Optimization of polysaccharides from Zagros oak leaf using RSM: Antioxidant and antimicrobial activities

Structure, chemical modification, and functional applications of mucilage from Mimosa pudica seeds - A review

Mimosa pudica (MP) is an ornamental plant due to seismonastic movements that close leaves and fall petioles in response to touch, wind, light, heat, cold, and vibration. The seeds of MP secrete smart, biocompatible, and non-toxic mucilage that has captivated researchers due to its widespread use in various fields such as pharmaceuticals and biotechnology. The mucilage is responsive to pH, salt solutions, and solvents and acts as a binder in tablet formulations for targeted drug delivery. The mucilage is chemically modifiable via acetylation, succinylation, and graft polymerization. Chemically modified MP mucilage appeared supersorbent for heavy metal ion uptake. Nanoparticles synthesized using mucilage as a reducing and capping agent displayed significant antimicrobial and wound-healing potential. Crosslinking of mucilage using citric acid as a crosslinking agent offers a sustained release of drugs. The present review is aimed to discuss extraction optimization, structure, modification, and the stimuli-responsive nature of mucilage. The review article will cover the potential of mucilage as emulsifying, suspending, bio-adhesive, gelling, and thickening agent. The role of mucilage as a capping and reducing agent for nanoparticles will also be discussed.

Structural diversity, functional versatility and applications in industrial, environmental and biomedical sciences of polysaccharides and its derivatives - A review

Recent efforts on the expansion of sustainable and commercial primal matters are essential to enhance the knowledge of their hazards and noxiousness to humans and their environments. For example, polysaccharide materials are widely utilized in food, wound dressing, tissue engineering, industry, targeted drug delivery, environmental, and bioremediation due to their attractive degradability, nontoxicity and biocompatibility. There are numerous easy, quick, and efficient ways to manufacture these materials that include cellulose, starch, chitosan, chitin, dextran, pectin, gums, and pullulan. Further, they exhibit distinctive properties when combined favourably with raw materials from other sources. This review discusses the synthesis and novel applications of these carbohydrate polymers in industrial, environmental and biomedical sciences.

Preparation and identification of novel antioxidant peptides from camel bone protein

Collagen hydrolysates are a vital source of bioactive peptides. The objective of this study was to prepare camel bone collagen hydrolysates with antioxidant activity, and to identify the peptides responsible for the antioxidant activity. To this end, single-factor and orthogonal tests were performed to explore the optimum preparation conditions. A hydrolysis time of 5 h, enzyme:substrate ratio of 1200 U/g, pH of 7.0, and a material:water ratio of 1:3.0 were adopted. Subsequently, the hydrolysates were purified using a series of chromatography procedures, and three novel peptides, GPPGPPGPPGPPGPPSGGFDF (hydroxylation), PATGDLTDFLK, and GSPGPQGPPGSIGPQ, possessing antioxidant abilities, were identified from the fraction using liquid chromatography-tandem mass spectrometry. The peptide PATGDLTDFLK showed excellent DPPH scavenging activity (39%) and a good cytoprotective effect on H₂O₂-induced oxidative stress damage in HepG2 cells with a 21.1% increase observed.

Paris polyphylla Sm. Induces Reactive Oxygen Species and Caspase 3-Mediated Apoptosis in Colorectal Cancer Cells In Vitro and Potentiates the Therapeutic Significance of Fluorouracil and Cisplatin

Paris polyphylla Sm. (Melanthiaceae) is an essential, vulnerable herb with a wide range of traditional applications ranging from fever to cancer in various communities. The use of P. polyphylla in India is limited to traditional healers. Here, we demonstrated that P. polyphylla extract (PPE) has good phenol, flavonoid, saponin, and steroidal saponin content and anti-oxidant activity with IC₅₀ 35.12 ± 6.1 μg/mL in DPPH and 19.69 ± 6.7 μg/mL in ABTS. Furthermore, PPE induces cytotoxicity in HCT-116 with IC₅₀ 8.72 ± 0.71 μg/mL without significant cytotoxicity inthe normal human colon epithelial cell line, CCD 841 CoN. PPE inhibits the metastatic property and induces apoptosis in HCT-116, as measured by Annexin V/PI, by increasing the production of reactive oxygen species (ROS) and caspase 3 activation. PPE acts synergistically with 5FU and cisplatin in HCT-116 and potentiates their therapeutic significance. Steroidal saponins with anticancer activities were detected in PPE by HR-LCMS. The present study demonstrated that PPE induces apoptosis by increasing ROS and activating caspase 3, which was attributed to steroidal saponins. PPE can be used as a potential natural remedy for colon cancer.

