Effects of different strains fermentation on nutritional functional components and flavor compounds of sweet potato slurry.

In this paper, we study the effect of microbial fermentation on the nutrient composition and flavor of sweet potato slurry, different strains of Aspergillus niger, Saccharomyces cerevisiae, Lactobacillus plantarum, Bacillus coagulans, Bacillus subtilis, Lactobacillus acidophilus, and Bifidobacterium brevis were employed to ferment sweet potato slurry. After 48 h of fermentation with different strains (10% inoculation amount), we compared the effects of several strains on the nutritional and functional constituents (protein, soluble dietary fiber, organic acid, soluble sugar, total polyphenol, free amino acid, and sensory characteristics). The results demonstrated that the total sugar level of sweet potato slurry fell significantly after fermentation by various strains, indicating that these strains can utilize the nutritious components of sweet potato slurry for fermentation. The slurry's total protein and phenol concentrations increased significantly, and many strains demonstrated excellent fermentation performance. The pH of the slurry dropped from 6.78 to 3.28 to 5.95 after fermentation. The fermentation broth contained 17 free amino acids, and the change in free amino acid content is closely correlated with the flavor of the sweet potato fermentation slurry. The gas chromatography-mass spectrometry results reveal that microbial fermentation can effectively increase the kinds and concentration of flavor components in sweet potato slurry, enhancing its flavor and flavor profile. The results demonstrated that Aspergillus niger fermentation of sweet potato slurry might greatly enhance protein and total phenolic content, which is crucial in enhancing nutrition. However, Bacillus coagulans fermentation can enhance the concentration of free amino acids in sweet potato slurry by 64.83%, with a significant rise in fresh and sweet amino acids. After fermentation by Bacillus coagulans, the concentration of lactic acid and volatile flavor substances also achieved its highest level, which can considerably enhance its flavor. The above results showed that Aspergillus niger and Bacillus coagulans could be the ideal strains for sweet potato slurry fermentation.

Effect of fermentation on structural properties and antioxidant activity of wheat gluten by Bacillus subtilis.

Bacillus subtilis has been extensively studied for its ability to inhibit the growth of harmful microorganisms and its high protease activity. In this study, Bacillus subtilis was used to ferment gluten and assess the effects of the fermentation process on the physicochemical, microstructure and antioxidant properties of gluten. The results of Fourier infrared spectroscopy (FT-IR) and circular chromatography (CD) showed a significant decrease in the content of α-helix structures and a significant increase in the content of ß-sheet structures in gluten after fermentation (p < 0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that glutenin was degraded into small molecular peptides with a molecular weight of less than 26 kDa after 24 h of fermentation; meanwhile, the fermentation process significantly increased the free amino acid content of the samples (p < 0.05), reaching 1923.38 µg/mL at 120 h of fermentation, which was 39.46 times higher than that at 24 h of fermentation (p < 0.05). In addition, the fermented back gluten has higher free radical scavenging activity and iron reduction capacity. Therefore, fermented gluten may be used as a functional food to alleviate oxidative stress. This study provides a reference for the high-value application of gluten.

Structural, Physicochemical, and Functional Properties of Wheat Bran Insoluble Dietary Fiber Modified With Probiotic Fermentation.

Insoluble dietary fiber (IDF) were isolated from wheat bran (WB) after microbial fermentation with single or mixed strain [Lactobacillus plantarum, Lactobacillus acidophilus, Bacillus subtilis or mixed lactic acid bacteria (L. plantarum and L. acidophilus with ration of 1:1)]. Structure, physicochemical, functional properties, and antioxidant activity of the wheat bran insoluble dietary fiber (W-IDF) modified by fermentation were studied. Fourier transformed infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) analysis suggested the successful modification of W-IDF. After fermentation with L. plantarum and mixed lactic acid bacteria, the water retention capacity (WRC), oil retention capacity (ORC), and water swelling capacity (WSC) of W-IDF were improved. The sodium cholate adsorption capacity (SCAC), and cation exchange capacity (CEC) of W-IDF modified with L. acidophilus fermentation were significantly increased. Although the cholesterol adsorption capacity (CAC) of W-IDF decreased after modification with probiotic fermentation, nitrite ion adsorption capacity (NIAC), and total phenolic content (TPC) were enhanced. Additionally, W-IDF modified by fermentation with B. subtilis or mixed lactic acid bacteria exhibited superior antioxidant capacity verified by DPPH, ABTS and total reducing power assays. Results manifested that microbial fermentation is a promising methods to modify the W-IDF to provide high-quality functional IDF for food processing and human health management.

