摘要：
Herein, an ingenious Halbach ring-mediated magnetic filter (HRMF) for capture, sterilization, and detection of foodborne pathogenic bacteria is developed. A composite material with magnetic nanoparticles (MNP) as the core and coated with polydopamine (PDA) and polyethylenimine (PEI) is synthesized, namely MNP@PDA@PEI. Under a Halbach ring, MNP@PDA@PEI can form chains to generate HRMF. Due to the positively charged of PEI, the HRMF could capture the negatively charged bacteria from solution via electrostatic adsorption. Within the HRMF, sterilization performance could be achieved due to the photothermal effect of MNP@PDA@PEI after 5 min of near-infrared light irradiation. More importantly, the number of bacteria could be calculated by bioluminescence method for measuring ATP, which are released from bacteria after photothermal sterilization. Listeria monocytogenes is chosen as a typical bacterium to evaluate the function of HRMF. The time of whole process has been greatly reduced to 38 min. The capture efficiency is 98.63%, and sterilization rate can achieve 99.96% in real samples. The limit of detection is 10.04 CFU/mL, representing a 10-fold decrease compared with bioluminescence method alone. The proposed platform might open a new way for on-site real-time detection of food borne pathogens, and hold potential to nondestructive sterilization in the food processing industry.
摘要：
Pantoea dispersa is a Gram-negative bacterium that exists in a variety of environments and has potential in many commercial and agricultural applications, such as biotechnology, environmental protection, soil bioremediation, and plant growth stimulation. However, P. dispersa is also a harmful pathogen to both humans and plants. This "double-edged sword" phenomenon is not uncommon in nature. To ensure survival, microorganisms respond to both environmental and biological stimuli, which could be beneficial or detrimental to other species. Therefore, to harness the full potential of P. dispersa, while minimizing potential harm, it is imperative to unravel its genetic makeup, understand its ecological interactions and underlying mechanisms. This review aims to provide a comprehensive and up-to-date overview of the genetic and biological characteristics of P. dispersa, in addition to potential impacts on plants and humans, as well as to provide insights into potential applications.
通讯机构：
[Xiaofeng Tan] A;[Si Qin] L;Authors to whom correspondence should be addressed.<&wdkj&>Key Laboratory of Non-Wood Forest Products of State Forestry Administration, College of Forestry, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>The Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Laboratory of Food Function and Nutrigenomics, College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Authors to whom correspondence should be addressed.
摘要：
Yellow glutinous rice wine is a traditional Chinese beverage created by soaking, boiling, and fermenting glutinous rice. The majority of current studies on the flavor of yellow glutinous rice wine are based on instrumental analysis, with sensory analysis being overlooked. In this study, 36 volatile chemicals in the fermentation process of yellow wine were annotated by GC-MS and then an OPLS-DA model was built to screen out 13 distinctive substances (VIP > 1, p < 0.01). The relative odor activity value (ROAV) was calculated using the threshold values of these chemicals and 10 substances, including alcohols, esters, and aldehydes, were found as key contributors to the overall flavor of yellow wine. Following that, consumers quantified the sensory descriptors of yellow wine using rate-all-that-apply (RATA), and correspondence analysis revealed three groups of characteristic flavors and odors. Alcohols and esters were found to be key producers of flowery and fruity scents in yellow wine, according to correlation analysis. We discovered two alcohols that are rarely found in yellow wine: [R,R]-2,3-butanediol and 1-phenylethanol. The former was found to be favorably connected with wine scent and pungent odor, and its specific effect on flavor should be researched further.
作者机构：
[欧阳佳] College of Food Science and Technology, Hunan Agricultural University, Changsha, 410128, China;[杨红; 宋晓燕] Hunan Changsha Qianhuke Distillery Co.Ltd., Changsha, 410600, China;Hunan Provincial Research Center of Engineering and Technology for Fermented Food, Changsha, 410128, China;[李清明; 苏小军; 王锋; 李文佳] College of Food Science and Technology, Hunan Agricultural University, Changsha, 410128, China, Hunan Provincial Research Center of Engineering and Technology for Fermented Food, Changsha, 410128, China
通讯机构：
[Su, X.] C;College of Food Science and Technology, China
通讯机构：
[Tang, ZH ] H;Hunan Agr Univ, Coll Food Sci & Technol, Changsha 410128, Peoples R China.;Hunan Engn Technol Res Ctr Rapeseed Oil Nutr Hlth, Changsha 410128, Peoples R China.
