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Buckwheat sprouts are rich in pectic polysaccharides, which possess numerous health-improving benefits. However, the precise structure-activity relationship of pectic polysaccharides from Tartary buckwheat sprouts (TP) is still scant, which ultimately restricts their applications in the food industry. Hence, both ultrasound-assisted Fenton treatment (UAFT) and mild alkali treatment (MATT) were utilized for the modification of TP, and then the effects of physicochemical characteristics of original and modified TPs on their bioactivities were assessed. Our findings reveled that the UAFT treatment could precisely reduce TP's molecular weight, with the levels decreased from 8.191 × 104 Da to 0.957 × 104 Da. Meanwhile, the MATT treatment could precisely reduce TP's esterification degree, with the values decreased from 28.04 % to 4.72 %. Nevertheless, both UAFT and MATT treatments had limited effects on the backbone and branched chain of TP. Moreover, our findings unveiled that the UAFT treatment could notably promote TP's antioxidant, antiglycation, and immunostimulatory effects, while remarkedly reduce TP's anti-hyperlipidemic effect, which were probably owing to that the UAFT treatment obviously reduced TP's molecular weight. Additionally, the MATT treatment could also promote TP's immunostimulatory effect, which was probably attributed to that the MATT treatment significantly decreased TP's esterification degree. Interestingly, the MATT treatment could regulate TP's antioxidant and antiglycation effects, which was probably attributed to that the MATT treatment simultaneously reduced its esterification degree and bound phenolics. Our findings are conducive to understanding TP's structure-activity relationship, and can afford a scientific theoretical basis for the development of functional or healthy products based on TPs. Besides, the UAFT treatment can be a promising approach for the modification of TP to improve its biological functions.
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Álcalis , Fagopyrum , Polissacarídeos , Ondas Ultrassônicas , Fagopyrum/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Polissacarídeos/isolamento & purificação , Álcalis/química , Antioxidantes/química , Antioxidantes/farmacologia , Ferro/química , Peróxido de Hidrogênio/química , Fenômenos Químicos , Animais , Peso MolecularRESUMO
Pectic polysaccharides are one of the most vital functional ingredients in quinoa microgreens, which exhibit numerous health-promoting benefits. Nevertheless, the detailed information about the structure-function relationships of pectic polysaccharides from quinoa microgreens (QMP) remains unknown, thereby largely restricting their applications as functional foods or fortified ingredients. Therefore, to unveil the possible structure-function relationships of QMP, the mild alkali de-esterification was utilized to modify QMP, and then the correlations of esterification degrees of native and modified QMPs to their biological functions were systematically investigated. The results showed that the modified QMPs with different esterification degrees were successfully prepared by the mild alkali treatment, and the primary chemical structure (e.g., compositional monosaccharides and glycosidic linkages) of the native QMP was overall stable after the de-esterified modification. Furthermore, the results revealed that the antioxidant capacity, antiglycation effect, prebiotic potential, and immunostimulatory activity of the native QMP were negatively correlated to its esterification degree. In addition, both native and modified QMPs exerted immunostimulatory effects through activating the TLR4/NF-κB signaling pathway. These results are conducive to unveiling the precise structure-function relationships of QMP, and can also promote its applications as functional foods or fortified ingredients.