Preparation and identification of an antioxidant peptide from wheat embryo albumin and characterization of its Maillard reaction products.

Wheat embryo albumin (WEA) extracted from wheat embryo possesses multiple effects including antioxidant, anti-inflammatory, and immunoregulatory effects. In this study, a single factor experiment was conducted to determine the optimal enzymolysis conditions of WEA. Five components (F1-F5) were obtained via ultrafiltration, among which F3 (molecular weight 3-5 kDa) displayed the best antioxidant activity. WEA and F3 were characterized by transmission electron microscopy, scanning electron microscopy, circular dichroism spectrum analysis, and amino acid composition tests. Results revealed that F3 significantly increased the contents of ß-tablets, aromatic amino acids, and hydrophobic amino acids compared to WEA. LC-MS/MS analysis demonstrated that F3 had more tyrosine and histidine moieties than WEA. Moreover, analysis of the Maillard reaction products (MRPs) showed that F3-MRPs had strong browning strength, ultraviolet absorption, higher number of free amino acids, and umami amino acid ratio compared with WEA. In conclusion, enzymolysis can improve the functional properties of WEA, which broadens the application spectrum of WEA in food and pharmaceutical fields. PRACTICAL APPLICATION: This study provides a new approach for identifying potential antioxidants and developing functional foods from WEA, and broadens the application spectrum of wheat germ resources.

In vitro dynamic digestion and anti-fatigue effects of wheat embryo albumin.

Wheat germ protein including wheat embryo albumin (WEA) demonstrates extensive biological activity. In vitro dynamic digestion of WEA was carried out under simulated gastrointestinal conditions. Anti-fatigue effects of WEA were evaluated using mice forced to swim. Results indicated that the digestibility of WEA decreased, antioxidant activity and the contents of aromatic amino acids (AAA) and hydrophobic amino acids (HAA) were significantly increased, and the ratio of essential amino acid (EAA) and non-essential amino acid (NEAA) were also changed during digestion. WEA significantly prolonged swimming time, reduced the accumulation of lactate dehydrogenase (LDH), blood urea nitrogen (BUN), and creatine kinase (CK). WEA also increased glycogen storage in liver and muscle. Meanwhile, WEA revealed antioxidant activity through enhancing the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) while decreasing the level of malondialdehyde (MDA). Notably, WEA enhanced the mRNA expression of mitochondrial biogenesis factors in the skeletal muscles of the mice. Therefore, WEA is suitable for preparation of energy foods with attractive anti-fatigue and health benefits.

Wheat embryo globulin nutrients ameliorate d-galactose and aluminum chloride-induced cognitive impairment in rats.

Wheat embryo globulin nutrient (WEGN), with wheat embryo globulin (WEG) as the main functional component, is a nutritional combination that specifically targets memory impairment. In this study, we explored the protective role of WEGN on Alzheimer's disease (AD)-triggered cognitive impairment, neuronal injury, oxidative stress, and acetylcholine system disorder. Specifically, we established an AD model via administration of d-galactose (d-gal) and Aluminum chloride (AlCl3) for 70 days, then on the 36th day, administered animals in the donepezil and WEGN (300, 600, and 900 mg/kg) groups with drugs by gavage for 35 days. Learning and memory ability of the treated rats was tested using the Morris water maze (MWM) and novel object recognition (NOR) test, while pathological changes and neuronal death in their hippocampus CA1 were detected via HE staining and Nissl staining. Moreover, we determined antioxidant enzymes by measuring levels of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) in serum, cortex, and hippocampus, whereas changes in the acetylcholine system were determined by evaluating choline acetyltransferase (ChAT), and acetylcholinesterase (AChE) activities, as well as choline acetylcholine (Ach) content. Results revealed that rats in the WEGN group exhibited significantly lower escape latency, as well as a significantly higher number of targeted crossings and longer residence times in the target quadrant, relative to those in the model group. Notably, rats in the WEGN group spent more time exploring new objects and exhibited lower damage to their hippocampus neuron, had improved learning and memory activity, as well as reversed histological alterations, relative to those in the model group. Meanwhile, biochemical examinations revealed that rats in the WEGN group had significantly lower MDA levels and AChE activities, but significantly higher GSH, SOD, and ChAT activities, as well as Ach content, relative to those in the model group. Overall, these findings indicate that WEGN exerts protective effects on cognitive impairment, neuronal damage, oxidative stress, and choline function in AD rats treated by d-gal/AlCl3.

