Effect of polysaccharide addition on food physical properties: A review

Monosaccharide composition analysis by 2D quantitative gsHSQCi

The physicochemical properties and biological activities of polysaccharides depend on their structures. Monosaccharide composition analysis is indispensable for the structural characterization of polysaccharides and is helpful in the quality control of polysaccharide preparation. Here, using a model mixture and tamarind seed polysaccharide as examples, we demonstrated that a quantitative 2D NMR method, gsHSQCi (three gradient-selective Heteronuclear Single Quantum Coherence spectra acquired with incremented repetition times, i = 1, 2, 3) can directly quantify a variety of monosaccharides in solution with adequate precision and accuracy, requiring no derivatization, postprocessing steps and column separation. Both anomeric and non-anomeric signals of monosaccharides can be utilized for content determination. More accurate quantification of fructose in a mixture containing nine monosaccharides is obtained, which is difficult to achieve by quantitative 1D 1HNMR and the common PMP-HPLC method (high-performance liquid chromatography through pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone) due to the peak overlapping and the poor derivatization efficiency, respectively. The results also revealed that Na[Fe(EDTA)] can serve as a proper relaxation-enhancing agent for saccharide samples to save experimental time. We expect that this approach can be applied as an alternative to analyzing the monosaccharide composition and be helpful in interpreting the structure of polysaccharides.

Extraction, purification, structural characterization, and bioactivities of the genus Rhodiola L. polysaccharides: A review

The genus Rhodiola L., an integral part of traditional Chinese medicine and Tibetan medicine in China, exhibits a broad spectrum of applications. This genus contains key compounds such as ginsenosides, polysaccharides, and flavonoids, which possess anti-inflammatory, antioxidant, hypoglycaemic, immune-enhancing, and anti-hypoxic properties. As a vital raw material, Rhodiola L. contributes to twenty-four kinds of Chinese patent medicines and 481 health food products in China, finding extensive application in the health food sector. Recently, polysaccharides have emerged as a focal point in natural product research, with applications spanning the medicine, food, and materials sectors. Despite this, a comprehensive and systematic review of polysaccharides from the genus Rhodiola L. polysaccharides (TGRPs) is warranted. This study undertakes a systematic review of both domestic and international literature, assessing the research advancements and chemical functional values of polysaccharides derived from Rhodiola rosea. It involves the isolation, purification, and identification of a variety of homogeneous polysaccharides, followed by a detailed analysis of their chemical structures, pharmacological activities, and molecular mechanisms, structure-activity relationship (SAR) of TGRPs. The discussion includes the influence of molecular weight, monosaccharide composition, and glycosidic bonds on their biological activities, such as sulfation and carboxymethylation et al. Such analyses are crucial for deepening the understanding of Rhodiola rosea and for fostering the development and exploitation of TGRPs, offering a reference point for further investigations into TGRPs and their resource utilization.

Improvement of antibacterial activity of polysaccharides via chemical modification: A review

Antibiotic residue and bacterial resistance induced by antibiotic abuse have seriously threatened food safety and human healthiness. Thus, the development and application of safe, high-efficiency, and environmentally friendly antibiotic alternatives are urgently necessary. Apart from antitumor, antivirus, anti-inflammatory, gut microbiota regulation, immunity improvement, and growth promotion activities, polysaccharides also have antibacterial activity, but such activity is relatively low, which cannot satisfy the requirements of food preservation, clinical sterilization, livestock feeding, and agricultural cultivation. Chemical modification not only provides polysaccharides with better antibacterial activity, but also promotes easy operation and large-scale production. Herein, the enhancement of the antibacterial activity of polysaccharides via acetylation, sulfation, phosphorylation, carboxymethylation, selenation, amination, acid graft, and other chemical modifications is reviewed. Meanwhile, a new trend on the application of loading chemically modified polysaccharides into nanostructures is discussed. Furthermore, possible limitations and future recommendations for the development and application of chemically modified polysaccharides with better antibacterial activity are suggested.

Rational modification of xanthan gum based on assistance of molecular dynamics simulation

Graft copolymerization is an effective approach to improve performance of polysaccharide. However, selecting the most suitable modification strategy can be challenging due to the intricate molecular structure. Rational design through computer aided molecular dynamics (MD) simulations requires substantial computational resources. This study designed a simplified MD simulation strategy and suggested that grafting acrylamide (AM) could effectively adjust the molecular conformation of xanthan gum (XG) and its derivatives, thus regulating its viscosity and gelation properties. To rationally modify XG, a uniform experimental design was applied to tune the grafting ratios ranging from 72 % to 360 %, resulting in XG-AM solutions with viscosity ranging from 9 to 104 mPa•s at a concentration of 0.3 %. XG-AM was crosslinked by acid phenolic resin to generate gel with the viscosity of 7890 mPa·s in 3 days, which was 13 times the viscosity of unmodified XG. The controllable gelation will enhance the efficacy of XG-AM in oil recovery. By integrating rational selection of grafting strategies based on simplified MD simulation of polysaccharide derivatives and controllable grafting modification with specified grafting rates, customized production of polysaccharide derivatives can meet the requirements of a diverse range of applications.

