Hongzhi Liu

Identification of chemical ingredients of peanut stems and leaves extracts using UPLC-QTOF-MS coupled with novel informatics UNIFI platform.

Peanut stems and leaves have been used traditionally as both herbal medicines and special food in Asia. In this study, the main functional compounds of peanut stems and leaves extracts were identified using UPLC separation coupled to high resolution mass spectrometry (QTOF-MS), and a traditional medicine library. Three different extraction solvents (ethyl acetate, petroleum ether and n-butanol) were evaluated to prepare the extracts of peanut stems and leaves. A total of 283 chemical compounds were identified in peanut stems and leaves extracts, of which 207 compounds are tentatively new identifications in Genus Arachis. The integration of data acquisition and processing with the traditional medicine library provides a simple, efficient process to effectively facilitate the identification of chemical ingredients in complex natural product extracts. The integrated workflow for separation, detection and identification of functional compounds in natural products using UPLC/QTOF-MS greatly improves productivity for development of traditional herbal medicines. Copyright

β-Glucans: Relationships between Modification, Conformation and Functional Activities

β-glucan is a type of polysaccharide which widely exists in bacteria, fungi, algae, and plants, and has been well known for its biological activities such as enhancing immunity, antitumor, antibacterial, antiviral, and wound healing activities. The conformation of β-glucan plays a crucial role on its biological activities. Therefore, β-glucans obtained from different sources, while sharing the same basic structures, often show different bioactivities. The basic structure and inter-molecular forces of polysaccharides can be changed by modification, which leads to the conformational transformation in solution that can directly affect bioactivity. In this review, we will first determine different ways to modify β-glucan molecules including physical methods, chemical methods, and biological methods, and then reveal the relationship of the flexible helix form of the molecule chain and the helix conformation to their bioactivities. Last, we summarize the scientific challenges to modifying β-glucan’s conformation and functional activity, and discuss its potential future development.

Effect of drying and loading methods on the release behavior of ciprofloxacin from starch nanoparticles.

Drug loading into and release from starch nanoparticles (StNPs), one kind of novel biological macromolecule, were investigated. Two drying methods (spray and vacuum freeze drying) and drug loading methods (coating and adsorption) were used for evaluation. 40% (w/w) of ciprofloxacin was loaded using coating method while only 7% for adsorption method. Glass transition temperature (Tg) and melting point temperature (Tmp) of ciprofloxacin loaded starch nanoparticles varied from 40°C to 55°C and 125°C to 175°C. Particles using adsorption method had lower loading rate of ciprofloxacin, higher Tg, Tmp and release rate compared to using coating method. Tg and Tmp were not affected by these two drying methods. Release rate of ciprofloxacin was higher from freeze dried particles than from spray dried particles using coating method. For adsorption method, drying methods had not effect on the release rate. A double decay exponential model was able to fit the release data suitably well with coefficient of determination (R(2))>0.97.

Rheological characteristics and chain conformation of mannans obtained from Saccharomyces cerevisiae

Mannans were extracted from S. cerevisiae, the rheological properties of mannan solutions were important in many industrial applications. In this paper, effects of mannans concentration, solution temperature, pH, salts and their concentrations on apparent viscosity were investigated. The conformational parameters of yeast mannans were determined by SEC-MALS-RI-DP. The Higiros 1 and Higiros 2 plots were obtained by capillary viscometry gave an intrinsic viscosity of 0.166 and 0.131dl/g. The yeast mannans solution showed Newtonian flow behavior at all the tested concentrations. The apparent viscosity of yeast mannans solution decreased continuously with the temperature increase (25°C-85°C) at a given shear rate. The viscosity did not change within the pH values of 4.0-10.0, however, it increased when the pH decreased from 4.0 to 2.0. The viscosity decreased with addition of CaCl2 up to 10mM and remained constant above this concentration. The conformational parameters (derived from [η] vs Mw and Rg vs Mw) showed yeast mannans existed as a sphere-like shape with many shorter branches. The special flow behavior and conformation of yeast mannans may make it preferable polysaccharide in food industry.

High-pressure microfluidisation pretreatment disaggregate peanut protein isolates to prepare antihypertensive peptide fractions

High-pressure microfluidisation (HPM) pretreatment was applied to increase in vitro antihypertensive activity of peanut peptide fractions (PPF). The morphology of protein in aqueous dispersion revealed that peanut protein isolate (PPI) disaggregated at relatively low pressure (≤120 MPa) and re-aggregated at relatively high pressures (150-210 MPa). The treated pressure of 120 MPa could lead to the most disaggregation of PPI. Small peptides contents, trichloroacetic acid-nitrogen soluble index (TCA-NSI) and degree of hydrolysis (DH) of peanut protein hydrolysates (PPH) all reached the highest at 120 MPa. Consequently, it possessed the highest angiotensin converting enzyme (ACE) and renin inhibitory activity. The highest surface hydrophobicity occurred at 120 MPa pretreatment samples. Thirty- nine oligopeptides at 120 MPa pretreatment were identified by ultra-performance liquid chromatography-quadrupole time-of-flight (UPLC-Q-TOF) mass spectrometer combined with Progenesis QI for Proteomics software compared with 29 and 35 at control and 210 MPa, respectively. This meant that disaggregation of PPI at 120 MPa resulted in the release of new hydrophobic peptide.

