gastrointestinal Digestion on Its Fatty Acid and Polyphenol Profile Stability

Agrofood coproducts are used to enrich meat products to reduce harmful compounds and contribute to fiber and polyphenol enrichment. Pork liver pâtés with added persimmon coproducts (3 and 6%; PR-3 and PR-6, respectively) were developed. Therefore, the aim was to study the effect of their in vitro gastrointestinal digestion on: the free and bound polyphenol profile (HPLC) and their colon-available index; the lipid oxidation (TBARs); and the stability of the fatty acid profile (GC). Furthermore, the effect of lipolysis was investigated using two pancreatins with different lipase activity. Forty-two polyphenols were detected in persimmon flour, which were revealed as a good source of bound polyphenols in pâtés, especially gallic acid (164.3 µg/g d.w. in PR-3 and 631.8 µg/g d.w. in PR-6). After gastrointestinal digestion, the colon-available index in enriched pâté ranged from 88.73 to 195.78%. The different lipase activity in the intestinal phase caused significant differences in bound polyphenols' stability, contributing to increased lipid oxidation. The fatty acids profile in pâté samples was stable, and surprisingly their PUFA content was raised. In conclusion, rich fatty foods, such as pâté, are excellent vehicles to preserve bound polyphenols, which can reach the colon intact and be metabolized by the intestinal microbiome.

Assessment of Antimicrobial Activity of Pomegranate, Cranberry, and Black Chokeberry Extracts against Foodborne Pathogens

Herbal and plant extracts are being applied to a wide range of foods against different types of foodborne pathogens. In the present study, ethanolic and aqueous extracts of different concentrations (5% v/v, 10% v/v, and 20% v/v) from cranberry (Vaccinium macrocarpon), black chokeberry (Aronia melanocarpa), and pomegranate (Punica granatum L.) plants were applied in five concentrations (62.5 to 1000 mg/mL) against foodborne strains of Staphylococcus aureus, Escherichia coli, and Streptococcus pyogenes. The results revealed that a low concentration of solvents (5% v/v) did not exhibit decreased antimicrobial activity in comparison with higher solvent concentrations (10% and 20% v/v). Additionally, both aqueous and ethanolic extracts were highly effective against pathogens even in their low concentrations (62.5 mg/mL and 125 mg/mL). Likewise, the extracts exhibited promising results (aqueous extracts of pomegranate, cranberry, and black chokeberry in a food-compatible concentration of 2% w/v) were applied to raw pork meatball production, and their antimicrobial activity was recorded versus Enterobacteriaceae, total mesophilic bacteria (TMB), lactic acid bacteria (LAB), Staphylococcus spp., Pseudomonas spp., and yeasts/molds. The outcome demonstrated that meatballs that contained aqueous extracts of pomegranate were more resistant to spoilage compared to all of the other samples, as it was preserved for more days. Likewise, these extracts of a plant origin could be used as natural preservatives in meat products, even in their low concentrations.