Influence of in vitro digestion process on polyphenolic profile of skin grape (cv. Italia) and on antioxidant activity in basal or stressed conditions of human intestinal cell line (HT-29)

Bioaccessibility and Antioxidant Capacity of Grape Seed and Grape Skin Phenolic Compounds After Simulated In Vitro Gastrointestinal Digestion

Grapes present recognized beneficial effects on human health due to their polyphenolic composition. The grape overproduction together with the wine sales down and the world socioeconomic situation makes the wine grape valorization a promising strategy to give an added-value to this natural product. The objective of the present work was to study the influence of in vitro gastrointestinal digestion on antioxidant capacity and polyphenolic profile of skin and seed extracts of different grape varieties (Tempranillo, Graciano, Maturana tinta and Hondarrabi zuri). After in vitro gastrointestinal digestion, total phenolic content (TPC) of seed polyphenolic extracts decreased significantly for all the varieties. The highest decrease was for Tempranillo going from 108 ± 9 to 50 ± 3 mg / g dry matter (dm). This variety also showed the highest decrease of 90% in antioxidant capacity. However, for all the skin polyphenolic extracts there was an increase in TPC. The highest variation was also for Tempranillo. It varied from 10.1 ± 0.8 to 55.1 ± 0.9 mg / g dm. Among red varieties Tempranillo skin polyphenolic extract showed the lowest undigested anthocyanin content but the highest bioaccessibility index (BI) of 77%. For flavanols, flavonols and procyanidins the seed polyphenolic extracts showed a BI at the intestinal phase between 11% for (+)-epicatechin gallate to 130% procyanidin A2. The results of this study suggest that grape skin extracts and grape seed extracts are a reliable source of bioaccessible antioxidant polyphenols, to be used for the development of antioxidant supplements with specific functionalities depending on the grape variety.

Novel Fermentation Strategies of Strawberry Tree Arbutus unedo Fruits to Obtain High Nutritional Value Products

The strawberry tree (Arbustus unedo) is a medicinal plant and an important source of biocompounds, potentially useful for pharmaceutical and chemical applications to prevent or treat several human diseases. The strawberry tree fruits have usually been used to produce traditional products such as jams and jellies and to obtain fermented alcoholic drinks, representing the most valuable derivative products. Other fermented products are potentially interesting for their nutritional value; however, the fermentation process needs to be controlled and standardized to obtain high-quality products/ingredients. In this work, we investigated two different fermentative procedures, using strawberry tree whole fruit and fruit paste as matrices inoculated with a selected starter strain of Saccharomyces cerevisiae LI 180-7. The physical, chemical, microbiological and nutritional properties of fermented products were evaluated, as well as their antioxidant activity. The new obtained fermented products are enriched in organic acids (acetic acid varied from 39.58 and 57.21 mg/g DW and lactic acid from 85.33 to 114.1 mg/g DW) and have better nutritional traits showing a higher amount of total polyphenols (phenolic acids, flavonoids and anthocyanins) that ranged from 1852 mg GAE/100 g DW to 2682 mg GAE/100 g DW. Also, the amount of isoprenoid increased ranging from 155.5 μg/g DW to 164.61 μg/g DW. In this regard, the most promising strategy seemed to be the fermentation of the fruit paste preparation; while the extract of fermented whole fruits showed the most powerful antioxidant activity. Finally, a preliminary attempt to produce a food prototype enriched in fermented strawberry tree fruits suggested the whole fruit fermented sample as the most promising from a preliminary sensory analysis.

Structure, in vitro digestive characteristics and effect on gut microbiota of sea cucumber polysaccharide fermented by Bacillus subtilis Natto

This study aimed to understand the structural, digestion and fecal fermentation behaviors of sea cucumber polysaccharide fermented by Bacillus subtilis Natto. Results showed that both sea cucumber polysaccharide (SP) and fermented sea cucumber polysaccharide (FSP) were sulfated polysaccharides mainly containing fucose. The physicochemical property, molecular weight, thermal property, and functional groups were no significant difference between SP and FSP, but the microscopic morphology and monosaccharide composition of FSP changed. Both SP and FSP showed similar digestion and fecal fermentation characteristics, that is, they could not be digested by saliva and gastric juice, but could be partially degraded by small intestine. Due to the decomposition of glycosidic bonds after intestinal digestion and fecal fermentation, the relative molecular mass of SP and FSP decreased. In terms of impacts on gut microbiota, Lachnospira, Bacteroides finegoldii, and Bifidobacteriaceae were significantly increased in SP, while Acinetobacter was significantly increased in FSP. This study provides a good understanding of the changes in the structure and digestive characteristics of sea cucumber polysaccharides caused by fermentation. That information will be beneficial for the development and application of new fermented sea cucumber products.