Ultrasound-Assisted Enzymatic Extraction and Bioactivity Analysis of Polypeptides from Cordyceps militaris

Cordyceps militaris is rich in protein, polysaccharide, cordycepin, and other active components, with anticancer and antioxidation functions. In order to improve the economic value of C. militaris, the protein was extracted from its fruiting body by alkali-soluble acid precipitation process, and the extraction technology was optimized by orthogonal test. The polypeptide was obtained by digesting those proteins with a complex enzyme. And the antimicrobial and anticancer activities of those polypeptides were evaluated by measuring inhibitory zone and cytotoxicity. The results showed that the optimal extraction conditions of protein were as follows: pH of 8.5, material-to-water ratio of 1 : 28, extraction time of 3.5 h, extraction three times, and the highest protein yield was 45.06%. The optimum enzymatic hydrolysis process of C. militaris polypeptide solution was as follows: the ratio of alkaline protease to papain was 4 : 3, the optimum temperature was 55°C, pH was 7.2, the enzyme dosage was 7000 U/mL, the enzymolysis time was 3.5 h, and the highest yield of peptide was 16.73%. Under those conditions, the polypeptides prepared from C. militaris (<3000 Da) showed good antibacterial activity against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus, with inhibitory zones of (12.08 ± 0.22), (6.67 ± 0.12), and (10.32 ± 0.23) mm, respectively. The results showed that the SAO-S (IC50 = 0.49 mg/L) and T24 (IC50 = 0.23 mg/L) were significantly inhibited by C. militaris polypeptide. Results from this study suggest that polypeptides can be utilized as a new approach for bioactive compounds production from C. militaris.

The Prospective Effect of Cinnamon and Chia on Submandibular Salivary Glands After Ciprofloxacin Administration in Albino Rats (Histological, Histochemical, and Ultrastructural Study)

Ciprofloxacin (CPFX®) is potent fluoroquinolone but has severe side effects. Cinnamon (CIN) and chia seeds are potent antioxidants. The current work aimed to compare the effect of CIN extract and chia seeds on CPFX®-treated submandibular salivary glands (SMGs). Thirty-two male albino rats were divided into four groups: Group 1: received saline. Group 2: received CPFX®. Group 3: received CIN extract after 4 h of CPFX® administration. Group 4: received ground chia seeds after 4 h of CPFX® administration. After 10 days, histological, histochemical, and ultrastructural examinations were done. Different examinations illustrated normal features of SMG in Groups 1 and 3. Group 2 showed degenerative signs. Group 4 showed normal features in some areas. Statistical results illustrated that Group 2 had highest mean vacuolation area%. Highest mean of PAS optical density (OD) was for Group 2. Concerning mercuric bromophenol blue stain OD; Group 1 showed highest mean OD. CPFX® has the deteriorative effect on SMG structure and ultrastructure. It leads to increased levels of glycosaminoglycans (GAGs) and decreased levels of total proteins. CIN extract showed more ameliorative effect compared to chia seeds.

Extraction Optimization of Mucilage from Seeds of Mimosa pudica by Response Surface Methodology

Mimosa pudica seed mucilage (MPM) is composed of glucuronoxylan, which is a swellable, pH-responsive and non-toxic biomaterial. Herein, we aimed to extract MPM from M. pudica seeds (MP seeds) to ascertain optimization of extraction conditions to get highest yield by response surface methodology, via Box-Behnken design (RSM-BBD). MPM was extracted from MP seeds by a hot water extraction method. The effects of four different parameters on the extraction yield of MPM were evaluated: pH of the extraction medium (1–10), seed/water contact time (1–12 h), the temperature of extraction medium (30–90 °C), and seed/water ratio (1:5–1:35 w/v). The maximum yield of MPM obtained by Design-Expert software was 10.66% (10.66 g/100 g) at pH 7, seed/water contact time of 6 h, extraction temperature of 50 °C, and seed/water ratio of 1:20 w/v. The p values of ANOVA were found to be less than 0.0001, which indicated that the extraction yield of MPM was significantly affected by all the study parameters. The results revealed that pH and extraction temperature were the most significant factors affecting the yield of MPM. MPM in compressed tablet form showed pH-responsive on–off switching behavior at pH 7.4 and 1.2 in a reversible manner. MPM in compressed tablet form sustained the release of itopride for 16 h following a super case-II transport mechanism and zero-order release kinetics.

