Release of phenolic compounds and antioxidant capacity of Chinese hawthorn “Crataegus pinnatifida” during in vitro digestion

Characterization of the active components and bioaccessibility of phenolics in differently colored foxtail millets

Differently colored foxtail millet (Setaria italica) cultivars were compared regarding their amylose, B-complex vitamin, vitamin E, and phenolic compositions, as well as the bioaccessibility of their phenolics in simulated in vitro digestion. Dark-colored foxtail millets contained more thiamine, pyridoxine, and tocopherols, but less riboflavin, than light-colored ones. Phenolics were more abundant in dark-colored cultivars. Insoluble bound fractions accounted for 75%-83% of the total phenolics, with ferulic acid detected as the most plentiful compound. The major bioaccessible phenolic was free ferulic acid, with 100%-120% bioaccessibility, depending on cultivar, followed by p-coumaric acid and isoferulic acid (50%-80%). These relatively high bioaccessibilities were likely due to the release of soluble conjugated or insoluble bound phenolics during digestion. However, the contents of other free phenolics were largely decreased following in vitro digestion, resulting in low bioaccessibility, which also means that the release from the conjugated and bound fractions was poor.

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.

Effect of Different Drying Methods on the Quality of Oudemansiella raphanipes

In this study, we used fresh Oudemansiella raphanipes as raw materials and pre-treated through hot air drying (HD), infrared radiation drying (ID), and vacuum freeze drying (VD) to investigate the effects of different drying methods on the rehydration rate, appearance quality, microstructure, and volatile flavor components of the dried products, as well as to determine the physicochemical properties and bioactivities of the polysaccharides in the dried O. raphanipes. The results showed that the VD O. raphanipes had the highest rehydration rate and the least shrinkage in appearance, and it better maintained the original color of the gills, but their aroma was not as strong as that of the HD samples. The scanning electron microscopy results indicate that VD maintains a good porous structure in the tissue, while HD and ID exhibit varying degrees of shrinkage and collapse. Seventy-five common volatile substances were detected in the three dried samples, mainly alkanes, alcohols, and esters. The polysaccharides (PS-H, PS-I, and PS-V) extracted from the dried samples of these three species of O. raphanipes had similar infrared spectral features, indicating that their structures are basically consistent. The highest yield was obtained for PS-V, and the polysaccharide content and glucuronic acid content of PS-I were higher than those of the remaining two polysaccharides. In addition, PS-V also showed better antioxidant activity and inhibitory activity against α-glucosidase as well as α-amylase. In conclusion, among the above three drying methods, the quality of O. raphanipes obtained by vacuum freeze drying is the best, and this experiment provides a theoretical basis for the selection of drying methods for O. raphanipes.

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.

Exploring the Antioxidant Potential of Blackberry and Raspberry Leaves: Phytochemical Analysis, Scavenging Activity, and In Vitro Polyphenol Bioaccessibility

The goal of this research was nutritional evaluation through the phytochemical analysis of blackberry and raspberry leaves, the screening of their biological activity (antioxidant capacity and inhibition of lipid peroxidation), and the investigation of the effect of in vitro gastrointestinal digestion (GID) of blackberry and raspberry leaves on the bioaccessibility of polyphenol subclasses. The concentrations of the analyzed liposoluble antioxidants were higher (p < 0.05) in blackberry leaves compared to raspberry leaves, while a significant (p < 0.05) higher content of water-soluble antioxidants was registered in raspberry leaves (with a total polyphenol content of 26.2 mg GAE/g DW of which flavonoids accounted for 10.6 mg/g DW). Blackberry leaves had the highest antioxidant capacity inhibition of the superoxide radicals (O2•-), while raspberry leaves registered the highest inhibition of hydroxyl radicals (•OH), suggesting a high biological potency in scavenging-free radicals under in vitro systems. The maximum inhibition percentage of lipid peroxidation was obtained for blackberry leaves (24.86% compared to 4.37% in raspberry leaves), suggesting its potential to limit oxidative reactions. Simulated in vitro digestion showed that hydroxybenzoic acids registered the highest bioaccessibility index in the intestinal phase of both types of leaves, with gallic acid being one of the most bioaccessible phenolics. The outcomes of this investigation reveal that the most significant release of phenolic compounds from blackberry and raspberry leaves occurs either during or after the gastric phase. Knowledge about the bioaccessibility and stability of polyphenol compounds during digestion can provide significant insights into the bioavailability of these molecules and the possible effectiveness of plant metabolites for human health.

Role of plant metabolites in the formation of bacterial communities in the rhizosphere of Tetrastigma hemsleyanum

Tetrastigma hemsleyanum Diels et Gilg, commonly known as Sanyeqing (SYQ), is an important traditional Chinese medicine. The content of bioactive constituents varies in different cultivars of SYQ. In the plant growth related researches, rhizosphere microbiome has gained significant attention. However, the role of bacterial communities in the accumulation of metabolites in plants have not been investigated. Herein, the composition of bacterial communities in the rhizosphere soils and the metabolites profile of different SYQ cultivars' roots were analyzed. It was found that the composition of microbial communities varied in the rhizosphere soils of different SYQ cultivars. The high abundance of Actinomadura, Streptomyces and other bacteria was found to be associated with the metabolites profile of SYQ roots. The findings suggest that the upregulation of rutin and hesperetin may contribute to the high bioactive constituent in SYQ roots. These results provide better understanding of the metabolite accumulation pattern in SYQ, and also provide a solution for enhancing the quality of SYQ by application of suitable microbial consortia.

