Fresh Shiitake Mushrooms Research Articles

Incorporation of carbon dots into polyvinyl alcohol/corn starch based film and its application on shiitake mushroom preservation

Developing eco-friendly edible packaging films with multi-functional properties is highly required. This study involved synthesizing carbon dots (CDs) from dragon fruit, then incorporating them into a composite film based on polyvinyl alcohol (PVA)/corn starch (CS) to create a functional package to extend the shelf life of fresh shiitake mushrooms. Functional composite films with varying levels of CDs were formulated. The films' characteristics of morphology, mechanical properties, antioxidant properties, etc. were then determined, as well as their preservation effect on the fresh shiitake mushrooms. The results showed that the PVA/CS/CDs composite film showed excellent mechanical property, Ultraviolet (UV) barrier capability, antioxidant and antimicrobial properties. Specifically, addition of 8 mg/mL CDs in the composite films reduced weight loss of shiitake mushrooms by 30.74 %, decreased the decline in soluble solids content by 10.48 %, and halved the reduction in total sugar content after a 7-day storage period compared to films without added CDs. Furthermore, the films effectively lowered the respiratory intensity and browning of the mushrooms. This research demonstrates that CDs can serve as an effective component for the development of eco-friendly edible packaging films, as well as for their application in food preservation.

Shiitake mushroom-derived extracellular nanovesicles: Preparation, characterization, and inhibition of Caco-2 cells

In this study, Shiitake mushroom-derived extracellular nanovesicles (SMDENVs) were isolated from fresh Shiitake mushrooms by ultracentrifugation and sucrose gradient ultracentrifugation. The morphological characteristics of SMDENVs were investigated via Transmission Electron Microscopy and Laser Scanning Confocal Microscopy. SMDENVs were spherical, hollow, and uniform in size, with an average diameter of 177.6 ± 51.4 nm. Based on the analysis of lipidomics and proteomics, 383 lipids species and 1290 proteins were identified in SMDENVs. Compared with the conventional liposomes, SMDENVs demonstrated higher stability in different environmental conditions. Furthermore, we observed that SMDENVs were cytocompatible and inhibited the proliferation of Caco-2 cells. SMDENVs could be phagocytized by Caco-2 cells in a time-dependent manner. Further, SMDENVs also inhibited the proliferation of Caco-2 cells in a dose-dependent manner, and the half-maximal inhibitory concentration (IC50) was 236.2 ± 3.2 μg/mL. Additionally, SMDENVs induced cellular apoptosis by increasing the levels of reactive oxygen species and decreasing the mitochondrial membrane potential.

Analysis of Volatile Aroma Components in Different Parts of Shiitake Mushroom (Lentinus edodes) Treated with Ultraviolet C Light-Emitting Diodes Based on Gas Chromatography-Ion Mobility Spectroscopy.

Further assessment of ultraviolet C light-emitting diode (UVC-LED) irradiation for influencing shiitake mushrooms' (Lentinus edodes) volatile and sensory properties is needed. In this study, a comparison of UVC-LED irradiation treatment on the flavor profiles in various parts of shiitake mushrooms was conducted using gas chromatography-ion mobility spectrometry (GC-IMS) and sensory analysis. Sixty-three volatile compounds were identified in shiitake mushrooms. The fresh shiitake mushrooms were characterized by the highest values of raw mushroom odors. After UVC-LED treatment, the content of C8 alcohols decreased, especially that of 1-octen-3-ol, while the content of aldehydes increased, especially the content of nonanal and decanal. The score of fatty and green odors was enhanced. For fresh samples, the mushroom odors decreased and the mushroom-like odors weakened more sharply when treated in ethanol suspension than when treated with direct irradiation. The fruit odors were enhanced using direct UVC-LED irradiation for fresh mushroom samples and the onion flavor decreased. As for shiitake mushroom powder in ethanol suspension treated with UVC-LED, the sweaty and almond odor scores decreased and the vitamin D2 content in mushroom caps and stems reached 668.79 μg/g (dw) and 399.45 μg/g (dw), respectively. The results obtained from this study demonstrate that UVC-LED treatment produced rich-flavored, quality mushroom products.