Characterization of an exopolysaccharide (EPS-3A) produced by Streptococcus thermophilus ZJUIDS-2-01 isolated from traditional yak yogurt

Yak yogurt, one of the naturally fermented dairy products prepared by local herdsmen in the Qinghai-Tibet Plateau, contains a diverse array of microorganisms. We isolated and identified a novel Streptococcus thermophilus strain, ZJUIDS-2-01, from the traditional yak yogurt. We further purified and carried out detailed structural, physiochemical, and bioactivity studies of an exopolysaccharide (EPS-3A) produced by S. thermophilus ZJUIDS-2-01. The weight-average molecular weight (Mw) of EPS-3A was estimated to be 1.38 × 10⁶ Da by High-Performance Gel Permeation Chromatography (HPGPC). The monosaccharide analysis established its composition to be glucose, galactose, N-acetyl-D-galactosamine, and rhamnose in a ratio of 5.2:2.5:6.4:1.0. The molecular structure of EPS-3A was determined by the combination of permethylation analysis, FT-IR, and NMR spectroscopic techniques. The ζ-potential measurements indicated that EPS-3A had a pKa value of ~4.40. The DSC yielded a melting point (T_m) of 80.4 °C and enthalpy change (ΔH) of 578 J/g for EPS-3A, comparable to those of the xanthan gum (XG), a commercial EPS. EPS-3A exhibited better O/W emulsion stability and flocculating capacity than XG. Furthermore, it also demonstrated similar antioxidant activity to XG and promising in vitro antibacterial properties. This work evidenced that EPS-3A derived from S. thermophilus ZJUIDS-2-01 holds the potential for food and industrial applications.

Recent Advancements in Microbial Polysaccharides: Synthesis and Applications

Polysaccharide materials are widely applied in different applications including food, food packaging, drug delivery, tissue engineering, wound dressing, wastewater treatment, and bioremediation sectors. They were used in these domains due to their efficient, cost-effective, non-toxicity, biocompatibility, and biodegradability. As is known, polysaccharides can be synthesized by different simple, facile, and effective methods. Of these polysaccharides are cellulose, Arabic gum, sodium alginate, chitosan, chitin, curdlan, dextran, pectin, xanthan, pullulan, and so on. In this current article review, we focused on discussing the synthesis and potential applications of microbial polysaccharides. The biosynthesis of polysaccharides from microbial sources has been considered. Moreover, the utilization of molecular biology tools to modify the structure of polysaccharides has been covered. Such polysaccharides provide potential characteristics to transfer toxic compounds and decrease their resilience to the soil. Genetically modified microorganisms not only improve yield of polysaccharides, but also allow economically efficient production. With the rapid advancement of science and medicine, biosynthesis of polysaccharides research has become increasingly important. Synthetic biology approaches can play a critical role in developing polysaccharides in simple and facile ways. In addition, potential applications of microbial polysaccharides in different fields with a particular focus on food applications have been assessed.

Sulfated Modification, Characterization and Potential Bioactivities of Polysaccharide From Ziziphus jujuba cv. Jinsixiaozao

In this study, jujube polysaccharide (JP) was extracted from Ziziphus jujuba cv. Jinsixiaozao and sulfated JP (SJP) was prepared. The optimum preparation conditions were as follows: reaction temperature 75°C, reaction time 1 h, ratio of chlorosulfonic acid-to-pyridine ( VCSA/ VPyr) 1. The degree of substitution of SJP was 0.664 ± 0.014. JP and SJP were typical heteropolysaccharides, which were composed of rhamnose, arabinose, xylose, mannose, glucose, and galactose, but the molar ratio of monosaccharides was different. Fourier transform infrared spectra showed that JP was sulfated successfully. Compared with JP, the molecular weight of SJP increased to 3.17 × 105 Da, its water solubility increased significantly, and its viscosity decreased significantly. When the microstructure of SJP was examined, it was found that the surface of the polysaccharides became loose and porous after sulfation. SJP had a higher hydroxyl radical scavenging activity than the unsulfated polysaccharide. Moreover, sulfation enhanced the antibacterial activity of the polysaccharides against Escherichia coli and Bacillus subtilis. Therefore, sulfation is an effective way to improve the biological activity of the polysaccharide, and SJP can be used as a potential antioxidant and antimicrobial agent in the field of food and medicine.

