摘要：
Chilled duck meat is a popularly consumed meat in China but easily perishes at room/low temperature. Kojic acid is usually used as an antimicrobial. This study investigated the sensory scores, total bacteria number, and total volatile base nitrogen (TVB-N) value of chilled duck meat under kojic acid treatment during storage. The results presented that kojic acid suppressed the growth of spoilage bacteria and prolonged the shelf-life of chilled duck meat by at least two days. In further investigation, the bacterial community composition was explored through high-throughput sequencing. Pseudomonas spp. were the predominant spoilage bacteria after 6-day storage and were significantly suppressed by kojic acid. Besides, Brochothrix showed drug resistance and became the dominant bacteria in the kojic acid treated sample after 6-day storage. In conclusion, kojic acid maintained the sensorial, chemical, and microbial quality of duck meat stored at low temperatures. Meanwhile, kojic acid enriched the bacteria composition and showed strong antimicrobial activity against Pseudomonas spp.
摘要：
This study used response surface methodology to determine the optimal conditions for extraction of polysaccharides from Pyracantha. fortuneana (PSPF), and studied the mechanism of PSPF-inducing apoptosis in human ovarian carcinoma Skov3 cells. Response surface methodology (RSM) were adopted to extract PSPF. The maximum value of polysaccharide yield was obtained under these optimal conditions. PSPF had good potential as an antioxidant. Exposure of cells to PSPF resulted in cytotoxicity through the induction of apoptosis, and the reactive oxygen species were increased, mitochondrial membrane potential decreased, DNA damage (detected as gamma- H2AX and RAD51 foci) was observed in Skov3 cells. In addition, PSPF could induce apoptosis of cancer cells. Therefore, PSPF should be explored as novel potential antioxidants and an anti-tumor drug in a clinical setting.
摘要：
The oxidation of phenolic compounds caused by polyphenol oxidase (PPO) often contributes to the browning and decaying of lotus root. However, methods are limited to solve this problem and to effectively extend the shelf life of fresh lotus. Thus, lactic acid bacteria (LAB) were used in this study as an alternative solution. Michaelies-Menten equations analysis indicated that gallic acid, chlorogenic acid and catechin of lotus were the most optimal substrates of PPO. So Lactobacillus plantarum (LH-B02), Lactobacillus acidophilus (LA-05) and Lactobacillus casei (LC-01) were cultivated at the presence of gradient concentrations of these phenols, presenting different dose-effect relationship. The decomposition of polyphenols by effective strains was detected by HPLC analysis, indicating that after interacted for 30 h, 84.17% of catechin was transformed by LH-B02. When LH-B02 suspension (1.44 × 1011 CFU L−1) were sprayed on the surface of the lotus root for 1, 3, 5, and 8 times, the color loss of treated lotus root was significantly reduced (p < 0.01), compared with the control during the storage of 15 d. Texture properties involving hardness, chewiness, springiness and cohesiveness of the lotus was significantly (p < 0.05) enhanced, especially for the samples sprayed five and eight times, suggesting that LAB could improve the postharvest properties of lotus root.
通讯机构：
[Zhang, Mingwei] G;Guangdong Acad Agr Sci, Sericultural & Agrifood Res Inst, Guangzhou 510610, Peoples R China.
关键词：
Digestion;Fermentation;Longan polysaccharide
摘要：
This study investigated the effect of Lactobacillus fermentum fermentation treatment on the gastrointestinal digestion and fermentation in vitro of polysaccharides from longan pulp. Polysaccharide isolated from unfermented and fermented longan pulp named LP and LP-F, respectively. The molecular weight of LP-F declined from 109.62 +/- 10.66 kDa to 51.46 +/- 6.26 kDa while that of LP declined from 221.63 +/- 2.41 kDa to 69.68 +/- 2.36 kDa with gastrointestinal digestion. At same time, the reducing sugars content of LP and LP-F were both increased significantly. In addition, after 48 h gut microbiota fermentation, there were more total short chain fatty adds and ace tic acid, as well as more Enterococcus, Bifidobacterium, and Clostridium in LP-F fermentation culture than those in LP fermentation culture. Moreover, LP-F fermentation culture showed lower pH value and less residual carbohydrate percentage than that of LP. These results indicated that LP-F is easier than LP to be fermented by human gut microbiota (C) 2020 Elsevier B.V. All rights reserved.
摘要：
The integrity of the intestinal mucosal barrier is important for the health of the host. In this study, longan pulp polysaccharides (LP) prevented the intestinal mucosal injury by increasing the expression of mucin 2, tight junction proteins zonulae occludens-1 (ZO-1), claudin-1, claudin-4, and adherens junction E-cadherin in cyclophosphamide-treated mice. To further identify the principle bioactive component of LP, four acidic polysaccharides (LPIa, LPIIa, LPIIIa, and LPIVa) were puri fi ed, and their intestinal protection activity in vitro was compared. LPIa, LPIIa, and LPIIIa displayed an ability to increase mRNA expression of ZO-1, claudin-1, occludin, and E-cadherin in differentiated Caco-2 cells, especially LPIa. LPIa has specific structure characteristics: porous surface structure, a high molecular weight (1.47 x 10(5) Da), and two specific glycosidic linkages of alpha-Araf-(1--> and -->5)-alpha-Araf-(1-->. These structure characteristics might primarily contribute to greater intestinal barrier protective effect of LPIa.
