Vitexin-rhamnoside encapsulated with zein-pectin nanoparticles relieved high-fat diet induced lipid metabolism disorders in mice by altering the gut microbiota.

This study aimed to investigate the modulatory effects of Vitexin-rhamnoside (VR) and Zein-VR-pectin nanoparticles (VRN) on lipid metabolism disorders induced by high-fat diet (HFD). The ingestion of VR or VRN attenuated dyslipidemia and fat accumulation in HFD mice, and improved intestinal dysbiosis by regulating the relative abundance of dominant bacteria, alleviating chronic inflammation and hepatic injury in HFD mice. The intervention effect of VRN was significantly higher than that of VR. After fecal microbiota transplantation (FMT) treatment, the fecal microbiota of VRN-treated donor mice significantly attenuated the symptoms associated with hyperlipidemia, confirming that VRN ameliorates HFD-induced disorders of lipid metabolism by modulating the gut microbiota, especially increasing the abundance of Rombousia and Faecalibaculum. Overall, VRN can regulate the gut microbiota and thus improve lipid metabolism. The present study provided new evidence that nanoparticles enhance the bioavailability of food bioactive ingredients.

Distinctions in structure, rheology, antioxidation, and α-glucosidase inhibitory activity of ß-glucans from different species.

To investigate the distinctions between ß-glucans from different species, Lentinula edodes ß-glucan (LG), yeast ß-glucan (YG), and oat ß-glucan (OG) were extracted with hot water and determined as ß-d-glucopyranose form by HPLC and FT-IR analysis. The molecular weight (Mw) of LG, YG, and OG was 670 kDa, 341 kDa, and 66 kDa, respectively. Scanning electron microscopy exhibited different micro surfaces of three ß-glucans and the relative crystallinity of YG was the highest (29.8 %), followed by that of LG (23.2 %) and OG (20.3 %) determined by X-ray diffraction. Congo red analysis and atomic force microscopy showed that LG and YG have triple helical structures. The apparent viscosity, storage modulus (G'), and loss modulus (G") of ß-glucans were increased with the increase of Mw. DPPH·, ABTS+·, HO·, and reducing power assays showed that ß-glucans from different species exhibited different antioxidant activities, and the DPPH· scavenging rate of 2 mg/mL LG reached >80 % higher than that of YG and OG. The α-glucosidase inhibitory activity of OG was better than YG and LG. In summary, ß-glucans from different species have different structures, physicochemical properties, and physiological functions, which provides theoretical evidence for the precise processing and utilization of ß-glucan.

Variations of quality and volatile components of morels (Morchella sextelata) during storage.

The postharvest senescence of morels was observed to be easily affected by temperature fluctuations. The objective of this study was to examine the influence of various storage temperatures on the postharvest senescence of morels. The study evaluated the variations of water content, respiration, nutrients substances, cell membrane permeability, and volatile compounds in morels stored at 20 °C and 4 °C. Results showed that low-temperature storage suppressed the loss of water and firmness, delayed the time of respiration and ethylene peak, and reduced the loss of nutrients and cell membrane permeability. Furthermore, the content of volatile compounds increased and then decreased during storage. The characteristic aroma substances of 1-octen-3-ol were identified using odor activity values and OPLS-DA analysis. The study observed a decrease in the content and changes of aroma compounds during low-temperature storage. This decrease may be attributed to the decreased activities of lipoxygenase (LOX) and alcohol dehydrogenase (ADH).

The Changes of Antioxidant Contents and Antioxidant Activities of the Tomato Cultivar Fentailang during the Maturity Stages.

The aim of this study was to analyze the contents of ascorbic acid, phenolics, flavonoids, carotenoids, lycopene, ß-carotene and their antioxidant activities in the different maturity stages of tomatoes. The results showed that tomatoes in pink and red stages exhibited higher contents of ascorbic acid concomitant with the correspondent higher hydrophilic antioxidant activities. The contents of phenolics, carotenoids and lycopene were increasing till the red maturity stage. Significant correlation between the DPPH radical scavenging activity and carotenoids, however lycopene was effective in its lowest concentration. The ß-carotene was intensively synthesized between the green and breaker maturity stages, and higher correlated with the FRAP capacity. These findings indicated that tomatoes can be considered as natural sources of bioactive compounds regardless of the maturity stages, while tomatoes in pink and red maturity stages has higher nutritional value and antioxidant activity.

Effects of Ultrasound-Assisted Extraction on Structure and Rheological Properties of Flaxseed Gum.