A Comprehensive Review of Phytochemistry and Biological Activities of Quercus Species

The Quercus genus provides a large amount of biomaterial with many applications in fields like pharmaceutics, cosmetics, and foodstuff areas. Due to the worldwide dissemination of the genus, many species were used for centuries in traditional healing methods or in the wine maturing process. This review aims to bring together the results about phytoconstituents from oak extracts and their biological applicability as antioxidants, antimicrobial, anticancer, etc. The literature data used in this paper were collected via PubMed, Scopus, and Science Direct (2010–June 2020). The inclusion criteria were papers published in English, with information about phytoconstituents from Quercus species (leaves, bark and seeds/acorns) and biological activities such as antioxidant, antibacterial, antiobesity, anti-acne vulgaris, antifungal, anticancer, antiviral, antileishmanial, antidiabetic, anti-inflammatory. The exclusion criteria were the research of other parts of the Quercus species (e.g., galls, wood, and twigs); lack of information about phytochemistry and biological activities; non-existent Quercus species reported by the authors. The most studied Quercus species, in terms of identified biomolecules and biological activity, are Q. brantii, Q. infectoria and Q. robur. The Quercus species have been reported to contain several phytoconstituents. The main bioactive phytochemicals are phenolic compounds, volatile organic compounds, sterols, aliphatic alcohols and fatty acids. The, Quercus species are intensely studied due to their antioxidant, anti-inflammatory, antimicrobial, and anticancer activities, provided by their phytochemical composition. The general conclusion is that oak extracts can be exploited for their biological activity and can be used in research fields, such as pharmaceutical, nutraceutical and medical.

Ultrasound-Assisted Enzymatic Extraction of Adenosine from Vietnamese Cordyceps militaris and Bioactivity Analysis of the Extract

Vietnamese Cordyceps militaris (C. militaris) has long been recognized as one of the most valuable traditional Chinese medicines. In this study, adenosine was extracted from Vietnamese C. militaris by ultrasound-assisted enzymatic extraction method (UAEE) using water as a solvent. Then, the effects of five single factors on adenosine content including pH, enzyme-to-material ratio, ultrasonic power, ultrasonic time, and ultrasonic temperature were determined. After that, three factors consisting of ultrasonic power, ultrasonic time, and ultrasonic temperature were chosen based on their effects on adenosine content. The simultaneous influence of these factors on the adenosine content was investigated by response surface method using central composite design. The adenosine content was evaluated by high-performance liquid chromatography method. Under the optimal conditions, the extract was evaluated for antioxidant and anticancer bioactivities. In addition, different extraction methods including aqueous extraction (AE), ultrasound-assisted extraction (UAE), and enzyme-assisted extraction (EAE) methods were carried out to compare with UAEE. As a result, it can be concluded that UAEE is a promising method for adenosine extraction and further studies regarding isolation and purification need to be conducted.

Chemical composition, sensory properties and bioactivities of Castanopsis lamontii buds and mature leaves

Castanopsis lamontii is used as functional herbal tea in southwest China. Usually, only buds rather than mature leaves are applied. To figure out whether mature leaves were suitable for producing herbal tea, chemical composition, sensory properties and bioactivities of Castanopsis lamontii bud infusion (CLB) and mature leaf infusion (CLM) were investigated. According to the results, CLB and CLM had similar non-volatile composition, but in different proportion. Meanwhile, CLB contained more types of volatiles than CLM, leading to distinguishable volatile profiles between them. Sensory assessment showed that CLB had sweet aftertaste and floral aroma. CLM tasted astringent and smelled grassy. Bioactivity evaluation indicated that CLB exhibited higher activities in scavenging free radicals and suppressing lipopolysaccharide-induced inflammation. Taken together, CLB had better overall acceptability in sensory quality and higher bioactivity, implying that Castanopsis lamontii buds were more suitable for producing herbal tea.

