Effects of celery powder on wheat dough properties and textural, antioxidant and starch digestibility properties of bread.

In order to investigate the effects of celery powder (CP) on bread quality, wheat flour was replaced by CP which was produced from two celery varieties ('Jinnan Shiqin' and 'Ventura') at different levels (1, 2, 3 and 5/100 g flour). For both kinds of CPs, Mixolab analysis showed that the water absorption of dough increased with the increase of CP, while the protein network weakening (C2), peak viscosity (C3) and crystallinity of starch (C5-C4) decreased. The specific volume of bread decreased at higher CP level, whereas its crumb hardness and chewiness showed a reverse trend. The addition of CP significantly increased the total phenolics content of bread, and thus caused a significant improvement in antioxidant activities. The addition of CP significantly reduced the content of rapidly digestible starch in bread, while the contents of slowly digestible starch and resistant starch were increased. Additionally, bread prepared with a higher CP content showed a lower predicted glycaemic index. Based on the results of sensory analysis, bread incorporated with 2 g/100 g flour for 'Jinnan Shiqin' or 1 g/100 g flour for 'Ventura' didn't show significant effect on its overall acceptability. The present study indicated that addition of CP could be an effective way to produce a bread with higher antioxidant activity and lower starch digestibility.

Anti-hyperlipidemic and hepatoprotective properties of wheat bran with different particle sizes.

BACKGROUND: Wheat bran has been shown to have health-promoting benefits in relation to diabetes, colorectal cancer, cardiovascular disease, constipation, irritable bowel syndrome, diverticulitis, and gastrointestinal disease. However, its effects on obesity, hyperglycemia, hepatotoxicity, and hyperlipidemia are not yet clear. The effects of the consumption of wheat bran of different particle sizes (coarse, 427.55 µm versus ultra-fine, 11.63 µm) on body weight, serum glucose, liver, and blood lipid metabolism levels in high-fat-diet induced rats fed for 5 weeks were investigated. RESULTS: The high-fat diet significantly increased body weight, serum glucose, serum and liver lipids, and malondialdehyde levels. However, addition of coarse and ultra-fine wheat bran to a high-fat diet decreased weight gain, reduced the levels of serum and liver total cholesterol, triglycerides, malondialdehyde, serum low-density lipoprotein, and serum glucose, and improved serum high-density lipoprotein. Moreover, when two particle sizes were compared, the highest impact was exhibited by the wheat bran containing the larger particle size. CONCLUSIONS: The results suggest that micronized wheat bran significantly improves anti-hyperlipidemic and hepatoprotective properties that might provide a safeguard to protect humans against metabolic syndrome abnormalities and other acute, recurrent, or chronic diseases. © 2018 Society of Chemical Industry.

Effect of rice protein hydrolysates on the short-term and long-term retrogradation of wheat starch.

In this study, the effect of rice protein hydrolysate (RPH) on the short-term and long-term retrogradation of wheat starch (WS) was investigated. Among the RPH produced using different proteolytic enzymes (alcalase, papain and protamex), WS incorporated protamex-hydrolyzed rice protein which hydrolyzed for 2 h (PRPH-2) exhibited the lowest gel hardness after storage for 7 and 14 days. Compared with native WS, rapid viscosity analyzer (RVA) analysis showed PRPH-2 addition significantly lowered peak viscosity, breakdown and setback values (P <0.05), whereas it increased pasting temperature of WS. Dynamic viscoelastic measurements indicated the presence of PRPH-2 resulted in a decrease in the storage modulus (G') and an increase in the loss tangent (tan δ). Differential scanning calorimetry (DSC) showed that PRPH-2 significantly decreased the retrogradation enthalpy (P < 0.05), enhanced the Avrami exponent (n), and decreased the crystallization rate constant (k) during 28 days of storage. In addition, low field nuclear magnetic resonance (LF-NMR) results showed that PRPH-2 could promote the mobility of water molecules in WS gel. These findings indicated that PRPH-2 may be used to inhibit the short-term and long-term retrogradation of WS, which can be potently used as a natural additive to improve the quality of wheat products.

Effect of water content of high-amylose corn starch and glutinous rice starch combined with lipids on formation of starch-lipid complexes during deep-fat frying.