Phenolic profile and α-glucosidase inhibitory potential of wampee (Clausena lansium (Lour.) Skeels) peel and pulp: In vitro digestion/in silico evaluations

To investigate the changes in phenolics, flavonoids, and their bio-activities of wampee (Clausena lansium (Lour.) Skeels) during digestion, the peel and pulp were subjected to simulated in vitro digestion, encompassing oral, gastric, small intestine, and large intestine digestion stages. The peel exhibited a total release of 91.93 mg GAE/g DW of phenolics and 61.86 mg RE/g DW of flavonoids, whereas the pulp displayed a release of 27.83 mg GAE/g DW of phenolics and 8.94 mg RE/g DW of flavonoids. Notably, the phenolics and flavonoids were mostly released during the oral digestion stage for peel, while they were mostly released during the small intestine digestion stage for pulp. The results of the targeted flavonoids analysis indicated that rutin and l-epicatechin were the two most widely released compounds in each digestion step. Moreover, myricetin has been identified as the best inhibitor against α-glucosidase, probably because it formed the most H-bonds, 8, with 6 catalytic residues, which was the highest number. Furthermore, the soluble substances released from the peel exhibited significantly higher antioxidant activities and inhibitory activity against α-glucosidase (p < 0.05) compared to those from the pulp. Positive correlations were observed between the total phenolic content or total flavonoid content and the antioxidant activities (r > 0.73 (peel), > 0.61 (pulp)), as well as α-glucosidase inhibitory activity (r <  - 0.48 (peel), < -0.64 (pulp)) of peel and pulp. In conclusion, these findings provide valuable insights into the digestive characteristics and health benefits of both wampee peel and pulp.

The Physicochemical Characterization and In Vitro Digestibility of Maple Sugar Sand and Downgraded Maple Syrups

The maple syrup industry generates substandard syrups and sugar sand as by-products, which are underused. In this study, we conducted a comprehensive analysis of the physicochemical composition of these products to assess their potential for valorization. Using HPLC analysis, we measured sugar and organic acid content as well as total polyphenol content using the Folin-Ciocalteu method. Additionally, we evaluated the in vitro digestibility using the TIM-1 model. We showed that the composition of ropy and buddy downgraded syrups is comparable to that of standard maple syrup, whereas sugar sand's composition is highly variable, with carbohydrate content ranging from 5.01 mg/g to 652.89 mg/g and polyphenol content ranging from 11.30 µg/g to 120.95 µg/g. In vitro bioaccessibility reached 70% of total sugars for all by-products. Organic acid bioaccessibility from sugar sand and syrup reached 76% and 109% relative to standard maple syrup, respectively. Polyphenol bioaccessibility exceeded 100% during digestion. This can be attributed to favorable extraction conditions, the breakdown of complex polyphenol forms and the food matrix. In conclusion, our study demonstrates that sugar sand and downgraded maple syrups exhibit digestibility comparable to that of standard maple syrup. Consequently, they hold potential as a source of polyphenols, sugar or organic acids for applications such as industrial fermentation or livestock feeds.

Bioaccessibility and transport of lentil hull polyphenols in vitro, and their bioavailability and metabolism in rats

Polyphenol-rich lentil hulls are a valuable by-product. In this study, lentil hulls were subjected to simulated in vitro digestion and caco-2 cell monolayer models to assess the bioaccessibility, transmembrane transport, and a rat model to examine the bioavailability and metabolism in vivo. Polyphenols were increasingly released during the in vitro digestion, and were found to contribute to the increased antioxidant activity. Among the bioaccessible polyphenols, catechin glucoside, kaempferol tetraglucoside, procyanidin dimer and dihydroxybenzoic acid-O-dipentoside were most efficiently transported across the caco-2 membrane, and responsible for promoting intestinal integrity as a result of enhanced expression of tight junction proteins. When ingested by rats, lentil hull polyphenols underwent extensive I and II phase metabolic reactions in vivo, including hydroxylation, methylation, glucuronidation and sulfation. Overall, results of this study showed that lentil hull polyphenols are bioaccessible and bioavailable, and lentil hulls as a by-product can be a valuable ingredient for future functional foods.

Role of simulated in vitro gastrointestinal digestion on biotransformation and bioactivity of astragalosides from Radix Astragali

Radix Astragali (RA) is commonly used in Asian herbal therapy or food supply, and astragalosides and flavonoids are its major components with diverse pharmaceutical effects. To provide new information on the potential cardiovascular benefits of RA administered orally, the bioaccessibility of these compounds with relevant in vitro digestion parameters was determined for four digestion phases (oral, gastric, small and large intestines) by ultrahigh-performance liquid chromatography quadrupole time-of-flight-mass spectrometry (UPLC-Q-TOF/MS). Meanwhile, we compared the effects of digestion products on advanced glycation end products (AGEs)-induced intracellular reactive oxygen species (ROS) levels in a human arterial endothelial cells (HAECs) model, and studied the potential of RA against oxidative stress-related cardiovascular disease. The changes of saponins and flavonoids composition and antioxidant activity after digestion in intestines were mainly due to the astragaloside IV (AS-IV) biosynthesis involving saponins acetyl isomerization and deacetylation, and the flavonoid glycosides converted to aglycone by deglycosylation processes. All these results suggest that acetyl biotransformation of RA in small intestine directly influenced the response to oxidative stress, and might provide a reference for elucidation of the multi-component action after oral RA in cardiovascular health care.

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.