关键词：
deep eutectic solvent;Bletilla striata polysaccharide;response surface methodology;antioxidant activity
摘要：
Taking the extraction yield of Bletilla striata polysaccharide (BSP) as the index and taking the type of deep eutectic solvents (DESs), extraction time, extraction temperature, DES water content, and solid-liquid ratio as the investigation factors, single-factor and Box-Behnken response surface tests were carried out to optimize the extraction process of BSP. Thus, the antioxidant activity of BSP on DPPH radicals, ABTS radicals and ferric reducing antioxidant power were determined. The results showed that the most suitable deep eutectic solvent was DES-2, namely choline chloride-urea. The optimal extraction conditions for BSP were an extraction time of 47 min, extraction temperature of 78 °C, water content of 35%, and solid-liquid ratio of 1:25. Under this optimized condition, the extraction yield of BSP was able to reach (558.90 ± 8.83) mg/g, and recycling studies indicated the good cycle stability of the DES. Antioxidant results showed that BSP had superior antioxidant activity and had a dose-response relationship with drug concentration. Compared with Bletilla striata polysaccharide obtained via conventional hot water extraction (BSP-W), the extraction yield of BSP obtained through this method (BSP-2) increased by 36.77%, the scavenging activity of DPPH radicals increased by 24.99%, the scavenging activity of ABTS radicals increased by 41.16%, and the ferric reducing antioxidant power increased by 49.19%. Therefore, DESs as new green reagents and BSP extracted with DESs not only had a high yield but also had strong antioxidant activity.
摘要：
本试验利用电子束及γ射线两种射线对渐狭蜡蚧菌(Lecanicillium attenuatum)3166进行诱变处理, 研究适于渐狭蜡蚧菌诱变选育的吸收剂量以及诱变菌株生物学特性。结果表明: 电子束及γ射线诱变渐狭蜡蚧菌的最适剂量均为200 Gy, 渐狭蜡蚧菌的电子束辐射敏感性D10值为191 Gy、γ射线D10值为366 Gy; 以产孢速率为指标筛选获得突变菌株8株, 其中5株的菌丝生长及产孢速率较出发菌株显著提高, 均为电子束诱变所得, 产孢速率分别较出发菌株提高了30.45%、31.55%、23.66%、64.83%、68.77%; 诱变菌株的胞外几丁质酶比活在培养5 d时达到峰值, 诱变株Ⅱ111、Ⅱ164、Ⅱ181的几丁质酶比活分别较出发菌株显著提高29.29%、54.45%、19.18%, 其中Ⅱ164酶比活可达1 707.41 U/mg prot; 胞外蛋白酶比活在培养7 d时达到峰值, Ⅱ111、Ⅱ164、Ⅱ181的蛋白酶比活分别较出发菌株显著提高17.98%、13.17%、16.50%, 其中Ⅱ111酶比活达到30.71 U/mg prot, 且渐狭蜡蚧菌诱变株生长速率与胞外酶比活有强相关性。本研究为渐狭蜡蚧菌后续的害虫防治及开发利用提供了理论基础。 In this study, electron beam and γ-ray were used to mutagenize Lecanicillium attenuatum 3166, and the absorbed dose suitable for mutation breeding of Lecanicillium attenuatum and the biological characteristics of the mutagenized strain were studied. The results showed that the optimal dose for electron beam and γ-ray mutagenesis of Lecanicillium attenuatum was 200 Gy, the electron beam D10 value of Lecanicillium attenuatum was 191 Gy, and the γ-ray D10 value was 366 Gy; eight mutant strains were screened and obtained with spore production rate as the index. Among them, the hypha growth and spore production rate of five strains significantly increased compared with the parent strain, which were all obtained by electron beam mutagenesis. The spore production rate increased by 30.45%, 31.55%, 23.66%, 64.83% and 68.77% respectively compared with the parent strain. The extracellular chitinase activity of the mutant strain reached the peak after five days of culture, and the chitinase activities of mutant strains Ⅱ111, Ⅱ164 and Ⅱ181 increased by 29.29%, 54.45% and 19.18% respectively, compared with that of the parent strain. The chitinase activity of mutant strain Ⅱ164 reached 1 707.41 U/mg prot; the extracellular protease activity reached its peak after 7-day culture, and the protease activities of Ⅱ111, Ⅱ164 and Ⅱ181 were significantly increased by 17.98%, 13.17% and 16.50% respectively as compared with those of the parent strain, wherein the enzyme activity of Ⅱ111 could reach 30.71 U/mg prot, and the growth rate of the mutant strain had a strong correlation with the extracellular enzyme activity. This study provides a theoretical basis for the follow-up pest control, development and utilization of Lecanicillium attenuatum.