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Antioxidantes , Chenopodium quinoa , Esterificação , Chenopodium quinoa/química , Relação Estrutura-Atividade , Antioxidantes/química , Antioxidantes/farmacologia , Antioxidantes/análise , Pectinas/química , Polissacarídeos/química , Prebióticos , Animais , Camundongos , Alimento Funcional , Células RAW 264.7 , NF-kappa B/metabolismoRESUMO
Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn) leaf has abundant rhamnogalacturonan-I enriched pectic polysaccharides, which exert various health-promoting effects. Nevertheless, the potential relationship between the chemical structure and the biological function of pectic polysaccharides from Tartary buckwheat leaves (TBP) remains unclear. Therefore, to bridge the gap between the chemical structure and the biological function of TBP, the impacts of ultrasound-assisted Fenton degradation (UFD) and mild alkaline de-esterification (MAD) on structural properties and biological effects of TBP were systematically studied. Compared with the native TBP (molecular mass, 9.537 × 104 Da), the molecular masses of degraded TBPs (TBP-MMW, 4.811 × 104 Da; TBP-LMW, 2.101 × 104 Da) were significantly reduced by the UFD modification, while their primary chemical structures were overall stable. Besides, compared with the native TBP (esterification degree, 22.73 %), the esterification degrees of de-esterified TBPs (TBP-MDE, 14.27 %; TBP-LDE, 6.59 %) were notably reduced by the MAD modification, while their primary chemical structures were also overall stable. Furthermore, the results revealed that both UFD and MAD modifications could significantly improve the antioxidant, antiglycation, and immunostimulatory effects of TBP. Indeed, TBP's biological effects were negatively correlated to its molecular mass and esterification degree, while positively linked to its free uronic acids. The findings demonstrate that both UFD and MAD modifications are promising techniques for the structural modification of TBP, which can remarkedly promote its biological effects. Besides, the present results are conducive to better understanding TBP's structure-bioactivity relationship.
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Fagopyrum , Pectinas , Folhas de Planta , Ondas Ultrassônicas , Folhas de Planta/química , Fagopyrum/química , Esterificação , Pectinas/química , Pectinas/farmacologia , Ferro/química , Peróxido de Hidrogênio/química , Antioxidantes/química , Antioxidantes/farmacologia , Polissacarídeos/química , Polissacarídeos/farmacologia , AnimaisRESUMO
Quinoa (Chenopodium quinoa Willd.) microgreens are widely consumed as healthy vegetables around the world. Although soluble dietary fibers exist as the major bioactive macromolecules in quinoa microgreens, their structural characteristics and bioactive properties are still unclear. Therefore, the structural characteristics and bioactive properties of soluble dietary fibers from various quinoa microgreens (QMSDFs) were investigated in this study. The yields of QMSDFs ranged from 38.82 to 52.31 mg/g. Indeed, all QMSDFs were predominantly consisted of complex pectic-polysaccharides, e.g., homogalacturonan (HG) and rhamnogalacturonan I (RG I) pectic domains, with the molecular weights ranged from 2.405 × 104 to 5.538 × 104 Da. In addition, the proportions between RG I and HG pectic domains in all QMSDFs were estimated in the range of 1: 2.34-1: 4.73 (ratio of galacturonic acid/rhamnose). Furthermore, all QMSDFs exhibited marked in vitro antioxidant, antiglycation, prebiotic, and immunoregulatory effects, which may be partially correlated to their low molecular weights and low esterification degrees. These findings are helpful for revealing the structural and biological properties of QMSDFs, which can offer some new insights into further development of quinoa microgreens and related QMSDFs as value-added healthy products.
