Effect of different drying methods on the product quality and bioactive polysaccharides of bitter gourd (Momordica charantia L.) slices

A review: Polysaccharides targeting mitochondria to improve obesity

Polysaccharides are one of the most important and widely used bioactive components of natural products, which can be used to treat metabolic diseases. Natural polysaccharides (NPs) have been the subject of much study and research in the field of treating obesity in recent years. Studies in the past have demonstrated that mitochondria are important for the initiation, progression, and management of obesity. Additionally, NPs have the ability to improve mitochondrial dysfunction via a variety of mechanisms. This review summarized the relationship between the structure of NPs and their anti-obesity activity, focusing on the anti-obesity effects of these compounds at the mitochondrial level. We discussed the association between the structure and anti-obesity action of NPs, including molecular weight, monosaccharide composition, glycosidic linkage, conformation and extraction methods. Furthermore, NPs can demonstrate a range of functions in adipose tissue, including but not limited to improving the mitochondrial oxidative respiratory chain, inhibiting oxidative stress, and maintaining mitochondrial mass homeostasis. The purpose of this work is to acquire a thorough understanding of the function that mitochondria play in the anti-obesity effects of NPs and to offer fresh insights for the investigation of how NPs prevent obesity and the creation of natural anti-obesity medications.

Insight into the changes in active metabolite profiles of noni (Morinda citrifolia L.) fruit subjected to different drying treatments

Noni fruit is renowned for its abundance of bioactive compounds. Drying is an important method for processing functional products derived from noni. However, limited information exists on how drying methods affect the active metabolite profiles of noni fruit. This study investigated the impact of four common drying methods, including hot-air drying (HAD), vacuum freeze drying (VFD), microwave drying (MWD), and far infrared drying (FID), on the physicochemical indexes, bioactive components, and functional properties of dried noni fruit slices using targeted and untargeted metabonomics analysis. The results showed significant variations in appearance, water migration, and microstructure of dried noni fruit slices subjected to the four drying methods. VFD treatment yielded better dried noni fruit products when compared to other drying methods. The superiority of VFD treatment was due to its uniform stratification, reduced collapse, better retention of bioactive components and antioxidants, and higher enzyme inhibitory rates. These findings suggest that VFD method is ideal for obtaining premium bioactive profiles and maintaining the biological activity of noni fruit.

Impact of ultrasonication and blanching as a pre-treatment on quality parameter of dried and rehydrated bitter gourd

Vegetables are owed to the restriction of seasonal availability and regional abundance; it becomes essential that vegetables are preserved safely during the off-season. These existing demands look for dried products with high nutritional and organoleptic properties similar to fresh products. This study aimed to investigate the effect of ultrasonication and blanching before hot air drying on the quality attributes of bitter gourd (Momordica charantia). Dried samples were rehydrated to find the efficiency of pre-treatment and physicochemical properties. M. charantia slices were pre-treated with ultrasonication and blanched and dried at two different temperatures, 50 °C and 60 °C. M. charantia pre-treated using ultrasonication and dried at 60 °C reduces the drying time to 50% and rehydration time to 40% compared to untreated samples. Physico-chemical analysis of ultrasonicated samples revealed to have better retention of moisture (dried - 3.6%, rehydrated - 88%), Colour ΔE (dried - 9.07, rehydrated - 1.6), ascorbic acid (dried - 513, rehydrated - 310 mg/100 g), phenol (dried - 302, rehydrated - 231 GAE mg/100 g) and β-carotene (dried - 68 µg/100 g, rehydrated - 39 µg/100 g) compared to blanching.

Effects of Different Drying Methods on the Structural Characteristics and Multiple Bioactivities of Rosa roxburghii Tratt Fruit Polysaccharides

Drying conditions significantly impact the compositions and microstructures of polysaccharides, leading to various effects on their chemical characteristics and bioactivities. The objective of this study was to investigate how different industrial drying techniques, i.e., hot air drying, infrared drying, microwave vacuum drying, and freeze drying, affect the structural properties and biological activities of polysaccharides extracted from Rosa roxburghii Tratt fruit (RRTP). Results revealed that these drying methods significantly altered the extraction yield, molecular weights, monosaccharide ratios, contents of uronic acid and total sugars, gelling properties, particle sizes, thermal stability, and microstructures of RRTPs. However, the monosaccharide composition and functional groups of polysaccharides remained consistent across the different drying techniques. Biological activity assays demonstrated that RRTPs, particularly those processed through microwave vacuum drying (MVD-RRTP), exhibited excellent anti-linoleic acid oxidation, robust anti-glycosylation effects, and significant α-glucosidase inhibition in vitro. The outcomes of this research demonstrate that microwave vacuum drying serves as an effective pre-extraction drying method for RRTPs, enhancing their biological activities. This technique is particularly advantageous for preparing RRTPs intended for use in functional foods and pharmaceuticals, optimizing their health-promoting properties for industrial applications.

Effects of Freeze-Thaw Pretreatment Combined with Hot Air on Snake Gourd (Trichosanthes anguina L.)

Snake gourd is a seasonal vegetable with a high water content and medicinal value, but the short harvest period limits the large-scale application of snake gourd. Therefore, the effects of freeze-thaw pretreatment (FT) combined with hot air (HD) on the drying characteristics, active ingredients and bioactivities of snake gourd were investigated. The results showed that FT pretreatment reduced browning and shortened the drying time by 44%; the Page model was the best fit for describing the drying process. The polysaccharide contents (21.70% in alcoholic extract (TG1) and 44.34% in water extract (TG2)) and total phenol contents (1.81% in TG1 and 0.88% in TG2) of snake gourd pretreated by FT-HD were higher than those of snake gourd pretreated by the corresponding HD treatment. The FT pretreatment decreased the molecular weight of snake gourd polysaccharides and increased the molar ratio of glucose. The extracts pretreated by FT-HD showed greater chemical, cellular antioxidant capacity and α-amylase and α-glucosidase inhibition than those pretreated by HD. FT-HD can be recommended for achieving a short drying time and high quality of snake gourd and can be used for the drying of other fruits and vegetables.

Extraction, structures, biological effects and potential mechanisms of Momordica charantia polysaccharides: A review

Momordica charantia L. is a kind of vegetable with medicinal value. As the main component of the vegetable, Momordica charantia polysaccharides (MCPs) mainly consist of galactose, galacturonic acid, xylose, rhamnose, mannose and the molecular weight range is 4.33 × 103-1.16 × 106 Da. MCPs have been found to have various biological activities in recent years, such as anti-oxidation, anti-diabetes, anti-brain injury, anti-obesity, immunomodulatory and anti-inflammation. In this review, we systematically summarized the extraction methods, structural characteristics and physicochemical properties of MCPs. Especially MCPs modulate gut microbiota and cause the alterations of metabolic products, which can regulate different signaling pathways and target gene expressions to exert various functions. Meanwhile, the potential structure-activity relationships of MCPs were analyzed to provide a scientific basis for better development or modification of MCPs. Future researches on MCPs should focus on industrial extraction and molecular mechanisms. In East Asia, Momordica charantia L. is used as both food and medicine. It is not clear whether MCP has its unique biological effects. Further study on the difference between MCPs and other food-derived polysaccharides will be helpful to the development and potential application of Momordica charantia L.

