Jianquan Kan

Purification and Structural Identification of Polysaccharides from Bamboo Shoots (Dendrocalamus latiflorus)

Three kinds of polysaccharides, namely, BSP1A, BSP2A, and BSP3B, were isolated from raw bamboo shoot (Dendrocalamus latiflorus) after purification and classification by DEAE cellulose-52 (ion-exchange chromatography) and Sephadex G-50. The molecular weights of BSP1A, BSP2A, and BSP3B were 10.2, 17.0 and 20.0 kDa, respectively, which were measured through GPC (gel performance chromtatography) methods. BSP1A contained arabinose, glucose, and galactose in a molar ratio of 1.0:40.6:8.7. BSP2A and BSP3B contained arabinose, xylose, glucose, and galactose in molar ratios of 6.6:1.0:5.2:10.4 and 8.5:1.0:5.1:11.1, respectively. The existence of the O-glycopeptide bond in BSP1A, BSP2A, and BSP3B was demonstrated by β-elimination reaction. FTIR spectra of the three polysaccharides showed that both BSP2A and BSP3B contained β-d-pyranose sugar rings. However, BSP1A exhibited both β-d-pyranose and α-d-pyranose sugar rings. Congo red test indicated that BSP1A and BSP2A displayed triple helix structures, but BSP3B did not. NMR spectroscopy revealed that BSP1A may exhibit a β-1,6-Glucan pyran type as the main link, and few 1,6-glycosidic galactose pyranose and arabinose bonds were connected; BSP2A mainly demonstrated →5)β-Ara(1→and→3)β-Gal(1→connection. Furthermore, BSP3B mainly presented →3)β-Glu(1→and→3)β-Gal(1→connection and may also contain few other glycosidic bonds.

Granular Structure and Physicochemical Properties of Starches from Amaranth Grain

The granular structure and physicochemical properties of starches isolated from grain amaranth cultivar K112 (Amaranthus cruentus L.) were studied in this study. Detailed physical and chemical analyses were performed by determining the granular morphology, crystallinity, particle size, thermal characteristics, blue value, enzyme susceptibility, and pasting properties. Results showed polygon-shaped A. cruentus L. K112 starch granules. The average diameter was 1.38 μm, in which half of the diameter was <2.91 μm. An A-type X-ray diffraction pattern was revealed with intense peaks of 15.2°, 17.5°, and 23.2°. The peak viscosity was 181 BU and the breakdown value was 2 BU. Amaranth starch obtained the highest pasting temperature (70.7°C) and enzymatic digestibility (absorbance value = 0.41 ± 0.013) compared with corn, cassava, and sweet potato starches.

Effect of Whole Grain Qingke (Tibetan Hordeum vulgare L. Zangqing 320) on the Serum Lipid Levels and Intestinal Microbiota of Rats under High-Fat Diet

This study investigated the hypolipidemic effect of whole grain Qingke (WGQ) and its influence on intestinal microbiota. Changes in the serum lipid, intestinal environment, and microbiota of Sprague-Dawley rats fed high-fat diets supplemented with different doses of WGQ were determined. Results showed that high doses of WGQ significantly decreased (P < 0.05) the Lees index, serum total cholesterol, low-density lipoprotein cholesterol, and non-high-density lipoprotein cholesterol levels whereas they increased the body weight of the rats. Cecal weight and short-chain fatty acid (SCFA) concentration increased with increasing WGQ dose. An Illumina-based sequencing approach showed that the relative abundance of putative SCFA-producing bacteria Prevotella and Anaerovibrio increased in the rats fed the WGQ diet. Principal component analysis revealed a significant difference in intestinal microbiota composition after the administration of the WGQ diet. These findings provide insights into the contribution of the intestinal microbiota to the hypolipidemic effect of WGQ.

Synthesis and characterization of retrograded starch nanoparticles through homogenization and miniemulsion cross-linking.