Extraction, Purification and Primary Characterization of Polysaccharides from Defatted Peanut (Arachis hypogaea) Cakes

The hot-water extraction, purification and characterization of polysaccharides from defatted peanut cake (PPC) were investigated in this study. A Box-Behnken factorial design (BBD) was used to investigate the effects of three independent variables, namely extraction temperature (X1), extraction time (X2) and ratio of water to raw material (X3). The optimum conditions were 85 °C, 3 h and 20:1 (mL/g) respectively. Regression analysis was done to reveal the experimental results which include 34.97% extraction rate while the value verified under these conditions was 34.49%. The crude PPC was sequentially further purified by Sephadex G-100 chromatography, and one purified fraction was obtained. The PPC purified fraction was characterized by FT-IR, HPAEC; SEC-MALLS. The average molecular weight of the PPC purified fraction was 2.383 × 105 Da. The polysaccharide was mainly composed of glucose, galactose, arabinose and xylose. The PPC have the typical absorption of polysaccharide.

Effects of microfluidization with ionic liquids on the solubilization and structure of β-d-glucan

In order to enhance the solubility of yeast β-D-glucan and enlarge the applicable area, we investigated dynamic high pressure microfluidization (DHPM) treatment with ionic liquids as solvent to prepare water-soluble yeast β-D-glucan (WSG). The solubility of β-D-glucan was greatly impacted by the pressure of DHPM, residence time, and ratio of β-D-glucan and EmimAc. The yield of WSG reached 79.25 % (w/w) with the water solubility of 72.50 % (w/w). The DHPM treatment did not destroy the ionic liquid structure therefore the ionic liquids could be recycled. FTIR and (13)C NMR spectrum results showed that WSG was the polysaccharides with (1→3)-β-D-glycosidic bonds, after modification, the hydrogen bonding was destroyed. The chain conformation of WSG in 0.1M NaNO3 aqueous solutions at 25 °C were studied by laser light scattering and viscometry. The Mark-Houwink equation was established to be [η]=2.09×10(-2) MW(0.63) (cm(3) g(-1)). According to the conformational parameters calculated from wormlike cylinder model, WSG existed as semi-stiff chain in aqueous solution.

Physical properties of supercritical fluid extrusion products composed of milk protein concentrate with carbohydrates

Supercritical fluid extrusion (SCFX) is a novel process combining traditional extrusion and supercritical fluid technologies. The objective of this study was (i) to assess the effect of sugar, maltodextrin and cornstarch on the physical properties of milk protein concentrate (MPC) puffed extrudates and (ii) to compare the physical and textural properties of SCFX puffed MPC products with commercially puffed cereal products. Results showed that the nutritious MPC puffed products with carbohydrates can be made with textural properties (hardness, brittleness and crispness) resembling those of the commercial samples. The porosity of F2 (0.573) was assessed to the commercial product C1 (0.543) and C2 (0.595), the specific length of F3 (50.41) was assessed to C1 (45.51) and F4 (80.14) was assessed to C2 (78.12). The hardness of extrudate F3 (435.49 KPa) was assessed to C2 (482.7 KPa). The Young’s modulus of F5 (87.03) was assessed to C2 (80.57). The starches affected the crispness of the extrudates, and sugar affected the hardness and brittleness significantly.

Changes in conformation and quality of vegetable protein during texturization process by extrusion

Abstract Texturized Vegetable Protein (TVP), as meat analogs, has garnered attention due to the nutritional advantages it offers over conventional animal proteins. During the extrusion process of TVP, under the comprehensive effects of temperature, shear force, and pressure, complex conformational changes and molecular interactions amongst protein, carbohydrate, lipid, and other components occur, all of which influence the quality of TVP. Control of the extrusion process is still one of the largest challenges in its evolution. Therefore, this review aims to summarize the development and current status of food extrusion technology for TVP production and give detailed descriptions about the conformational changes of the main components during the extrusion process, focusing on the effects of barrel temperature, moisture content, feed rate and screw speed on TVP quality. Lastly, we discuss approaches to characterize the extrusion process and propose a new system analysis model.

An improved method for the measurement of 3-monochloropropanediol esters by matrix solid-phase dispersion supported liquid–liquid extraction

Summary n3-Monochloropropanediol (3-MCPD) esters are contaminants produced from the high-temperature processing of edible oils. The accurate measurement of 3-MCPD using an easy-to-follow and reliable method that uses a readily available instrument is important. Here, we report an acid transesterification heptafluorobutyrylimidazole (HFBI) derivatisation method for the accurate measurement of 3-MCPD esters in edible oils. We developed a dispersed matrix solid-phase supported liquid–liquid extraction (DMSP-SLE) system to remove impurities. Both the transesterification and DMSP-SLE conditions were optimised. A good linear relationship was obtained within the range of 0.05–10xa0mgxa0kg−1 (R2xa0≥xa00.999) in both blank solvent and an oil sample. The limit of detection was 20.36xa0μgxa0kg−1. The average recovery of the 3-MCPD esters spiked at 0.5, 1.0 and 2.0xa0mgxa0kg−1 into a blank oil matrix was in a range from 105.09xa0±xa02.77% to 120.16xa0±xa010.88%. The method we developed was further confirmed by performing detection on a Food Analysis Performance Assessment Schemexa0(FAPAS) sample.