Comparative elucidation of bioactive and antioxidant properties of red dragon fruit peel as affected by electromagnetic and conventional drying approaches

The effects of near-infrared (NIRD), mid-infrared (MIRD), far-infrared (FIRD), microwave (MWD), and hot air drying (HAD) on drying kinetic, colour, phytochemical composition, and antioxidant activity of red dragon fruit peel (RDFP) was evaluated. Results indicated that drying methods induced varying microstructural and chemical changes on RDFP, significantly influencing moisture removal rates and phytochemical retention. The lowest drying time was observed for MWD, while MIRD presented the highest drying time. FIRD drying was more favourable for retaining TPC, TFC, betacyanin and betaxanthin, while the ascorbic acid content was better retained during MIRD and NIRD. Enhancements in ABTS, CUPRAC and reducing power were associated with FIRD, and NIRD and MIRD enhanced DPPH and HRSA. Overall, chemical modifications induced by drying improved the phytochemical and antioxidant properties but presented adversative effects on ascorbic acid and DPPH. The study presented an essential background for the optimal drying of RDFP.

Effect of in vitro simulated digestion on the physicochemical properties and pancreatic lipase inhibitory activity of fucoidan

BACKGROUND

Fucoidan has an anti-obesity effect. However, there are few studies on its mechanism. In this study, we investigated the in vitro and in silico inhibitory properties of fucoidan against pancreatic lipase for the first time. We examined the changes in composition, structure, and pancreatic lipase inhibition of fucoidan during in vitro digestion.

RESULTS

Simulated saliva-gastrointestinal digestion resulted in a slight decrease in the molecular weight of fucoidan but no significant changes in the monosaccharide composition, sulfate content, and functional groups. Moreover, the digestion process significantly increased the inhibition of pancreatic lipase by fucoidan. The study on the type of inhibition showed that the inhibition of pancreatic lipase by fucoidan belonged to mixed inhibition with competitive inhibition. Molecular docking analysis showed that fucoidan could bind to the active site of pancreatic lipase.

CONCLUSION

This study indicates that fucoidan can be a potential functional food for anti-obesity. © 2024 Society of Chemical Industry.

Anti-biofilm mechanism of a synthetical low molecular weight poly-d-mannose on Salmonella Typhimurium

In this study, a low molecular weight poly-d-mannose (LMWM) was separated from a mixed polysaccharide synthesized previously. Monosaccharide composition, Fourier-Transform infrared spectroscopy (FT-IR), periodate oxidation and smith degradation were determined. After safety evaluation, the inhibition of LMWM on the different biofilm formation stages of Salmonella enterica serovar Typhimurium (S. Typhimurium) was tested in vitro. Furthermore, the effect of LMWM on the adhesion of S. Typhimurium to Caco-2 cells and cell surface hydrophobicity (CSH) were observed. Results indicated that LMWM was a homopolysaccharide without cytotoxicity and hemolysis, containing both α-mannose and β-mannose. It showed obvious anti-biofilm activity on S. Typhimurium and mainly activated on the initial adhesion and formation stage, even better than the commercial S. cerevisiae mannan (CM). LMWM inhibited the adhesion of S. Typhimurium on Caco-2 cells with the inhibition rate of 61.04 % at 2 mg/ml. Meanwhile, LMWM decreased the hydrophobicity of S. Typhimurium cell surface. In conclusion, the inhibitory effect on S. Typhimurium biofilm was not caused by bacteriostatic or bactericidal activity of LMWM. The specific anti-adhesion and the decrease of bacterial CSH by LMWM may closely relate to anti-biofilm mechanism. This study provides some supports for the application of LMWM as antibiotics alternative on S. Typhimurium in the future.

Optimization and characterization of pectin extracted from hawthorn by deep eutectic solvent

In this study, hawthorn pectin was extracted from dried hawthorn with deep eutectic solvent(DES) and compared with the traditional extraction methods such as acid extraction (AE) and ultrasonic-assisted extraction (UAE). Under optimal conditions, with a molar ratio of choline chloride to urea at 1:3, a water content of 30 %, a liquid-to-solid ratio of 30:1 (mL/g), an extraction temperature of 80 °C, an extraction time of 60 min, and a pH of 1, the yield of hawthorn pectin was 4.33 % ± 0.02 %. The measured results were consistent with the prediction. In addition, compared with AE and UAE, the experimental results showed that DES had a higher yield, a lower degree of esterification, and a slightly different monosaccharide composition from other extraction methods. The results of infrared spectroscopy and scanning electron microscopy showed that DES had a fine microstructure and coarser surface, and the main chemical structure of DES didn't change. The rheological analysis showed that DES had lower apparent viscosity than AE and UAE. These results represent a green source for pectin extraction with high pectin yield and good performance. In conclusion, the deep eutectic solvent has good application prospects in extracting hawthorn pectin.

Polysaccharide extracted from cultivated Sanghuangporous vaninii spores using three-phase partitioning with enzyme/ultrasound pretreatment: Physicochemical characteristics and its biological activity in vitro

Sanghuangporous vaninii, as a valuable dietary supplement and medicinal ingredient, contains abundant bioactive polysaccharides that have health-promoting effects. In the present study, four polysaccharides (SVSPs-C, SVSPs-E, SVSPs-U, and SVSPs-E/U) were extracted for the first time from S. vaninii spores by three-phase partitioning (TPP), enzyme pretreatment before TPP (E-TPP), ultrasonic pretreatment before TPP (U-TPP), and enzyme pretreatment followed by ultrasonic before TPP (E/U-TPP) methods, respectively. Their physicochemical characteristics and in vitro pharmacological functions were determined and compared. Results showed that four TPP-based extraction methods had remarkable impacts on the extraction yield, chemical properties, monosaccharide compositions, and molecular weights (Mw) of SVSPs. Specifically, SVSPs-E/U obtained by E/U-TPP showed the highest extraction yield (25.40 %), carbohydrate content (88.50 %), and the lowest protein content (0.86 %). The four SVSPs had high-Mw (183.8-329.1 kDa) and low-Mw (23.0-156.4 kDa) fractions and mainly consisted of galactose, glucose, and mannose with different contents. In vitro bioactivities assays indicated that SVSPs-E/U possessed stronger antioxidant, hypoglycemic, hypouricemic, immunostimulatory, and antitumor activities than those of SVSPs-C, SVSPs-E, and SVSPs-U. Therefore, our results provide an efficient and promising extraction technique for bioactive polysaccharides from S. vaninii spores, as well as SVSPs had the potential to be applied in functional food, pharmaceutical, and cosmetics fields.

