Preparation, structural characteristics, and application of taro polysaccharides in food

Progress in the preparation, structure and bio-functionality of Dictyophora indusiata polysaccharides: A review

Dictyophora indusiata (D. indusiata) is an elegant fungus known as the "mushroom queen" because of its rich nutritional value and resemblance to dancers wearing clean white dresses. Due to the harsh growth environment, the yield of D. indusiata is relatively low. Polysaccharides are the most abundant component among them and it is valued for its unique physiological function. Multiple extraction and purification methods have been used to separate and purify polysaccharides from D. indusiata. These polysaccharides have demonstrated strong biological activities in vitro and in vivo, including anti-inflammatory, anti-tumour, immunomodulatory, antioxidant and anti-hyperlipidemic effects. In addition, D. indusiata polysaccharides have shown promising potential for development and application in the areas of food, healthcare products, pharmaceuticals, and cosmetics. Recent advances in the extraction, purification, structural characterization, biological activities and application prospects of D. indusiata polysaccharides were summarized. This review may enrich the knowledge about bioactive polysaccharides from D. indusiata and provide a theoretical basis. Due to diverse potential health-promoting properties of D. indusiata polysaccharides, further development for their application in functional foods and pharmaceuticals is expected.

Structural Characteristics and Immunological Function of a New Non-Starch Polysaccharide from Red Sprout Taro

Taro is a tuber crop that is used for nutritional and medicinal purposes due to its abundance of non-starch polysaccharides (NSPs). Red Sprout taro is a local variety in Southern China, but the characteristics and bioactivities of its NSPs are currently unknown. In this study, NSPs were isolated from the corms of Red Sprout taro using hot-water extraction, ion-exchange chromatography, and ethanol precipitation; their molecular weight, monosaccharide composition, structural formulae, and immunomodulatory effects were examined. A novel NSP named Colocasia esculenta polysaccharide 1 (CEP1) was purified and characterized and was shown to mainly consist of glucose (60.49%) and galactose (25.92%) and have a molecular weight of 4556.272 kDa. The backbone of CEP1 consisted primarily of →4)-α-D-Glcp-(1→, →4,6)-β-D-Galp-(1→, and →3)-β-D-Galp-(1→ residues, with a branch consisting of the β-D-Glcp-(1→ residue. In addition, 25-400 µg/mL CEP1 was shown to have immunomodulatory effects on RAW264.7 macrophages. CEP1 not only increased cell viability, phagocytic capacity, inducible nitric oxide synthase secretion, and nitric oxide generation in RAW264.7 cells, but it also activated M1 and M2 macrophages to generate tumor necrosis factor α, interleukin 6, transforming growth factor β, and interleukin 10. These findings could lead to the use of CEP1 from Red Sprout taro as a possible immunomodulatory polysaccharide in functional foods.

Polysaccharides from Porphyra haitanensis: A Review of Their Extraction, Modification, Structures, and Bioactivities

Porphyra haitanensis (P. haitanensis), an important food source for coastal residents in China, has a long history of medicinal and edible value. P. haitanensis polysaccharides are some of the main active ingredients in P. haitanensis. It is worth noting that P. haitanensis polysaccharides have a surprising and satisfactory biological activity, which explains the various benefits of P. haitanensis to human health, such as anti-oxidation, immune regulation, anti-allergy, and anticancer properties. Hence, a systematic review aimed at comprehensively summarizing the recent research advances in P. haitanensis polysaccharides is necessary for promoting their better understanding. In this review, we systematically and comprehensively summarize the research progress on the extraction, purification, structural characterization, modification, and biological activity of P. haitanensis polysaccharides and address the shortcomings of the published research and suggest area of focus for future research, providing a new reference for the exploitation of polysaccharides from P. haitanensis in the fields of medicine and functional foods.

Isolation and structure elucidation of the compounds from Teucrium hyrcanicum L. and the investigation of cytotoxicity, antioxidant activity, and protective effect on hydrogen peroxide-induced oxidative stress

BACKGROUND

Teucrium hyrcanicum L. (family Lamiaceae) is widely distributed in the North and Northwest of Iran. It has been used in the form of tea, tonic, and tincture for the treatment of various diseases such as cough, rheumatism, and fever.

METHODS

In this study, the total phenolic and flavonoid contents, antioxidant and cytotoxic activities of methanol extract and different fractions of T. hyrcanicum were measured. Furthermore, the potential ability of T. hyrcanicum to protect against H2O2-induced oxidative stress was tested on the NIH3T3 cell line. Then, the isolation and structure elucidation of the compounds were performed on the most potent fractions. Finally, the quantification of isolated compounds in methanol extract (ME) was done by the HPLC method. Isolated phytochemicals were assessed for the cytotoxic and antioxidant activities.