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Chenopodium quinoa , Antioxidantes , Esterificação , Nível de Saúde , PrebióticosRESUMO
Background: Biochar amendments enhance crop productivity and improve agricultural quality. To date, studies on the correlation between different amounts of biochar in pakchoi (Brassica campestris L.) quality and rhizosphere soil microorganisms are limited, especially in weakly alkaline soils. The experiment was set up to explore the effect of different concentrations of biochar on vegetable quality and the correlation between the index of quality and soil bacterial community structure changes. Methods: The soil was treated in the following ways via pot culture: the blank control (CK) without biochar added and with biochar at different concentrations of 1% (T1), 3% (T2), 5% (T3), and 7% (T4). Here, we investigatedthe synergistic effect of biochar on the growth and quality of pakchoi, soil enzymatic activities, and soil nutrients. Microbial communities from pakchoi rhizosphere soil were analyzed by Illumina MiSeq. Results: The results revealed that adding 3% biochar significantly increased plant height, root length, and dry weight of pakchoi and increased the contents of soluble sugars, soluble proteins, Vitamin C (VC), cellulose, and reduced nitrate content in pakchoi leaves. Meanwhile, soil enzyme activities and available nutrient content in rhizosphere soil increased. This study demonstrated that the the microbial community structure of bacteria in pakchoi rhizosphere soil was changed by applying more than 3% biochar. Among the relatively abundant dominant phyla, Gemmatimonadetes, Anaerolineae, Deltaproteobacteria and Verrucomicrobiae were reduced, and Alphaproteobacteria, Gammaproteobacteria, Bacteroidia, and Acidimicrobiia relative abundance increased. Furthermore, adding 3% biochar reduced the relative abundance of Gemmatimonas and increased the relative abundances of Ilumatobacter, Luteolibacter, Lysobacter, Arthrobacter, and Mesorhizobium. The nitrate content was positively correlated with the abundance of Gemmatimonadetes, and the nitrate content was significantly negatively correlated with the relative abundance of Ilumatobacter. Carbohydrate transport and metabolism in the rhizosphere soil of pakchoi decreased, and lipid transport and metabolism increased after biochar application. Conclusion: Overall, our results indicated that applying biochar improved soil physicochemical states and plant nutrient absorption, and affected the abundance of dominant bacterial groups (e.g., Gemmatimonadetes and Ilumatobacter), these were the main factors to increase pakchoi growth and promote quality of pakchoi. Therefore, considering the growth, quality of pakchoi, and soil environment, the effect of using 3% biochar is better.
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Carvão Vegetal , Microbiota , Solo , Solo/química , Rizosfera , Nitratos , Microbiologia do Solo , Bactérias , PlantasRESUMO
Tartary buckwheat green leaves are considered to be among the most important by-products in the buckwheat industry. Although Tartary buckwheat green leaves are abundant in pectic polysaccharides, their potential applications in the food industry are quite scarce. Therefore, to promote their potential applications as functional or fortified food ingredients, both deep-eutectic-solvent-assisted extraction (DESE) and high-pressure-assisted deep eutectic solvent extraction (HPDEE) were used to efficiently and selectively extract pectic polysaccharides from Tartary buckwheat green leaves (TBP). The results revealed that both the DESE and HPDEE techniques not only improved the extraction efficiency of TBP but also regulated its structural properties and beneficial effects. The primary chemical structures of TBP extracted using different methods were stable overall, mainly consisting of homogalacturonan and rhamnogalacturonan-I (RG-I) pectic regions. However, both the DESE and HPDEE methods could selectively extract RG-I-enriched TBP, and the proportion of the RG-I pectic region in TBP obviously improved. Additionally, both the DESE and HPDEE methods could improve the antioxidant and anti-glycosylation effects of TBP by increasing its proportion of free uronic acids and content of bound polyphenolics and reducing its molecular weight. Moreover, both the DESE and HPDEE methods could partially intensify the immunostimulatory effect of TBP by increasing its proportion of the RG-I pectic region. These findings suggest that DES-based extraction techniques, especially the HPDEE method, can be promising techniques for the efficient and selective extraction of RG-I-enriched TBP.
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To promote the potentially industrial applications of thinned unripe kiwifruits, two deep eutectic solvent-based methods, including deep eutectic solvent-assisted extraction (DAE) and microwave-assisted deep eutectic solvent extraction (MDE), were optimized for the extraction of polysaccharides from thinned unripe kiwifruits (YKP). Results showed that the yields of YKP-D prepared by DAE and YKP-DM prepared by MDE were extremely higher than YKP-H prepared by hot water extraction. Furthermore, YKP-H, YKP-D, and YKP-DM were mainly composed of pectic polysaccharides, including homogalacturonan (HG) and rhamnogalacturonan I (RG I) domains. Besides, both YKP-D and YKP-DM exhibited stronger antioxidant, anti-glycosylation, and immunomodulatory effects than those of YKP-H, and their higher contents of uronic acids and bound polyphenols as well as lower molecular weights could partially contribute to their bioactivities. Overall, these results revealed that the developed MDE method could be utilized as a promising method for highly efficient extraction of YKP with superior beneficial effects.