Investigation of the Antibacterial Activity and Subacute Toxicity of a Quercus crassifolia Polyphenolic Bark Extract for its Potential Use in Functional Foods

Oak wood is used in barrels for wine aging. During aging, polyphenols are transferred from the barrels to the liquid. Although the bioactivity of oak polyphenols in wines has been extensively studied, no investigation exists on their toxicological properties, which limits their use as functional safe ingredients for other products. In this work, the chemical composition of a polyphenolic extract of Quercus crassifolia bark (QCBe) was studied by GC-MS. Its antibacterial properties on probiotic and pathogenic bacteria and its subacute-oral toxicity were determined as a way to understand the potential impact from its addition to fermented food as a functional ingredient. QCBe shows a selective inhibition of Escherichia coli compared with Lactobacillus bulgaricus and Streptococcus thermophylus. According to the toxicity evaluation, the subacute no-observed-adverse-effect-level was achieved at 11 mg/kg bw/day, whereas the subacute lowest-observed-adverse-effect-level for kidney damage was at 33 mg/kg bw/day. These results suggest that, given the fact an adverse effect was observed after subacute administration of this extract, further longer term toxicological studies are needed to provide sufficient safety evidence for its use in humans. PRACTICAL APPLICATION: Mexico's yogurt market is growing which creates opportunities for the development of some yogurt products as functional foods. As a first step to evaluate its potential use in yogurt formulation, the antibacterial effect of a Quercus crassifolia polyphenolic extract (QCBe) on probiotic bacteria and its subacute-oral toxicity in rats were studied. A low inhibition on probiotic bacteria growth was observed after QCBe addition to Lactobacillus bulgaricus and Streptococcus thermophylus cultures. Exposure to QCBe for a subacute duration resulted in renal injury in rats at dosages greater than or equal to 33 mg/kg/bw/day. This adverse effect indicates the importance of performing further long-term toxicological assessments prior to the addition of QCBe to a food like yogurt, which is regularly eaten by consumers.

Bioactive exopolysaccharide from Neopestalotiopsis sp. strain SKE15: Production, characterization and optimization

Fungal exopolysaccharides are powerful resources of medicinal applications. Neopestalotiopsis sp. SKE15 was isolated and identified according to phenotypical and genotypical analyses (GenBank Accession No. MG649986). The exopolysaccharide (EPS) was produced by cultivation of mycelia in broth culture and extracted. The production was optimized to 2.02 g/l after selection of agitation, temperature, FeSO₄ and K₂HPO₄ concentrations as the most influencing factors using Placket-Burman design and then by applying response surface methodology. Analytical Tools showed that the EPS is composed of a polysaccharide (1.5-2.1 × 10⁶ Da) and its probable low molecular weight derivatives, in a wide range of chain lengths, among them an oligosaccharide of about 1970 Da was dominant. GC-MS (Gas chromatography-mass spectrometry) analysis revealed the EPS was mainly constructed from d-glucose, sorbitol and D-galactose. The EPS showed antibacterial activity against Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633 and Pseudomonas aeruginosa ATCC 27853. DPPH (1,1-diphenyl-2-picryl-hydrazyl) and hydroxyl radical scavenging activity assays showed strong antioxidant activity of the EPS. A challenge with three different cancerous cell lines showed cytotoxic activity of the EPS at final concentration of 100 and 200 μg/ml. Further investigation on medicinal applications of the biopolymer is promising.

Preparation, identification and molecular docking study of novel osteoblast proliferation-promoting peptides from yak (Bos grunniens) bones

The aim of this study was to isolate and identify osteogenic bioactive peptides from yak bones collagen, while simultaneously investigating their underlying mechanisms for promoting osteoblast proliferation. Response surface methodology (RSM) was employed to investigate the effect of hydrolysis variables on the production of peptides with osteoblast proliferation-promoting activity (OPPA). The concentration of soluble peptides reached 0.5169 mg mL-1, which was well matched with the value (0.5189 mg mL-1) predicted by the model, with the following optimized conditions: hydrolysis time, 3.6 h; pH, 6.12; hydrolysis temperature, 54 °C; E/S (enzyme to substrate) of 5637 U g-1. Hydrolysates were then separated using an ultrafiltration membrane system, and the peptides (<3 kDa) possessed excellent OPPA with a dose-response relationship. A total of 59 novel peptides were identified by HPLC-MS/MS with Mascot analysis. GPSGPAGKDGRIGQPG (GP-16) and GDRGETGPAGPAGPIGPV (GD-18) were selected for docking to investigate the underlying mechanisms of interaction. The molecular docking study revealed that osteoblast proliferation stimulation activity of GP-16 and GD-18 was mainly attributed to the formation of very strong hydrogen bonds with the epidermal growth factor receptor (EGFR). These results indicate that such peptides are promising in the discovery of potential candidates for the future industrial production of functional peptides, which could be used in the mediated treatment of osteoporosis.