Implication of the Polymeric Phenolic Fraction and Matrix Effect on the Antioxidant Activity, Bioaccessibility, and Bioavailability of Grape Stem Extracts

The bioaccessibility and bioavailability of phenolics compounds of two grape stem extracts with different composition were studied. High polymeric extract (HPE) presented a higher content of total phenolics (TPC), procyanidins, hemicelluloses, proteins, and ashes, whereas low procyanidin extract (LPE) showed a higher fat, soluble sugars, and individual phenolic compounds content. Corresponding to its higher total phenolics content, HPE possesses a higher antioxidant activity (TEAC value). The digestion process reduced the antioxidant activity of the HPE up to 69%, due to the decrease of TPC (75%) with a significant loss of polymeric compounds. LPE antioxidant activity was stable, and TPC decreased by only 13% during the digestion process. Moreover, a higher antioxidant phenolic compounds bioavailability was shown in LPE in contrast to HPE. This behaviour was ascribed mainly to the negative interaction of polymeric fractions and the positive interaction of lipids with phenolic compounds. Therefore, this study highlights the convenience of carrying out previous studies to identify the better extraction conditions of individual bioavailable phenolic compounds with antioxidant activity, along with those constituents that could increase their bioaccessibility and bioavailability, such as lipids, although the role played by other components, such as hemicelluloses, cannot be ruled out.

Effects of in vitro simulated digestion and fecal fermentation of polysaccharides from straw mushroom (Volvariella volvacea) on its physicochemical properties and human gut microbiota

Herein, the fermentation and digestion behavior of Volvariella volvacea polysaccharide (VVP) were examined through the in vitro simulation experiment. The results revealed that succeeding the simulated salivary gastrointestinal digestion, the molecular weight of VVP was reduced by only 8.9 %. In addition, the reducing sugar, uronic acid, monosaccharide composition and Fourier transform infrared spectroscopy characteristics of VVP did not change significantly, which indicate that saliva-gastrointestinal could not digest VVP. However, 48 h of fecal fermentation of VVP dramatically reduced its molecular weight by 40.4 %. Furthermore, the molar ratios of the monosaccharide composition altered considerably due to the degradation of VVP by microorganisms and the metabolysis into different short-chain fatty acids (SCFAs). Meanwhile, the VVP also raised the proportion of Bacteroidetes to Firmicutes and promoted the proliferation of some beneficial bacteria including Bacteroides and Phascolarctobacterium, whereas it inhibited the growth of unfavorable bacteria such as Escherichia-shigella. Therefore, VVP has the potential to have a positive influence on health and hinder diseases by improving the intestinal microbial environment. These findings provide a theoretical foundation to further develop Volvariella volvacea as a healthy functional food.

Simultaneous Removal of Mycotoxins by a New Feed Additive Containing a Tri-Octahedral Smectite Mixed with Lignocellulose

