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Zhang Y.,China Agricultural University | Qin N.,China Agricultural University | Luo Y.,China Agricultural University | Luo Y.,Beijing Higher Institution Engineering Research | Shen H.,China Agricultural University
Journal of Food Protection

Biogenic amines, ATP-related compounds, sensory attributes, total volatile basic nitrogen, microbial flora (total viable bacteria, Pseudomonas, Aeromonas, and H2S-producing bacteria), and free amino acids were determined in common carp (Cyprinus carpio var. Jian) stored at 20 and 0°C. Pseudomonas and H2S-producing bacteria became the dominant bacteria in carp stored at 20 and 0°C, whereas Aeromonas rapidly increased only in carp stored at 0°C. Inosine monophosphate, which is responsible for flavor and freshness, increased to a maximum of 2.37 μmol/g after 12 h at 20°C and to 4.72 μmol/g after 3 days at 0°C. Putrescine and cadaverine were the dominant amines in carp and their concentrations were significantly correlated (P < 0.05) with total volatile basic nitrogen and sensory scores in all samples during the storage. Significant correlations also were observed between histamine and total volatile basic nitrogen and sensory scores only in samples stored at 20°C. Arginine decreased while putrescine increased in all samples. A significant decrease (P < 0.05) in histidine was observed after 24 h of storage, which coincided with an increase in histamine after 36 h in samples stored at 20°C. Hypoxanthine concentrations were significantly correlated with the microbial species (P < 0.01) and sensory scores (P < 0.05) and seems to be a reliable marker for quality of carp fillets stored at 20 and 0°C. Copyright ©, International Association for Food Protection. Source

Wang Q.,China Agricultural University | Du Z.,China Agricultural University | Zhang H.,China Agricultural University | Zhao L.,China Agricultural University | And 4 more authors.
International Journal of Food Sciences and Nutrition

This study aimed to evaluate the beneficial effects of polyphenol extract of adlay (Coix lacryma-jobi L. var. ma-yuen Stapf.) (PEA) on gut microbiota in rats fed a high-cholesterol diet (HCD). Rats were fed HCD containing 1% cholesterol (w/w), with or without a daily intragastric supplement of 200 mg/kg body weight PEA. Results showed that PEA significantly ameliorated increases in serum cholesterol and low-density lipoprotein cholesterol values and significantly restored high-density lipoprotein cholesterol values. The HCD-induced imbalance of gut microflora was modulated by the consumption of PEA. Most bacterial strains influenced by PEA are related to host lipid metabolism. The abundances of one Erysipelotrichales strains and two Clostridia strains were lower in the PEA group than in the control. Phenolic compounds in PEA were identified by HPLC. The findings indicate that PEA may be a useful dietary supplement in the treatment of elevated cholesterol levels and the imbalanced gut microbial ecology. © 2015 Taylor & Francis. Source

Zhao Y.,Capital Normal University | Zhao Y.,Beijing Higher Institution Engineering Research | Zhao Y.,Shenzhen ZhongKe TianYue Technology Co. | Zhao Y.,CAS Shenzhen Institutes of Advanced Technology | And 2 more authors.

In this paper, we propose an iterative beam hardening correction method that is applicable for the case with multiple materials. By assuming that the materials composing scanned object are known and that they are distinguishable by their linear attenuation coefficients at some given energy, the beam hardening correction problem is converted into a nonlinear system problem, which is then solved iteratively. The reconstructed image is the distribution of linear attenuation coefficient of the scanned object at a given energy. So there are no beam hardening artifacts in the image theoretically. The proposed iterative scheme combines an accurate polychromatic forward projection with a linearized backprojection. Both forward projection and backprojection have high degree of parallelism, and are suitable for acceleration on parallel systems. Numerical experiments with both simulated data and real data verifies the validity of the proposed method. The beam hardening artifacts are alleviated effectively. In addition, the proposed method has a good tolerance on the error of the estimated x-ray spectrum. © 2015 Zhao, Li. Source

Li J.,Beijing Technology and Business University | Li J.,Beijing Higher Institution Engineering Research | Shi Y.,Northwest University, China | Zhu Y.,Beijing Technology and Business University | And 5 more authors.
Journal of Agricultural and Food Chemistry

Water-in-oil-in-water (W/O/W) emulsions are effective vehicles for embedding application of active compounds but limited by their thermodynamic instability and rapid release properties. The present study added bovine serum albumin, whey protein isolate, whey protein hydrolysate, sodium caseinate, carboxymethylcellulose sodium, fish gelatin, apple pectin, gum arabic,-carrageenan, and hydroxypropyl chitosan separately to the internal or external aqueous phase to investigate their effects on the physical stabilities and controlled release properties of W/O/W emulsions. The effects of the natural macromolecules in the internal and external aqueous phases were different and depended upon the macromolecule structure and its mass fraction. The addition of the natural macromolecule strengthened the interfaces of emulsions, which improved the physical stability. The natural macromolecules that improved the stability often did not improve controlled release. Therefore, the balance between these properties needs to be considered when adding natural macromolecules to a W/O/W emulsion. © 2016 American Chemical Society. Source

Ren F.,China Agricultural University | Ren F.,Key Laboratory of Functional Dairy | Ren F.,Beijing Higher Institution Engineering Research | Zhang S.,China Agricultural University | And 8 more authors.
Food Chemistry

A tripeptide library consisting of 373 tripeptides (nine repeats) based on bovine α-S1 casein and β-lactoglobulin was synthesised chemically, purified by HPLC and the angiotensin-converting enzyme (ACE) inhibitory activities were assayed. Of the 364 tripeptides assayed, 144 showed a relative ACE inhibitory activity higher than 50% and 43 higher than 60%, at a set concentration of 2.5 mM. More potent tripeptides were found from α-S1 casein than from β-lactoglobulin. The high percentage of Pro/Tyr in caseins could be the reason for this. Fifteen tripeptides with relative activities higher than 50% were selected and assayed for their IC 50, using hippuryl-l-histidyl-l-leucine as the substrate. The most potent peptide showed an IC 50 of 0.85 μM. © 2011 Published by Elsevier Ltd. Source

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