Rapid determination of chemical components and antioxidant activity of the fruit of Crataegus pinnatifida Bunge by NIRS and chemometrics

OBJECTIVE

To establish a method for quality evaluation of the fruit of Crataegus pinnatifida Bunge, also known as Shanzha, by near-infrared spectroscopy combined with chemometrics.

METHOD

Seventy-two batches of Shanzha samples were collected, and the content of total components (flavonoids, phenols and organic acids), monomer components (chlorogenic acid, hyperoside and isoquercitrin), as well as the antioxidant activity of 60% ethanol extract were determined by usual methods. Then, all measured values were correlated with the near infrared spectra of Shanzha, and the partial least squares regression models were established. As to improve the model performance, various methods for spectra pretreatment and wavelength selection were investigated.

RESULTS

After optimization, the models obtained the coefficients of determination in both calibration and prediction >0.9, and the residual prediction deviations >3, indicating that the models had good prediction abilities.

CONCLUSION

The present method can serve as an alternative to the methods for comprehensive and rapid quality evaluation of Shanzha.

Integrative Analysis of Metabolome and Transcriptome Reveals Molecular Insight into Metabolomic Variations during Hawthorn Fruit Development

Hawthorn (Crataegus pinnatifida var. major), a cultivated fruit tree, is native and unique to China. Its fruits have high nutritional, health, and medicinal values. However, the development and ripening process of hawthorns is accompanied by dramatic changes in flavor, aroma, and bioactive phytochemicals, which are the fundamental factors that contribute to the potential health benefits and establishment of fruit quality. Therefore, an exploration of the dynamic changes in metabolites and their regulatory networks during the development of hawthorn fruits can elucidate the formation mechanisms of active substances in hawthorn fruits. In this study, we used a broad targeted metabolomics approach to identify and analyze the dynamics of metabolites in hawthorn fruits at five developmental stages. The results revealed 998 primary and secondary metabolites that were classified into 15 categories. The accumulation levels of most sugars increased during fruit development and then accelerated at the fruit ripening stage. The accumulation levels of a few organic acids (e.g., citric acid, isocitric acid, and quinic acid) continuously increased. Many organic acids exhibited significant decreasing trends. Among the 561 secondary metabolites detected, 189 were phenolic acids and 199 were flavonoids. The levels of many flavonoids were significantly reduced at later stages of fruit development; in contrast, the levels of two anthocyanins significantly increased during fruit ripening. Correlation analysis revealed that there is a certain correlation within and between primary as well as secondary metabolites during fruit development. Furthermore, the integration of metabolomic and transcriptomic data in this study revealed that changes in the expression of some differentially expressed genes (DEGs) were associated with the accumulation of metabolites such as sugars, organic acids, and flavonoids, e.g., the upregulated expression levels of CS (citrate synthase) genes were consistent with the continued accumulation of citric acid. Overall, this study demonstrates the metabolic changes that occur during the development of hawthorn fruit, explores the molecular mechanisms that underlie metabolite changes during fruit development, and lays a strong theoretical foundation for the improvement of hawthorn fruit quality and the development of functional components.

Olive pectin-chitosan nanocomplexes for improving stability and bioavailability of blueberry anthocyanins

Blueberry anthocyanins (ANCs) are natural dietary bioactive colorants, but are unstable and easily degraded. To improve their stability, we constructed the nanocarriers for ANCs through an electrostatic self-assembly method, using chitosan (CS) and olive pectin (PC). Results showed that the CS-ANCs-PC nanocomplexes had nanoscale particle size (81.22 ± 0.44 nm), and an encapsulation efficiency of 91.97 ± 0.33% at pH 3.0, 1:1:5 ratio (m/v) of CS: ANCs: PC. Fourier transform infrared and UV-visible spectra demonstrated that ANCs can be embedded into the CS-PC carrier through electrostatic interaction. CS-ANCs-PC with stacked spherical particle structure had good thermal stability by scanning electron microscope and thermogravimetric analysis. Compared with free anthocyanins, CS-ANCs-PC possessed better DPPH· and ·OH scavenging activities, stronger environmental stability, and better targeted release in vitro digestion. This study may provide an important fundamental basis for improving the stability of anthocyanins in the blueberry industry.

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.

Profile and activity of phenolic antioxidants in chrysanthemum (Huangshan Gongju) as affected by simulated digestions

The phenolics are the main bioactive substances of Huangshan Gongju, a famous chrysanthemum of China, but their digestive characteristics are still unknown. To explore the digestive properties of Huangshan Gongju phenolics, the flower was extracted and subjected to simulated digestions, and their phenolic profile and activity were analyzed. The results indicated that the total phenolics content and antioxidant activity of the extract varied with the simulated digestion steps, and they generally decreased in the oral and small intestine digestions but increased in the gastric digestion, and high correlations were detected between the total phenolics content and antioxidant activity (0.873 < r < 0.979, p < .01). The change of phenolic profile during the simulated digestions was similar to that of total phenolics content, and six individual phenolics were identified and quantified, and three of them, including chlorogenic acid, apigenin-7-O-rutinoside, and apigenin-7-O-6″-acetylglucoside showed higher recovery (>64.29%), implying they may be the main functional phenolics of Huangshan Gongju. PRACTICAL APPLICATIONS: This study proved that most phenolics in Huangshan Gongju were relatively stable during digestion. The finding may guarantee the application of Huangshan Gongju in the field of functional foods.