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Although quinoa is nutritious, its high fat content and lipase activity make it easily oxidized during storage. Meanwhile, quinoa's lipid composition and changes during storage are still unknown. Therefore, we stored fresh quinoa flour at low temperature and low humidity (LL), normal temperature and normal humidity (NN), and high temperature and high humidity (HH) conditions for 120 days to assess its oxidative stability and to monitor the changes in lipid composition. Herein, the contents of fatty acids, the peroxide values, the malondialdehyde values, and the lipase activity in quinoa flour during storage are determined to evaluate its oxidation stability. At LL and NN conditions, the contents of fatty acids, the peroxide values, the malondialdehyde values, and the lipase activity changed slowly. They were 3 (LL) and 5 times (NN), 2.7 (LL) and 4.7 times (NN), 1.4 (LL) and 2.3 times (NN), and 1.5 (LL) and 1.6 times (NN) the initial content at storage up to 120 d. However, with the prolongation of storage time under HH conditions, they all increased significantly to 8, 6.6, 3, and 2 times the original content. Moreover, during the storage of quinoa under LL, NN, and HH conditions for 120 days, we continuously monitored the lipid composition of quinoa grains with UPLC-Q-Exactive Orbitrap MS/MS. We identified a total of 14 subclasses of 229 lipids, including 90 significantly different lipid species. PCA and PLS-DA showed that quinoa lipids in HH conditions changed significantly with prolonged storage; among these, the TG and DG classes were the most susceptible to oxidation, which could distinguish fresh quinoa from oxidized quinoa. Simultaneously, we also found that lipase activity has a significant impact on lipid metabolism through correlation analysis, which also indicates that enzyme inactivation treatment can slow down lipid hydrolysis and oxidation during storage. To explore the mechanism of these changes, we also identified twelve important lipid metabolism pathways during quinoa storage. In conclusion, our study advances knowledge of the storage stability and lipid oxidation mechanisms of quinoa and provides a theoretical basis for setting the shelf life of quinoa.
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Buckwheat green leaves are commonly consumed as functional tea materials due to their various beneficial effects. Although buckwheat green leaves have abundant soluble dietary fibers (SDFs), the information about their structural properties and functional properties remains unknown, largely hindering their applications as functional/health products. Hence, to enhance the usage and application of SDFs from buckwheat green leaves as value-added health products, the structures and biological activities of SDFs derived from different buckwheat green leaves were investigated and compared. Results revealed that SDFs derived from Tartary buckwheat green leaves (TBSDF) and common buckwheat green leaves (CBSDF) were rich in complex pectic-polysaccharides, mainly composing of homogalacturonan (HG) and rhamnogalacturonan I (RG I) pectic domains. Besides, TBSDF had higher proportion of RG I pectic domains than that of CBSDF. Furthermore, the existence of a high content of complex pectic-polysaccharides in TBSDF and CBSDF could contribute to their various biological activities, such as antioxidant, antiglycation, fat/bile acid binding, anticancer, and prebiotic effects. These results can provide some new insights into further development of buckwheat green leaves and related SDFs as value-added health products.
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Fagopyrum , Fagopyrum/química , Polissacarídeos/química , Folhas de Planta/química , Antioxidantes/análise , Fibras na Dieta/análiseRESUMO
Pisum sativum L., commonly referred to as dry, green, or field pea, is one of the most common legumes that is popular and economically important. Due to its richness in a variety of nutritional and bioactive ingredients, the consumption of pea has been suggested to be associated with a wide range of health benefits, and there has been increasing focus on its potential as a functional food. However, there have been limited literature reviews concerning the bioactive compounds, health-promoting effects, and potential applications of pea up to now. This review, therefore, summarizes the literature from the last ten years regarding the chemical composition, physicochemical properties, processing, health benefits, and potential applications of pea. Whole peas are rich in macronutrients, including proteins, starches, dietary fiber, and non-starch polysaccharides. In addition, polyphenols, especially flavonoids and phenolic acids, are important bioactive ingredients that are mainly distributed in the pea coats. Anti-nutritional factors, such as phytic acid, lectin, and trypsin inhibitors, may hinder nutrient absorption. Whole pea seeds can be processed by different techniques such as drying, milling, soaking, and cooking to improve their functional properties. In addition, physicochemical and functional properties of pea starches and pea proteins can be improved by chemical, physical, enzymatic, and combined modification methods. Owing to the multiple bioactive ingredients in peas, the pea and its products exhibit various health benefits, such as antioxidant, anti-inflammatory, antimicrobial, anti-renal fibrosis, and regulation of metabolic syndrome effects. Peas have been processed into various products such as pea beverages, germinated pea products, pea flour-incorporated products, pea-based meat alternatives, and encapsulation and packing materials. Furthermore, recommendations are also provided on how to better utilize peas to promote their development as a sustainable and functional grain. Pea and its components can be further developed into more valuable and nutritious products.