Study of okra pectin prepared by sweeping frequency ultrasound/freeze-thaw pretreatment on corrosion inhibition of ANSI 304 stainless steel in acidic environment

Green and efficient metal corrosion inhibitors are very essential, and natural okra pectin (OP) can fulfill this need with rational use of resources. OP was prepared by water-alcohol extraction method after freeze-thaw pretreatment (FTP)/sweeping frequency ultrasound pretreatment (SFUP), and used for corrosion inhibition of ANSI 304 stainless steel (304 SS) in 1 M hydrochloric acid (HCl). The molecular weight, hydrodynamic diameter and monosaccharide composition of OP were analyzed to determine the factors on the corrosion inhibition of 304 SS. During SFUP of okra, the time-domain variation of ultrasound field was monitored by piezoelectric film sensor, its frequency-domain variation was monitored by a hydrophone, and analyzed respectively by oscilloscope and spectrum analyzer. Static weight-loss method, electrochemical and microscopic analyses were used to evaluate the corrosion inhibition efficiency of OP at temperatures (25, 30, 40, 50 °C) and concentrations (0, 0.2, 0.5, 1, 2 g·L-1) to optimize corrosion inhibition performance. It was found that OP by FTP and SFUP had higher corrosion inhibition efficiency on metals in acidic environment. According to static weight-loss method, the corrosion inhibition efficiency of OP with concentration of 2 g·L-1 (25 °C) was improved to 90.27 % in the FTP group and 93.53 % in the SFUP group, which 5.14 % and 8.93 % higher than Control (without pretreatment). Meanwhile, the corrosion inhibition efficiency decreased gradually as the temperature increased. OP corrosion inhibition performance fit Langmuir adsorption isothermal model as a mixed adsorption based on physical adsorption. It was a mixed inhibitor to protect 304 SS from corrosion.

Comparative Study of the Structural Characteristics and Bioactivity of Polysaccharides Extracted from Aspidopterys obcordata Hemsl. Using Different Solvents

The polysaccharides extracted from Aspidopterys obcordata are thought to have anti-urolithiasis activity in Drosophila kidney stones. This study aimed to assess the effects of different extraction solvents on the yield, chemical composition, and bioactivity of polysaccharides from A. obcordata. A. obcordata polysaccharides were extracted by using four solutions: hot water, HCl solution, NaOH solution, and 0.1 M NaCl. The results revealed that the extraction solvents significantly influenced the extraction yields, molecular weight distribution, monosaccharide compositions, preliminary structural characteristics, and microstructures of polysaccharides. The NaOH solution's extraction yield was significantly higher than the other extraction methods. Vitro antioxidant activity assays revealed that the NaOH solution extracted exhibited superior scavenging abilities towards DPPH and ABTS radicals and higher FRAP values than other polysaccharides. The vitro assays conducted for calcium oxalate crystallization demonstrated that four polysaccharides exhibited inhibitory effects on the nucleation and aggregation of calcium oxalate crystals, impeded calcium oxalate monohydrate growth, and induced calcium oxalate dihydrate formation. The NaOH solution extracted exhibited the most pronounced inhibition of calcium oxalate crystal nucleation, while the hot water extracted demonstrated the most significant suppression of calcium oxalate crystal aggregation. Therefore, it can be inferred that polysaccharides extracted with NaOH solution exhibited significant potential as a viable approach for extracting polysaccharides from stems due to their superior yield and the remarkable bioactivity of the resulting products.

Structural Characteristics and Multiple Bioactivities of Volvariella volvacea Polysaccharide Extracts: The Role of Extractive Solvents

The chemical structures and functional properties of plant-based polysaccharides are critically influenced by extractive solvents, but their roles are not clear. In this study, the structural characteristics and multiple bioactivities of Volvariella volvacea polysaccharides (VVPs) subjected to water (VVP-W), alkalis (sodium hydroxide, VVP-A), and acids (citric acid, VVP-C) as extractive solvents are investigated systematically. Of the above three polysaccharides, VVP-W exhibited the highest molecular weights, apparent viscosity, and viscoelastic properties. Functional analyses revealed that VVP-C had an excellent water-holding capacity, foaming properties, and emulsifying capacity, while VVP-A exhibited a promising oil-holding capacity. Moreover, VVP-C displayed strong inhibitory effects on α-amylase and α-glucosidase, which could be attributed to its content of total phenolics, proteins, and molecular weights. These findings have important implications for selecting the appropriate extraction techniques to obtain functional polysaccharides with targeted bioactive properties as food additives.

Heat source replacement strategy using catalytic infrared: A future for energy saving drying of fruits and vegetables

Drying is an important process for fruits and vegetables, which requires a lot of heat and the heat sources are mainly coal, electricity, natural gas, and solar energy. Most of the heat is usually wasted due to the long drying process and poor transfer efficiency. The use of coal also pollutes the environment. The national electricity curtailment policy regulates the drying industry. Therefore, the fruits and vegetables drying industry is facing new challenges due to its own development needs and external factors. Catalytic infrared drying (CIR) technology brings solutions to these problems. Compared with other drying technologies, CIR has a high drying efficiency and can effectively reduce the use of electric energy, avoid waste, and minimize pollution of water. However, improper processing conditions still cause quality deficits such as severe browning, and the drying is difficult due to weak infrared penetration. Although CIR has shortcomings, it is still expected to establish an energy-saving and efficient fruit and vegetable drying system.

Evaluation of antioxidation, regulation of glycolipid metabolism and potential as food additives of exopolysaccharide from Sporidiobolus pararoseus PFY-Z1

At present, there are relatively few studies on the production of exopolysaccharide (EPS) by yeasts. Therefore, exploring the properties of EPS produced by yeast can not only enrich the source of EPS, but also play an important role in its future application in the food field. The aim of this study was to explore the biological activities of EPS (named SPZ) from Sporidiobolus pararoseus PFY-Z1, as well as the dynamic changes in physical and chemical properties that occur during simulated gastrointestinal digestion, and the effects of SPZ on microbial metabolites during fecal fermentation in vitro. The results revealed that SPZ had good water solubility index, water-holding capacity, emulsifying ability, coagulated skim milk, antioxidant properties, hypoglycemic activities, and bile acid-binding abilities. Furthermore, the content of reducing sugars increased from 1.20 ± 0.03 to 3.34 ± 0.11 mg/mL after gastrointestinal digestion, and had little effect on antioxidant activities. Moreover, SPZ could promote the production of short-chain fatty acids during fermentation for 48 h, in particular, propionic acid and n-butyric acid increased to 1.89 ± 0.08 and 0.82 ± 0.04 mmol/L, respectively. Besides this, SPZ could inhibit LPS production. In general, this study can help us to better understand the potential bioactivities, and the changes in bio-activities of compounds after digestion of SPZ.

