Effect of Vacuum Pre-cooling on the Circulation and Shelf Quality of Postharvest Baby Cabbage

To optimize the treatment conditions for vacuum pre-cooling of baby cabbage and maintain the fresh quality of postharvest baby cabbage, a central composite response surface experiment with two factors and three levels was conducted on the basis of analyzing the effects of different vacuum pre-cooling final temperature (0, 2 and 4 ℃) and different vacuum pre-cooling final pressure (400, 600, 800 and 1000 Pa) on the pre-cooling of postharvest baby cabbage. The results showed that compared with the control without pre-cooling and the pre-cooling group with final temperature of 0 ℃, the pre-cooling with final temperature of 2~4 ℃ at the final pressure of 600 Pa could better maintain the appearance quality of postharvest baby cabbage, inhibit the increase of respiratory rate and malondialdehyde (MDA) content. Under the condition of final temperature of 2 ℃, compared with the control without pre-cooling and the pre-cooling group with a final pressure of 1000 Pa, pre-cooling with final pressures of 400~800 Pa could also better maintain the appearance quality of postharvest baby cabbage, inhibit the increase of respiratory rate and MDA content. Further central composite response surface experiments showed that the optimal conditions for vacuum pre-cooling of postharvest baby vegetables were final temperature of 4.0 ℃ and final pressure of 600 Pa. The vacuum pre-cooling condition not only maintained good quality of postharvest baby vegetable, but also increased the content of soluble protein, total phenols, and ascorbic acid by 18.78%, 18.47% and 33.23%, respectively. Therefore, appropriate vacuum pre-cooling treatment is a highly potential commercialization technology that could effectively maintain the good quality of postharvest baby vegetable during circulation and shelf life

Multi-omics-based investigation of Bifidobacterium’s inhibitory effect on glioma: regulation of tumor and gut microbiota, and MEK/ERK cascade

Glioma, the most prevalent primary tumor of the central nervous system, is characterized by a poor prognosis and a high recurrence rate. The interplay between microbes, such as gut and tumor microbiota, and the host has underscored the significant impact of microorganisms on disease progression. Bifidobacterium, a beneficial bacterial strain found in the human and animal intestines, exhibits inhibitory effects against various diseases. However, the existing body of evidence pertaining to the influence of Bifidobacterium on glioma remains insufficient. Here, we found that Bifidobacterium reduces tumor volume and prolongs survival time in an orthotopic mouse model of glioma. Experiments elucidated that Bifidobacterium suppresses the MEK/ERK cascade. Additionally, we noted an increase in the α-diversity of the tumor microbiota, along with an augmented relative abundance of Bifidobacterium in the gut microbiota. This rise in Bifidobacterium levels within the intestine may be attributed to a concurrent increase in Bifidobacterium within the glioma. Additionally, Bifidobacterium induced alterations in serum metabolites, particularly those comprised of organonitrogen compounds. Thus, our findings showed that Bifidobacterium can suppress glioma growth by inhibiting the MEK/ERK cascade and regulating tumor, and gut microbiota, and serum metabolites in mice, indicating the promising therapeutic prospects of Bifidobacterium against glioma

Association between increased levels of amyloid-β oligomers in plasma and episodic memory loss in Alzheimers disease

