摘要：
Lotus root (Nelumbo nucifera G.) is a high economic value crop in the world. In this study, the storage characteristics (color, sensory, texture, and fatty acids) of lotus root ("Elian No.5") were evaluated at different harvest periods (September 2018, October 2018, November 2018, December 2018, and January 2019). Moreover, the storage characteristics were evaluated after the shortterm and long-term storage of lotus root at 4 degrees C and 20 degrees C. The hardness of lotus root significantly decreased at both temperatures (4 degrees C and 20 degrees C) during the first 3 days of storage. In contrast, the decrease in hardness delayed at 4 degrees C (beyond 3 days of storage). Further, genes related to hardness at different storage temperatures were identified using the RNA-seq and qRT-PCR. The results of this study provide a reference for lotus root storage and a basis for the molecular breeding of longterm-storable lotus root.
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.
作者机构：
[徐筱莹] College of Food Science and Engineering Wuhan Polytechnic University, Wuhan, 430023, China;[胡晓潇; Shan T.-T.] College of Biology and Pharmaceutical Engineering Wuhan Polytechnic University, Wuhan, 430023, China;Hubei Engineering Research Center for Fresh Food, Wuhan, 430023, China;[易阳] College of Food Science and Engineering Wuhan Polytechnic University, Wuhan, 430023, China<&wdkj&>Hubei Engineering Research Center for Fresh Food, Wuhan, 430023, China;[王宏勋; 王丽梅] College of Biology and Pharmaceutical Engineering Wuhan Polytechnic University, Wuhan, 430023, China<&wdkj&>Hubei Engineering Research Center for Fresh Food, Wuhan, 430023, China
摘要：
<jats:p>Red coloration contributes to fruit quality and is determined by anthocyanin content in peach (<jats:italic>Prunus persica</jats:italic>). Our previous study illustrated that anthocyanin accumulation is strongly regulated by light, and the effect of induction differs according to light quality. Here we showed that both ultraviolet-A (UVA) and ultraviolet-B (UVB) irradiation promoted anthocyanin biosynthesis in “Hujingmilu” peach fruit, and a combination of UVA and UVB had additional effects. The expression of anthocyanin biosynthesis and light signaling related genes, including transcription factor genes and light signaling elements, were induced following UV irradiation as early as 6 h post-treatment, earlier than apparent change in coloration which occurred at 72 h. To investigate the molecular mechanisms for UVA- and UVB-induced anthocyanin accumulation, the genes encoding ELONGATED HYPOCOTYL 5 (HY5), CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1), Cryptochrome (CRY), and UV RESISTANCE LOCUS 8 (UVR8) in peach were isolated and characterized through functional complementation in corresponding Arabidopsis (<jats:italic>Arabidopsis thaliana</jats:italic>) mutants. <jats:italic>PpHY5</jats:italic> and <jats:italic>PpCOP1.1</jats:italic> restored hypocotyl length and anthocyanin content in Arabidopsis mutants under white light; while <jats:italic>PpCRY1</jats:italic> and <jats:italic>PpUVR8.1</jats:italic> restored <jats:italic>AtHY5</jats:italic> expression in Arabidopsis mutants in response to UV irradiation. Arabidopsis <jats:italic>PpHY5/hy5</jats:italic> transgenic lines accumulated higher amounts of anthocyanin under UV supplementation (compared with weak white light only), especially when UVA and UVB were applied together. These data indicated that PpHY5, acting as AtHY5 counterpart, was a vital regulator in UVA and UVB signaling pathway. In peach, the expression of <jats:italic>PpHY5</jats:italic> was up-regulated by UVA and UVB, and PpHY5 positively regulated both its own transcription by interacting with an E-box in its own promoter, and the transcription of the downstream anthocyanin biosynthetic genes <jats:italic>chalcone synthase 1</jats:italic> (<jats:italic>PpCHS1</jats:italic>), <jats:italic>chalcone synthase 2</jats:italic> (<jats:italic>PpCHS2</jats:italic>), and <jats:italic>dihydroflavonol 4-reductase</jats:italic> (<jats:italic>PpDFR1</jats:italic>) as well as the transcription factor gene <jats:italic>PpMYB10.1</jats:italic>. In summary, functional evidence supports the role of PpHY5 in UVA and UVB light transduction pathway controlling anthocyanin biosynthesis. In peach this is via up-regulation of expression of genes encoding biosynthetic enzymes, as well as the transcription factor <jats:italic>PpMYB10.1</jats:italic> and <jats:italic>PpHY5</jats:italic> itself.</jats:p>
作者机构：
[Qiqi Y.; Wen L.; Qianhui H.; Heng G.] College of Food Science and Engineering, Wuhan Polytechnic University, Wuhan, 430023, China;Fresh Food Engineering and Technology Research Center of Hubei Province, Wuhan, 430023, China;College of Biological and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan, 430023, China;[Wenfu H.; Min Z.] College of Food Science and Engineering, Wuhan Polytechnic University, Wuhan, 430023, China<&wdkj&>Fresh Food Engineering and Technology Research Center of Hubei Province, Wuhan, 430023, China;[Hongxun W.] Fresh Food Engineering and Technology Research Center of Hubei Province, Wuhan, 430023, China<&wdkj&>College of Biological and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan, 430023, China
摘要：
A SiOx coating prepared via plasma-enhanced chemical vapor deposition (PECVD) techniquewas used as a transition layer between polylactic acid (PLA) and chitosan (CS) to form a three-layer composite film of PLA/SiOx/CS. The effect of oxygen plasma irradiation time (0 s, 30s and 60s) on SiOx surface and PLA-CS interface was examined based on the contact angle, pull-off test and scanning electron microscope (SEM). The mechanical, barrier and antibacterial properties of PLA/SiOx/CS films were also investigated. The results showed that oxygen plasma irradiation improved the hydrophilicity of the SiOx surface and the adhesive strength between SiOx-CS of PLA/ SiOx/CS films in a time-dependent manner. SEM examination revealed a gap between PLA/CS layers, but the interfacial separation among layers in PLA/SiOx/CS films disappeared as the transition layer of SiOx and oxygen plasma irradiation (60s) intensified. Notably, the oxygen barrier property and antibacterial activity of PLA/ SiOx/CS films were dramatically enhanced. Additionally, moisture resistance was slightly decreased following the incorporation of the CS coating compared with the PLA film. The tensile strength of the composite film also increased with the number of layers, while elongation at break decreased. The prepared PLA/SiOx/CS films with multifunction are promising applied in food packaging as biobased materials. (C) 2020 Elsevier B.V. All rights reserved.
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.