Comparative Evaluation of the Physiochemical Properties, and Antioxidant and Hypoglycemic Activities of Dendrobium officinale Leaves Processed Using Different Drying Techniques

Dendrobium officinale leaves have the potential to be processed into natural antioxidants, functional foods, and food additives. To maximally maintain their quality, fresh D. officinale leaves were dehydrated using different drying methods, i.e., hot air drying (HD), microwave drying (MD), infrared drying (IRD), and freeze drying (FD), and then the physicochemical properties, microstructure, and biological activities of the dried samples were compared. The results showed that, with the FD method, the samples had a porous microstructure, maintained the highest phenolic content, and demonstrated the highest antioxidant and hypoglycemic activities. Among the three thermal drying methods, with the IRD method, the samples retained higher phenolic contents, showed stronger DPPH free-radical scavenging, ferric ion reducing, ferrous ion chelating, and α-glucosidase inhibitory abilities, and more strongly promoted glucose metabolism in insulin-resistant HL-7702 cells than the samples with the MD and HD methods. These results suggested that FD was the most suitable method. However, IRD might be a promising alternative, owing to the high cost and long time needed for FD for the large-scale drying of D. officinale leaves.

Newly formed phenolics selectively bound to the graded polysaccharides of lychee pulp during heat pump drying using UPLC-ESI-QqQ-TOF-MS/MS

Our study investigated heat pump drying (HPD) effects on phenolic-polysaccharide adducts of three lychee pulp grades, their composition and bound phenolic contents. During HPD, the hexose content in water soluble polysaccharide (WSP) increased continuously, and the pentose and glucuronic acid contents in WSP and dilute alkali soluble pectin (ASP) together with the hexose content in ASP increased initially and then decreased due to polysaccharide hydrolases pectinase, polygalacturonase and cellulase. After HPD, the bound phenolic content in WSP, ASP and water unextractable polysaccharide (WUP) significantly increased. Protocatechualdehyde and 3,4-dihydroxybenzeneacetic acid were newly generated phenolics and the former combined with all the three polysaccharide grades, while the latter selectively combined with only WSP. During HPD, WSP and ASP surface structures were gradually broken and became loose, but WUP surface structure was a complete and rough sheet structure. Alkaline hydrolysis caused sparser, more porous surfaces of the three polysaccharide grades. The polyphenol selectivity could be related to substrate selectivity of endogenous oxidases and the type of phenolic compounds.

Recent advances in the influences of drying technologies on physicochemical properties and biological activities of plant polysaccharides

Plant polysaccharides, as significant functional macromolecules with diverse biological properties, are currently receiving increasing attention. Drying technologies play a pivotal role in the research, development, and application of various foods and plant polysaccharides. The chemical composition, structure, and function of extracted polysaccharides are significantly influenced by different drying technologies (e.g., microwave, infrared, and radio frequency) and conditions (e.g., temperature). This study discusses and compares the principles, advantages, disadvantages, and effects of different drying processes on the chemical composition as well as structural and biological properties of plant polysaccharides. In most plant-based raw materials, molecular degradation, molecular aggregation phenomena along with intermolecular interactions occurring within cell wall components and cell contents during drying represent primary mechanisms leading to variations in chemical composition and structures of polysaccharides. These differences further impact their biological properties. The biological properties of polysaccharides are determined by a combination of multiple relevant factors rather than a single factor alone. This review not only provides insights into selecting appropriate drying processes to obtaining highly bioactive plant polysaccharides but also offers a fundamental theoretical basis for the structure-function relationship of these compounds.

Characterization, in vitro digestibility, antioxidant activity and intestinal peristalsis in zebrafish of Dioscorea opposita polysaccharides

The soluble crude polysaccharides from Dioscorea opposita (DOP1 and DOP2) were prepared and characterized. DOP1 and DOP2 obtained carbohydrate (65.71% and 70.18%, respectively), uronic acid (63.71% and 24.84%, respectively) and protein (8.09% and 9.51%, respectively) with molecular weight of 49.24 kDa and 21.62 kDa, respectively. DOP samples were mainly composed of mannose, glucose, galacturonic acid, galactose, and glucuronic acid. The digestibility in vitro, antioxidant activity and intestinal peristalsis effect were then investigated. DOP1 and DOP2 were degraded with decreased molecular weights (39.58 kDa and 18.56 kDa respectively), increased reducing sugar contents (from 16.95% to 19.27%; 12.45% to 15.50% respectively) and free monosaccharides (from 0.89% to 1.42%; 0.90% to 1.14% respectively) after gastric digestion. Both DOP1 and DOP2 were resistant to intestinal digestion, suggesting that DOP samples can be considered as a dietary fiber. Additionally, DOP1 and DOP2 exhibited antioxidant activities positively correlated with the concentration and remained the activities after gastrointestinal digestion in vitro. Furthermore, DOP reduced the fluorescence intensity significantly, indicating DOP can promote the intestinal peristalsis of zebrafish larvae (5 pdf) at 500 μg/mL. Therefore, DOP1 and DOP2 have a better functionality as dietary fibers, including antioxidant activity and intestinal peristalsis promotion, which can be developed as functional foods.

Effect of in vitro simulated digestion and fecal fermentation on Boletus auripes polysaccharide characteristics and intestinal flora

Boletus auripes is edible and medicinal boletus mushrooms rich in diverse nutrients and bioactive compounds, of which indigestible dietary polysaccharides are the most abundant compounds involved the regulation of gut microbes. However, the physicochemical, digestive, and fermentation characteristics of Boletus auripes polysaccharide (BAP) are not well studied. This study aimed to investigate the influence of different digestive stages on BAP's physicochemical characteristics and biological activities, and its effect on intestinal flora. We found that mannose (0.23 %), glucose (0.31 %), galactose (0.17 %), and fucose (0.19 %) were the main monosaccharides of BAP, with a high-molecular-weight (Mw) and a low-Mw fraction of 2084.83 and 62.93 kDa, respectively. During the course of digestion, there were slight alterations in the chemical composition, monosaccharide composition, and Mw of BAP. Despite these changes, the fundamental structural features of BAP remained largely unaffected. Moreover, the antioxidant and hypoglycemic activities of BAP were weakened under simulated saliva-gastrointestinal digestion. However, gut microbiota decomposed and utilized BAP to generate various short-chain fatty acids during fermentation, which decreased the pH of fecal cultures. Meanwhile, BAP modulated the gut microbiota composition and increased the relative abundance of Bacteroidetes. These findings suggest that BAP have potential for maintaining intestinal health and protecting against interrelated diseases.

Selenium-enriched crude polysaccharide from Rosa roxburghii Tratt ameliorates cadmium-induced acute kidney injury in mice by modulating intestinal microorganisms

Cadmium is a toxic heavy metal that can cause serious damage to the body. It can trigger the oxidative stress response and damage various organs of the body (kidney, liver, brain, lung, testis, etc.). Selenium polysaccharides are considered to possess better antioxidant, immune regulation, and heavy metal removal activities than other polysaccharides, But few reports focused on Selenium Polysaccharides in Rosa roxburghii Tratt. The purpose of this study was to isolate crude polysaccharides (RRP), and crude Selenium polysaccharides (SeRRP) from Rosa roxburghii Tratt fruit and determine their structure, antioxidant activity, and protective effects on cadmium-exposed mice (PONY-2020-FL-62). Results showed that SeRRP had lower half-maximal inhibitory concentration (IC50) and higher superoxide dismutase (SOD) activity. The intake of food and body weight decreased, while the kidney index and liver index increased significantly after acute cadmium exposure. Most significantly, SeRRP ameliorates kidney injury by improving the kidney index. Furthermore, changes in the gut microbiota may be related to SeRRP or RRP. SeRRP and RRP decreased the Firmicutes/Bacteroidetes ratio, and increased the abundance of beneficial bacteria (Lachnospiraceae, Muribaculaceae, and Ruminococcaceae, etc.). These findings indicate that SeRRP and RRP have the potential to be functional food against oxidant and heavy metal exposure.