Simultaneous removal of mycotoxins has been poorly addressed, and a limited number of studies have reported the efficacy of feed additives in sequestering a large spectrum of mycotoxins. In this study, a new mycotoxin-adsorbing agent was obtained by properly mixing a tri-octahedral smectite with a lignocellulose-based material. At a dosage of 1 mg mL⁻¹, these materials simultaneously adsorbed frequently occurring mycotoxins and did not exert a cytotoxic effect on intestinal cells. Chyme samples obtained by a simulated GI digestion did not affect the viability of Caco-2TC7 cells as measured by the MTT test. In addition, the chyme of the lignocellulose showed a high content of polyphenols (210 mg mL⁻¹ catechin equivalent) and good antioxidant activity. The properties of the individual constituents were maintained in the final composite, and were unaffected by their combination. When tested with a pool of seven mycotoxins at 1 µg mL⁻¹ each and pH 5, the composite (5 mg mL⁻¹) simultaneously sequestered AFB₁ (95%), FB₁ (99%), ZEA (93%), OTA (80%), T-2 (63%), and DON (22%). HT-2 adsorption did not occur. Mycotoxin adsorption increased exponentially as dosage increased, and occurred at physiological pH values. AFB₁, ZEA and T-2 adsorption was not affected by pH in the range 3–9, whereas OTA and FB₁ were adsorbed at pH values of 3–5. The adsorbed amount of AFB₁, ZEA and T-2 was not released when pH rose from 3 to 7. FB₁ and OTA desorption was less than 38%. Langmuir adsorption isotherms revealed high capacity and affinity for adsorption of the target mycotoxins. Results of this study are promising and show the potential of the new composite to remove mycotoxins in practical scenarios where several mycotoxins can co-occur.

Assessment of in-vitro bioaccessibility and antioxidant capacity of phenolic compounds extracts recovered from grapevine bunch stem and cane by-products

Grapevine woody by-products contain bioactive substances, mainly phenolic compounds (PCs), whose beneficial health effects initially depends on their levels of intake and bioavailability. Therefore, in-vitro simulated gastrointestinal digestion (GID; oral, gastric and intestinal phases) was performed to evaluate the bioaccessibility and antioxidant capacity (AC) of PCs extracts recovered from grapevine bunch stem and cane from Malbec grape cultivar. The total PCs in cane and bunch stem extracts were 74 and 20% bioaccessible, respectively. Syringic acid, cinnamic acid, ε-viniferin, naringenin and myricetin were highly bioaccessible, noticeably ε-viniferin in cane extract with 137%. The high bioaccessibility observed, particularly for compounds at high concentration such as ε-viniferin, will help to better understand the bioactive potential of these by-products. In this sense, bunch stems and canes can be considered as new and sustainable sources of bioactive substances for applications as functional ingredients or nutraceuticals in food and pharmaceutical industries.

Plant Polyphenols-Biofortified Foods as a Novel Tool for the Prevention of Human Gut Diseases

Plant food biofortification is recently receiving remarkable attention, as it aims to increase the intake of minerals, vitamins, or antioxidants, crucial for their contribution to the general human health status and disease prevention. In this context, the study of the plant’s secondary metabolites, such as polyphenols, plays a pivotal role for the development of a new generation of plant crops, compensating, at least in part, the low nutritional quality of Western diets with a higher quality of dietary sources. Due to the prevalent immunomodulatory activity at the intestinal level, polyphenols represent a nutritionally relevant class of plant secondary metabolites. In this review, we focus on the antioxidant and anti-inflammatory properties of different classes of polyphenols with a specific attention to their potential in the prevention of intestinal pathological processes. We also discuss the latest biotechnology strategies and new advances of genomic techniques as a helpful tool for polyphenols biofortification and the development of novel, healthy dietary alternatives that can contribute to the prevention of inflammatory bowel diseases.

Grapevine as a Rich Source of Polyphenolic Compounds

Grapes are rich in primary and secondary metabolites. Among the secondary metabolites, polyphenolic compounds are the most abundant in grape berries. Besides their important impacts on grape and wine quality, this class of compounds has beneficial effects on human health. Due to their antioxidant activity, polyphenols and phenolic acids can act as anti-inflammatory and anticancerogenic agents, and can modulate the immune system. In grape berries, polyphenols and phenolic acids can be located in the pericarp and seeds, but distribution differs considerably among these tissues. Although some classes of polyphenols and phenolic acids are under strict genetic control, the final content is highly influenced by environmental factors, such as climate, soil, vineyard, and management. This review aims to present the main classes of polyphenolic compounds and phenolic acids in different berry tissues and grape varieties and special emphasis on their beneficial effect on human health.