The objectives of this study were to investigate whether the plasma levels of oligomeric amyloid-β (OAβ) were affected in Alzheimers disease (AD) and to examine the associations (or possible correlations) between plasma OAβ levels and memory performance. Thirty subjects with AD and 28 cognitively normal controls were recruited in the study. The multimer detection system (MDS) was used to measure the levels of OAβ in the plasma. In addition to assessing the general cognitive function with the Mini-Mental State Examination (MMSE), Cognitive Abilities Screening Instrument (CASI), and Alzheimers Disease Assessment Scale–cognitive portion (ADAS-Cog), the common objects memory test (COMT) was used to examine the episodic memory performance. Pearsons and partial correlation analyses were conducted to explore the associations between cognitive performance and OAβ levels in the plasma. A receiving operating curve (ROC) analysis was used to discriminate between the AD and control groups. The plasma OAβ levels in the AD group were significantly higher than those in the control group [1.88 (0.38) ng/ml vs 1.20 (0.40) ng/ml, p < 0.001]. The elevated levels of plasma OAβ showed a strong correlation with cognitive performance in patients with AD, including an inverse correlation with scores on the MMSE (r = − 0.43, p = 0.02), CASI (r = − 0.56, p < 0.01), and the immediate recall (r = − 0.45, p = 0.01), 5-min delayed recall (r = − 0.56, p < 0.01), and 30-min delayed recall (r = − 0.71, p < 0.001) tests of the COMT, and a positive correlation with the ADAS-Cog scores (r = 0.59, p < 0.001). The EDTA plasma Aβ oligomer optical density (OD) value measured using the MDS could discriminate between the AD and control groups with an area under the curve (AUC) of 0.89. The optimal sensitivity and specificity were 82.1% and 90.0%, respectively. The elevated levels of OAβ in the plasma distinguished the AD and control groups and were associated with the severity of symptoms, especially memory performance, in patients with AD. Our results suggested that plasma OAβ could potentially be a simple and non-invasive blood-based biomarker for AD diagnosis. Furthermore, longitudinal studies are warranted to explore the application of plasma OAβ levels as a valid diagnostic biomarker in patients with AD.This work was supported by the National Key Technology Research and Development Program of the Ministry of Science and Technology of China (2017YFC1311100), Beijing Municipal Science and Technology Commission (grant numbers: Z161100000516001, Z161100002616021), and National Natural Science Foundation of China (grant number: 81701777, 81500918)

Potato Dry Rot Caused by <em>Fusarium</em> spp. and Mycotoxins Accumulation and Management

Dry rot of potato (Solanum tuberosum L.) is an important postharvest disease during storage. The decay can be caused by several different species of Fusarium spp., such as, F. sambucinum, F. coeruleum, F. oxysporum, F. avenaceum, F. culmorum. The pathogen of Fusarum spp. causing dry rot of potato is considerable different in different countries and regions. The typical symptom of potato dry rot is sunken and wrinkled brown to black tissue patch on tuber with less dry matter and shriveled flesh. Fusarium spp. only invades host through wound or natural orifice during pre-harvest, storage and transportation period. Some Fusarium species infection associated with mycotoxins accumulation, which has phytotoxicity and mycotoxicoses in humans and animals. Synthetic fungicide is the main strategy to control the dry rot of potato, however, there are series of problem, such as environmental pollution, pathogen resistance. An integrated approach to manage the disease includes the introduction of resistant cultivar, appropriate cultural practices, and storage conditions combined with the application of synthetic fungicides pre-harvest or post-harvest. Moreover, some chemical fungicides and microbial antagonists have been integrated into potato dry rot management

Contamination, Detection and Control of Mycotoxins in Fruits and Vegetables

Mycotoxins are secondary metabolites produced by pathogenic fungi that colonize fruits and vegetables either during harvesting or during storage. Mycotoxin contamination in fruits and vegetables has been a major problem worldwide, which poses a serious threat to human and animal health through the food chain. This review systematically describes the major mycotoxigenic fungi and the produced mycotoxins in fruits and vegetables, analyzes recent mycotoxin detection technologies including chromatography coupled with detector (i.e., mass, ultraviolet, fluorescence, etc.) technology, electrochemical biosensors technology and immunological techniques, as well as summarizes the degradation and detoxification technologies of mycotoxins in fruits and vegetables, including physical, chemical and biological methods. The future prospect is also proposed to provide an overview and suggestions for future mycotoxin research directions

Isolating, Identifying, and Analyzing the Biological Characteristics of Pathogens Causing Postharvest Disease in Fresh <i>Radix Astragali</i>

Radix Astragali (RA) is the root of Astragalus membranaceus var. mongholicus (Bunge) P.K. Hsiao. In order to determine targeted and effective methods for treating mold infections in fresh RA, pathogenic fungi were isolated and identified using morphology and molecular biology techniques, and factors affecting the growth of the pathogenic fungi, such as temperature, pH, light, and carbon and nitrogen sources, were analyzed. Changes in the main active ingredients of RA, such as carbohydrates, flavonoids, and saponins, were detected before and after infection with pathogenic fungi. The results showed that Penicillium polonicum, Trichothecium roseum, and Fusarium equiseti were the main pathogens causing postharvest disease in fresh RA. The optimum growth temperature for the three pathogens was 25 °C; P. polonicum was able to grow at an alkaline pH of 8–9, while T. roseum and F. equiseti grew better and had higher levels of sporulation under acidic conditions with pH values of 5–6. Different carbon and nitrogen sources had different effects on mycelium growth and sporulation. Darkness was favorable for the growth and sporulation of the three pathogens. Compared with healthy RA, the total carbohydrate, flavonoid, and saponin contents of the RA samples infected with the three fungi decreased. This study provides a theoretical basis for the scientific and precise control of RA postharvest disease during storage by targeting different pathogens and their growth conditions