Effects of in vitro digestion on protein degradation, phenolic compound release, and bioactivity of black bean tempeh

The nutritional value and bioactivity of black beans are enhanced when fermented as tempeh, but their bioaccessibility and bioactivity after ingestion remain unclear. In this study, black bean tempeh and unfermented black beans were digested in vitro and changes in protein degradation, phenolic compound release, angiotensin I-converting enzyme (ACE)-inhibitory activity, and antioxidant activity between the two groups were compared. We observed that the soluble protein content of digested black bean tempeh was generally significantly higher than that of digested unfermented black beans at the same digestion stage (P < 0.05). The degree of protein hydrolysis and the content of <10 kDa peptides were also significantly higher in the digested black bean tempeh than in digested unfermented black beans (P < 0.05). SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and reversed-phase high-performance liquid chromatography (RP-HPLC) analysis showed that most macromolecular proteins in tempeh had been degraded during fermentation and more of the small peptides were released from black bean tempeh during digestion, respectively. Compared to that of the unfermented black beans, the level of ACE inhibition of black bean tempeh was lower, but this significantly increased to 82.51% following digestion, closing the gap with unfermented black beans. In addition, the total respective levels of phenolics, flavonoids, and proanthocyanidins released from black bean tempeh were 1.21, 1.40, and 1.55 times those of unfermented black beans following in vitro digestion, respectively. Antioxidant activity was also significantly higher in digested black bean tempeh than in digested unfermented black beans and showed a positive correlation with phenolic compound contents (P < 0.05). The results of this study proved that, compared to unfermented black beans, black bean tempeh retained protein and phenolic compound bioaccessibility and antioxidant activity and showed an improved ACE-inhibitory activity even after consumption.

Food Applications and Potential Health Benefits of Hawthorn

Hawthorn (Crataegus) is a plant of the Rosaceae family and is widely grown throughout the world as one of the medicinal and edible plants, known as the “nutritious fruit” due to its richness in bioactive substances. Preparations derived from it are used in the formulation of dietary supplements, functional foods, and pharmaceutical products. Rich in amino acids, minerals, pectin, vitamin C, chlorogenic acid, epicatechol, and choline, hawthorn has a high therapeutic and health value. Many studies have shown that hawthorn has antioxidant, anti-inflammatory, anticancer, anti-cardiovascular disease, and digestive enhancing properties. This is related to its bioactive components such as polyphenols (chlorogenic acid, proanthocyanidin B2, epicatechin), flavonoids (proanthocyanidins, mucoxanthin, quercetin, rutin), and pentacyclic triterpenoids (ursolic acid, hawthornic acid, oleanolic acid), which are also its main chemical constituents. This paper briefly reviews the chemical composition, nutritional value, food applications, and the important biological and pharmacological activities of hawthorn. This will contribute to the development of functional foods or nutraceuticals from hawthorn.

A review of in vitro methods to evaluate the bioaccessibility of phenolic compounds in tropical fruits

International guidelines strongly advise about the frequent and varied intake of plant in diet. In this scenario, the consumption of fruits is closely related to health benefits due to the abundant presence of bioactive substances. Accordingly, the production of tropical fruits has stood out worldwide, reaching records since the past decade. However, to ensure that phenolic substances are indeed used by the body, they need to be accessible for absorption. For this purpose, several methods are used to assess the phenomenon of bioaccessibility. We provide information on i) in vitro methods for the evaluation of the bioaccessibility of phenolic compounds in tropical fruits, including their derivatives and by-products; ii) a study performed using a semi-dynamic in vitro digestion model; iii) simulated digestion with a dialysis membrane step, polyphenol transport/uptake using cell culture, and in vitro colonic fermentation process. Although standardized static and semi-dynamic in vitro digestion methods already exist, few studies use these protocols to assess the bioaccessibility of polyphenols in tropical fruits. To guarantee that in vitro digestion assays reproduce consistent results compared to in vivo reference methods, it is essential to universalize standardized methods that allow the comparison between results, enabling the validation of in vitro digestion methods.

A dynamic view on the chemical composition and bioactive properties of mulberry fruit using an in vitro digestion and fermentation model

Mulberry is a kind of fruit rich in nutrients, however, the beneficial effects of mulberry fruits are related not only to the amount consumed, but also to the bioavailability of these nutrients in the organism. Hence, the aim of this study was to evaluate the bioaccessibility of main bioactive compounds from mulberry fruit using an in vitro digestion model, the changes in bioactivities as well as intestinal flora were also investigated. The results showed that the particle size of the mulberry fruit was gradually reduced (from 196.87 to 60.85 μm), as well as the phenolics and carbohydrates were significantly released during the digestion and maximized in the first 15 min in the intestinal phase (1752 ± 2.80 mg GAE per 100 g, DW; 277.402 ± 2.80 mg GE per 100 g, DW, respectively). Meanwhile, the bioaccessibility indices for phenolic compounds and carbohydrates were 55.49% and 84.62%. The antioxidant activity and α-glucosidase inhibitory effect of the mulberry fruit were positively correlated with their total content of released phenolic compounds. And the phenolic compounds (2,4,6-trihydroxybenzoic acid, cyanidin-3-O-glucoside, 3,4-dihydroxybenzoic acid and gallic acid) were the main compounds that inhibit the α-glucosidase activity by binding to its active cavity through hydrogen bonds. In addition, the mulberry fruit undigested fractions could be further fermented by intestinal microorganisms to produce short-chain fatty acids (SCFAs), which decreased the colon pH value (from 5.93 to 4.79) and the Firmicutes/Bacteroidetes ratio which was beneficial for obesity. Our results indicated that the mulberry fruit exhibited good bioactivity during digestion and fermentation, and could be a promising candidate as a dietary source of functional foods.