Moisture affects the combination of starch granules and fatty acids in deep-fat frying. In this study, high-amylose corn starch (HACS) and glutinous rice starch (GRS) with various water contents were fried in rapeseed oil at 170 °C for 7 min. The complex index (CI) of the GRS-lipid and HACS-lipid complexes improved as the moisture content increased from 6% to 40%; however, further increasing the water content from 40% to 60% led to a decrease in the CI. At a moisture content of 40%, the CI of the HACS-lipid complexes was higher than that of the GRS-lipid complexes. Fatty acid content analysis revealed that the total fatty acid content at different moisture contents in the HACS-lipid complexes was higher than that in the GRS-lipid complexes both before gelatinization and after enzyme hydrolysis. In addition, the total fatty acid content in the HACS-lipid complexes and GRS-lipid complexes at 40% moisture content was the highest among all the measured moisture contents. Scanning electron microscopy revealed that both the HACS and GRS granules lost their integrity after deep-fat frying, and no free lipid droplets were noted among the starch granules after defatting. Both Fourier-transform infrared spectroscopy and fluorescence microscopy verified that HACS combined with lipids yielded a stronger lipid-binding capacity than that of GRS at a moisture content of 40%. The study results may be potentially useful in the deep-fat frying of starchy food to produce foods with lower fatty acid content.

Purification, characterization and immunomodulatory activity of water extractable polysaccharides from the swollen culms of Zizania latifolia.

The swollen culms of Zizania latifolia is a popular vegetable and traditional herbal medicine mainly consumed in some Asian countries. In our previous study, water extractable polysaccharide (ZLPs-W) and alkali extractable polysaccharide (ZLPs-A) was sequentially prepared from the swollen culms of Zizania latifolia. In vitro cell assay revealed that ZLPs-W without cytotoxicity had higher immunomodulatory activity than ZLPs-A. Therefore, in this study, ZLPs-W was further separated to three purified polysaccharides of ZLPs-W1, ZLPs-W2, and ZLPs-W3 by anion exchange chromatography and size exclusive chromatography in sequence. They were found to be homogeneous polysaccharides in ß-type glycosidic linkage. ZLPs-W1 and ZLPs-W2 without triple helix conformation mainly contained Glc in molar percentage of 96.47% and 85.1%, respectively. ZLPs-W3 with triple helix conformation mainly consisted of Man, Rha, GalA, Glc, Gal and Ara in the molar ratio of 10.23:14.14:37.44:17.14:16.54:4.51. In addition, all the three purified polysaccharides could effectively enhanced the proliferation, phagocytosis, and nitric oxide production of murine macrophage RAW 264.7, suggesting that they possessed a potent immunostimulatory activity and could be developed as immunomodulator in medicine or functional food areas.

Determination of optimum experimental conditions for preparation and functional properties of hydroxypropylated, phosphorylated and hydroxypropyl-phosphorylated glutinous rice starch.

Optimization of the preparation of hydroxypropylated, phosphorylated and hydroxypropyl-phosphorylated glutinous rice starch was performed using a response surface methodology comprising three variables at three levels. Multi-linear regression was used to fit the degree of substitution and molar substitution against. Optimal reaction conditions were 9h, 42°C, 10% (hydroxypropylated), 148min, 150°C, 7% (phosphorylated) and 95min, 140°C, 7.8% (hydroxypropyl-phosphorylated). For hydroxypropylated, predicted optimal and experimental molar substitution values were found to be identical: 0.20. Both the phosphorylated and hydroxypropyl-phosphorylated, the predicted optimal and experimental degree of substitution values was 0.02. Static rheological analysis revealed a pseudoplastic nature for native and modified starches and an increase in apparent viscosity following modification. Dynamic rheological analysis indicated an entanglement network system for native glutinous rice starch suspension, but weak elastic gel-like structure for modified starches as the storage modulus (G') exceeded the loss modulus (G"). Additionally, chemical modification improved the freeze-thaw stability, swelling power, solubility and paste clarity.

Characterization, antioxidant activity and immunomodulatory activity of polysaccharides from the swollen culms of Zizania latifolia.

The swollen culms of Zizania latifolia have been used as a vegetable and traditional herbal medicine in China, Japan, Korea and Southeast Asia countries. Up to date, there is little information about the polysaccharides from the swollen culms of Zizania latifolia and their potential bioactivities. In the present study, water extractable polysaccharide (ZLPs-W) and alkali extractable polysaccharide (ZLPs-A) was sequentially prepared from the swollen culms of Zizania latifolia. Both of ZLPs-W and ZLPs-A was found to be non-starch polydisperse heterpolysaccharide with ß-type glycosidic linkage. ZLPs-W with triple helix conformation mainly composed of GalA, Glc and Gal. ZLPs-A without triple helix conformation mainly composed of Glc, Gal, Xyl and Ara. In in vitro antioxidant assay, ZLPs-W and ZLPs-A exhibited good scavenging activities. The EC50 of DPPH radical, superoxide radical and hydroxy radical scavenging activities for ZLPs-A is 1.87, 1.13 and 0.38mg/mL compared with that for ZLPs-W is 2.95, 3.99 and 0.5mg/mL, respectively. Moreover, in vitro cell assay revealed that ZLPs-W without cytotoxicity has higher immunomodulatory activity than ZLPs-A in terms of stimulation of phagocytic ability and NO production in murine macrophage RAW 264.7. At the treated concentration of 400µg/mL and 100µg/mL, ZLPs-W induced a highest phagocytosis index (1.76) and NO product (29.12µmol/L), respectively. The results suggest that polysaccharide from the swollen culms of Zizania latifolia could be explored as potential natural antioxidant and immunomodulatory agents in medicine or functional food fields.