Bioactive polysaccharides from Momordica charantia as functional ingredients: a review of their extraction, bioactivities, structural-activity relationships, and application prospects

Momordica charantia L. is a well-known medicine and food homology plant with high pharmaceutical and nutritional values. Polysaccharides are carbohydrate polymers connected by glycosidic bonds, one of the key functional ingredients of M. charantia. Recently, M. charantia polysaccharides (MCPs) have attracted much attention from industries and researchers due to their anti-oxidant, anti-tumor, anti-diabetes, anti-bacteria, immunomodulatory, neuroprotection, and organ protection activities. However, the development and utilization of MCPs-based functional foods and medicines were hindered by the lack of a deeper understanding of the structure-activity relationship (SAR), structural modification, applications, and safety of MCPs. Herein, we provide an overview of the extraction, purification, structural characterization, bioactivities, and mechanisms of MCPs. Besides, SAR, toxicities, application, and influences of the modification associated with bioactivities are spotlighted, and the potential development and future study direction are scrutinized. This review provides knowledge and research underpinnings for the further research and application of MCPs as therapeutic agents and functional food additives.

A Poly-D-Mannose Synthesized by a One-Pot Method Exhibits Anti-Biofilm, Antioxidant, and Anti-Inflammatory Properties In Vitro

In this study, D-mannose was used to synthesize poly-D-mannose using a one-pot method. The molecular weight, degree of branching, monosaccharide composition, total sugar content, and infrared spectrum were determined. In addition, we evaluated the safety and bioactivity of poly-D-mannose including anti-pathogen biofilm, antioxidant, and anti-inflammatory activity. The results showed that poly-D-mannose was a mixture of four components with different molecular weights. The molecular weight of the first three components was larger than 410,000 Da, and that of the fourth was 3884 Da. The branching degree of poly-D-mannose was 0.53. The total sugar content was 97.70%, and the monosaccharide was composed only of mannose. The infrared spectra showed that poly-D-mannose possessed characteristic groups of polysaccharides. Poly-D-mannose showed no cytotoxicity or hemolytic activity at the concentration range from 0.125 mg/mL to 8 mg/mL. In addition, poly-D-mannose had the best inhibition effect on Salmonella typhimurium at the concentration of 2 mg/mL (68.0% ± 3.9%). The inhibition effect on Escherichia coli O157:H7 was not obvious, and the biofilm was reduced by 37.6% ± 2.9% at 2 mg/mL. For Staphylococcus aureus and Bacillus cereus, poly-D-mannose had no effect on biofilms at low concentration; however, 2 mg/mL of poly-D-mannose showed inhibition rates of 33.7% ± 6.4% and 47.5% ± 4%, respectively. Poly-D-mannose showed different scavenging ability on free radicals. It showed the best scavenging effect on DPPH, with the highest scavenging rate of 74.0% ± 2.8%, followed by hydroxyl radicals, with the scavenging rate of 36.5% ± 1.6%; the scavenging rates of superoxide anion radicals and ABTS radicals were the lowest, at only 10.1% ± 2.1% and 16.3% ± 0.9%, respectively. In lipopolysaccharide (LPS)-stimulated macrophages, poly-D-mannose decreased the secretion of nitric oxide (NO) and reactive oxygen species (ROS), and down-regulated the expression of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Therefore, it can be concluded that poly-D-mannose prepared in this research is safe and has certain biological activity. Meanwhile, it provides a new idea for the development of novel prebiotics for food and feed industries or active ingredients used for pharmaceutical production in the future.

Anti-Inflammatory and Anti-Oxidative Effects of Polysaccharides Extracted from Unripe Carica papaya L. Fruit

This study evaluated the antioxidative and anti-inflammatory activities of polysaccharides extracted from unripe Carica papaya L. (papaya) fruit. Three papaya polysaccharide (PP) fractions, namely PP-1, PP-2, and PP-3, with molecular weights of 2252, 2448, and 3741 kDa, containing abundant xylose, galacturonic acid, and mannose constituents, respectively, were obtained using diethylaminoethyl-Sepharose™ anion exchange chromatography. The antioxidant capacity of the PPs, hydroxyl radical scavenging assay, ferrous ion-chelating assay, and reducing power assay revealed that the PP-3 fraction had the highest antioxidant activity, with an EC50 (the concentration for 50% of the maximal effect) of 0.96 mg/mL, EC50 of 0.10 mg/mL, and Abs700 nm of 1.581 for the hydroxyl radical scavenging assay, ferrous ion-chelating assay, and reducing power assay, respectively. In addition, PP-3 significantly decreased reactive oxygen species production by 45.3%, NF-κB activation by 32.0%, and tumor necrosis factor-alpha and interleukin-6 generation by 33.5% and 34.4%, respectively, in H2O2-induced human epidermal keratinocytes. PP-3 exerts potent antioxidative and anti-inflammatory effects; thus, it is a potential biofunctional ingredient in the cosmetic industry.

Impact of Stabilization Technology on the Extraction Yield and Functionality of Macroconstituents from Biomass: A Systematic Review

Biomass contains different macroconstituents (polysaccharides, lipids, and proteins) with nutritional and functional properties. However, after harvest or processing, stabilization of biomass is necessary to preserve the macroconstituents from degradation by microbial growth and enzymatic reactions. Because these stabilization methods affect the structure of the biomass, extraction of valuable macroconstituents can be impacted. Literature, in general, focuses on either stabilization or extraction, but systematic information on the interlinkage between these processes has rarely been reported. This review summarizes recent research on physical, biological, and chemical stabilization methods on macroconstituent extraction yields and functionalities. Often, freeze drying as a stabilization method resulted in a good extraction yield and functionality, independent of the macroconstituent. Less documented treatments, such as microwave drying, infrared drying, and ultrasound stabilization, result in better yields compared to conventional physical treatments. Biological and chemical treatments were rarely performed but could be promising as stabilization methods before performing an extraction step.

Effects of traditional and advanced drying techniques on the physicochemical properties of Lycium barbarum L. polysaccharides and the formation of Maillard reaction products in its dried berries

This study explored the effect of three different industrial drying methods on the physicochemical, nutritional, and safety profile of goji berries. The hot-air (HD) and microwave drying (MD) methods yielded berries with relatively high polysaccharide content, while vacuum freeze-drying (FD) yielded dried berries with better sensory qualities but relatively less polysaccharide content. The polysaccharides obtained from the HD and MD berries had lower molecular weight, high antioxidant activity and high degrees of Maillard reaction. Further investigations revealed that all three methods, in particular HD and MD, generated high levels of intermediate Maillard reaction products (55.8-86.3 mg/kg) and advanced glycation end-products (fluorescent intensity of 26784-51712), based on significant reduction of reducing sugar and amino acids in the HD and MD berries (p < 0.05). These findings highlight the need to scrutinize the effectiveness of traditional and emerging drying technologies used to produce safe fruits.