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Fruit thinning is a common practice employed to enhance the quality and yield of kiwifruits during the growing period, and about 30-50% of unripe kiwifruits will be thinned and discarded. In fact, these unripe kiwifruits are rich in nutrients and bioactive compounds. Nevertheless, the applications of thinned young kiwifruits and related bioactive compounds in the food and functional food industry are still limited. Therefore, to promote the potential applications of thinned young kiwifruits as value-added health products, the extraction, characterization, and evaluation of beneficial effects of phenolic compounds from thinned young fruits of red-fleshed Actinidia chinensis cv 'HY' were examined in the present study. A green and efficient ultrasound-assisted deep eutectic solvent extraction (UADE) method for extracting phenolic compounds from thinned young kiwifruits was established. A maximum yield (105.37 ± 1.2 mg GAE/g DW) of total phenolics extracted from thinned young kiwifruits by UADE was obtained, which was significantly higher than those of conventional organic solvent extraction (CSE, about 14.51 ± 0.26 mg GAE/g DW) and ultrasound-assisted ethanol extraction (UAEE, about 43.85 ± 1.17 mg GAE/g DW). In addition, 29 compounds, e.g., gallic acid, chlorogenic acid, neochlorogenic acid, catechin, epicatechin, procyanidin B1, procyanidin B2, quercetin-3-rhamnoside, and quercetin-3-O-glucoside, were identified in the kiwifruit extract by UPLC-MS/MS. Furthermore, the contents of major phenolic compounds in different kiwifruit extracts prepared by conventional organic solvent extraction (EE), ultrasound-assisted ethanol extraction (UEE), and ultrasound-assisted deep eutectic solvent extraction (UDE) were compared by HPLC analysis. Results revealed that the content of major phenolics in UDE (about 15.067 mg/g DW) was significantly higher than that in EE (about 2.218 mg/g DW) and UEE (about 6.122 mg/g DW), suggesting that the UADE method was more efficient for extracting polyphenolics from thinned young kiwifruits. In addition, compared with EE and UEE, UDE exhibited much higher antioxidant and anti-inflammatory effects as well as inhibitory effects against α-glucosidase and pancreatic lipase, which were closely associated with its higher content of phenolic compounds. Collectively, the findings suggest that the UADE method can be applied as an efficient technique for the preparation of bioactive polyphenolics from thinned young kiwifruits, and the thinned young fruits of red-fleshed A. chinensis cv 'HY' have good potential to be developed and utilized as functional foods and nutraceuticals.
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Quinoa leaf is consumed as a promising value-added vegetable in the diet. Although quinoa leaf is rich in soluble dietary fibers, the knowledge regarding their chemical structures and biological activities is still limited, which astricts their application in the functional food industry. Thus, to improve the precise use and application of soluble dietary fibers (SDFs) isolated from quinoa leaves in the food industry, the physicochemical structures and bioactivities of SDFs isolated from different quinoa leaves were systematically investigated. Results indicated that quinoa leaves were rich in SDFs, ranging from 3.30 % to 4.55 % (w/w). Quinoa SDFs were mainly composed of acidic polysaccharides, such as homogalacturonan and rhamnogalacturonan I, which had the molecular weights in the range of 4.228 × 104 -7.059 × 104 Da. Besides, quinoa SDFs exerted potential in vitro antioxidant activities, lipid and bile acid-adsorption capacities, immunoregulatory activities, and prebiotic effects, which might be partially associated with their molecular mass, content of uronic acid, and content of bound polyphenol. Collectively, these findings are beneficial to better understanding the chemical structures and bioactivities of SDFs extracted from different quinoa leaves, which can also provide a scientific basis for developing quinoa SDFs into functional foods in the food industry.