Is delayed gastric emptying so terrible after pylorus-preserving pancreaticoduodenectomy? Prevention and management.

AIM: To explore some operative techniques to prevent the occurrence of delayed gastric emptying (DGE) after pylorus-preserving pancreaticoduodenectomy (PPPD). METHODS: One hundred and eighty-six patients in a single medical center who accepted PPPD were retrospectively studied. The incidence of DGE was investigated and the influence of some operative techniques on the prevention of DGE was analyzed. RESULTS: During the operative process of PPPD, the methods of detached drainage of pancreatic fluid and bile and gastric fistulization were used. Postoperatively, six patients suffered DGE among the 186 cases; the incidence was 3.23% (6/186). One of them was complicated with intraabdominal infection at the same time, and two with pancreatic leakage. CONCLUSION: Appropriate maneuvers during operation are essential to avoid postoperative DGE in PPPD. The occurrence of DGE is avoidable. It should not be used as an argument to advocate hemigastrectomy in PPPD.

[Expression and purification of avian influenza virus H5N1 NP protein, and screening interaction proteins of host cells in vitro].

OBJECTIVE: To express and purify H5N1 influenza virus (A/Anhui/1/2005) NP in prokaryotic system and to explore the NP-interacting proteins of human bronchial epithelial cells BEAS-2B in vitro. METHODS: The full length H5N1 NP gene fragment was amplified by PCR, inserted into prokaryotic expression vector (pET30a) to generate NP expression plasmid pET30a-NP. After transforming pET30a-NP into E. coli (BL21), the expression of soluble NP protein was induced by IPTG. The expressed NP protein was purified by two steps with metal chelation chromatography and ion exchange chromatography. Then the total proteins of BEAS-2B cells was extracted for screening the components which have protein-protein interaction with purified NP by pull-down and LC-MS/MS methods. RESULTS: The expression of H5N1 NP protein could be induced by IPTG in bacterial system using expression plasmid pET30a-NP. The soluble NP was purified. Twenty proteins were found by pull-down and LC-MS/MS, the further experiments may be needed to prove protein-protein interaction between them. CONCLUSION: The soluble H5N1 NP fusion protein with high purity was obtained and twenty proteins were found which could interact with it by pull-down and LC-MS/MS.

[Study on the immunogenicity of adeno-vector vaccine against H5N1 influenza A virus].

OBJECTIVE: To construct adenovirus vector vaccine against H5N1 influenza virus and study on the immunogenicity. METHODS: In this study, we amplified hemagglutinin (HA) gene sequence of H5N1 influenza virus (A/Anhui/1/2005), then constructed an adenovirus vector vaccine (Adv-HA), followed by tests in BALB/c mice for the immunogenicity with the vaccine and immunization strategies. RESULTS: The recombinate Adv-HA vaccine could effectively induce both humoral and cellular immunity against human H5N1 influenza virus. CONCLUSION: The Adv-HA vaccination against H5N1 influenza is a potential strategy and worthy of further investigation.

Nonopsonic phagocytosis of Lactobacilli by mice Peyer's patches' macrophages.

The ingestion of lactobacilli is of great importance for the probiotic effect of host gut Peyer's patches (PPs) macrophages. The present study is in time focus on the investigation of the factors determining the ingestion of lactobacilli by PPs macrophages. Physicochemical properties of cell surface and adhesive property of nine Lactobacillus strains were examined in the present work. The association of the bacteria with PPs macrophage was checked with macrophage monolayers on coverslips. The influence of lactobacilli on macrophages phagocytic capacity was also investigated with a neutral red uptake assay in vitro. The results show that the macrophages could ingest lactobacilli in a strain dependent manner, and the most ingested strain is L. plantarum Lp6 compared to other tested strains, which displayed strain specific enhancement on the phagocytic activity of PPs macrophages. And there is no correlation between the physicochemical or adhesive properties of the cell surface and the ingestion. The association of L. plantarum Lp6 with PPs macrophage could be decreased by Protease K treatment. Surface proteins of L. plantarum Lp6 could promote the ingestion of fluorescent latex beads by PPs macrophages. In conclusion, the hydrophobicity of the cell surface might not be the key factor determining the association of lactobacilli with PPs macrophages. Cell surface proteins are the media for the binding L. plantarum Lp6 to macrophages.