In this study, flaxseed gum (FG) was extracted using hot water extraction and ultrasonic-assisted extraction. The yield, molecular weight distribution, monosaccharide composition, structure, and rheological properties of FG were analyzed. The FG yield (9.18) achieved using ultrasound-assisted extraction (this sample was labeled as UAE) was higher than the yield (7.16) achieved with hot water extraction (this sample was labeled as HWE). The polydispersity, monosaccharide composition, and characteristic absorption peaks of the UAE were similar to that of the HWE. However, the UAE had a lower molecular weight and looser structure than the HWE. Moreover, zeta potential measurements indicated that the UAE exhibited better stability. An analysis of the rheological properties showed that the viscosity of the UAE was lower. Thus, the UAE had an effectively better yield of FG, preliminarily modified structure, and rheological properties, and provided a theoretical basis for its application in food processing.

Encapsulation of vitexin-rhamnoside based on zein/pectin nanoparticles improved its stability and bioavailability.

To improve the solubility, stability, and bioavailability of vitexin-rhamnoside (VR) isolated from hawthorn, it was encapsulated by the zein-pectin nanoparticles system. When the mass ratio of zein to pectin was 1:4, the particle size of nanoparticles was 222.7 nm, and the encapsulation efficiency of VR was 67%. Analysis with the scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) revealed that the zein-VR-pectin nanoparticles were spherical and uniformly distributed. The hydrogen bonding and electrostatic interactions were the main forces to assemble the nanoparticles. The nanoparticle had good stability at pH 3-8.5 with particle sizes ranging from 234 to 251 nm, and the nanoparticles were able to resist the relatively lower ionic strength. In vitro simulated digestion and rat in vivo intestinal perfusion experiments showed that the nanoparticles exhibited significant slow-release properties and the highest absorption rate in the duodenal segment of rats, with Ka and Papp of 0.830 ± 0.11 and 17.004 ± 1.09. These results provided a theoretical and technological approach for the construction of flavonoids delivery system with slow-release properties and improved bioavailability.

Antioxidant potential and in vitro inhibition of starch digestion of flavonoids from Crataegus pinnatifida.

Hawthorn flavonoids were extracted by enzymolysis associated ultrasonic procedure. Thirteen flavonoids were identified by HPLC/ESI-QTOF/MS, and the major components were procyanidin C1, rutin-rhamnoside, vitexin-rhamnoside, and catechin. Hawthorn flavonoids exhibited strong free radical scavenging activities against DPPH, ABTS, and hydroxyl radicals. Total and intercellular antioxidant experiments revealed that the free hydro-PSC value was 295.32 ± 12.20 µmol of VCE/g DW, and the free cellular antioxidant activity (CAA) values were 168.60 ± 4.87 µmol of QE/g DW in the no PBS wash protocol and 49.53 ± 1.75 µmol of QE/g DW in the PBS wash protocol. In addition, hawthorn flavonoids exhibited higher α-amylase and α-glucosidase inhibitory activities. The wheat starch digestibility was also reduced by hawthorn flavonoids as well. The results indicated that enzymolysis associated ultrasonic extraction was advisable for extracting flavonoids from hawthorn, and hawthorn flavonoids might be recommended as a potential food supplement with hypoglycemic activities.

Pectin oligosaccharides improved lipid metabolism in white adipose tissue of high-fat diet fed mice.

Impacts of pectin oligosaccharide (POS) got from hawthorn fruitage on adiponectin signaling pathway and white adipose metabolism in mice fed with high-fat control. The results showed that POS significantly inhibited the levels of inflammatory cytokines TNF-α and IL-6, and down-regulated expression of CD68. POS dramatically reduced gene expression contents of fatty acid composite concerning enzymes ACC and FAS, as well as TG synthesis-related enzymes SCD-1 and DGAT1 as compared to a high-fat group (HFC). POS dramatically increased expression levels of oxidation-related enzymes of fatty acid ACO, CPT-1, and TG deposition-related enzymes ATGL and HSL as contrast to the high-fat control group. In addition, POS activated adiponectin-mediated AdipoR1/AMPK/PPARα signaling path by upregulating expression levels of AdipoR1, AMPK and PPARα. The results demonstrated that POS can improve lipid metabolism of adipose tissue, and contribute to the creation of functional foods to prevent and treat lipid metabolism disorders. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01109-9.

Variations in the structural and functional properties of flaxseed gum from six different flaxseed cultivars.