关键词：
hydrocolloids;chemical model system;heterocyclic amines;advanced glycation end products;grilled beef patties
摘要：
Effectively inhibiting the formation of heterocyclic amines (HAs) and advanced glycation end products (AGEs) is crucial to human health. In the present study, chemical model systems were used to evaluate the inhibitory effects of seven hydrocolloids on HA and AGE formation. The results showed that hydrocolloids effectively inhibited the formation of two major AGEs. However, their inhibitory action against HA formation showed unexpected results, wherein alginic acid, carrageenan and konjac glucomannan promoted the formation of 2-Amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP), harmane, norharmane and 2-amino-3,8-dimethyl-imidazo [4,5-f]-quinoline (MeIQx). Only chitosan and pectin showed significant inhibitory effects on HAs, reducing HA levels by 34.5-56.3% and 30.1-56.6%, respectively. In grilled beef patties, the addition of 1.5% chitosan and pectin significantly decreased AGE and HA content by 53.8-67.0% and 46.9-68.1%, respectively. Moreover, it had a limited impact on quality and sensory properties. Further mechanism studies conducted in model systems revealed that chitosan and pectin decreased the formation of key intermediates of AGEs and HAs. These findings suggest that chitosan and pectin are powerful inhibitors against AGE and HA formation with minimal impact on food quality. Therefore, their application in meat preparation and processing could effectively decrease human dietary exposure to HAs and AGEs.
期刊：
FRONTIERS IN NUTRITION,2023年10:1238748 ISSN：2296-861X
通讯作者：
Yang, R.
作者机构：
[Xiao, Yu] College of Food Science and Technology, Hunan Agricultural University, Changsha, China;[Yang, Baoru] Department of Biochemistry and Food Chemistry, University of Turku, Turku, Finland;[Yang, Runqiang] College of Food Science and Technology, Whole Grain Food Engineering Research Center, Nanjing Agricultural University, Jiangsu, Nanjing, China
通讯机构：
[Yang, R.] C;College of Food Science and Technology, Jiangsu, China
通讯机构：
[Han, XX ; Chen, F] H;Hunan Univ, Natl Engn Res Ctr High Efficiency Grinding, Changsha 410082, Peoples R China.;Hunan Univ, State Key Lab Adv Design & Manufacture Vehicle Bod, Changsha 410082, Peoples R China.
摘要：
Light-based 3D bioprinting is now employed widely to fabricate geometrically complex constructs for various biomedical applications. However, the inherent light scattering defect creates significant challenges in patterning dilute hydrogels to form high-fidelity structures with fine-scale features. Herein, we introduce a photoinhibiting approach that can effectively suppress the light scattering effect via a mechanism of simultaneous photoabsorption and free-radical reaction. This biocompatible approach significantly improves the printing resolution (~1.2 - ~2.1 pixels depending on swelling) and shape fidelity (geometric error less than 5%), while minimising the costly trial-and-error procedures. The capability in patterning 3D complex constructs using different hydrogels is demonstrated by manufacturing various scaffolds featuring intricate multi-sized channels and thin-walled networks. Importantly, cellularised gyroid scaffolds (HepG2) are fabricated successfully, exhibiting high cell proliferation and functionality. The strategy established in this study promotes the printability and operability of light-based 3D bioprinting systems, allowing numerous new applications for tissue engineering. ‘Light-based bioprinting is employed in the fabrication of complex constructs but achieving high resolution remains challenging due to light scattering effects. Here, the authors develop a photoinhibiting additive which suppresses light scattering and demonstrate printing of functional scaffolds