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Chenopodium quinoa , Chenopodium quinoa/química , Polissacarídeos/química , Peso Molecular , Folhas de Planta/química , Prebióticos/análiseRESUMO
Pectic-polysaccharides are considered as one of the most abundant bioactive components in okra, which possess various promising health-promoting effects. However, the knowledge regarding the structure-bioactivity relationship of okra pectic-polysaccharides (OPP) is still limited. In this study, effects of various degrees of esterification (DEs) on in vitro antioxidant and immunostimulatory activities of OPP were analyzed. Results displayed that OPP with high (42.13%), middle (25.88%), and low (4.77%) DE values were successfully prepared by mild alkaline de-esterification, and their primary chemical structures (compositional monosaccharide and glycosidic linkage) and molecular characteristics (molecular weight distribution, particle size, and rheological property) were overall stable. Additionally, results showed that the notable decrease of DE value did not significantly affect antioxidant activities [2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and nitric oxide (NO) radical scavenging abilities as well as ferric reducing antioxidant power (FRAP)] of OPP, suggesting that the DE was not closely related to its antioxidant activity. In fact, the slight decrease of antioxidant activity of OPP after the alkaline de-esterification might be attributed to the slight decrease of uronic acid content. Nevertheless, the immunostimulatory effect of OPP was closely related to its DE, and a suitable degree of acetylation was beneficial to its in vitro immunostimulatory effect. Besides, the complete de-acetylation resulted in a remarkable reduction of immune response. The findings are beneficial to better understanding the effect of DE value on antioxidant and immunomodulatory activities of OPP, which also provide theoretical foundations for developing OPP as functional foods or health products.
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Although sweet tea is rich in bioactive polysaccharides, the knowledge regarding their structures, bioactivities, and gut microbial metabolism is still limited. Therefore, in order to promote the application of sweet tea polysaccharide (STP) in the food industry, the pressurized hot water extraction (PHWE) of STP was optimized, and its structural properties and biological effects as well as microbial fermentation characteristics were investigated. The maximum extraction yield (4.64 % ± 0.03 %) of STP extracted by PHWE was obtained under the optimal conditions. Both homogalacturonan and arabinogalactan might exist as major polysaccharide fragments in STP. Additionally, STP exerted obviously in vitro antioxidant, anti-diabetic, and immunostimulatory effects, which might be related to its chemical properties, such as uronic acids, conjugated polyphenolics, and esterification degree. Furthermore, STP could be consumed by intestinal microbiota, and its fermentability was about 54 % at the end stage of fecal fermentation. Indeed, STP could modulate the microbial composition via improving the growth of several beneficial microbes, causing the release of beneficial short-chain fatty acids. Collectively, the findings indicate that the PHWE is an efficient method for extracting bioactive polysaccharides from sweet tea, and results can also provide a scientific basis for developing STP into functional foods or functional ingredients.