Although flaxseed gum (FG) has been widely studied, the differences in its structure and function with respect to various flaxseed cultivars remain unclear. In this study, our objective was to examine the differences between FG samples obtained from different flaxseed cultivars based on their structural and functional properties. Specifically, FG samples from the different cultivars were extracted via hot water extraction followed by ethanol precipitation. Thereafter, they were analyzed via zeta potential measurements, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), and scanning electron microscopy (SEM). The results demonstrated that the different cultivars showed significantly different FG yields (p < .05; range, 5.83%-7.36%). Further, the FTIR spectra of the FG samples were slightly different but showed typical polysaccharide absorption peaks. Furthermore, the XRD patterns obtained predominantly showed an amorphous region and a small crystalline region, while the SEM images obtained at 1,000× magnification revealed that the samples had smooth and irregular surfaces, with a scaly structure. However, at 20,000× magnification, the FG samples showed slight structural differences. Additionally, the zeta potentials of the FG samples (range, -19.4 to -30.6 mV; p < .05) were cultivar-dependent and indicated the presence of negatively charged macromolecules. This implies that the FG samples from the different cultivars show diverse structural properties. Our findings not only provide useful information regarding FG samples extracted from different cultivars but also serve as a theoretical basis for the application of FG in food processing.

Pectic Oligogalacturonide Facilitates the Synthesis and Activation of Adiponectin to Improve Hepatic Lipid Oxidation.

SCOPE: Adiponectin (ADPN), a kind of adipokines, plays an important role in the regulation of lipid metabolism. The objective of this study is focused on the ADPN to investigate the functional mechanisms of pectin oligosaccharide (POS) from hawthorn fruit in the improvement of hepatic fatty acid oxidation. METHOD AND RESULTS: High-fat fed mice are used in this experiment. POS is administrated with the doses of 0.25, 0.75, and 1.5 g kg-1 diet, respectively. The results demonstrate that gene and protein expressions of ADPN synthesis regulators involved in PKA/ERK/CREB and C/EBPα/PPARγ pathways are upregulated by POS administration. POS also activates the AdiopR1/AMPKα/PGC1 and AdipoR2/PPARα signaling pathways to improve the fatty acid oxidation in the liver, which is further accelerated by the enhancement of mitochondrial functions. CONCLUSION: POS can act as an ADPN activator to improve lipid metabolism, leading it to the applications of biomedical and functional foods for ameliorating chronic liver diseases resulted from a high-energy diet.

In vitro and in vivo antioxidant activities of soy protein isolate fermented with Bacillus subtilis natto.

The Bacillus subtilis natto fermented soy protein isolate (FSPI) exhibited concentration-dependent scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS+·) and hydroxyl (·OH) free-radicals. In addition, FSPI administration significantly increased superoxide dismutase activity in mice liver and serum by 20.2% and 86.2%, and suppressed the production of malondialdehyde by 51.3% and 35.1%, respectively, compared to high-fat control (HFC) group. Notably, the movement of mice treated with FSPI was livelier and more active, and its weight gain was significantly lower than that of both NC and HFC groups. The production and accumulation of perirenal fat was also significantly inhibited by FSPI, however, no significant difference in TG and TC levels were observed between FSPI and HFC groups. The results revealed the great potential of FSPI applying in the development of health food or sports food.

Optimization of pH conditions to improve the spore production of Clostridium butyricum NN-2 during fermentation process.

Clostridium butyricum, an anaerobic spore-forming bacillus, is a common human and animal gut commensal bacterium. Spore is an important structure for C. butyricum to tolerate environmental stress. However, it is not easy to form in common fermentation process of C. butyricum. In this study, the parameters for optimizing the spore formation of C. butyricum NN-2 were defined. The results showed that the pH value was a crucial factor that significantly affected the spore formation of C. butyricum NN-2. Down-regulation steps of pH value from 6.5 to 5.5 over time during the cultural process significantly (p < 0.05) promoted spore formation of C. butyricum NN-2, allowing for the sporulation rate of > 90%. In addition, the duration of pH regulation also had significant effects on the spore formation of C. butyricum NN-2. The results revealed a highly effective strategy for enhancing the spore production of C. butyricum.

Preparation and characterization of highly lipophilic modified potato starch by ultrasound and freeze-thaw treatments.