Wheat embryo globulin protects against acute alcohol-induced liver injury in mice.

Wheat Embryo Globulin (WEG) is a high-quality plant-derived protein with anti-inflammatory, antioxidant, and immunity enhancement effects. WEG was prepared and characterized using free amino acid analysis, circular dichroism (CD), and scanning electron microscope (SEM). The liver protection effect of WEG on mice after acute alcohol stimulation was also investigated. Male KM mice were randomly divided into four groups (n = 10). Animals were orally administrated with WEG (60 mg/kg), silymarin (50 mg/kg), and the same volume of saline solution daily for 30 days, before administering an alcohol-intragastric injection. Results displayed that the liver index, the levels of serum total cholesterol (TC), serum triglyceride (TG), liver malondialdehyde (MDA) and the mRNA expression of CYP2E1were significantly decreased in WEG-treated mice compared with the model group. Meanwhile, the levels of serum high-density lipoprotein-cholesterol (HDL-C), hepatic reduced glutathione (GSH), superoxide dismutase (SOD) and the mRNA expression of ADH2 and ALDH2 were remarkably increased. Effect of WEG on histopathology of liver tissue confirmed its protective function. Meanwhile, GSH level of ileal was significantly increased, MDA was remarkably decreased in WEG-treated mice, which also indicated that WEG possessed a positive effect on intestinal micro ecological environment health to some extent. In conclusion, WEG is a promising agent for the prevention of acute alcoholic liver injury.

Preparation, characterization, and cytotoxicity evaluation of self-assembled nanoparticles of diosgenin-cytarabine conjugate.

Diosgenin (DG) isolated from yam roots revealed various bioactivities and applications as drug carrier. In the present study, a conjugate of DG with cytarabine (Ara-C) was used to prepare the self-assembled nanoparticles (NPs) of DG-Ara-C by a nanoprecipitation method. Dynamic light scattering (DLS) as well as transmission electron microscopy (TEM) were employed to analyze the size and the morphology of NPs, respectively. The stability and absorption of DG-Ara-C NPs were measured. Additionally, the cytotoxicity of the NPs was determined via MTT assay. The results indicated that the average particle size of DG-Ara-C NPs was around 190 nm with a narrow size distribution (PDI = 0.1). TEM showed that DG-Ara-C NPs had a spherical morphology. Compared to free DG or Ara-C, the self-assembled DG-Ara-C NPs exhibited a better anti-tumor activity against solid tumor cells as well as leukemia cells. In conclusion, DG possesses dual role in the self-assembled NPs of DG-Ara-C conjugate, being as a promising anticancer drug and drug carrier.

Synthesis, anticancer activity and potential application of diosgenin modified cancer chemotherapeutic agent cytarabine.

Diosgenin (DG), a steroidal saponin, is mainly found in yam tubers. DG and its derivatives displayed significant pharmacological activities against inflammatory, hyperlipidemia, and various cancers. DG was selected to modify the cancer chemotherapeutic agent cytarabine (Ara-C) due to its anti-tumor activities as well as lipophilicity. After characterization, the biomembrane affinity and the kinetic thermal processes of the obtained DG-Ara-C conjugate were evaluated by differential scanning calorimetry (DSC). Thin hydration method with sonication was applied to prepare the DG-Ara-C liposomes without cholesterol since the DG moiety has the similar basic structure with cholesterol with more advantages. Dynamic Light Scattering (DLS) analysis and cytotoxic analysis were employed to characterize the DG-Ara-C liposomes and investigate their biological activities, respectively. The results indicated that DG changed the biomembrane affinity of Ara-C and successfully replaced the cholesterol during the liposome preparation. The DG-Ara-C liposomes have an average particle size of around 116 nm with a narrow size distribution and revealed better anti-cancer activity against leukemia cells and solid tumor cells than that of free DG or Ara-C. Therefore, it can be concluded that DG displayed the potential application as an anti-cancer drug carrier to improve the bio-activities, since DG counted for a critical component in modulating the biomembrane affinity, preparation of liposome, and release of hydrophilic Ara-C from lipid vesicles.