Evolution behavior of volatile components of shiitake mushrooms during infrared-assisted spouted bed drying

The present study aimed to investigate the effect of different drying temperatures and airflow speeds on the number and species of volatile components in infrared-assisted spouted bed dried (IRSBD) Shiitake mushrooms. The dynamics changes in volatile components (determined by HS-SPME-GC-MS) during drying under optimal conditions were also monitored. Results revealed that the maximum number of volatile components (69 species) was observed at a temperature of 55 °C and airflow speed of 8.0 m/s, of which the volatile components in Shiitake mushrooms varied significantly over the drying process at this condition. Fresh Shiitake mushrooms mainly composed of volatile substances such as alcohols, ketones and acids. During the early drying stage (0–40 min), the levels of alcohols and ketones gradually decreased, while the species and levels of aldehydes, esters, and volatile sulfur-containing compounds (VSCs) increased. In the middle stage (40–120 min), levels of alcohols, esters, aldehydes, acids, and alkanes species increased, while the levels of VSCs decreased. For the last stage (120–200 min), the levels of sulfur-containing heterocyclic compounds, aldehydes, esters, acids, pyrazines, and alkanes were all increased. The findings of this study provide insights into the flavor formation mechanism during IRSBD of Shiitake mushrooms and offer a theoretical reference for the production of industrial flavorful dried goods.

MYOLO: A Lightweight Fresh Shiitake Mushroom Detection Model Based on YOLOv3

Fruit and vegetable inspection aids robotic harvesting in modern agricultural production. For rapid and accurate detection of fresh shiitake mushrooms, picking robots must overcome the complex conditions of the growing environment, diverse morphology, dense shading, and changing field of view. The current work focuses on improving inspection accuracy at the expense of timeliness. This paper proposes a lightweight shiitake mushroom detection model called Mushroom You Only Look Once (MYOLO) based on You Only Look Once (YOLO) v3. To reduce the complexity of the network structure and computation and improve real-time detection, a lightweight GhostNet16 was built instead of DarkNet53 as the backbone network. Spatial pyramid pooling was introduced at the end of the backbone network to achieve multiscale local feature fusion and improve the detection accuracy. Furthermore, a neck network called shuffle adaptive spatial feature pyramid network (ASA-FPN) was designed to improve fresh shiitake mushroom detection, including that of densely shaded mushrooms, as well as the localization accuracy. Finally, the Complete Intersection over Union (CIoU) loss function was used to optimize the model and improve its convergence efficiency. MYOLO achieved a mean average precision (mAP) of 97.03%, 29.8M parameters, and a detection speed of 19.78 ms, showing excellent timeliness and detectability with a 2.04% higher mAP and 2.08 times fewer parameters than the original model. Thus, it provides an important theoretical basis for automatic picking of fresh shiitake mushrooms.

Xtend® packaging and Aloe vera coating benefit shelf life and safety maintenance of fresh shiitake mushrooms

Xtend® packaging and Aloe vera coating benefit shelf life and safety maintenance of fresh shiitake mushrooms

Biodegradable PBAT/PLA packaging maintained the quality of postharvest shiitake mushroom by modified humidity and atmosphere

Packaging with plastic films is the most common preservation technique used to extend the shelf life of shiitake mushrooms. However, due to ‘white pollution’, it is essential to develop biodegradable films with efficient preservation properties. Here, the effects of biodegradable polybutylene adipate (PBAT)/poly(lactic acid) (PLA) blend films on the quality of shiitake mushrooms were investigated. The mushrooms were stored for 14 days at 4 ± 1 ℃. The results showed lower CO2 level inside the PBAT/PLA film, but the O2 level was comparable to that in low-density polyethylene (LDPE) package. PBAT/PLA treatment effectively prevented condensation of water vapor inside the package, and could significantly (p < 0.05) slow down the respiration rate, inhibit caps opening, improve phenolic contents and PAL activity, maintain firmness as well as delay senescence. In addition, due to the suitable relative humidity inside the PBAT/PLA film, it was more effective in reducing microbial counts and preserving the appearance of the shiitake mushrooms, thus extending more than 4–6 days of shelf life compared to the LDPE film. These results suggested that besides the in-package gas composition, it is also important to control the level of water vapor permeability to avoid condensation and decelerate degradation of packaged fresh shiitake mushroom. This environmental-friendly PBAT/PLA film exhibited high versatility in shiitake mushroom packaging.