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Polissacarídeos , Água , Fermentação , Polissacarídeos/química , Água/química , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Chá/químicaRESUMO
The present study aimed to evaluate the influence of ultrasound assisted H2O2/ascorbic acid reaction on the structural characteristic and immunostimulatory activity of a ß-D-glucan isolated from D. indusiata, so as to reveal its potential structure-immunostimulatory activity relationship. A purified ß-D-glucan, named as DP, was quickly isolated from D. indusiata, and further identified as a 1,3-ß-D-glucan with 1,6-ß-D-Glcp as branched chains, which exhibited a rigid rod chain conformation in 0.9 % (w/v) of NaCl solution. Furthermore, results showed that the primary structure of DP was overall stable after the degradation by ultrasound assisted H2O2/ascorbic acid reaction. However, the molar mass and chain conformation of DP obviously changed. In addition, DP and its degraded products exerted remarkable immunostimulatory activity in vitro and in vivo, which could activate the nuclear factor-κB (NF-κB) signaling pathway through toll-like receptor 4 (TLR4). Indeed, the immunostimulatory activity of DP was closely-correlated to its molar mass and chain conformation. An appropriate degradation of molar mass could promote its immunostimulatory activity. While the transformation of chain conformation from rigid rod to random coil could cause the significant decrease of its immunostimulatory activity. These findings are beneficial to better understanding the structure-immunostimulatory activity relationship of ß-D-glucans from edible mushrooms.
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Glucanos , beta-Glucanas , Ácido Ascórbico , Basidiomycota , Glucanos/química , Glucanos/farmacologia , Peróxido de Hidrogênio , NF-kappa B , Cloreto de Sódio , Receptor 4 Toll-Like , beta-Glucanas/química , beta-Glucanas/farmacologiaRESUMO
The leaf of sweet tea (Lithocarpus litseifolius) is widely used as an edible and medicinal plant in China, which is rich in bioactive polysaccharides. In order to explore and promote the application of sweet tea polysaccharides in the functional food industry, the microwave-assisted deep eutectic solvent extraction (MDAE) of polysaccharides from sweet tea leaves was optimized, and the structural properties and biological functions of sweet tea polysaccharides prepared by MDAE (P-DM) were investigated and compared with that of hot water extraction (P-W). The maximum yield (4.16% ± 0.09%, w/w) of P-DM was obtained under the optimal extraction conditions (extraction time of 11.0 min, extraction power of 576.0 W, water content in deep eutectic solvent of 21.0%, and liquid-solid ratio of 29.0 mL/g). Additionally, P-DM and P-W possessed similar constituent monosaccharides and glycosidic bonds, and the homogalacturonan (HG) and arabinogalactan (AG) might exist in both P-DM and P-W. Notably, the lower molecular weight, higher content of total uronic acids, and higher content of conjugated polyphenols were observed in P-DW compared to P-W, which might contribute to its much stronger in vitro antioxidant, anti-diabetic, antiglycation, and prebiotic effects. Besides, both P-DW and P-W exhibited remarkable in vitro immunostimulatory effects. The findings from the present study indicate that the MDAE has good potential to be used for efficient extraction of bioactive polysaccharides from sweet tea leaves and P-DM can be developed as functional food ingredients in the food industry.
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Tremella fuciformis is an edible and medicinal mushroom. Polysaccharides from T. fuciformis have received increasing attention due to their diversely pharmacological activities. In this study, the digestive behavior and fermentation characteristics of T. fuciformis polysaccharides (TFP) were studied. The results revealed that the reducing sugar content, chemical composition, molecular weight, rheological property, constituent monosaccharide, and FT-IR spectrum of TFP were not altered after the in vitro simulated digestion, indicating that it was indigestible under different simulated digestion conditions. However, the physicochemical characteristics of TFP, including reducing sugar content, molecular weight, constituent monosaccharide, and free monosaccharide released, were obviously altered after the in vitro fermentation for 48 h, indicating that it was remarkably utilized by intestinal microbiota in human feces. Notably, TFP could obviously modulate the microbial composition via promoting the relative abundances of Phascolarctobacterium, Bacteroides, and Lachnoclostridium. Moreover, TFP could also increase the production of short-chain fatty acids, including acetic, propionic, n-butyric, and n-valeric acids, after the in vitro fermentation for 48 h. These results showed that TFP was stable under the simulated digestion conditions, but could be utilized by intestinal microbiota in human feces, and might possess the potential to improve intestinal health.