Effects of sulfated, phosphorylated and carboxymethylated modifications on the antioxidant activities in-vitro of polysaccharides sequentially extracted from Amana edulis.

In this study, four sequentially extracted polysaccharides (AEPs) from Amana edulis were modified by sulphation, phosphorylation, and carboxylation modifications (S-AEPs, P-AEPs, C-AEPs), and compared for their anti-oxidant activities. After modification, sugar and protein contents were decreased and uronic acid content was increased in comparison to native AEPs. UV absorption showed similar maximum absorption peaks of modified derivatives which indicated their homogeneous nature. FTIR spectra confirmed the conversion of hydroxyl groups to OS, COO, and POH bonds, respectively. The phosphorylated derivatives (P-AEPs) displayed the highest DPPH, hydroxyl radical, and ferrous ions radical scavenging abilities. Sulfated polysaccharides (S-AEPs) were observed with high reducing ability. The C-AEPs maintained the stable antioxidant properties after carboxylation modification. Our results indicated that the chemical modification of different polysaccharide components has significantly affected their antioxidant potential for their use in food industry and human health.

Aromatic effects of immobilized enzymatic oxidation of chicken fat on flaxseed (Linum usitatissimum L.) derived Maillard reaction products.

To control the oxidation in chicken fat by immobilized lipoxygenase (LOX), Maillard reaction products (MRPs) with chicken flavor were prepared and analyzed for flavor mechanism. >50% activity of immobilized LOX was retained after repeated use for five times or five weeks. The oxidized chicken fats were prepared by thermal, free LOX, and immobilized LOX treatments. After addition of chicken fats, Maillard reaction produced more aliphatic aldehydes and alcohols (126.0-839.5 ng/g and 493.5-2332.4 ng/g, respectively) which resulted in noticeable enhanced reaction, but the content of sulfur compounds such as thiols and thiophenes decreased significantly (870.8-1233.9 ng/g and 1125.0-2880.3 ng/g, respectively), and the structure of sulfur compounds could easily form alkyl side chains. However, there was no significant difference in sensory and flavors between oxidized chicken after treatments, which may be related to oxidized degree. The mechanism was proposed or aromatic effects of oxidized chicken fat on flaxseed derived MRPs.

Microstructural, Textural, Sensory Properties and Quality of Wheat-Yam Composite Flour Noodles.

Herein, feasibility of supplementing wheat flour with Chinese yam powder (CYP) for noodle preparation was assessed. After supplementation with CYP, the alterations in chemical, texture, cooking, rheological, and microstructure attributes of noodles were observed. Due to higher protein and lower gluten, 20% of CYP promoted the stable network of gluten and starch particles. However, the excessive addition reduced the flexibility and the chewiness. The adverse changes were observed at 40% substitution level in texture profile analysis (TPA) and rheological parameters due to disrupted gluten-protein network which accelerated the exposure of starch particles. The CYP incorporation up to 20% showed better mouthfeel but further addition lowered the total sensory scores. Scanning Electronic Microscopy (SEM) analysis confirmed the modifications in noodles microstructure as CYP addition affected starch granule structure. In general, 30% substitution significantly improved the textural and rheological properties of noodles, indicating the potential of Chinese yam powder for industrial application.

The rheological properties and emulsifying behavior of polysaccharides sequentially extracted from Amana edulis.