Influencia del método de secado (horno con convección vs horno microondas), sobre la composición nutricional de diferentes forrajes

La alimentación es el costo más importante en la producción animal. El objetivo de esta investigación fue comparar los métodos de secado en diferentes forrajes para la obtención de materia seca,  horno con convección de aire (HC) y horno microondas (HM), y su efecto sobre la composición nutricional de cada forraje. Se estudiaron seis forrajes comúnmente utilizados en la producción animal: maíz duro amarillo (MA) (Zea mays), pasta de soya (PS) (Glycine max L.), rechazo de verde (RV) (Musa × paradisiaca), ensilaje de maíz (EM) , alfalfa (AL) (Medicago sativa) y raigrás perenne (RP) (Lolium perenne). Se analizaron 40 muestras de cada forraje, cada forraje fue secado en HC, así como en HM y se estimó el contenido de materia seca (MS),  luego se le realizó un análisis bromatológico; Proteína bruta (Pb), extracto etéreo (EE), fibra bruta (Fb) y cenizas. Se utilizaron un análisis de varianza y prueba de Tukey (p<0.05) para determinar diferencias entre medias. Los resultados demuestran que existen diferencias (p<0.05) en el contenido de (MS), siendo el HM quien alcanza un mayor nivel de MS en MA, PS, RV y AL,  el RP tuvo valores más altos con el HC mientras que en el EM el contenido de MS no varía con los métodos de secado. Los métodos de secado tuvieron incidencia en la composición química de los forrajes, así por ejemplo de los 6 forrajes analizados en la Pb se observó diferencias en 5, Fb en 3, EE en 1 y cenizas en 4. Livestock feeding is the most important cost in animal production. The objective of this research is to compare the drying methods on different forages for obtaining dried matter, convection oven (CO) and microwave oven (MO), and the effect of each method on the nutritional composition of each forage. Six types of forages, commonly used in animal production, were studied: yellow hard corn (YC) (Zea mays), soybean paste (SP) (Glycine max L.), banana reject (BR) (Musa × paradisiaca), corn silage (CS), alfalfa (AL) (Medicago sativa) and perenial ryegrass (PR) (Lolium perenne). 40 samples of each forage  were analized, each forage was dried using CO and MO, and the dried matter content was estimated, then a bromatological analysis was done. Crude protein (Cp), ethereal extract (EE), crude fiber (Cf) and ashes. A variance analysis and tukey test (p<0.05)  were used to determine differences between means.  Results show that differences  (p<0.05) exist in the content of DM, being that MO reaches the highest level of DM in YC, SP, BR and AL, the PR had higher values with the CO while in the CS the content of DM does not vary with the drying methods. The drying methods had incidence on the chemical composition of forages, for example of the six forages analized  in the Cp differences were observed in 5, Cf in 3, EE in 1 and ashes in 4.

Effects of in vitro digestion and fecal fermentation on physico-chemical properties and metabolic behavior of polysaccharides from Clitocybe squamulosa

The aim of this study was to establish a human digestion model in vitro to explore the degradation characteristics of a novel high-purity polysaccharide from Clitocybe squamulosa (CSFP2). The results showed that the content of reducing sugars (C_R ) of CSFP2 increased from 0.13 to 0.23 mg/mL, the molecular weight (Mw) of CSFP2 decreased significantly during the saliva-gastrointestinal digestion. The constituent monosaccharides of CSFP2, including galactose, glucose, and mannose, were stable during in vitro digestion, but their molar ratios were changed from 0.023: 0.737: 0.234 to 0.496: 0.478: 0.027. The surface of CSFP2 changes from a rough flaky structure to a scattered flocculent or rod-shaped structure after the gastrointestinal digestion. However, the apparent viscosity of CSFP2 was overall stable during in vitro digestion. Moreover, CSFP2 still maintains its strong antioxidant capacity after saliva-gastrointestinal digestion. The results showed that CSFP2 can be partially decomposed during digestion. Meanwhile, some physico-chemical properties of the fermentation broth containing CSFP2 changed significantly after gut microbiota fermentation. For example, the pH value (from 8.46 to 4.72) decreased significantly (p < 0.05) after 48 h of fermentation. the OD ₆₀₀ value increased first and then decreased (from 2.00 to 2.68 to 1.32) during 48-h fermentation. In addition, CSFP2 could also increase the amounts of short-chain fatty acids (SCFAs) (from 5.5 to 37.15 mmol/L) during fermentation (in particular, acetic acid, propionic acid, and butyric acid). Furthermore, the relative abundances of Bacteriodes, Bifidobacterium, Catenibacterium, Lachnospiraceae_NK4A136_group, Megasphaera, Prevotella, Megamonas, and Lactobacillus at genus level were markedly increased with the intervention of CSFP2. These results provided a theoretical basis for the further development of functional foods related to CSFP2.

Ultrasound improves the thermal stability and binding capacity of ovomucin by promoting the dissociation of insoluble ovomucin aggregates

Ovomucin (OVM) is a natural glycoprotein with various biological activities but poor solubility. This study aimed to enhance the solubility of OVM by using an ultrasonic-assisted method. The effect of ultrasound (US) on the structure, thermal stability and biological functions of OVM aggregates was evaluated. It was found that insoluble OVM aggregates were dissociated and the solubility increased significantly to 90.0 % after US under 400 W for 45 min. US also improved the onset temperature (To) and denaturation temperature (Td) of OVM. More importantly, the cholesterol binding capacity of both OVM and its digestion products were significantly improved after US (p < 0.05). The gastrointestinal digestion products of US-OVM also showed higher α-amylase and α-glucosidase inhibition than native OVM aggregates. US-induced dissociation of OVM aggregates and the conversion of β-sheet and β-turn to random coil, resulting in the exposure of hydrophobic binding sites may be an important reason for the enhanced stability and adsorption capacity. These findings suggested that US was an effective method for preparing soluble OVM and improved its adsorption capacity, which can further facilitate the application of OVM in the food industry.