摘要：
Lotus (Nelumbo nucifera Gaertn) is a wetland vegetable famous for its nutritional and medicinal value. Phenolic compounds are secondary metabolites that play important roles in the browning of fresh-cut fruits and vegetables, and chemical constituents are extracted from lotus for medicine due to their high antioxidant activity. Studies have explored in depth the changes in phenolic compounds during browning, while little is known about their synthesis during the formation of lotus rhizome. In this study, transcriptomic analyses of six samples were performed during lotus rhizome formation using a high-throughput tag sequencing technique. About 23 million high-quality reads were generated, and 92.14% of the data was mapped to the reference genome. The samples were divided into two stages, and we identified 23,475 genes in total, 689 of which were involved in the biosynthesis of secondary metabolites. A complex genetic crosstalk-regulated network involved in the biosynthesis of phenolic compounds was found during the development of lotus rhizome, and 25 genes in the phenylpropanoid biosynthesis pathway, 18 genes in the pentose phosphate pathway, and 30 genes in the flavonoid biosynthesis pathway were highly expressed. The expression patterns of key enzymes assigned to the synthesis of phenolic compounds were analyzed. Moreover, several differentially expressed genes required for phenolic compound biosynthesis detected by comparative transcriptomic analysis were verified through qRT-PCR. This work lays a foundation for future studies on the molecular mechanisms of phenolic compound biosynthesis during rhizome formation.
摘要：
Longan polysaccharides are valuable compounds with many biological activities. Lactobacillus fermentum was selected to ferment longan pulp and the polysaccharides from unfermented and fermented longan pulp (denoted as LP and LP-F, respectively) were isolated. Their physicochemical, immunomodulatory and prebiotic activities were investigated. The results revealed that LP-F, the molecular weight of which was lower than that of LP, contained less neutral sugar, uronic acid and glucose but more arabinose, galactose, rhamnose and mannose. Compared with LP, LP-F had better solubility, lower apparent viscosity and particle size. LP-F exhibited stronger stimulation on macrophages secretion of NO and IL-6, as well as better proliferation of Leuconostoc mesenteroides and Lactobacillus casei. In summary, fermentation treatment could change the physicochemical properties and enhance the bioactivity of polysaccharides from longan pulp. (C) 2018 Published by Elsevier B.V.
关键词：
acid-sensing ion channels;Asic2a;Asic4;methylation;morris water maze;walnut oil
摘要：
<jats:title>Abstract</jats:title><jats:p>Although Walnut oil (<jats:styled-content style="fixed-case">WO</jats:styled-content>) has been reported to enhance cognitive function, the underlying molecular mechanisms are not well understood. This study was designed to assess the effects of <jats:styled-content style="fixed-case">WO</jats:styled-content> on spatial memory in rats through modulation of the expression of acid‐sensing ion channel genes, <jats:italic>Asic2a</jats:italic> and <jats:italic>Asic4</jats:italic>. To investigate the effect of <jats:styled-content style="fixed-case">WO</jats:styled-content> on cognitive performance, we supplemented the diet of female rats with <jats:styled-content style="fixed-case">WO</jats:styled-content>. The results showed that supplementation with <jats:styled-content style="fixed-case">WO</jats:styled-content> at doses of 2.2 and 11gkg<jats:sup>−1</jats:sup>day<jats:sup>−1</jats:sup> significantly improved learning and memory. In vitro treatment of rat hippocampal neuronal cells with appropriate doses of <jats:styled-content style="fixed-case">WO</jats:styled-content> revealed a significant increase in the expression of <jats:italic>Asic2a</jats:italic> and <jats:italic>Asic</jats:italic>4 in a dose‐dependent manner at both the <jats:styled-content style="fixed-case">mRNA</jats:styled-content> and protein levels. We conclude that <jats:styled-content style="fixed-case">WO</jats:styled-content> intake might help to prevent cognitive decline, particularly in the elderly, and that <jats:styled-content style="fixed-case">ASIC</jats:styled-content> genes in neurons can be the targets of compounds contained in the oil.</jats:p>
摘要：
To investigate the structure, in vitro digestibility and activity of polysaccharides from lotus root, their main fractions named LRPs were isolated and purified by gel filtration chromatography. Structural analyses indicated that: LRPs were alpha-(1 -> 6)-D-heteroglucans mainly composed of Glc-(1 ->, -> 6)-Glc(1 ->, -> 6)-Gal (1 ->, -> 4,6)-Gal- (1 -> and -> 3,6)-Glc-(1 ->, at a molar ratio of 1.00: 4.33: 0.83: 0.13: 1.14; the total molar percentage of other monosaccharides in LRPs, including Man, Rha, GalA and Ara, was 8.10%; the molecular weights of LRPs was in the range of 1.33 kDa to 5.30 kDa. According to the change of molecular weight and the productions of reducing sugar and free monosaccharide, the simulated experiments of salivary, gastric and intestinal digestion confirmed that LRPs were almost undigestible. Moreover, LRPs showed the scavenging ability against DPPH and hydroxyl radicals, the growth inhibition ability against SGC7901 and HepG2 cancer cells in vitro, and the immunostimulating effect on the NO and TNF-alpha productions of macrophages in vitro. LRPs nearly remain their initial structure and activities in upper gastrointestinal tract and have health-improving potentials. (C) 2019 Published by Elsevier B.V.