Hypoglycemic Effects in Alloxan-Induced Diabetic Rats of the Phenolic Extract from Mongolian Oak Cups Enriched in Ellagic Acid, Kaempferol and Their Derivatives

Our previous reports showed that crude extract prepared with 50% ethanol (ethanol crude extract, ECE) from Mongolian oak cups possessed excellent in vitro antioxidant capacities as well as inhibitory activities against α-glucosidase, α-amylase and protein glycation caused by its enrichment in phenolics, including mainly ellagic acid, kaempferol and their derivatives. Nevertheless, few in vivo studies on antidiabetic activities of these phenolics were conducted. The present study investigated hypoglycemic effects with normal and diabetic rats being administrated orally without or with ECE at 200 and 800 mg/kg for 15 days. In normal rats, no significant differences were exhibited after ECE administration in body weight, fasting blood glucose level, levels of cholesterol, triglyceride, LDL and AST in serum, organ indexes, and levels of GSH and MDA in organs. In diabetic rats, the fasting blood glucose level, indexes of heart and liver, and levels of cholesterol and triglyceride in serum and MDA in heart tissue were significantly decreased. Moreover, HDL levels in serum and SOD activities in the four organs of diabetic rats were significantly improved after ECE administration at 800 mg/kg. Thus, in addition to inhibiting α-glucosidase, α-amylase and protein glycation reported previously, oak cups might contain novel dietary phytonutrients in preventing abnormal changes in blood glucose and lipid profile and attenuating oxidant stress in vivo. The results also implied that it is ellagic acid, kaempferol and their derivatives enriched in ECE that might play vital roles in managing type 1 as well as type 2 diabetes.

Ultrasound-assisted Extraction of Polysaccharide from Radix Bupleuri using Response Surface Methodology and Antioxidant Research of the Polysaccharide

This report used Response Surface Methodology (RSM) to analyze the conditions that extracting polysaccharide compound from Radix Bupleuri using ultrasonic wave. For determining the optimal extraction conditions, four independent variables, temperature (°C), ultrasonic intensity (UI, W/cm2), dilution rate (water-material ratio, mL/g) and time (min), were investigated using Box-Behnken design. In the results, the best condition after optimization was dilution rate of 35.0:1, UI of 24.5 W/cm2, temperature of 69.5°C and time of 14.6 min. Extraction efficiency was 7.67% and the purity reached 44.14%. It illustrates that the ultrasound-assisted extraction (UAE) was efficient and suitable for extracting polysaccharide from Radix Bupleuri. This paper also investigated the antioxidant activity of Radix Bupleuri polysaccharide (RBP) on superoxide anion radical, hydroxyl radical, and 2,2-diphenyl-1-picry-hydrazyl (DPPH), in vitro experiment. The result indicated that RBP could remarkably sweep away the hydroxyl radical, and had the capacity for clearing away superoxide radical and DPPH.

Ultrasonic-assisted enzymatic extraction of a water soluble polysaccharide from dragon fruit peel and its antioxidant activity

A novel water soluble polysaccharide from dragon fruit peel named DFPWSP-1 was isolated and purified and chemical analysis was performed. The results indicated that DFPWSP-1, with an average molecular weight of 2.98 × 10² kDa, mainly contained galacturonic acid, glucose and galactose. Then, a Box–Behnken design (BBD) was employed to optimize the ultrasonic-assisted enzymatic extraction (UAEE) of DFPWSP-1. The optimal extraction conditions for the maximum yield of DFPWSP-1 were a cellulase volume of 104 U, an enzymolysis time of 2.06 h, an ultrasonication power of 105 W and a ratio of solution to sample of 8.5 mL g⁻¹. Under these conditions, the extraction yield of DFPWSP-1 was 20.28%. Furthermore, the polysaccharide DFPWSP-1 exhibited a significant scavenging activity of 2-diphenyl-picrylhydrazyl (DPPH) radical, superoxide anion and hydroxyl radical. DFPWSP-1 may be a potential natural antioxidant in the food industry.

A novel water soluble polysaccharide from dragon fruit peel named DFPWSP-1 was isolated and purified and chemical analysis was performed.

