UPLC-QqQ/MS combined with similarity assessment of 17 nucleic acid constituents in 147 edible fungi from Sichuan Basin, China

Evaluating Two Fungicides, Prochloraz-Manganese Chloride Complex and Seboctylamine Acetate, to Control Cobweb Disease in White Button Mushroom Caused by Cladobotryum mycophilum

Cobweb disease in white button mushroom (Agaricus bisporus) is a newly identified disease caused by Cladobotryum mycophilum in China. Currently, there are few highly effective and safe fungicides for controlling this disease in the field. This study assessed the fungicidal effect of prochloraz-manganese chloride complex and seboctylamine acetate against C. mycophilum, as well as their ability to control cobweb disease. Additionally, the residues of these fungicides in the mycelium and the mushroom were evaluated. The extent of the fungicidal effect against the pathogen was determined based on the efficiency of crop production. The results revealed that, in addition to the potent inhibitory effect of prochloraz-manganese chloride complex on the hyphae of C. mycophilum, the domestically developed seboctylamine acetate exhibited high toxicity, inhibiting both mycelial growth and spore germination of C. mycophilum, with EC50 values of 0.990 mg/L and 0.652 mg/L, respectively. Furthermore, the application of the two chemical agents had no adverse effects on the mycelial growth and fruiting body growth of A. bisporus, and the residual amount of chemical agent was lower than the maximum residue limit standard. The field application results showed that 400 mg/L of prochloraz-manganese chloride complex and 6 mg/L of seboctylamine acetate resulted in 61.38% and 81.17% disease control respectively. This study presents efficient and safe fungicides for controlling cobweb disease in white button mushroom. Additionally, a residue determination analysis of the fungicide seboctylamine acetate in mushroom crops is described.

Internet of Things (IoT)-Based Environmental Monitoring and Control System for Home-Based Mushroom Cultivation

The control and monitoring of the environmental conditions in mushroom cultivation has been a challenge in the mushroom industry. Currently, research has been conducted to implement successful remote environmental monitoring, or, in some cases, remote environmental control, yet there is not yet a combination of both these systems providing live stream images or video. As a result, this research aimed to design and develop an Internet of things (IoT)-based environmental control and monitoring system for mushroom cultivation, whereby the growth conditions of the mushrooms, such as temperature, humidity, light intensity, and soil moisture level, are remotely monitored and controlled through a mobile and web application. Users would be able to visualize the growth of the mushroom remotely by video and images through the Internet. The respective sensors are implemented into the mushroom cultivation process and connected to the NodeMCU microcontroller, which collects and transfers the data to the cloud server, enabling remote access at any time through the end device with internet connection. The control algorithm regulates the equipment within the cultivational chamber autonomously, based on feedback from the sensors, in order to retain the optimum environment for the cultivation of mushrooms. The sensors were tested and compared with manual readings to ensure their accuracy. The implementation of IoT toward mushroom cultivation would greatly contribute to the advancement of the current mushroom industry which still applies the traditional cultivation approach.

The Effect of Dielectric Barrier Discharge Plasma Gas and Plasma-Activated Water on the Physicochemical Changes in Button Mushrooms (Agaricus bisporus)

Button mushrooms (Agaricus bisporus) are highly popular worldwide due to their rich nutritional value and health benefits. However, the rapid water loss rate and browning restrict their economic value. The atmospheric cold plasma (ACP) generated by the plasma equipment used by dielectric barrier discharge preservation technology is widely used for food preservation since it is cost-efficient and environmentally friendly, generating no chemical residues. This study established four treatment groups, namely the direct ACP treatment group (DBD), plasma-activated water immersion group (PAW), pure water immersion group (PW), and control group (control), to explore the effect that ACP preservation technology has on button mushrooms. The results indicated that ACP treatment decreased the pH of pure water from 5.90 ± 0.03 to 5.16 ± 0.03, while significantly increasing the temperature (p < 0.05). During the storage period, the browning index (BI) and E value were the lowest in the PAW group, which exhibited the best hardness and sensory properties. Neither the pH nor water activity changed significantly during the storage period in any of the groups. The polyphenol oxidase (PPO) activity in the button mushroom decreased significantly compared with the control after plasma-activated water treatment. In summary, plasma-activated water significantly reduced the BI and E value of button mushrooms, inhibited PPO activity, and yielded the most stable sensory properties for the optimal preservation of button mushrooms.