In order to explore the potential application of combined physical treatment in producing highly lipophilic modified starch, the effects of ultrasound combined with freeze-thaw treatment on the microstructure and physicochemical properties of potato starch were investigated. The samples treated by combined treatment had the roughest structure and the oil adsorptive capacity value increased from 59.62% (native starch, NS) to 80.2% (7 cycles of ultrasound-freeze-thaw treatment starch, 7UT-FTS). Compared to NS, the crystalline type and chemical groups of modified starches did not change, but the relative crystallinity, enthalpy change, and paste viscosity decreased to varying degrees, while the gelatinization temperature increased. The digestibility of raw modified starch was higher than that of NS, but this phenomenon disappeared after gelatinization. 7UT-FTS showed better resist-digestibility than NS after encapsulating oil. Hence, this would be an efficient and environmentally friendly way to produce modified starch with safety, highly lipophilic and heat resistance.

Optimization of production conditions of rice α-galactosidase II displayed on yeast cell surface.

The yeast surface displayed rice α-galactosidase II (YSD rice α-Gal II) was generated with the pYD1 vector. The expression and cultural conditions for the improvement of production of YSD rice α-Gal II were optimized. The results showed that several induction factors, which were the initial cell density, inoculation ratio, galactose (inducer) concentration, induction time and temperature, determined the activity and expression efficiency of YSD rice α-Gal II. Meanwhile, the medium composition also affected its activity and production. Moreover, the production of YSD rice α-Gal II was further improved by continuous feeding of galactose in the fermenter level. The highest production was obtained at an initial cell density of OD600 = 2.9, 2% inoculation ratio, and 2% galactose, with 0.6 g/L compound nitrogen source ((NH4)2SO4/urea = 2/1, w/w) and 5 g/L sucrose, followed by continuous feeding of galactose (20 g/L with flow rate of 1.5 mL/h). At such conditions, the enzyme activity and productivity reached to 676.2 U/g (DCW) and 1548.5 U/L, respectively, 26.4- and 63.7-fold to that before optimization. The results provided a basic and effective strategy for the industrial production of YSD rice α-Gal II.

Preparation and properties of water-in-oil shiitake mushroom polysaccharide nanoemulsion.

Shiitake mushroom (Lentinus edodes) polysaccharide (SMP), an important immunomodulatory substance, is usually hard to be absorbed by the intestinal tract, because of its macromolecule characteristics. The objective of this study was to develop the water-in-oil (W/O) nanoemulsion to improve its absorption efficiency and the biological activity. Based on the results of pseudoternary phase diagram, the formulation of nanoemulsion were optimized as IPM/polysaccharide/Tween80-Span85/anhydrous ethanol = 39/16/33.75/11.25 (v/v/v/v), used as the oil, aqueous phase, surfactant and co-surfactant, respectively. Under this condition, the droplet size of a W/O SMP nanoemulsion was 144.5 nm, with the polydispersity of 0.128 and the great stability. Moreover, the anti-tumor activity of SMP was notably improved after nano-emulsification. The results demonstrated that SMP nanoemulsion has great potential for applying in health food and pharmaceutical industry.

A universal mini-vector and an annealing of PCR products (APP)-based cloning strategy for convenient molecular biological manipulations.

Currently, the most widely used strategies for molecular cloning are sticky-end ligation-based cloning, TA cloning, blunt-end ligation-based cloning and ligase-independent cloning. In this study we have developed a novel mini-vector pANY1 which can simultaneously meet the requirements of all these cloning strategies. In addition, the selection of appropriate restriction digestion sites is difficult in some cases because of the presence of internal sites. In this study, an annealing of PCR products (APP)-based sticky-end cloning strategy was introduced to avoid this issue. Additionally, false positives occur during molecular cloning, which increases the workload of isolating positive clones. The plasmid pANY1 contains a ccdB cassette between multiple cloning sites, which efficiently avoids these false positives. Therefore, this mini-vector should serve as a useful tool with wide applications in biosciences, agriculture, food technologies, etc.

Expression and Characterization of Recombinant Sucrose Phosphorylase.

SPase is widely used in the food, cosmetics, and pharmaceutical industries. Previously, a SPase gene was cloned from Bifidobacterium longum JCM1217 and constructed into Escherichia coli BL21. In this paper, its expression conditions were optimized. The results showed that several induction factors determined the expression efficiency of SPase. The initial cell density, IPTG concentration, and induction time and temperature significantly (p < 0.01) affected the total protein content and activity of expressed SPase. The highest expression efficiency was obtained at an initial cell density of OD600 = 0.5, with 0.05 mM IPTG, followed by shaking at 180 rpm and incubation at 30 °C for 15 h. The purified SPase had a specific activity of 122.1 U/mg, which was raised by 1.85 -fold more than that before optimization, and its recovery yield was 86%. Furthermore, SPase also showed higher thermostability. The results of this study provide essential information for the industrial production of SPase.