A new and convenient route to synthesizing retrograded starch nanoparticles (RS3NPs) through homogenization combined with a water-in-oil miniemulsion cross-linking technique was developed. The RS3NPs were optimized using Box-Behnken experimental design. Homogenization pressure (X1), oil/water ratio (X2), and surfactant (X3) were selected as independent variables, whereas particle size was considered as a dependent variable. Results indicated that homogenization pressure was the main contributing variable for particle size. The optimum values for homogenization pressure, oil/water ratio, and surfactant were 30MPa, 9.34:1, and 2.54g, respectively, whereas the particle size was predicted to be 288.2 nm. Morphological, physical, chemical, and functional properties of the RS3NPs were the assessed. Scanning electron microscopy and dynamic light scattering images showed that RS3NP granules were broken down to size of about 222.2nm. X-ray diffraction results revealed a disruption in crystallinity. The RS3NPs exhibited a slight decrease in To, but Tp and Tc increased and narrowest Tc-To. The solubility and swelling power were also increased. New peaks at 1594.84 and 1403.65cm(-1) were observed in the FTIR graph. However, homogenization minimally influenced the antidigestibility of RS3NPs. The absorption properties improved, and the adsorption kinetic described the contact time on the adsorption of captopril onto RS3NPs. In vitro release experiment indicated that the drug was released as follows: 21% after 2h in SGF, 42.78% at the end of 8h (2h in SGF and 6h in SIF), and 92.55% after 12h in SCF. These findings may help better utilize RS3NP in biomedical applications as a drug delivery material.

Identification and characterization of a novel angiotensin I-converting enzyme inhibitory peptide (ACEIP) from silkworm pupa

The angiotensin I-converting enzyme inhibitory peptide (ACEIP) was isolated and characterized from silkworm pupae and purified using Sephadex G-25 gel filtration. The structure and physicochemical properties of pupa ACEIP were analyzed. The α-P3 fraction exhibited the most potent ACE inhibitory activity. After purification via semi-preparative reverse-phase HPLC (RP-HPLC) and HPLC, the α-P3-6-b component was revealed to have the highest ACE inhibitory activity (IC50=28.3 μg/mL). Edman degradation revealed a Val-Glu-Ile-Ser amino acid sequence in which novel active sequences were identified. Physicochemical property testing showed that purified pupa ACEIP exhibits good solubility, heat resistance, and acid resistance that all indicate ACEIP derived from silkworm pupa is an excellent food-derived ACEIP.

Characterization of a novel polysaccharide isolated from Rosa roxburghii Tratt fruit and assessment of its antioxidant in vitro and in vivo

In this study, a novel water-soluble polysaccharide (RRTP1-1) was obtained from Rosa roxburghii Tratt fruit through the ultrasonic-assisted extraction followed by anion-exchange and size-exclusion chromatography purification. The primary structure of RRTP1-1 was investigated by UV, FT-IR, HPLC, GC-MS, 1H and 13C NMR spectroscopy. Chemical composition analysis revealed that RRTP1-1 had an average molecular weight of 97.58kDa and consisted of Man, Rha, GlcA, GalA, Glc, Gal, Ara and Xyl in a molar ratio of 2.88:1.39:2.83:1.00:69.11:3.04:2.52:3.41. This polysaccharide was proven to be a kind of glucan, owning a backbone structure of →6)-α-d-Glcp-(1→6)-α-d-Glcp-(1→. Congo red test indicated that RRTP1-1 had no triple helix structure. Antioxidation tests performed in vitro revealed that RRTP1-1 possessed obviously DPPH, hydroxyl and superoxide radicals scavenging activities. Furthermore, antioxidant assays in vivo showed that RRTP1-1 at 200 or 400mg/kg dose could significantly enhance the activities of antioxidant enzymes (CAT, SOD, and GSH-Px), increase TAOC values, and decrease the LPO and MDA levels in different degrees in the serum of D-Gal aging-induced mice. The present results suggested that RRTP1-1 could be a new source of natural antioxidants for applications in functional foods and dietary supplemental products.

Analysis of Peanut Using Near-Infrared Spectroscopy and Gas Chromatography–Mass Spectrometry: Correlation of Chemical Components and Volatile Compounds

Peanut contains protein, oil, oleic acid, and linoleic acid its flavor is largely determined by pyrazine and aldehyde compounds. Both nutritional value and flavor are standards for measuring peanut quality. In this report, the contents of protein, oil, oleic acid, and linoleic acid were determined using near-infrared reflectance spectroscopy, and flavor compounds were identified using headspace solid-phase microextraction combined with gas chromatography–mass spectrometry in 12 different peanut cultivars. Our results showed that the content of oleic acid in raw peanut ranged from 35.69 to 82.79 g/100 g oil and the linoleic acid content ranged from 2.92 to 44.19 g/100 g oil, with high coefficients of variation. The coefficients of variation of protein and oil were lower, with content of 26.97–33.07 g/100 g raw materials and 45.53–55.53 g/100 g raw materials, respectively. Overall, 14 volatile components were isolated and identified, among which pyrazine and aldehyde compounds were the major aroma components in 12 different peanut cultivars.. Based on these results, peanuts with high protein content have high linoleic oil levels but low oleic oil levels, and roasted peanuts have a high content of pyrazines but low content of aldehydes. The results of this study will enable manufacturers to develop simple tests that predict the flavor of roasted peanuts based on their composition.