Optimization conditions for extracting polysaccharide from Angelica sinensis and its antioxidant activities

In this study, polysaccharides from Angelica sinensis were extracted using the ultrasound-assisted extraction method. Based on the results of single factor experiments and orthogonal tests, three independent variables—water/raw material ratio, ultrasound time, and ultrasound power—were selected for investigation. Then, we used response surface methodology to optimize the extraction conditions. The experimental data were fitted to a quadratic equation using multiple regression analysis, and the optimal conditions were as follows: water/raw material ratio, 43.31 mL/g; ultrasonic time, 28.06 minutes; power, 396.83 W. Under such conditions, the polysaccharide yield was 21.89 ± 0.21%, which was well matched with the predicted yield. In vitro assays, scavenging activity of superoxide anion radicals, hydroxyl radicals, and 2,2-diphenyl-1-picry-hydrazyl radical showed that polysaccharides had certain antioxidant activities and that hydroxyl radicals have a remarkable scavenging capability. Therefore, these studies provide reference for further research and rational development of A. sinensis polysaccharide.

Response surface design for accumulation of selenium by different lactic acid bacteria

The accumulation of selenium (Se) by Lactobacillus delbrueckii ssp. bulgaricus (Lb) and Streptococcus thermophilus (St) at the different cultivation conditions, including initial pH, inoculum dose (%), and temperature (°C), was investigated in this work. Se enrichment efficiency was optimized using the Design-Expert software for response surface methodology on a basis of single-factor experiment. The antioxidant activities of Se-enriched Lactic acid bacteria (LAB) were also investigated. The qualitative analysis of Se-enriched LAB was performed by FT-IR spectra. The cell morphology and chemical element components were measured by a scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy. The results indicated that the optimum initial pH, inoculum doses, and temperatures of Lb and St were 5.96, 6.73%, 33.24 °C, and 6.37, 6%, 40 °C, respectively. Under the optimal conditions, the ratios of Se enrichment reached 94.34% for Lb and 97.05% for St. Furthermore, Se-enriched LAB enhanced scavenging rates on DPPH, ABTS free radical, and also heightened reducing activity. The FT-IR results showed that the two Se-enriched strains had similar characteristic absorption peaks, which were further demonstrated that both Se biomasses had the same carbonyl, carboxyl, and hydroxyl groups. Elemental selenium nanoparticles were verified around cell surfaces of Se-enriched LAB, which implied that both strains had detoxification ability when grown in liquid media containing selenite.

Extraction Optimization, Purification and Physicochemical Properties of Polysaccharides from Gynura medica

Extraction of polysaccharides from Gynura medica (GMPs) was optimized by response surface methodology (RSM). A central composition design including three parameters, namely extraction temperature (X₁), ratio of water to raw material (X₂) and extraction time (X₃), was used. The best conditions were extraction temperature of 91.7 °C, extraction time of 4.06 h and ratio of water to raw material of 29.1 mL/g. Under the optimized conditions, the yield of GMPs was 5.56%, which was similar to the predicted polysaccharides yield of 5.66%. A fraction named GMP-1 was obtained after isolation and purification by DEAE-52 and Sephadex G-100 gel chromatography, respectively. GMP-1, with a molecular weight of 401 kDa, mainly consisted of galacturonic acid (GalA), xylose (Xyl), glucose (Glu). Infrared spectroscopy was used to characterize the major functional groups of GMP-1 and the results indicated that it was an acidic polysaccharide. The antioxidant and α-glucosidase inhibitory activities of GMPs and GMP-1 were determined in vitro. The results indicated that GMPs and GMP-1 show potential for use in functional foods or medicines.

Optimization of Process Parameters forε-Polylysine Production by Response Surface Methods

ε-Polylysine (ε-PL) is a highly safe natural food preservative with a broad antimicrobial spectrum, excellent corrosion resistances, and great commercial potentials. In the present work, we evaluated theε-PL adsorption performances of HZB-3B and D155 resins and optimized the adsorption and desorption conditions by single-factor test, response surface method, and orthogonal design. The complexes of resin andε-PL were characterized by SEM and FITR. The results indicated that D155 resin had the bestε-PL adsorption performance and was selected for the separation and purification ofε-PL. The conditions for the static adsorption ofε-PL on D155 resin were optimized as follows:ε-PL solution 40 g/L, pH 8.5, resins 15 g/L, and absorption time 14 h. The adsorption efficiency ofε-PL under the optimal conditions was 96.84%. Theε-PL adsorbed on the D155 resin was easily desorbed with 0.4 mol/L HCl at 30°C in 10 h. The highest desorption efficiency was 97.57% and the overall recovery ofε-PL was 94.49% under the optimal conditions. The excellentε-PL adsorption and desorption properties of D155 resin including high selectivity and adsorption capacity, easy desorption, and high stability make it a good candidate for the isolation ofε-PL from fermentation broths.