The rheological properties and emulsifying behavior of four polysaccharides (HBSS, CHSS, DASS, and CASS) sequentially extracted from Amana edulis (AEPs) were investigated under various concentrations, temperatures, pH levels, and ionic strengths. The apparent viscosity of the four AEPs solutions at 1% (w/w) concentration were found to be CHSS > DASS > HBSS > CASS. When the AEPs were heated to 100 οC, they showed lower colloidal viscosity, whereas after refrigeration and chilling, higher apparent viscosities were observed. The apparent viscosity of four AEPs at pH 10 or pH 4 was lower than that at pH 7. The apparent viscosity increased at a lower sodium ion concentration and then declined with an increase in ion concentration. The storage modulus (G') and loss modulus (G″) increased with an increase in oscillation frequency. The emulsifying activity and stability were enhanced as the concentration of the four AEPs increased. The emulsifying activity and stability of the AEPs were steady within the pH range of 2-10 and NaCl concentration range of 0-0.4 mol/L. Our results implied that these polysaccharides can be utilized as a novel hydrocolloid source for natural thickeners in the food industry.

The rheological properties of differentially extracted polysaccharides from potatoes peels.

The effects of concentration, temperature, pH, and salt ion concentration on the apparent viscosity of potato peel (PP) polysaccharide solutions were studied. The results showed that the PP polysaccharides exhibited the characteristics of "non-Newtonian fluid". The apparent viscosity of the PP polysaccharides decreased under acidic, alkaline conditions, and with the increasing temperature. At the increasing concentration of PAC with the addition of four ion concentrations, the apparent viscosity was decreased gradually. The apparent viscosity of PAL increased with four ion concentrations, while that of PW increased initially with the rising concentration of Na+, Mg2+, and K+ and then decreased. Addition of Ca2+ lowered the apparent viscosity initially which was followed by further increase. The results of dynamic rheological experiment showed that the loss modulus G″ of PP polysaccharide was higher than the storage modulus G' at lower frequencies, and vice versa at higher frequencies. With the increasing concentration of PP polysaccharides, the values of the intersection of G' and G″ were lowered. The results showed that the rheological properties of PP polysaccharide solutions were affected by concentration, temperature, pH, and salt ions.

Acute, genetic and sub-chronic toxicities of flaxseed derived Maillard reaction products.

In present study, the acute, genetic, and sub-chronic toxicities of flaxseed derived Maillard reaction products (MRPs) were investigated. Acute toxicity results showed that the 50% lethal dose (LD50) of MRPs in rats was >15.0 g/kg body weight (BW); whereas, the 50% effective dose (ED50) of MRPs was 12.3 g/kg BW. Ames test demonstrated that the back-mutation colonies for MRPs addition of 5,000 µg/dish was positive, which displayed certain mutagenicity. There were no significant differences in micronucleus rate and sperm deformity rate among different dose groups. The sub-chronic toxicity confirmed that less than 0.75 gMRPs/kg BW intake did not affect weight, food intake, mortality, gross pathology, histology, hematology, and serum biochemistry. The obtained results can provide an imperative reference on the safety of a meat flavoring agents.

Modification of wheat bran insoluble dietary fiber with carboxymethylation, complex enzymatic hydrolysis and ultrafine comminution.

To improve the industrial application of wheat bran insoluble dietary fiber (W-IDF), three modification methods (carboxymethylation, complex enzymatic hydrolysis, and ultrafine comminution) were compared on the basis of structural, physicochemical, functional, and antioxidant properties of W-IDF. FT-IR, DSC and SEM analysis showed that modifications contributed to alteration in morphology and arrangement of chemical bonds in W-IDF. Carboxymethylation effectively improved the water retention (WRC), water swelling (WSC), and glucose adsorption capacities (GAC); complex enzymatic hydrolysis greatly improved the oil retention (ORC), GAC, and nitrite ion adsorption capacities (NIAC). Although ultrafine comminution reduced the WRC and ORC, while positively influenced the GAC and NIAC. Moreover, total phenol content, total antioxidant capacity, DPPH radical scavenging capacity, Fe2+ chelating capacity and total reducing power were improved in modified W-IDF. Our results confirmed that carboxymethylation can improve the nutritive quality and sensory properties of W-IDF (nutritive ingredient) in food products.

Physicochemical and antioxidant potential of polysaccharides sequentially extracted from Amana edulis.