Phytochemical profiles, antioxidant, and antiproliferative activities of red-fleshed apple as affected by in vitro digestion

The aim of this study was to characterize the phenolic profiles in the extracts and digesta (after in vitro digestion) of different red-fleshed apple fruit parts and to assess the effects of digestion on the in vitro antioxidant capacity and antiproliferative activity. The main polyphenols were identified by UPLC-MS/MS and HPLC. Our results indicate that the digesta had less total phenolics, flavonoids, and anthocyanins, but more free phenolic acids, than the extracts. An analysis of the in vitro antioxidant capacity (including ABTS radical scavenging activity, DPPH radical-scavenging capacity, ferric reducing antioxidant power [FRAP], and cellular antioxidant activity [CAA]) revealed that the digestion decreased the ABTS, DPPH, and FRAP values, but increased the CAA values, relative to the corresponding values for extracts. These results suggest that the digestion improved the effectiveness of the phenolic substances. Moreover, our findings imply that the digestion promoted the antiproliferative activity of red-fleshed apple peels and flesh relative to the extracts. Future in vivo investigations are warranted based on the results of the current study. PRACTICAL APPLICATION: The effects of an in vitro digestion on the phenolic compounds as well as the antioxidative and antiproliferative activities of red-fleshed apple were evaluated. The resulting data may clarify the bioavailability of the polyphenols in red-fleshed apple and enable scientists and consumers to exploit natural polyphenols.

Polyphenol Extracts from Three Colombian Passifloras (Passion Fruits) Prevent Inflammation-Induced Barrier Dysfunction of Caco-2 Cells

Chronic intestinal inflammation is associated with pathophysiology of obesity and inflammatory bowel diseases. Gastrointestinal inflammation increases barrier dysfunction exacerbating the immune response and perpetuating chronic inflammation. Anti-inflammatory flavonoids may prevent this intestinal barrier dysfunction. The purpose of this study was to evaluate the polyphenol composition of Colombian Passifloraedulis var. Flavicarpa (Maracuyá), Passifloraedulis var. Sims (Gulupa), and Passifloraligularis var. Juss (Granadilla) (passion fruits) and to evaluate their ability to inhibit disruption of intestinal barrier dysfunction of Caco-2 (colorectal adenocarcinoma) cells by an inflammatory cocktail (IC). Polyphenols (flavan-3-ols, phenolic acids, flavonols), xanthenes, and a terpene were identified in passion fruits. Cyanidin 3-rutinoside, (+)-catechin and ferulic acid were the most abundant phenolics in P. edulis var. Flavicarpa, P.edulis var. Sims, and P.ligularis var. Juss, respectively. Fruit extracts prevented loss of transepithelial electrical resistance in Caco-2 cells treated with the IC. Among the extracts, P. ligularis var. Juss was most effective at maintaining Caco-2 transepithelial electrical resistance (TEER) with ~73% relative to the IC-treated cells with about 43% of initial TEER values. This fruit had cyanidin-3-rutinoside, (+)-catechin, (−)-epicatechin, and ferulic acid in its phenolic profile. Results of this work support the hypothesis that consumption of passion fruit extracts could benefit intestinal health.

Effects of dietary grape seed polyphenols supplementation during late gestation and lactation on antioxidant status in serum and immunoglobulin content in colostrum of multiparous sows1

The aim of this study was to determine the effects of dietary grape seed polyphenols (GSP) supplementation during the late gestation and lactation period on reproductive performance, antioxidative status in serum, nutrient composition, and Ig content in colostrum of multiparous sows. On day 80 of gestation, a total of 64 sows with similar body condition were allocated to a completely randomized block design with 4 dietary treatments (n = 16 sows per treatment): 1) basal diet (CON, control group); 2) basal diet supplemented with 200 IU/kg vitamin E (200VE, positive control group); 3) basal diet supplemented with 200 mg/kg GSP (200GSP); and 4) basal diet supplemented with 300 mg/kg GSP (300GSP). The trial lasted 56 d until the piglets were weaned on day 21 of lactation. Reproductive performance, parameters of antioxidative status, and levels of progesterone (P4) and estradiol (E2) in serum, nutrient composition, and Ig content in colostrum of sows were determined. The number of dead fetuses was reduced, and farrowing survival was significantly improved in the litters from 300GSP-fed (P < 0.05). Preweaning survivability significantly increased in the litters from sows fed 200GSP and 200VE (P < 0.05). The activity of superoxide dismutase and glutathione peroxidase (GSH-Px) in the serum was significantly increased in sows fed 200GSP and 300GSP (P < 0.05). The activity of GSH-Px in the serum also significantly increased in sows fed 200VE (P < 0.05). Sows fed 300GSP had the greatest levels of P4 and E2 in the serum, which was significantly greater than sows fed 200VE and CON (P < 0.05). No significant differences were found among treatments for the content of solids-not-fat, fat, protein, and lactose in colostrum (P > 0.05). However, sows fed GSP had greater IgM and IgG content in colostrum compared with sows fed 200VE and CON (P < 0.05). In conclusion, dietary GSP supplementation during late gestation and lactation improved the farrowing survival and preweaning survivability, enhanced the antioxidant status and hormone levels in serum, and increased the IgM and IgG content in colostrum of sows.