Multi-Optimization of Ultrasonic-Assisted Enzymatic Extraction of Atratylodes macrocephala Polysaccharides and Antioxidants Using Response Surface Methodology and Desirability Function Approach

Rhizoma Atractylodes macrocephala polysaccharides (RAMP) have been reported to have a variety of important biological activities. In this study, an ultrasonic-assisted enzymatic extraction (UAEE) was employed to obtain the highest extraction yield and strongest antioxidant activity of RAMP and optimized by a multi-response optimization process. A three-level four-factor Box-Behnken design (BBD) was performed as response surface methodology (RSM) with desirability function (DF) to attain the optimal extraction parameters. The DPPH scavenging percentage was used to represent the antioxidant ability of RAMP. The maximum D value (0.328), along with the maximum yield (59.92%) and DPPH scavenging percentage (13.28%) were achieved at 90.54 min, 57.99 °C, 1.95% cellulase and 225.29 W. These values were further validated and found to be in good agreement with the predicted values. Compared to the other extraction methods, both the yield and scavenging percentage of RAMP obtained by UAEE was favorable and the method appeared to be time-saving and of high efficiency. These results demostrated that UAEE is an appropriate and effective extraction technique. Moreover, RSM with DF approach has been proved to be adequate for the design and optimization of the extraction parameters for RAMP. This work has a wide range of implications for the design and operation of polysaccharide extraction processes.

Improvement of antioxidant and moisture-preserving activities of Sargassum horneri polysaccharide enzymatic hydrolyzates

In the previous study, we have found that polysaccharides isolated from Sargassum horneri exhibited bioactivities. The aim of this study was to investigate the antioxidant and moisture-preserving activities of molecular weight alteration of Sargassum horneri polysaccharide in vitro. For this purpose, the homogeneous active polysaccharide SHP was isolated from Sargassum horneri, and response surface methodology was employed to optimize the enzymatic degradation conditions to get SHP-derived fragments with different molecular weight. Results proved that the polysaccharide is capable of scavenging both ABTS and DPPH radicals in vitro. The study revealed that the polysaccharides had strong moisture-absorption and -retention capacities as compared to propanediol and glycerin. Furthermore, these data demonstrated that molecular weight had a certain effect on antioxidant activities and strong moisture-retention capacities of the polysaccharide from Sargassum horneri.

Lignin degradation in corn stalk by combined method of H2O2 hydrolysis and Aspergillus oryzae CGMCC5992 liquid-state fermentation

BACKGROUND

Lignin peroxidase (LiP) is the primary enzyme responsible for lignin degradation. In our previous work, in order to shorten the pretreatment time and increase the lignin degradation, we have pretreated the corn stalk (CS) using a combination of Aspergillus oryzae CGMCC 5992 solid-state fermentation and H2O2 treatment.

RESULTS

In the present study, one-factor-at-a-time design and response surface design were applied to optimize the nutritional constituents for LiP production in liquid-state fermentation by A. oryzae CGMCC 5992 and the conditions for CS degradation by A. oryzae CGMCC 5992. The optimal medium included CS of 30 g/L, glucose of 4.6 g/L, sodium nitrate of 1.2 g/L, corn steep liquor of 1 g/L, yeast extract of 1.2 g/L, and vitamin B1 of 0.15 g/L. Under these optimal conditions, the LiP production reached its maximum of 652.34 U/L. The optimal condition for CS degradation included CS of 20 g, A. oryzae CGMCC 5992 broth of 50 mL, 1.5 % H2O2 solution of 80 mL, H2O2 flow rate of 0.4 mL/min, water volume of 240 mL (water/material ratio of 12:1), hydrolysis temperature of 39 °C, and hydrolysis time of 8 h. Before hydrolysis, CS and water were pretreated at 113 °C for 11 min. Under these optimal conditions, the sugar yield reached its maximum of 46.28 %.

CONCLUSIONS

Our newly developed method had great advantages in pretreatment of CS due to its quickness, convenience, safety, no special equipment and high sugar yield.Graphical abstractThe schematic diagram of corn straw hydrolysis.

Optimization of ultrasonic-assisted alkaline extraction of polysaccharides from Phellodendron amurense Rupr. pollen using response surface methodology and its structure features

To investigate extraction technology and determine the optimal extraction conditions of polysaccharides from Phellodendron amurense Rupr. pollen (PARPP), an alkaline extraction method was carried out to extract PARPP with ultrasonic treatment.