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Microbioma Gastrointestinal , Basidiomycota , Fezes/microbiologia , Fermentação , Humanos , Monossacarídeos , Polissacarídeos/química , Polissacarídeos/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , AçúcaresRESUMO
Polysaccharides exist as one of the most abundant components in lotus leaves, which attract increasing attention owing to their promising health-promoting benefits. In this study, the digestive and microbial degradation characteristics of lotus leaf polysaccharides (LLP) were studied by using an in vitro gastrointestinal model. The results suggested that LLP was stable in the human upper gastrointestinal tract in vitro according to its digestive stabilities at different simulated digestion stages. Conversely, the indigestible LLP (LLPI) could be remarkably utilized by intestinal microbiota in human feces during in vitro fermentation, and its fermentability was 58.11% after the in vitro fermentation of 48 h. Indeed, the microbial degradation characteristics of LLPI during in vitro fermentation by human fecal inoculum were revealed. The results showed that the content of reducing sugars released from LLPI obviously increased from 0.498 to 2.176 mg/mL at the initial fermentation stage (0-6 h), and its molecular weight sharply decreased from 4.08 × 104 to 2.02 × 104 Da. Notably, the molar ratios of arabinose (Ara), galactose (Gal), and galacturonic acid (GalA) in LLPI decreased from 2.89 to 1.40, from 5.46 to 3.72, and from 21.24 to 18.71, respectively, suggesting that the utilization of arabinose and galactose in LLPI by intestinal microbiota was much faster than that of galacturonic acid at the initial fermentation stage. Additionally, LLPI could remarkably regulate gut microbial composition by increasing the abundances of several beneficial microbes, including Bacteroides, Bifidobacterium, Megamonas, and Collinsella, resulting in the promoted generation of several short-chain fatty acids, especially acetic, propionic, and butyric acids. The findings from the present study are beneficial to better understanding the digestive and microbial degradation characteristics of LLP, which indicate that LLP can be used as a potential prebiotic for the improvement of intestinal health.
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In this study, dynamic variations in physicochemical characteristics of polysaccharides from 'Wuyi rock' tea (WYP) at different simulated digestion and fecal fermentation stages in vitro were studied. Results revealed that physicochemical characteristics of WYP were slightly altered after the simulated digestion in vitro, and its digestibility was about 8.38%. Conversely, physicochemical characteristics of the indigestible WYP, including reducing sugar, chemical composition, constituent monosaccharide, molecular weight, and FT-IR spectrum, were obviously altered after the fecal fermentation in vitro, and its fermentability was about 42.18%. Notably, the indigestible WYP could remarkably modulate the microbial composition via promoting the proliferation of profitable intestinal microbes, such as Bacteroides, Lactococcus, and Bifidobacterium. Moreover, it could also enhance the generation of short-chain fatty acids. The results showed that WYP was slightly digested in the gastrointestinal tract in vitro, but could be obviously utilized by intestinal microbiota, and might possess the potential to improve intestinal health.
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The present study aimed to explore the impacts of in vitro simulated saliva-gastrointestinal digestion on physicochemical and biological properties of the polyphenolic-protein-polysaccharide ternary complex (PPP) extracted from Hovenia dulcis. The results revealed that the in vitro digestion did remarkably affect physicochemical properties of PPP, such as content of reducing sugar release, content of bound polyphenolics, and molecular weight distribution, as well as ratios of compositional monosaccharides and amino acids. In particular, the content of bound polyphenolics notably decreased from 281.93 ± 2.36 to 54.89 ± 0.42 mg GAE/g, which might be the major reason for the reduction of bioactivities of PPP after in vitro digestion. Molecular weight of PPP also remarkably reduced, which might be attributed to the destruction of glycosidic linkages and the disruption of aggregates. Moreover, although biological activities of PPP obviously decreased after in vitro digestion, the digested PPP (PPP-I) also exhibited remarkable in vitro antioxidant and antiglycation activities, as well as in vitro inhibitory effects against α-glucosidase. These findings can help to well understand the digestive behavior of PPP extracted from H. dulcis, and provide valuable and scientific supports for the development of PPP in the industrial fields of functional food and medicine.