RESULTS

The results indicated that the methanol fraction (MF) had the highest amount of phenolic and flavonoid contents (69.36 mg GAE/g extract and 68.95 mg QE/g extract). The highest radical scavenging activities were observed from MF and ME (IC50 44.32 and 61.12 μg.ml-1, respectively). The best cytotoxicity was obtained by ethyl acetate fraction (EF) against A431 and MCF7 cell lines (IC50 values of 235.4and 326.6 μg.ml-1, respectively). The pretreatment with MF exerts the highest reduction in malondialdehyde (MDA) formation (IC50 2.51 μM, p < 0.001) compared to the H2O2 group (5.77 μM). Also, MF significantly inhibited H2O2-induced Glutathione (GSH) oxidation (p < 0.001). Furthermore, two phenolic compounds, acteoside and quercetin, were isolated and identified in MF and EF, respectively. The IC50 values of acteoside and quercetin in the DPPH assay were 7.19 and 5.56 µg.ml-1, respectively. Both quercetin and acteoside significantly reduced the MDA formation and inhibited GSH oxidation, which was comparable with BHA (as a standard antioxidant) (p < 0.05). Acteoside demonstrated significant cytotoxicity against all tested cell lines (IC50 = 32 to 145 μg.ml-1). The HPLC quantification of isolated compounds revealed that the quantity of acteoside and quercetin in ME were 93.31 and 16.87 μg.mg-1, respectively.

CONCLUSION

The isolated compounds (quercetin and acteoside) had significant antioxidant activities and revealed a protective effect on H2O2-induced oxidative stress which was comparable with BHA.

Preparation, analysis and properties of shaddock ped polysaccharide and its derivatives

The shaddock ped polysaccharide (SPP) was extracted by ultrasound-assisted enzyme method. Phosphorylated shaddock ped polysaccharides (P-SPP) and acetylated shaddock ped polysaccharides (Ac-SPP) were obtained by chemical modification of SPP. The characterization methods such as infrared spectroscopy and nuclear magnetism were employed to characterize the structures of the two derivatives. The antioxidant activity of SPP and its derivatives was investigated by measuring their DPPH radical scavenging capacity, hydroxyl radical ion scavenging capacity and superoxide anion scavenging capacity. In comparison, P-SPP showed better antioxidant activity. The results indicated that the antioxidant activity of the polysaccharides varied with different chemical modifications.

Ultrasonic/cellulase-assisted extraction of polysaccharide from Garcinia mangostana rinds and its carboxymethylated derivative

Response surface methodology was selected to explore the ultrasonic-assisted cellulase extraction conditions of Garcinia mangostana rind polysaccharides (GMRPs), and the optimum values of each condition were as follows: ratio of raw material to liquid of 1:50 g/mL, ultrasonic time of 40 min, enzyme concentration of 4 %, and ultrasonic power of 179 W. Based on the above conditions, the average extraction rate of GMRPs was 15.56 %. GMRPs were modified by carboxymethylation, and the relationship between the amount of chloroacetic acid and the substitution degree of carboxymethylated derivative was compared. Based on the results of single factor experiment, it was shown that the amount of chloroacetic acid significantly affected the degree of substitution of derivative products. The above research provides some valuable theoretical references for the preparation of GMRPs and its carboxymethylation products.

Ultrasound-assisted enzyme extraction and properties of Shatian pomelo peel polysaccharide

In this study, Shatian pomelo peel was used as the raw material for extracting polysaccharides using hot water extraction (HW) and ultrasonic-assisted enzyme (UVE) methods, respectively. The optimal parameters for extractingShatian pomelo peel polysaccharides (StPP) using the ultrasound-assisted enzymatic method were determined using response surface methodology (RSM). The optimal conditions for the extraction of StPP were as follows: ultrasound power 350 W, ultrasound time 50 min, enzymatic digestion time 50 min, compound enzyme addition 1.5%, and enzymatic digestion temperature 55 °C. The yield of StPP was found to be 30.1310% under these conditions. Comparing the physicochemical properties and antioxidant activity of StPP extracted using different methods, it was observed that ultrasound-assisted enzyme extraction resulted in higher yield, sugar content and glucuronic acid content of StPP compared to traditional hot water extraction. Additionally, StPP extracted by ultrasound-assisted enzyme extraction showed better antioxidant activity. These results suggest that ultrasound-assisted enzymatic extraction is an effective method to enhance the activity of natural polysaccharides.

Preparation and Antioxidant Activity of Acetylated Mung Bean Peel Polysaccharides

Mung bean peel polysaccharides are one of the main active components in mung bean peel. Acetylated mung bean peel polysaccharides were prepared by extracting and acetylating them, and characterized by infrared and ultraviolet methods to preliminarily understand the structural characteristics and activity of acetylated mung bean peel polysaccharides. Acetylation modification can improve the structure of polysaccharides, thereby causing changes in their properties. The product obtained after acetylation modification exhibited new characteristic absorption peaks at 1732 cm-1 , and the scavenging ability of hydroxyl radicals was improved. Therefore, acetylation modification of mung bean peel polysaccharides could enhance the activity by improving the structure, which provided an experimental basis for the application of mung bean peel polysaccharides.