Polyphenol Content of Green Pea (Pisum sativum L.) Hull under In Vitro Digestion and Effects of Digestive Products on Anti-Inflammatory Activity and Intestinal Barrier in the Caco-2/Raw264.7 Coculture Model

Green pea hulls are a byproduct of the processing of green pea and are rich in phenolic substances. In the present study, in vitro digestion, human colonic adenocarcinoma cell line (Caco-2) monolayer, and the Caco-2/macrophage cell lines of the murine origin (Raw264.7) coculture model were established to investigate the release of polyphenols, absorption, and transport of digestive products and their effects on inflammation and intestinal barrier. During the digestive process, polyphenols were constantly released from the pea hulls, reaching the maximum amount in the small intestine (total phenolic content (TPC): 5.41 ± 0.04 mg gallic acid (GAE)/g dry weight (DW)), and the digestive products (800 μg/mL) could reduce the secretion of NO (50.9%), IL-6 (50.6%), and TNF-α (24.6%) and inhibit the mRNA expression of cyclooxygenase-2 (COX-2) (37.2%) and inducible nitric oxide synthase (iNOS) (91.1%) compared with the lipopolysaccharide (LPS) group. A total of 12 phenolic components were quantified by ultraperformance liquid chromatography-linear ion trap orbitrap tandem mass spectrometry (UHPLC-LTQ-OrbiTrap-MS) technology. Kaempferol trihexoside in digestive products could be absorbed and transported (1.25 ± 0.13 ng quercetin/mL). The digestive products could promote the expression of claudin-1 (210.8%), occludin (64.9%), and zonulin occludin-1 (ZO-1) (52.0%) compared with the LPS group and exert anti-inflammatory effects after being absorbed. The results indicated that pea hull polyphenols could be continuously released and absorbed to play a positive role in protecting the intestinal barrier and anti-inflammatory activity.

In vitro digestion of the whole blackberry fruit: bioaccessibility, bioactive variation of active ingredients and impacts on human gut microbiota

In vitro digestion and fermentation of blackberry fruit was investigated, and results showed that the phenolics were mainly released in gastric phase while carbohydrates in small intestinal phase. The bioaccessibility for phenolics and carbohydrates were 42.80% and 69.30%, indicating most of phenolics still remain in colon and available for intestinal flora. The total phenolics released during the digestion account for the improvement of antioxidant and hypoglycemic activities. Especially, cyanidin-3-O-glucoside with higher released amount and bioaccessibility index (63.21%), exhibited the strongest α-glucosidase inhibitory activity. After fermentation, the non-digestible fractions of blackberry affected the ecosystem of the intestinal tract by decreasing the colonic pH (△pH = 1.10), enhancing the production of SCFAs and modulating gut microbiota composition (the ratio of Firmicute/Bacteroidetes decreased from13.18 to 0.87). The results provided insights into the digestive properties and health benefits of blackberry fruit after consumption.

Effects of compound of hawthorn (Crataegus pinnatifida) and Chinese yam (Dioscorea opposita Thunb.) extracts on growth performance, intestinal health, and immune function in weaned pigs

Plant extracts were considered as natural resources to alleviate weaning stress in pig production. A 28-day study (Phase 1: d 0-14 and Phase 2: d 15-28) was conducted to investigate the effects of compound of hawthorn and yam extracts on growth performance, intestinal health, and immune function in weaned pigs. A total of 144 weaned pigs with average body weight (BW) of 7.89 ± 1.09 kg were assigned to three treatments with six replicates pens by BW and sex. Dietary treatments included negative control (NC), corn-soybean meal basal diet; positive control (PC), NC + 0.08% enzyme preparations and 0.3% acidifiers; and CHY, NC + 0.3% compound of hawthorn and yam extracts. Compared with NC-fed pigs, pigs fed CHY had greater (p < 0.05) growth performance in Phase 1. The CHY-fed pigs had greater (p < 0.05) activities of duodenal lipase, trypsin, and greater (p < 0.05) serum concentrations of total antioxidant capacity and glutathione peroxidase. The CHY-fed pigs had improved (p < 0.05) jejunal morphology and greater (p < 0.05) ileac valeric acid and colonic propionic acid, isobutyric acid concentrations than NC- and PC-fed pigs. In conclusion, CHY can improve growth performance and is a promising additive in weaned pig diets.

Effect of in vitro digestion on the bioaccessibility and bioactivity of phenolic compounds in fractions of Eugenia pyriformis fruit

Uvaia is a Brazilian fruit species that has great economic and nutritional potential, in addition to being a good source of compounds of biological interest. In this study, we evaluated for the first time the influence of in vitro gastrointestinal digestion on the bioaccessibility and bioactivity of phenolic compounds from two fractions of uvaia (edible and seed). It was observed that the content of total phenolic compounds was about 3 times higher in the seed (undigested extract), but reduced significantly after intestinal digestion (-50.08%). In turn, the total flavonoid content was about 5 times higher in the undigested seed extract. After intestinal digestion, the flavonoid content increased in the edible fraction (+109.49%) and decreased in the uvaia seed (-70.20%). The heatmap analysis showed that after intestinal digestion, there was an increase in the relative intensity of the flavonoids, while phenolic acids reduced their intensity. The antioxidant capacity of the undigested extract was 4-7 times greater for the seed, but decreased after intestinal digestion (-8.04-27.23%), while the antioxidant capacity of the edible fraction increased by 72.12-107.89% in this same stage of digestion. Thus, the content of phenolic compounds and antioxidant capacity were higher in the uvaia seed, and the bioaccessibility of the bioactive compounds in this fruit were dependent on the fraction and digestive phase evaluated. These results can contribute to the establishment of uvaia as a novel ingredient for preparations with functional claims.