Structural characteristics and ameliorative effect of a polysaccharide from Corbicula fluminea industrial distillate against acute liver injury induced by CCl4 in mice

Corbicula fluminea distillate as an important industrial by-product of C. fluminea during steaming process is rich in amino acids, proteins and polysaccharides, showing potential hepatoprotective effect. In this study, a polysaccharide (CFDP) was obtained from C. fluminea distillate by three-phase partitioning combined with (NH₄)₂SO₄ precipitation at a saturation of 60 %. The structural characteristics, antioxidant activity in vitro, and hepatoprotection against mice CCl₄-induced acute liver damage of CFDP were studied. Results demonstrated that CFDP was a water-soluble homogenous polysaccharide predominantly comprising glucose (>98 %), with a weight-average molecular weight of 1.4 × 10⁷ Da, and exhibiting potent antioxidant benefits in vitro. CFDP had a backbone of (1 → 4)-α-d-glucopyranosyl (Glcp) and a small amount of (1 → 4, 6)-α-D-Glcp. The branch formed at C-6 comprised by (1→)-α-D-Glcp and (1→)-α-D-N-acetylglucosamine. CFDP possessed excellent hepatoprotective activity against acute liver damage caused by CCl₄ in mice, mainly by ameliorating weight reduction and organ injures, alleviating hepatic function and serum lipid metabolism, suppressing oxidative stress and inflammatory responses, as directly verified by histopathological examination. Moreover, CFDP improved gut microbiota by up-regulating the relative abundance of total bacteria and probiotics such as Firmicutes, Bacteroidete, Rumminococcaceae, Lactobacillaceae, accompanied by promoting short chain fatty acid production. Therefore, our findings indicated that CFDP can be developed as a healthy food supplement for the prevention of chemical livery injury.

Microwave assisted fluidized bed drying of bitter gourd: Modelling and optimization of process conditions based on bioactive components

Bitter gourds were dried under varied drying conditions in a microwave assisted fluidized bed dryer, and the process was optimized using response surface methodology. Microwave power, temperature and air velocity were used as process variables for drying and the process parameters were varied between 360 and 720 W, 40-60 °C and 10-14 m/s, respectively. The responses determined for deciding the optimal criteria were vitamin C, total phenolics, IC₅₀, total chlorophyll content, vitamin A content, rehydration ratio, hardness and total color change of the dried bitter gourd. Statistical analyses were done by using response surface methodology, which showed that independent variables affected the responses to a varied extent. The optimum drying conditions of 550.89 W microwave power, 55.87 °C temperature, and 13.52 m/s air velocity were established for microwave assisted fluidized bed drying to obtain highest desirability for the dried bitter gourd. At optimum conditions, validation experiment was done to ensure the suitability of models. Temperature and drying time plays an important role in the deterioration of bioactive components. Faster and shorter heating led to the greater retention of bioactive components. Taking the aforesaid results into consideration, our study recommended MAFBD as a promising technique with minimum changes in quality attributes of bitter gourd.

Comparison of chemical property and in vitro digestion behavior of polysaccharides from Auricularia polytricha mycelium and fruit body

The antioxidant activity of Auricularia polytricha is associated tightly with its polysaccharide concentration, molar mass and architecture. This study aims to explore the differences in structural and physicochemical traits and oxidation resistances between the polysaccharides from fruit body (ABPs) and mycelial (IAPs) of Auricularia polytricha. The results showed that ABPs and IAPs were constituted by glucose, glucuronic acid, galactose and mannose. However, the molecular weight distribution of IAPs (3.22 × 10⁴ Da (52.73%) and 1.95 × 10⁶ Da (24.71%)) was wider than that of ABPs (5.4 × 10⁶ Da (95.77%)). The shear-thinning performance and viscoelastic behavior of both IAPs and ABPs are representative. IAPs are scattered in sheets, with folds and holes, and have a triple helix structure. ABPs are compact in structure and clear in texture. The main functional groups and thermal stability of both polysaccharides were similar. Concerning the in-vitro oxidation resistance, both of the studied polysaccharides exhibited the potent potential to scavenge hydroxyl radicals (IC₅₀ = 3.37 ± 0.32 and 6.56 ± 0.54 mg/mL, respectively) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals (IC₅₀ = 0.89 ± 0.22 and 1.48 ± 0.63 mg/mL, respectively), as well as the moderate reduction power. In addition, IAPs and ABPs were both completely undigested in simulated contexts of saliva, small intestine and stomach, and the two polysaccharide types maintained high DPPH and hydroxyl radical scavenging activities. DDPH scavenging rate during digestion was positively correlated with uronic acid content. To conclude, this study suggests the potential of IAPs as an equivalent alternative to ABPs.

Properties of plant-derived soluble dietary fibers for fiber-enriched foods: A comparative evaluation

Plant-derived soluble dietary fibers (SDF) have many important physiological functions and the applications of SDF vary based on their properties, which are worth further investigating for fiber-enriched food production. In this study, SDF derived from konjac, apple, chicory, flaxseed, orange, psyllium seed, soybean and oat were purified, and their structural, physicochemical and functional properties were systematically evaluated. Monosaccharide composition analysis showed that these SDF belonged to heteropolysaccharides, of which konjac, psyllium seed, apple, soybean and oat SDF were glucomannan, arabinoxylan, pectin, arabinogalactan and glucan, respectively. The molecular weight of konjac glucomannan (KGM, 5.22 × 10⁶ Da) was the highest, and inulin, soybean arabinogalactan (SA) and oat glucan (OG) had higher water solubility. Moreover, KGM, apple pectin (AP), flaxseed SDF (FS) and psyllium seed arabinoxylan (PA) exhibited better water-holding capacity, swelling capacity, emulsifying activity and stability. Rheological studies and texture profile analysis suggested that KGM had the best viscosity and gelation ability. In addition, AP and orange SDF (OS) showed better α-amylase inhibitory activity, while OS and KGM had higher pancreatic lipase inhibitory activity. Also, KGM and FS displayed fine cholesterol absorption capacity. To summary, these functional properties illustrated the feasibility of SDF to regulate blood sugar and blood lipid levels.

The effect of structure and preparation method on the bioactivity of polysaccharides from plants and fungi

Polysaccharides are not only the main components in the cell walls of plants and fungi, but also a structure that supports and protects cells. In the process of obtaining polysaccharides from raw materials containing cell walls, the polysaccharides on the cell walls are the products and also a factor that affects the extraction rate. Polysaccharides derived from plants and fungi have mild characteristics and exhibit various biological activities. The biological activity of polysaccharides is related to their chemical structure. This review summarizes the effects of the physicochemical properties and structure of polysaccharides, from cell walls in raw materials, that have an impact on their biological activities, including molecular weight, monosaccharide composition, chain structure, and uronic acid content. Also, the structure of certain natural polysaccharides limits their biological activity. Chemical modification and degradation of these structures can enhance the pharmacological properties of natural polysaccharides to a certain extent. At the same time, the processing method affects the structure and yield of polysaccharides on the cell wall and in the cell. The extraction and purification methods are summarized, and the effects of preparation methods on the structure and physiological effects of polysaccharides from plants and fungi are discussed.

Structure and bioactivity of polysaccharide from a subseafloor strain of Schizophyllum commune 20R-7-F01

Fungal polysaccharide is a kind of biomacromolecule with multiple biological activities, which has a wide application prospect and may play an important role in organisms to cope with extreme environments. Herein, we reported an extracellular polysaccharide (EPS) produced by Schizophyllum commune 20R-7-F01 that was isolated from subseafloor sediments at ~2 km below the seafloor, obtained during expedition 337. The monosaccharide of EPS was glucose and its molecular weight was 608.8 kDa. Methylation and NMR analysis indicated that the backbone of the EPS was (1 → 3)-β-D-glucan with a side chain (1 → 6) β-D-glucan linking at every third residue. Bio-active assays revealed that the EPS had potent antioxidant activity and could promote RAW264.7 cells viability and phagocytosis. These results suggest that fungi derived from sediments below seafloor are important and new source of polysaccharides and may be involved in the adaptation of fungi to anoxic subseafloor extreme ecosystem.