Preparation and characterization of resistant starch type IV nanoparticles through ultrasonication and miniemulsion cross-linking

This study aimed to assess the properties of resistant starch type IV (chemically modified starch, RS4) prepared from a new and convenient synthesis route by using ultrasonication combined with water-in-oil miniemulsion cross-linking technique. A three-factor Box-Behnken design and optimization was used to minimize particle size through the developed RS4 nanoparticles. The predicted minimized Z-Avel (576.1nm) under the optimum conditions of the process variables (ultrasonic power, 214.57W; sonication time, 114.73min; and oil/water ratio, 10.54:1) was very close to the experimental value (651.0nm) determined in a batch experiment. After preparing the RS4 nanoparticles, morphological, physical, chemical, and functional properties were assessed. Results revealed that RS4 nanoparticle size reached about 600nm. Scanning electron microscopy images showed that ultrasonication induced notches and grooves on the surface. Under polarized light, the polarized cross was impaired. X-ray diffraction results revealed that the crystalline structure was disrupted. Smaller or no endotherms were exhibited in DSC analysis. In the FTIR graph, new peaks at 1532.91 and 1451.50cm(-1) were observed, and pasting properties were reduced. Amylose content, solubility, and SP increased, but RS content decreased. Anti-digestibility remained after ultrasonication. The prepared RS4 nanoparticles could be extensively used in biomedical applications and in the development of new medical materials.

Hypolipidaemic effect and mechanism of paprika seed oil on Sprague–Dawley rats

BACKGROUND Details regarding the functional properties of paprika seed oil are relatively scarce. In this study the hypolipidaemic effects and mechanisms of paprika seed oil on Sprague-Dawley rats are explored, which may improve the usage of paprika seed source and provide a theoretical basis of paprika seed oil for the alleviation of hyperlipidaemia. RESULTS In capsaicin and paprika seed oil (PSO) groups, total cholesterol (TC) and total triglyceride (TG) in serum and liver lipids of rats were significantly decreased (P < 0.05). The contents of serum HDL cholesterol were increased and the contents of serum LDL cholesterol were decreased (P < 0.05). Real-time PCR analyses revealed that the hepatic mRNA expression of fatty acid synthetase (FAS) is decreased and the expression levels of HSL is increased (P < 0.05). The mRNA expression of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) is decreased and the expression levels of low-density lipoprotein receptor (LDLR) is significantly improved (P < 0.05). The cholesterol 7-hydroxylase (CYP7A1) expression is regulated to control the cholesterol-to-bile acid transformation and cholesterol excretion is promoted. Capsaicin and unsaturated fatty acid PSO can activate and improve the mRNA expression of transient receptor potential vanilloid type-1 (TRPV1) and peroxisome proliferators-activated receptors (PPARα). CONCLUSION The hypolipidaemic effects of paprika seed oil (PSO) may be attributed to the inhibition of lipid synthesis via suppressing the expression of HMG-CoAR, CYP7A1 and FAS, meanwhile, promoting the metabolism and excretion of lipids via up-regulating the expression of LDLR, HSL, TRPV1 and PPARα.

Zanthoxylum alkylamides ameliorate protein metabolism disorder in STZ-induced diabetic rats

This study aimed to evaluate the protein metabolism effect of Zanthoxylum alkylamides and to explore the potential mechanism in streptozotocin (STZ)-induced diabetic rats. Diabetic rats were orally treated with 2, 4 and 8 mg per kg bw of alkylamides daily for 28 days. Alkylamides decreased the relative weight of the liver and food intake, significantly increased the relative skeletal muscle weight and significantly decreased the blood urea nitrogen levels. Insulin, insulin-like growth factor 1, total protein (TP) and albumin (ALB), globular proteins and ALB proteins/globulin protein levels in serum significantly increased. TP, RNA content and RNA/DNA ratio significantly increased in the skeletal muscle of diabetic rats. Real-time quantitative polymerase chain reaction results indicated that alkylamides significantly increased the mRNA expression of insulin receptor (InR), IGF1 and insulin-like growth factor 1 receptor (IGF1R) in the liver and skeletal muscle. Moreover, the mRNA and protein expression levels of PI3K, PKB and mTOR significantly increased, whereas those of atrogin-1, muscle ring finger 1 and FOXO in the skeletal muscle significantly decreased. Alkylamides may advance protein synthesis by the PI3K/PKB/mTOR signalling pathway and attenuate the catabolism of protein through the ubiquitin–proteasome pathway. Therefore, it was possible that alkylamides ameliorate protein metabolism disorders in diabetic rats by activating the mTOR pathway.