The complete chloroplast genome of Crataegus bretschneideri Schneid. (Rosaceae)

Crataegus bretschneideri Schneid., with an unclear phylogenic position, is mainly distributed in northeast and inner mongolia area of China. In this study, the complete chloroplast genome sequence of C. bretschneideri was determined by using Illumina high-throughput sequencing method. The chloroplast genome was 159,607 bp in length and consisted of a large single-copy (LSC) region (87,601 bp), a small single-copy (SSC) region (19,312 bp), separated by a pair of inverted repeat (IRs: 26,347 bp, each) regions. It comprised a total of 114 unique genes, including 80 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Phylogenetic analysis based on complete chloroplast genomes indicated that C. bretschneideri was closely related to C. marshallii Eggl in the subfamily Maloideae. This complete chloroplast genome will provide valuable insight into evolution, molecular breeding, and phylogenetic analysis of Crataegus species.

Changes in Antioxidant Properties and Amounts of Bioactive Compounds during Simulated In Vitro Digestion of Wheat Bread Enriched with Plant Extracts

Cereal preparation can be an excellent source of substances with proven health-promoting properties. Unfortunately, some types of bread, such as white flour bread, are devoid of many valuable nutrients. Therefore, it is necessary to look for ways to increase its density and nutritional value. The aim of the study was to investigate the effect of stabilized plant extracts on the quality of bread, its antioxidant activity and polyphenol content, and to evaluate the stability of bioactive compounds and antioxidant activity during in vitro digestion. The research material was the wheat bread baked with spray dried microcapsules of hawthorn bark, soybeans and onion husks in maltodextrin or inulin carriers. The addition of plant extracts resulted in the presence of phenolic compounds in the wheat bread, and its antioxidant activity significantly increased. There was no significant difference in antioxidant activity between breads containing microcapsules with different carriers. During in vitro digestion, procyanidins and isoflavones in bread were more resistant to the digestive processes than other compounds. The antioxidant activity during simulated digestion was the highest at the stage of gastric digestion, and its value depended on the extract used and the analytical method applied.

New Insight into the Phylogeny and Taxonomy of Cultivated and Related Species of Crataegus in China, Based on Complete Chloroplast Genome Sequencing

Hawthorns (Crataegus L.) are one of the most important processing and table fruits in China, due to their medicinal properties and health benefits. However, the interspecific relationships and evolution history of cultivated Crataegus in China remain unclear. Our previously published data showed C. bretschneideri may be derived from the hybridization of C. pinnatifida with C. maximowiczii, and that introgression occurs between C. hupehensis, C. pinnatifida, and C. pinnatifida var. major. In the present study, chloroplast sequences were used to further elucidate the phylogenetic relationships of cultivated Crataegus native to China. The chloroplast genomes of three cultivated species and one related species of Crataegus were sequenced for comparative and phylogenetic analyses. The four chloroplast genomes of Crataegus exhibited typical quadripartite structures and ranged from 159,607 bp (C. bretschneideri) to 159,875 bp (C. maximowiczii) in length. The plastomes of the four species contained 113 genes consisting of 79 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. Six hypervariable regions (ndhC-trnV(UAC)-trnM(CAU), ndhA, atpH-atpI, ndhF, trnR(UCU)-atpA, and ndhF-rpl32), 196 repeats, and a total of 386 simple sequence repeats were detected as potential variability makers for species identification and population genetic studies. In the phylogenomic analyses, we also compared the entire chloroplast genomes of three published Crataegus species: C. hupehensis (MW201730.1), C. pinnatifida (MN102356.1), and C. marshallii (MK920293.1). Our phylogenetic analyses grouped the seven Crataegus taxa into two main clusters. One cluster included C. bretschneideri, C. maximowiczii, and C. marshallii, whereas the other included C. hupehensis, C. pinnatifida, and C. pinnatifida var. major. Taken together, our findings indicate that C. maximowiczii is the maternal origin of C. bretschneideri. This work provides further evidence of introgression between C. hupehensis, C. pinnatifida, and C. pinnatifida var. major, and suggests that C. pinnatifida var. major might have been artificially selected and domesticated from hybrid populations, rather than evolved from C. pinnatifida.

Bound Polyphenols from Insoluble Dietary Fiber of Defatted Rice Bran by Solid-State Fermentation with Trichoderma viride: Profile, Activity, and Release Mechanism

This study is aimed at exploring the release of bound polyphenols (BP) from insoluble dietary fiber (IDF) and its mechanism by solid-state fermentation (SSF) via Trichoderma viride. The results indicated that BP released by SSF (5.55 mg GAE/g DW) was significantly higher than by alkaline hydrolysis. In addition, 39 polyphenols and catabolites were detected, and the related biotransformation pathways were speculated. Quantitative analysis showed that SSF released more ferulic acid, p-coumaric acid, and organic acids, which led to advances in antioxidant, α-amylase, and α-glucosidase inhibitory activities. Furthermore, structural characteristics (scanning electron microscopy, X-ray diffraction, thermos gravimetric analysis, and Fourier transform infrared spectroscopy) and dynamic changes of carbohydrate-hydrolyzing enzymes indicated that the destruction of hemicellulose and the secretion of xylanase were vital for releasing BP. Overall, this study demonstrated that SSF was beneficial to release BP from IDF, which could provide insight into utilizing agricultural byproducts in a more natural and economical way.