Changes in anthocyanins and volatile components of purple sweet potato fermented alcoholic beverage during aging.

Purple sweet potato was fermented into alcoholic beverage. By using LC-MS analysis, 12 types of anthocyanins were found in the purple sweet potato alcoholic beverage (PSPFAB); these were based on cyanidin and peonidin as aglycones. The anthocyanins in young PSPFAB mainly consisted of acylates. The acylated anthocyanins, however, degraded gradually with aging. Cyanidin 3-sophoroside-5-glucoside and peonidin 3-sophoroside-5-glucoside were found to be major anthocyanins in the PSPFAB after two years of aging. Moreover, 52 kinds of volatile components were detected in PSPFAB by GC-MS analysis. Alcohol and ester substances constituted a major proportion of these volatile components of PSPFAB. After two years of aging, levels of high-alcohols such as 1-pentanol remarkably decreased to below the detection limit, while the level of total esters increased significantly. Such variation of aromas enriched and improved the flavor of PSPFAB.

Pectin penta-oligogalacturonide reduces cholesterol accumulation by promoting bile acid biosynthesis and excretion in high-cholesterol-fed mice.

Haw pectin penta-oligogalacturonide (HPPS) has important role in improving cholesterol metabolism and promoting the conversion of cholesterol to bile acids (BA) in mice fed high-cholesterol diet (HCD). However, the mechanism is not clear. This study aims to investigate the effects of HPPS on cholesterol accumulation and the regulation of hepatic BA synthesis and transport in HCD-fed mice. Results showed that HPPS significantly decreased plasma and hepatic TC levels but increased plasma high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (apoA-I) levels, compared to HCD. BA analysis showed that HPPS markedly decreased hepatic and small intestine BA levels but increased the gallbladder BA levels, and finally decreased the total BA pool size, compared to HCD. Studies of molecular mechanism revealed that HPPS promoted hepatic ATP-binding cassette transporter A1 (ABCA1), ATP-binding cassette transporter G1 (ABCG1), and scavenger receptor BI (SR-BI) expression but did not affect ATB binding cassette transporter G5/G8 (ABCG5/8) expression. HPPS inactivated hepatic farnesoid X receptor (FXR) and target genes expression, which resulted in significant increase of cholesterol 7α-hydroxylase 1 (CYP7A1) and sterol 12α-hydroxylase (CYP8B1) expression, with up-regulations of 204.2% and 33.5% for mRNA levels, respectively, compared with HCD. In addition, HPPS markedly enhanced bile salt export pump (BSEP) expression but didn't affect the sodium/taurocholate co-transporting polypeptide (NTCP) expression. In conclusion, the study revealed that HPPS reduced cholesterol accumulation by promoting BA synthesis in the liver and excretion in the feces, and might promote macrophage-to-liver reverse cholesterol transport (RCT) but did not liver-to-fecal RCT.

Pectin Penta-Oligogalacturonide Suppresses Intestinal Bile Acids Absorption and Downregulates the FXR-FGF15 Axis in High-Cholesterol Fed Mice.

Haw pectin penta-oligogalacturonide (HPPS), purified from the hydrolysates of haw pectin, has important role in decreasing hepatic cholesterol accumulation and promoting bile acids (BA) excretion in the feces of mice fed a high-cholesterol diet (HCD). However, the mechanism is not clear. This study aims to investigate the effects of HPPS on BA reabsorption in ileum and biosynthesis in liver of mice. Results showed that HPPS increased fecal BA output by approximately 110%, but decreased ileal BA and the total BA pool size by approximately 47 and 36%, respectively, compared to HCD. Studies of molecular mechanism revealed that HPPS significantly decreased the mRNA and protein levels of farnesoid X receptor (FXR) in the small intestine of mice and inactivated the fibroblast growth factor 15 (FXR-FGF15) axis, which increased the mRNA and protein levels of CYP7A1 by approximately 204 and 104%, respectively, compared to HCD. Interestingly, the mRNA and protein levels of apical sodium-dependent bile acid transporter (ASBT) in the small intestine were approximately 128 and 73% higher in HPPS-fed mice than those in HCD-fed mice, respectively. However, no significant difference was detected for ASBT expression between HCD group and BA sequestrant cholestyramine group. These findings indicate that HPPS can suppress intestinal BA reabsorption and promoting hepatic BA biosynthesis. We speculated that HPPS could be ASBT competitive inhibitor rather than BA sequestrant in inhibiting BA reabsorption in ileum and improving cholesterol metabolism.