Amana edulis polysaccharides (AEPs) specifically HBSS, CHSS, DASS, and CASS were sequentially extracted with four different solvents. The present study characterized the AEPs with particular focus on their physicochemical and anti-oxidant based functional properties. Initially, monosaccharide analysis revealed arabinose (31.7%, 32.5%, 36.5%) as the main sugar in HBSS, CHSS, and DASS whereas, galactose (31.4%) in CASS besides their respective molecular weights of 6.29 × 102, 1.5 × 102, 8.1 × 102, and 2.6 × 103 kD. HBSS showed the maximum solubility, while, CASS was observed for higher foam capacity and foam stability. Among all the fractions, DASS was observed with higher thermal stability. HBSS showed the highest ABTS+ scavenging activity. HBSS and CASS had higher DPPH and OH- scavenging activities. DASS depicted the highest chelation and reducing ability. To summarize, these polysaccharides fractions may be further utilized for their enormous prospective in functional foods preparation.

Licochalcone B Extracted from Glycyrrhiza uralensis Fisch Induces Apoptotic Effects in Human Hepatoma Cell HepG2.

The present study explored the molecular mechanism by which licochalcone B induces the cell cycle arrest and apoptosis in human hepatoma cell HepG2. Initial extraction and identification were performed by HPLC, UPLC-TOF-MS/MS, and NMR analysis, respectively. Licochalcone B inhibited the HepG2 growth with IC50 (110.15 µM) after 24 h, caused morphological distortion, and seized the cell cycle in the G2/M phase (cell arrest in G2/M:43.1 ± 2.2% for 120 µM versus 23.7 ± 1.2% for control), as well as induced apoptosis and intracellular ROS generation. Furthermore, exposure to licochalcone B markedly affected the cell cycle (up/down regulation) at mRNA and protein levels. Apoptosis was induced through the activation of receptor-mediated and mitochondrial pathways. The inhibition of Caspase 8 and Caspase 9 proteins abolished the licochalcone B induced apoptosis. The present work suggested that licochalcone B may further be identified as a potent functional food component with specific health benefits.

Evaluation of structural, functional, and anti-oxidant potential of differentially extracted polysaccharides from potatoes peels.

Potato peel was used for the extraction of three types of polysaccharides (PW, PAL, and PAC) using water, alkaline, and acid treatments, respectively. The structure of the PP polysaccharides was examined by means of Fourier transform infrared spectroscopy (FT-IR) analysis and Gas chromatography-mass spectrometry (GC-MS). The results suggest that the extracted polysaccharides constituted essentially three functional groups: CO, CH, and OH. The polysaccharides were comprised of low proportions of proteins, 17-23% uronic acids, and approximately 70% carbohydrates. PAL, PW, and PAC with molecular weights of 2.25 × 103, 2.18 × 103, and 1.92 × 103 kDa, respectively, were composed of rhamnose, xylose, mannose, arabinose, glucose, and galactose. Functional properties (solubility, oil holding capacity, foaming, and emulsion properties) of these polysaccharides were evaluated. Among three, PAL showed the highest fat-binding capacity which was 7.50 g/g with the solubility of 95.06%. The three polysaccharides possessed appreciable in vitro anti-oxidant (scavenging DPPH and ABTS+ radicals, chelating ferrous ions, and reducing power) potential. PAL exhibited the strongest reducing power, scavenging activity on DPPH radicals and chelating capability on ferrous ions. PP polysaccharides can be used as promising natural antioxidants in food, pharmaceutical, and cosmetic preparations.

Synthesis and biological evaluation of arginyl-diosgenin conjugate as a potential bone tissue engineering agent.

Water-soluble arginyl-diosgenin (Arg-DG) conjugate was designed, synthesized, and evaluated for a biological activity. The Arg-DG conjugate was characterized using FT-IR, 1 H NMR, 13 C NMR, and HPLC-MS analyses, followed by a biological activity evaluation. Compared with DG, the Arg-DG conjugate showed a decreased cytotoxicity against L929 cells and an increased antiproliferative activity against hepatocellular cells. The safety of the Arg-DG conjugate was confirmed using the highly sensitive Alamar Blue assay, which indicated that it increased the cellular metabolic activity at suitable concentrations. The Arg-DG conjugate promoted an endothelial tube formation as well. Furthermore, the Arg-DG conjugate improved the bone morphogenetic protein 2 (BMP2)-induced osteoblastic differentiation with synergistic effects on alkaline phosphatase (ALP) activity and mineralization. These results suggest that the Arg-DG conjugate developed in this study has great potentials for biomedical applications such as bone tissue engineering.