Effect of in vitro digestion on phenolics and antioxidant activity of red and yellow colored pea hulls

To explore the effect of digestion on pea hull phenolics, an in vitro model consisting sequential oral, gastric, small and large intestinal digestions was applied to pea hulls. The phenolic content and antioxidant activity of the samples collected from these digestion steps were determined. The phenolics in these samples generally decreased in the order of sequential digestions in both red and yellow hull series, and no significant increase of total phenolic content (TPC), total flavonoid content (TFC) and individual phenolics were found in most digested groups compared with the corresponding control groups. The antioxidant activity of the samples generally changed according to their TPC and strong correlations (r > 0.92, p < 0.001) existed between them in red hull series. The present study implies that phenolics are released gradually from pea hulls during in vitro digestion and their release was mainly due to the pH of the digestion.

Structural characteristic of a sulfated polysaccharide from Gracilaria Lemaneiformis and its lipid metabolism regulation effect

A sulfated polysaccharide extracted from Gracilaria lemaneiformis (GLP) with a prominent effect in regulating lipid metabolism was isolated. The molecular weight was 31.5 kDa and it was composed mainly of galactose, glucose and xylose. Fourier-transform infrared (FT-IR) spectrum and nuclear magnetic resonance (NMR) analysis suggested that GLP was composed of the following repeating unit: [3-β-Gal-4(OSO3)-1→4-α-3,6-anhydrogal-2(OSO3)-1→]. GLP could significantly decrease serum total cholesterol, triglyceride and free fatty acid levels and lower alanine aminotransferase and aspartate aminotransferase activities in high-fat-diet mice. Additionally, GLP could keep the body weight and attenuate accumulation of fat surrounding the liver and epididymis induced by high-fat diet. Results of RT-PCR indicated that GLP might regulate lipid metabolism and accelerate free fatty acid oxidation by up-regulating the expression of the PPARα, ACS and CPT1a gene. The present study suggests that GLP may be potentially useful for regulating lipid metabolism.

Protective effect of hawthorn extract against genotoxicity induced by benzo(<alpha>)pyrene in C57BL/6 mice

Benzo(<alpha>)pyrene [B(<alpha>)P], widely originated from environmental pollution or food process such as roasting and frying, is a strong mutagen and potent carcinogen. Utilization of hawthorn has been reported against physical mutagens. Our study found that hawthorn extract (HE) contained abundant phenolic compounds, wherein chlorogenic acid was 2.78 mg/g, procyanidine B2 was 3.58 mg/g, epicatechin was 2.99 mg/g DW, which may contribute to anti-genotoxicity activity. So, the role of HE against B(<alpha>)P-induced genotoxicity in C57BL/6 mice was further assessed. Fifty mice were distributed into five groups: control group, B(<alpha>)P group (30 mg/kg, i.p.), B(<alpha>)P + HE-L group (100 mg/kg, i.g.), B(<alpha>)P + HE-M group (200 mg/kg, i.g.), B(<alpha>)P + HE-H group (400 mg/kg, i.g.). Mice were orally administered with solutions of HE for 10 days and injected intraperitoneally with B(<alpha>)P for 3 days from the 8th day. Results showed that B(<alpha>)P can induce significantly pathological damage in liver, lung and spleen, as well as decrease white blood cells (WBCs). Remarkably elevated levels of reactive oxygen species (ROS), DNA strand breaks (DSBs) and G1 cell cycle arrest were also found in B(<alpha>)P group, with upregulated expressions of p-H2AX, p-p53 and p21 in bone marrow cells. With administration of HE, liver, lung and spleen injury significantly mitigated, while WBCs were evidently increased in B(<alpha>)P-treated mice. Consistently, HE markedly reduced level of ROS, DSBs and G1 cell cycle arrest accompanied by reducing expressions of p-H2AX, p-p53 and p21 in bone marrow cells. Combined, these results indicated a protective role of HE on B(<alpha>)P-induced genotoxicity.

Effect of roasting and in vitro digestion on phenolic profiles and antioxidant activity of water-soluble extracts from sesame

The effects of roasting and in vitro digestion on total phenolic content (TPC), total flavonoid content (TFC), phenolic profiles, and antioxidant activity of water-soluble extracts from six varieties of sesame were investigated in this study. Our results showed that the major phenolic compounds in raw, roasted and digested sesame were gallic acid (GA), protocatechuic acid (PA), 4-hydroxybenzoic acid (4 HBA), ferulic acid (FA) and quercetin (Quer). Roasting significantly increased the TPC, pinoresinol diglucoside (PD), sesamol, as well as the content of phenolic compounds (especially GA, PA, 4 HBA and Quer) in sesame, but kept or reduced the TFC, sesamin and sesamolin. After roasting, the antioxidant potency composite index (ACI) of six varieties of sesame was significantly increased by 29.8%-216.6%. Additionally, the ACI of gastric digestion was significantly higher than that of oral and intestinal digestion during the in vitro digestion of the roasted-sesame, except for the varieties of Ganzhi 9 and Ganzhi 17. This study showed that five phenolic compounds (GA, PA, 4 HBA, p-coumaric acid, Quer) and sesamol of the water-soluble extracts contributed to the antioxidant activities of the digestive products of sesame.