Extraction, purification, structural characteristic, health benefit, and product application of the polysaccharides from bamboo shoot: A review

Bamboo shoot is a kind of widely distributed natural green vegetable, which has a long history of consumption and cultivation, and has edible, nutritional and economic value. Bamboo shoot is nutrient-rich food with carbohydrates, fats, proteins, polysaccharides, flavonoids, alkaloids and other chemical components, can meet the body's needs. Notably, bamboo shoot polysaccharides are the most attractive saccharides, most of which are water-soluble polysaccharides, and their various biological activities have been paid more attention by researchers. With the deepening of research on bamboo shoot polysaccharides, they have been found to have anti-diabetic, anti-oxidant, anti-inflammatory, anti-complement activities, immunomodulatory, etc. Further research on bamboo shoot polysaccharides, their sources, molecular weights, chemical structures, monosaccharide compositions and structural characteristics are constantly explored. In order to better research and development of bamboo shoot polysaccharides, it is necessary to carry on a comprehensive arrangement. Here, the extraction and purification methods, structural characteristics, health benefits, structure-activity relationships and product applications of bamboo shoot polysaccharides were systematically reviewed. This article will deepen the understanding of bamboo shoot polysaccharides, provide knowledge base for further research on bamboo shoot polysaccharides, and expand the vision for developing related products.

Efficient conversion of cane molasses into Tremella fuciformis polysaccharides with enhanced bioactivity through repeated batch culture

Tremella fuciformis polysaccharide (TFPS) is a natural mushroom mucopolysaccharide widely used in health foods, medical care, cosmetic and surgical materials. In this study, we developed an efficient strategy for the repeated batch production of highly bioactive TFPS from the agro-industrial residue cane molasses. Cane molasses contained 39.92 % sucrose (w/w), 6.36 % fructose and 3.53 % glucose, all of which could be utilized by T. fuciformis spores, whereas, the TFPS production efficiency only reached 0.74 g/L/d. Corn cobs proved to be the best immobilized carrier that could tightly absorb spores and significantly shorten the fermentation lag period. The average yield of TFPS in eight repeated batch culture was 5.52 g/L with a production efficiency of 2.04 g/L/d. The average fermentation cycle after optimization was reduced by 61.61 % compared with the initial conditions. Compared to glucose as a carbon source, cane molasses significantly increased the proportion of low-molecular-weight TFPS (TFPS-2) in total polysaccharides from 3.54 % to 17.25 % (w/w). Moreover, TFPS-2 exhibited potent antioxidant capacity against four free radicals (O2-, ABTS+, OH, and DPPH). In conclusion, this study lays the foundation for the efficient conversion of cane molasses and production of TFPS with high bioactivity.

A review on extraction, purification, structural characteristics, biological activities, applications of polysaccharides from Hovenia dulcis Thunb. (Guai Zao)

Hovenia dulcis Thunb. (H. dulcis) is a widely distributed plant with a long history of cultivation and consumption. As a common plant, it has economic, edible and medicinal value. H. dulcis polysaccharides are one of their main bioactive ingredients and have many health benefits, such as anti-diabetes, antioxidation, anti-glycosylation, anti-fatigue, immune regulation activities and alcoholic liver disease protection activity. In this paper, the research progress of H. dulcis polysaccharides in extraction, purification, structural characteristics, biological activities, existing and potential applications were reviewed, which could provide new valuable insights for future studies.

An active derivatization detection method for inline monitoring the isolation of carbohydrates by preparative liquid chromatography

Polysaccharides have unique physio-chemical properties and various biological functions and have rapidly expanded interest over the last two decades. The purification of polysaccharides and their degraded oligosaccharides is challenging because carbohydrates have no chromophore and need a proper detector to monitor the chromatographic elution process. This study proposed an active derivatization detection (ADD) method based on active splitting from post-column flow, a microchannel reactor for efficient derivatization of polysaccharide reducing sugars with p-hydroxybenzoic acid hydrazide, and in-line detection by the UV detector of liquid chromatography system. The method and device were validated by the use of 11 monosaccharides, sulfated oligosaccharides (from degraded carrageenan), and polysaccharides (from Zizania latifolia). It has shown much better performance than the traditional phenol-sulfuric acid method (gold standard). Moreover, the ADD module presumes an add-in to the original preparative LC system, independent of the scale of the purification process and type of system. The developed method is versatile for chromatographic separation of carbohydrates and lays the foundation for their subsequent studies.