Extraction, characterization, antioxidant and anti-tumor activities of polysaccharides from Camellia fascicularis leaves

The ultrasonic-assisted extraction of polysaccharides from Camellia fascicularis (PCF) was optimized using response surface methodology. After separation and purification with DEAE-52 cellulose and Sephadex G-200 glucan gel columns, the purified polysaccharide components of PCFa-1 and PCFc-1 were analyzed for their structural characterization, antioxidant and anti-tumor activities in vitro. The results indicated that liquid to material ratio of 42 mL/g, ultrasonic time of 53 min, ultrasonic temperature of 73 °C, and ultrasonic power of 215 W were the optimum extraction conditions for PCF with maximum yields (4.05 %). PCFa-1 and PCFc-1 contained 5.88 % and 9.58 % uronic acid content, with 7.53 and 108.91 kDa of average molecular weights, respectively. The PCFa-1 was mainly constituted of galactose, arabinose, and glucose, while PCFc-1 was primarily composed of arabinose, glucose, galacturonic acid, and rhamnose. Fourier transform infrared spectra revealed that PCFa-1 and PCFc-1 contained typical polysaccharide bands. Scanning electron microscopy showed that the surface of PCFa-1 and PCFc-1 were irregular and clumpy structures. Nuclear magnetic resonance showed that PCFa-1 and PCFc-1 were mainly α-glycosidic bond conformation. Furthermore, the PCFc-1 showed better antioxidant capacities than PCFa-1 against hydroxyl, DPPH, and ABTS radicals and exhibited more potent toxicity on A549 and HepG2 cells. These research results suggested that PCF, especially PCFc-1, possesses great potential as natural antioxidants and anti-tumor drugs.

Elucidation of physicochemical properties of polysaccharides extracted from Cordyceps militaris fruiting bodies with different drying treatments and their effects on ulcerative colitis in zebrafish

Dry fruiting bodies of Cordyceps militaris (CMF) have been widely used in folk tonic foods and traditional herbal medicine in East Asia. Drying treatment serves as the last step in CMF industrial processes. In this work, the physicochemical properties of polysaccharides from C. militaris fruiting bodies (CMFPs) with hot air drying (HD), far-infrared radiation drying (ID) and vacuum freeze-drying (FD) treatments were analyzed, and their effects on ulcerative colitis (UC) were further investigated in oxazolone-induced zebrafish. The results showed that physicochemical properties of CMFP-H, CMFP-I and CMFP-F were obvious different. CMFPs could repair the intestinal mucosal barrier, inhibit ROS generation and the activities of MDA and MPO, and improve the activities of SOD, CAT, ACP, AKP and LZM. Further detection indicated that CMFPs could better improve UC via activating the MyD88/NF-κB signaling pathway in vivo. However, CMFP-H, CMFP-F and CMFP-I exhibited diverse regulation effects on specific immune-related enzymes and cytokines. The data would be helpful for finding practical and rapid drying methods for macro-fungi and further exploring CMFPs as functional food ingredients or complementary medicines for the treatments of UC.

Structural Characteristics and the Antioxidant and Hypoglycemic Activities of a Polysaccharide from Lonicera caerulea L. Pomace

In this study, a novel polysaccharide, LPP, was obtained from Lonicera caerulea L. pomace by ultrasonic-assisted heating and was purified by Sephadex G-100. The structural characteristics of LPP showed that the molecular weight (Mw) was 8.53 × 104 Da; that it was mainly composed of galacturonic acid, followed by galactose; that it possessed the characteristic functional groups of polysaccharides; and that it had an absence of O-glycosidic bonds and crystalline and triple helix structures. Furthermore, LPP exhibited a favorable thermodynamic stability and antioxidant, hypoglycemic, and hypolipidemic activities in a dose-dependent manner in vitro, demonstrating that LPP can be used as an agent to regulate glycolipid metabolism. Additionally, the relationship between its bio-activities is discussed in this paper. The results revealed that the RP, •OH, and NO2− radicals had synergistic promoting effects, and polysaccharides with a strong antioxidant ability may have excellent hypoglycemic and hypolipidemic effects. Collectively, these results suggest that LPP has a strong bio-activity, and that Lonicera caerulea L. pomace can be used as a potential polysaccharide source.

Effect of various drying methods on the physicochemical characterizations, antioxidant activities and hypoglycemic activities of lychee (Litchi chinensis Sonn.) pulp polysaccharides

Suitable drying method is critical for the preservation of physicochemical and pharmacological quality of lychee pulp polysaccharides (LPPs). In current work, the effects of five drying methods, i.e. air drying (A), infrared drying (I), heat pump drying (H), vacuum freeze drying (F) and freeze vacuum drying combined with heat pump drying (FH) on the physicochemical characterizations, antioxidant activities and hypoglycemic activities of LPPs were explored. Results showed all five drying methods led to thermal aggregation of LPPs and the stronger the thermal effect induced by drying, the more serious the aggregations were. Additionally, the thermal aggregation significantly affected the composition, structure and biological activity of LPPs. Less thermal aggregation was observed in LPPF and LPPFH, which exhibited stronger oxygen, DPPH and ABTS radical scavenging activities, higher ferric-reducing power and better α-glycosidase and α-amylase inhibition activities, resulting from their higher contents of neutral sugar, protein and uronic acid and lower molecular weight than LPPA and LPPI. Besides, FH consumed about half drying time and one fifth energy of F. Therefore, from industrial perspective, FH is a promising alternative to F for producing LPPs by comprehensively considering physicochemical characterizations, bioactivity as well as energy consumption.

In vitro simulated digestion affecting physicochemical characteristics and bioactivities of polysaccharides from barley (Hordeum vulgare L.) grasses at different growth stages

In this study, three polysaccharides (BGPs: BGPs-Z21, BGPs-Z23, and BGPs-Z31) were successively extracted from barley (Hordeum vulgare L.) grasses (BG) at different growth stages, including seedling (Z21), tillering (Z23), and stem elongation (Z31). The effects of in vitro simulated saliva-gastrointestinal digestion on the physicochemical characteristics and biological activities of BGPs were investigated and compared. Results showed that the simulated saliva-gastrointestinal digestion had considerable influences on reducing sugar content, chemical components, monosaccharide constituents, and molecular weights of BGPs but hardly affected their preliminarily structural characteristics. Moreover, the antioxidant activities of BGPs were weakened after the simulated saliva-gastrointestinal digestion, but their bile acid-binding capacities were remarkably enhanced. The digested BGPs-Z31 by gastric juice possessed better antioxidant benefit, and bile acid-binding capacity (80.33 %) than other digested products. Overall, these results indicated that BGPs obtained from BG are valuable for functional foods as promising bioactive ingredients.