Analytical characterization of nucleotides and their concentration variation in drinking water treatment process

Nucleotides, as the basic building blocks of nucleic acids, widely exist in aqueous environment. In this study, we developed a solid phase extraction-high performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS) method for the analysis of 5'-adenosine monophosphate (AMP), 5'-uridine monophosphate (UMP), 5'-cytidine monophosphate (CMP) and 5'-guanosine monophosphate (GMP). The method achieved limits of detection (LODs) of 0.1-1.0 ng/L, and recoveries of 85-95% for the four tested nucleotides. The occurrence and concentrations of the four nucleotides in water from eight representative drinking water treatment and distribution systems in China were determined using this method. All four nucleotides were detectable in water treatment plant (WTP) influent and effluent, at concentrations of up to 30 ng/L and with occurrence frequency of around 90%. The concentrations of identified nucleotides increased 3-10 times after 10 km of water age in the water distribution system. Biological filters and coagulation increased the concentrations of nucleotides, conversely, active carbon, ozonation, and ultrafiltration membrane removed nucleotides in water. The effects of active carbon and coagulation were further confirmed using laboratory-controlled experiment. In addition, monochlorinated nucleotides were identified as the chlorination products of nucleotides.

The Small Molecule Fractions of Floccularia luteovirens Induce Apoptosis of NSCLC Cells through Activating Caspase-3 Activity

Floccularia luteovirens is a rare wild edible and medicinal fungus endemic to the Qinghai-Tibet Plateau. In this study, the hollow fiber membranes with molecular weights of 50 kDa, 6 kDa and 3 kDa were used to extract different fractions of F. luteovirens, which were named as #1, #2 and #3. Then the antitumor activity of these fractions on NSCLC cell lines, PC9 and NCI-H460, were investigated by using MTT assay, flow cytometry analysis and Western blot assay. The results indicated that the #2 and #3 fractions showed obviously inhibitory activities on PC9 and NCI-H460 tumor cells and proved that these small molecule fractions induced apoptosis of NSCLC cells by activating caspase-3. Finally, a total of 15 components, including six amino acids, two nucleosides, two glycosides, two terpenoids, one phenylpropanoid, one ester and one alkaloid, were identified in #2 and #3 fractions. This is the first evidence that the small molecule components of F. luteovirens were able to inhibit lung cancer by inducing apoptosis in a caspase-3 manner. The present study indicated the benefits of F. luteovirens in lung cancer treatment, which might be a potential resource of functional food and drugs.

A Practical Method for Determination of Nine Nucleosides in Tricholoma matsutake by UPLC/MS and Quantitative Analysis of Multicomponents Using Single Marker Method

Nucleosides can be used as quality evaluation indicators of Tricholoma matsutake. In this work, a new ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MS) strategy for quantitative analysis of multiple components using a single marker (QAMS) was proposed to determine nine nucleosides (adenosine, cytidine, guanosine, inosine, uridine, 2'-deoxyadenosine, 2'-deoxycytidine, 2'-deoxyguanosine, and 2'-deoxyuridine) in T. matsutake. Guanosine was set as the internal reference substance, whose content in T. matsutake was determined using the conventional external standard method. Relative correction factors (RCFs) between guanosine and eight other nucleosides were measured. The concentrations of the eight components were calculated with the obtained RCFs by QAMS. An ultrasonic extraction method is used for sample preparation. This method was validated to be sensitive, precise, and accurate with the LODs of 0.31-1.9 ng, the overall intraday and interday variations less than 4.08%, and the overall recovery over 89.0%. The correlation coefficients (r ²) of the calibration curves were higher than 0.9918. The values of vector angle analysis were above 0.99845, which indicates no significant differences between the conventional external standard method and the present QAMS method. As far as we know, this is also the first report of UPLC/MS analysis of nucleoside compounds by QAMS, providing an efficient and feasible quality assessment method for other natural products containing nucleosides.

Dielectric properties of edible fungi powder related to radio-frequency and microwave drying

Edible fungi are rich in nutrition, but they are susceptible to spoilage, and often prolonged by drying. RF and microwave energy drying have the advantages of short drying time, high energy efficiency and good process control. However, to develop an effective dielectric drying method, it is important to understand dielectric properties, the major factor characterizing the interaction between the electromagnetic energy and the food. At present, there is a lack of research on dielectric properties of edible fungi. In this study, a vector network analyzer and an open-ended coaxial-line probe were employed to measure the dielectric parameters. The dielectric parameters were observed at different temperatures (25–85 °C) for edible fungi powder with moisture content ranging from 5 to 30% wet basis over a frequency range of 1–3000 MHz. The relationship between the dielectric properties and frequency, temperature, and moisture content were obtained via regression analysis. Further, the dielectric penetration depth was calculated, and the effects of frequency, moisture content, and temperature on the penetration depth were also analyzed. The results showed that the dielectric properties of edible fungi powder increased with an increase in moisture content and temperature, while they decreased with increasing frequency. At high moisture content and temperature, the increase in dielectric properties was slightly larger than that at low moisture content and temperature. The dielectric properties changed more evidently at lower radio frequencies than at higher radio frequencies. The penetration depth decreased with an increase in temperature, moisture content, and frequency. It can be concluded that a large penetration depth at radio frequencies below 100 MHz could be used to dry edible fungi on a large scale, whereas microwave energy could be employed for drying edible fungi on a small scale.