Functional Components, Antioxidant Activity and Hypoglycemic Ability Following Simulated Gastro-Intestinal Digestion of Pigments from Walnut Brown Shell and Green Husk

To assess the effects of digestion on the functional components of walnut pigment and their bioactivities, we developed an in vitro model simulating gastro-intestinal digestion. Results showed an increase in the contents of flavonoids and conjugated phenols (with retention rates higher than 100%) in husk pigment after digestion. The lowest of the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging abilities was reached in the group with the minimum flavonoid content after digestion. Close correlation was observed between free phenol content and total reducing power, as the reducing power among different groups of husk pigment was in consistent with free phenols changes. The inhibitory effect of walnut pigment on α-amylase with/without digestion enzyme was similar. However, shell pigment showed improved inhibitory effect on α-glucosidase activity, with an increased inhibitory rate of 5.42%. In general, the antioxidant activity and hypoglycemic ability of walnut pigment were prone to chemical and enzymatic changes during simulated digestion, which were also related to the alteration of flavonoids and phenols.

The influence of the extraction method on bioactivity of the root of Tetrastigma hemsleyanum

Tetrastigma hemsleyanum is traditionally used as a folk medicine and functional food in China. Its extracts have been confirmed to have many bioactivities. However, the effect of extracting temperature on its bioactivity has not been reported. In this research, the total flavonoids content (TFC), total polyphenol content (TPC), antiproliferative, antioxidant, and anti-inflammatory activities of ethanol extracts and water extracts (extracted at 55, 70, 85, and 100°C) were observed. The results indicated that ethanol extracts showed better antioxidant activity with DPPH EC50 of 504.1 ± 3.8 μg/ml and ABTS EC50 of 851.4 ± 3.9 μg/ml. A better antiproliferative activity on HepG2, PC12, Caco-2, and Hela cells was observed on ethanol extracts. The results of anti-inflammatory activities also indicated that all of the extracts can reduce the NO production of LPS-stimulated macrophage with dose-independent manner. In summary, the results showed that the antiproliferative, antioxidant, and anti-inflammatory activities of water extracts decreased with the increasing temperature to some extent.

Extraction optimization, antioxidant activity, and tyrosinase inhibitory capacity of polyphenols from Lonicera japonica

The objective of this research was twofold: first, to optimize the extraction process of Lonicera japonica polyphenols using a response surface methodology, and second, to study the antioxidant activity and tyrosinase inhibitory capacity of the polyphenols of different purities. High-speed shearing homogenization extraction was used to extract the polyphenols from L. japonica. The antioxidant activity and the effect of polyphenols on tyrosinase activity were studied using free radical scavenging assay and the tyrosinase method, respectively. The optimal extraction conditions with an extraction yield of 6.96% for polyphenols were determined as follows: ethanol volume fraction 57%, shearing time 3.30 min, and solid-liquid ratio 1:58. Lonicera japonica polyphenols exhibited potent scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and inhibitory capacity on tyrosinase. The results suggested that L. japonica polyphenols could be explored as a natural antioxidant and tyrosinase inhibitor.

An RNA Sequencing Transcriptome Analysis and Development of EST-SSR Markers in Chinese Hawthorn through Illumina Sequencing

Chinese hawthorn (Crataegus pinnatifida) is an important ornamental and economic horticultural plant. However, the lack of molecular markers has limited the development and utilization of hawthorn germplasm resources. Simple sequence repeats (SSRs) derived from expressed sequence tags (ESTs) allow precise and effective cultivar characterization and are routinely used for genetic diversity analysis. Thus, we first reported the development of polymorphic EST-SSR markers in C. pinnatifida with perfect repeats using Illumina RNA-Seq technique. In total, we investigated 14,364 unigenes, from which 5091 EST-SSR loci were mined. Di-nucleotides (2012, 39.52%) were the most abundant SSRs, followed by mono- (1989, 39.07%), and tri-nucleotides (1024, 20.11%). On the basis of these EST-SSRs, a total of 300 primer pairs were designed and used for polymorphism analysis in 70 accessions collected from different geographical regions of China. Of 239 (79.67%) pairs of primer-generated amplification products, 163 (54.33%) pairs of primers showed polymorphism. Finally, 33 primers with high polymorphism were selected for genetic diversity analysis and tested on 70 individuals with low-cost fluorescence-labeled M13 primers using capillary electrophoresis genotyping platform. A total of 108 alleles were amplified by 33 SSR markers, with the number of alleles (Na) ranging from 2 to 14 per locus (mean: 4.939), and the effective number of alleles (Ne) ranging from 1.258 to 3.214 (mean: 2.221). The mean values of gene diversity (He), observed heterozygosity (Ho), and polymorphism information content (PIC) were 0.524 (range 0.205–0.689), 0.709 (range 0.132–1.000), and 0.450 (range 0.184–0.642), respectively. Furthermore, the dendrogram constructed based on the EST-SSR separated the cultivars into two main clusters. In sum, our study was the first comprehensive study on the development and analysis of a large set of SSR markers in hawthorn. The results suggested that the use of NGS techniques for SSR development represented a powerful tool for genetic studies. Additionally, fluorescence-labeled M13 markers proved to be a valuable method for genotyping. All of these EST-SSR markers have agronomic potential and constitute a scientific basis for future studies on the identification, classification, and innovation of hawthorn germplasms.

Bioaccessibility, antioxidant activity and modulation effect on gut microbiota of bioactive compounds from Moringa oleifera Lam. leaves during digestion and fermentation in vitro

This study aims to investigate the bioaccessibility, bioactivity and gut microbiota modulation effect of Moringa oleifera Lam. leaves after in vitro gastrointestinal digestion and colonic fermentation.

Extrusion of apple pomace increases antioxidant activity upon in vitro digestion

Apple pomace, a by-product of juice production, is a high-fibre, high-polyphenol functional food ingredient.