Examining the Factors Influencing Transport Sector CO2 Emissions and Their Efficiency in Central China

The fast development of the transport sector has resulted in high energy consumption and carbon dioxide (CO2) emissions in China. Though existing studies are concerned with the factors influencing transport sector CO2 emissions at the national level (or in megacities), little attention has been paid to the comprehensive impact of socio-economic, urban form, and transportation development on transport sector carbon emissions and emissions efficiency in central China. This paper examines the comprehensive impact of the transport sector&rsquo;s carbon emissions from six provinces in central China, during the period from 2005 to 2016, based on the panel data model. The dynamic change of CO2 emissions efficiency is then analyzed using the Global Malmquist Luenberger Index. The results indicate that, firstly, economic growth, road density, the number of private vehicles, and the number of public vehicles have caused greater CO2 emissions during the study period, while the freight turnover, urbanization level, and urban population density had repressing effects on CO2 emissions. Secondly, an uneven distribution of CO2 emissions and CO2 emissions efficiency was found among different provinces in central China. Thirdly, changes in CO2 emissions efficiency were mainly due to technical changes. Finally, we present some policy suggestions to mitigate transport sector CO2 emissions in central China

Effects of Ozone Treatment on Postharvest Mucor Rot of <i>Codonopsis pilosula</i> Caused by <i>Actinomucor elegans</i>

Fresh Codonopsis pilosula is highly susceptible to fungus contamination during post-harvest storage, which not only compromises the quality of C. pilosula but also contributes mycotoxin contamination, posing a significant threat to human health. Studies have indicated that ozone treatment can inhibit post-harvest diseases in fruits and vegetables. The impact of ozone treatment on the disease incidence, disease severity index, and weight loss rate of the fresh C. pilosula infected with Actinomucor elegans was investigated through the spray inoculation of A. elegans on C. pilosula tissues. Changes in the main active ingredients of C. pilosula after ozone treatment were analyzed, and the effects of ozone treatment on the integrity of cell membranes in C. pilosula tissue and reactive oxygen species (ROS) metabolism were studied. The results showed that ozone treatment had a significant inhibitory effect on the A. elegans-induced mucor rot in C. pilosula, significantly reducing the incidence of the disease. Compared with the control group, the ozone-treated group maintained the effective components of C. pilosula well. Furthermore, ozone treatment reduced the cell membrane permeability and Malondialdehyde (MDA) content in C. pilosula, significantly increased the activity of antioxidant enzymes in the ROS metabolism pathway, prevented oxidative stress caused by the accumulation of ROS in C. pilosula tissues, and maintained the integrity of cell membranes

Rapid Determination of Ochratoxin A in Grape and Its Commodities Based on a Label-Free Impedimetric Aptasensor Constructed by Layer-by-Layer Self-Assembly

A simple and sensitive label-free impedimetric aptasensor for rapid determination of ochratoxin A (OTA) has been developed, which was based on the combination between thiolated aptamer and gold nanoparticles by layer-by-layer self-assembly. Because of the interaction between aptamer and OTA, the relative normalized electron-transfer resistance (&#916;Rct) values obtained by electrochemical impedance spectroscopy (EIS) was proportional to the concentration of OTA and showed a good linear relationship from 0.1 to 10.0 ng/mL, with a lower detection limit (0.030 ng/mL) than one-step thiolated DNA aptasensor. The established method was successfully applied to detect and analyze OTA in table wine and grape juice, and the recovery was 90.56%&#8315;104.21% when PVP effective removed of phenolic substances. The label-free impedimetric aptasensor was used for rapid detection and quantitation of OTA in the inoculated grapes with the Aspergillus Nigri (H1), and the production of OTA (62.4 &#956;g/kg, 20 &#956;g/kg) far exceeded the maximum levels of 2 &#956;g/kg after inoculation for three days. The developed method exhibited a good specificity, high sensitivity, time-efficient, and it could be applied to detect the OTA concentration in grape and its commodities