Gut microbiota modulation, prebiotic and bioactive characteristics of date pomace polysaccharides extracted by microwave-assisted deep eutectic solvent

This study investigated the characteristics of polysaccharides from date pomace using microwave-assisted deep eutectic solvents. The impact on the gut microbiota and probiotics growth was examined in vitro. The study also examined its antioxidant properties, ability to inhibit enzymes linked to diabetes and high blood pressure, impact on cell growth, and physical properties. The isolated MPS had an average molecular weight of 8073.38 kDa and contained mannose, galacturonic acid, galactose, glucose, and fructose in specific proportions. At a concentration of 1000 mg/L, MPS showed strong antioxidant activity, with significant scavenging rates in various tests such as DPPH (57.0 ± 1.05 %) and ABTS (66.4 ± 2.48 %). MPS displayed 77 %, 80 %, and 43 % inhibition for α-amylase, α-glucosidase, and ACE-inhibition, respectively. MPS displayed significant antiproliferative effects, achieving 100 % and 99 % inhibition against Caco-2 and MCF-7 cells at 2500 mg/L, respectively. MPS showed broad-spectrum antibacterial properties against both Gram-positive and Gram-negative foodborne bacteria. Gemmiger formicilis, Blautia species, Collinsella aerofaciens, and Bifidobacterium longum showed strong positive correlations, suggesting increased SCFA production. Network analysis indicated species correlations, with 86 % showing negative correlations with Escherichia and Enterococcus saccharolyticus. MPS was abundant in Firmicutes, Actinobacteria, and Proteobacteria phyla. Date pomace could serve as a dietary fiber source, promoting better health.

Adaptive mechanism of the marine bacterium Pseudomonas sihuiensis-BFB-6S towards pCO2 variation: Insights into synthesis of extracellular polymeric substances and physiochemical modulation

Marine bacteria can adapt to various extreme environments by the production of extracellular polymeric substances (EPS). Throughout this investigation, impact of variable pCO2 levels on the metabolic activity and physiochemical modulation in EPS matrix of marine bacterium Pseudomonas sihuiensis - BFB-6S was evaluated using a fluorescence microscope, excitation-emission matrix (EEM), 2D-Fourier transform infrared correlation spectroscopy (2D-ATR-FTIR-COS), FT-NMR and TGA-DSC. From the results at higher pCO2 levels, there was a substantial reduction in EPS production by 58-62.8 % (DW). In addition to the biochemical composition of EPS, reduction in carbohydrates (8.7-47.6 %), protein (7.1-91.5 %), and lipids (16.9-68.6 %) content were observed at higher pCO2 levels. Functional discrepancies of fluorophores (tyrosine and tryptophan-like) in EPS, speckled differently in response to variable pCO2. The 2D-ATR-FTIR-COS analysis revealed functional amides (CN, CC, CO bending, -NH bending in amines) of EPS were preferentially altered, which led to the domination of polysaccharides relevant functional groups at higher pCO2. 1H NMR analysis of EPS confirmed the absence of chemical signals from H-C-COOH of proteins, α, β anomeric protons, and acetyl group relevant region at higher pCO2 levels. These findings can contribute new insights into the influence of pCO2 on the adaptation of marine microbes in future ocean acidification scenarios.

Effect of monosaccharide composition and proportion on the bioactivity of polysaccharides: A review

Polysaccharides have been widely used in pharmaceutical and food industries due to their diverse bioactivity, high safety, and few or no side effects. However, inability to quickly produce, screen, and synthesize bioactive polysaccharides is the limiting factor for their development and application. Structural features determine and influence the bioactivity of polysaccharides. Among them, monosaccharide is the basic unit of polysaccharide, which not only affects electrification, functional group, and bioactivity of polysaccharide but also is one of the simplest polysaccharide indexes to be detected. At present, effects of monosaccharide composition and proportion on anti-inflammatory, antioxidant, antitumor, immunomodulatory, antibacterial, and prebiotic activities of polysaccharides are reviewed. Further problems need to be considered during regulation and analysis of monosaccharide composition and proportion of polysaccharides. Overall, present work will provide help and reference for production, development, and structure-function investigation of polysaccharides based on their monosaccharide.

Antibacterial activity of a polysaccharide isolated from Artemisia argyi leaf against Staphylococcus aureus and mechanism investigation

Abuse of antibiotics has led to excessive amounts of antibiotic residues in food and environment, thus enhancing pathogenic bacterium resistance and threatening human health. Therefore, searching and developing safe and green antibiotic alternatives are necessary. In this study, an Artemisia argyi leaf polysaccharide (AALP) fraction was extracted and analyzed. Chemical composition analysis showed that the carbohydrate, uronic acid, protein, and polyphenol content in AALP were 68.3 % ± 4.13 %, 9.4 % ± 0.86 %, 1.79 % ± 0.27 %, and 0.16 % ± 0.035 %, respectively. Chromatographic results suggested that AALP contained rhamnose, arabinose, glucosamine, galactose, glucose, xylose, mannose, galacturonic acid, and glucuronic acid in a molar ratio of 9.26, 1.35, 1.18, 3.04, 48.51, 2.33, 31.26, 3.93, and 9.08; the weight average molecular weight, number average molecular weight, and polydispersity of AALP were 5.41 kDa, 4.63 kDa, and 1.168, respectively. Fourier transform infrared spectroscopy indicated that AALP constituted the polysaccharide-specific groups of CH, CO, and OH. Meanwhile, AALP showed a dose-dependent inhibitory effect on Staphylococcus aureus in the inhibition zone assay, and the minimal inhibitory concentration was 1.25 mg/mL. Furthermore, AALP disrupted the cell wall, depolarized the inner membrane potential, and inhibited the activities of succinate dehydrogenase and malate dehydrogenase in S. aureus.