Bioaccessibility of polyphenols and antioxidant properties of the white grape by simulated digestion and Caco-2 cell assays: Comparative study with its winemaking product

The primary objective of this study was to assess the changes on phenolic composition and AC (antioxidant capacity) of white grape and its winemaking product, during in vitro gastrointestinal (GI) digestion. Phenolic compounds were evaluated by HPLC-MS/MS. The AC was measured by in vitro (FRAP, ABTS and DPPH) and cellular (Caco-2 cells) assays. Digestion had a reducing effect on phenolic content, being only 31% and 67% of native polyphenols from grapes and wines, respectively, potentially bioaccessible. At same polyphenol concentration, cellular AC of nondigested and digested foods was the same, indicating that changes in phenolic profile did not modify the bioactivity. Phenolic acids, in addition to quercetin, were the most resistant polyphenols to digestion, and would be the most relevant to explain the biological activity of digested foods. Results indicate that the changes occurred in the native phenolic profile of foods as a consequence of GI digestion, do not modify the bioactivity of white grapes and wines.

Altered morphokinetics in equine embryos from oocytes exposed to DEHP during IVM

Di-(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer with endocrine-disrupting properties. In this study, we used an equine model to investigate DEHP concentrations in ovarian follicular fluid (FF), and to determine the effects of exposure of oocytes to potentially toxic concentrations of DEHP during in vitro maturation (IVM) on embryo development and quality. Embryo development was evaluated using time-lapse monitoring (TLM), a photomicroscopic tool that reveals abnormalities in cleavage kinetics unobservable by conventional morphology assessment. Blastocyst bioenergetic/oxidative status was assessed by confocal analysis. The possibility that verbascoside (VB), a bioactive polyphenol with antioxidant activity, could counteract DEHP-induced oocyte oxidative damage, was investigated. DEHP was detected in FF and in IVM media at concentrations up to 60 nM. Culture of oocytes in the presence of 500 nM DEHP delayed second polar body extrusion, reduced duration of the second cell cycle, and increased the percentage of embryos showing abrupt multiple cleavage, compared with controls. Mitochondrial activity and intracellular levels of reactive oxygen species were reduced in blastocysts from DEHP-exposed oocytes. VB addition during IVM limited DEHP-induced blastocyst damage. In conclusion, DEHP is detectable in equine FF and culture medium, and oocyte exposure to increased concentrations of DEHP during IVM affects preimplantation embryo development. Moreover, TLM, reported for the first time in the horse in this study, is an efficient tool for identifying altered morphokinetic parameters and cleavage abnormalities associated with exposure to toxic compounds.

Effects of in vitro gastrointestinal digestion on phenolic compounds and antioxidant activity of different white winemaking byproducts extracts

The effect of in vitro gastrointestinal digestion on phenolic composition and antioxidant activity of different white winemaking byproducts extracts (grape pomace and its parts: seeds, skins and stems) was evaluated. Fourteen individual phenolic compounds were evaluated by UHPLC. The antioxidant activity was measured by DPPH and ORAC assays. Differences on phenolic profile and antioxidant activity were observed depending on the digestion phase, the type of byproduct, the phenolic group and the antioxidant activity assay. In general, digestion had a reducing effect on TPC and antioxidant activity; however, ORAC values of seed and stem extracts increased after digestion and some recovery indexes of the phenolic groups were very high. Results indicate that extracts from white winemaking byproducts are a reliable source of bioaccessible antioxidant compounds, which could be used as functional food ingredients.