Preparation and analysis of polysaccharide from Solanum tuberdsm

The crude Solanum tuberdsm polysaccharides (STP) were extracted with hot water. In the process of extraction, proteins, pigments, small molecules and salts in the mixture were removed by Sevage reagent, diatomite and distilled water dialysis, respectively. In addition, the process conditions of protein removal by response surface methodology (RSM) were optimized, and the optimum process conditions of Sevage method were established as follows: ultrasound power 350 W, ultrasound time 20 min, deproteinization twice, volume ratio of polysaccharide solution to Sevage reagent 1:1 (mL/mL). Under these conditions, the protein removal rate was 93.14%.

Ultrasonic-assisted extraction, characteristics and activity of Ipomoea batatas polysaccharide

Ipomoea batatas polysaccharides (IBPs) have many important physiological functions. The optimal extraction conditions were extraction time of 40 min, solid-liquid ratio of 1:8 and ultrasonic power of 240 W. 1D/2D nuclear magnetic resonance (1D/2D NMR) analysis showed that the main chain of IBP-1A was mainly composed of →4)-α-D-Glcp-(1→ and →3, 6)-β-D-Glcp-(1→ residues. In vivo experiments showed that polysaccharide significantly increased the levels of antioxidation-related enzymes and metabolites in older mice. It could significantly relieve oxidative stress injury and delay aging. Therefore, this study provided a new theoretical basis for the development of IBPs as antioxidant food.

Ultrasound-assisted extraction and analysis of maidenhairtree polysaccharides

The maidenhairtree polysaccharides (MTPs) have important application prospects. So, the extraction, purification, structure, derivatization and biological activities of polysaccharides from leaves, fruits, and testae of maidenhairtree were disscussed. Polysaccharides were extracted by collaborative extraction methods such as ultrasound-assisted extraction and microwave-assisted extraction. The ultrasound-assisted extraction had higher content and higher efficiency. The structural characteristics and structure-activity relationship of maidenhairtree polysaccharides were studied in order to provide theoretical basis and technical support for the further development and utilization of maidenhairtree polysaccharides.

Ultrasound-assisted extraction and characteristics of maize polysaccharides from different sites

Antitumor, antioxidant, hypoglycemic, and immunomodulatory properties are all exhibited by maize polysaccharides. With the increasing sophistication of maize polysaccharide extraction methods, enzymatic method is no longer limited to a single enzyme to extract polysaccharides, and is more often used in combination with ultrasound or microwave, or combination with different enzymes. Ultrasound has a good cell wall-breaking effect, making it easier to dislodge lignin and hemicellulose from the cellulose surface of the maize husk. The "water extraction and alcohol precipitation" method is the simplest but most resource- and time-consuming process. However, the "ultrasound-assisted extraction" and "microwave-assisted extraction" methods not only compensate for the shortcoming, but also increase the extraction rate. Herein, the preparation, structural analysis, and activities of maize polysaccharides were analyzed and discussed.

Preparation and Analysis of Pueraria lobata Polysaccharides

Pueraria lobata polysaccharides (PLPs) were obtained by a hot water extraction method. Starting from the single factor experiment, the extraction was optimized by response surface methodology, and the following optimal extraction parameters were obtained: the extraction temperature was 84 °C, the liquid-solid ratio was 11 mL/g, the extraction time was 73 min, and the extraction rate of polysaccharides was 8.59%. The Sevag method was used to remove the protein soluble in water and H₂O₂ was used to remove the pigment; then PLPs were precipitated with three times of anhydrous ethanol, soluble salts and other small molecules were removed by dialysis, and finally refined PLPs were obtained by freeze-drying.

Ultrasound-assisted extraction and properties of polysaccharide from Ginkgo biloba leaves

Response surface methodology (RSM) was used to optimize the ultrasound-assisted extraction conditions of Ginkgo biloba leaves polysaccharide (GBLP). The optimum extraction conditions for the ultrasound-assisted extraction of GBLP were obtained as liquid to material ratio of 30 mL/g, ultrasonic power of 340 W, and extraction time of 50 min. Under these conditions, the yield of GBLP was 5.37 %. Two chemically modified polysaccharides, CM-GBLP and Ac-GBLP, were obtained by carboxymethylation and acetylation of GBLP. The physicochemical properties of these three polysaccharides were comparatively studied and their in vitro antioxidant activities were evaluated comprehensively. The results showed that the solubility of the chemically modified polysaccharides was significantly enhanced and the in vitro antioxidant activity was somewhat improved. This suggests that carboxymethylation and acetylation are effective methods to enhance polysaccharide properties, but the results exhibited some uncontrollability. At the same time, GBLP has also shown high potential for research and application.