Storage temperature effect on quality related with cell wall metabolism of shiitake mushrooms (Lentinula edodes) and its modeling

Fresh shiitake mushrooms (Lentinula edodes) are susceptible to temperature fluctuation, thus easy to soften. In this study, the effects of temperature during storage on the softening mechanism of postharvest shiitake mushrooms were studied. The firmness, cell wall polysaccharide contents, chitin and cellulose contents, cell wall degrading enzyme activities, and their gene expression levels were evaluated. The relationship between the indicators and the accumulated storage temperature was also analyzed. Results showed that decreasing firmness was concomitant with cell wall components reduction, the increase in enzymatic activities and gene expression levels. Increasing the storage temperature promoted these changes. Thus, cell wall polysaccharides modification induced by the cell wall degrading enzymes played a key role in the temperature-mediated softening mechanism of postharvest shiitake mushrooms. The firmness, 10 mol L-1 NaOH-soluble polysaccharide, total polysaccharide, chitin and cellulose contents, β-1,3-glucanase activity, expressions of Letlg1, Leglu1, Leexg1, Leexg2, Lepus30a and Lechi1 were fitted well with accumulated storage temperature, implying that they were related to the firmness loss and could describe the effects of storage temperature and time on softening process in shiitake mushrooms.

Comparison of Fumigation and Immersion of Essential Oils on Quality and Physiology of Fresh Shiitake Mushrooms (Lentinus edodes)

The effects of different essential oils with fumigation or immersion on sensory and physiological quality of fresh shiitake mushrooms were evaluated during the storage. Shiitake mushrooms were treated with essential oils (grapefruit essential oil, rosemary essential oil, cinnamon essential oil) by fumigation and immersion respectively. The surface color, browning degree, sensory evaluation, hardness, soluble protein content, total phenolic content and DPPH· scavenging ability of shiitake mushrooms were measured during the storage. The results showed that hardness, sensory qualities and soluble protein decreased gradually with the extension of storage period in all the treatments and rosemary essential oil had better effect on maintaining cap color, sensory quality, total phenolic content and DPPH· scavenging ability compared with other treatments. In general, immersion treatment showed better effect on shiitake mushrooms preservation than fumigation treatment.

Effects of light irradiation on the textural properties and energy metabolism of postharvest shiitake mushrooms ( Lentinula edodes )

Shiitake mushrooms (Lentinula edodes) easily get deteriorated along with softening during the storage. And energy dissipation is associated with senescence and deterioration of many agro-products. In this study, the evident effect of light irradiation on the softening and the energy dissipation mechanism of shiitake mushrooms (L. edodes) during storage was investigated. Postharvest shiitake mushrooms were treated with light irradiation of 2,300–2,800 lux, and stored at 10°C and 90% RH for 18 days. Textural properties, reactive oxygen species (ROS) level, antioxidant activity, antioxidase activity, malondialdehyde (MDA) content, electrolyte leakage, energy status, enzyme activities, total phenolic content, and genes expressions related to energy metabolism were determined. Results indicated that compared with non-irradiation, qualities of shiitake mushrooms treated with light irradiation were better maintained until 18 days of storage. Light irradiation exerted better effects on maintaining the textural properties of shiitake mushrooms, led to the lower ROS level and cell membrane peroxidation. Moreover, a higher energy status was detected with light irradiation, which could be attributed to the enhanced enzyme activities (H+-ATPase, Ca2+-ATPase, SDH, and CCO activities) and relative gene expressions. Novelty impact statement Light irradiation in the range of 2,300–2,800 lux applied on fresh shiitake mushrooms during the storage, exerted effect on texture properties maintenance, led to the low levels of MDA content, electrolyte leakage, and antioxidant activities. Meanwhile, higher energy status and enhanced enzyme activities as well as relative gene expressions were detected in light-irradiated mushrooms. This study provides a potential application of light irradiation in maintaining the shelf life and storage quality of postharvest shiitake mushrooms, as well as a perspective on correlation between textual quality and energy metabolism.

Effects of negative air ions treatment on the quality of fresh shiitake mushroom (Lentinus edodes) during storage

Fresh shiitake (Lentinus edodes) is prone to brown, pileus-opening and flavor-loss during storage. Therefore, it is important to find an effective preservation method for fresh shiitake. Negative air ions (NAI) are negatively-charged molecules or atoms in the air, and can affect the physiological metabolism of live cells and be conveniently used with low cost. In this study, NAI treatment was performed at different times and the physico-chemical characteristics, microstructure, membrane potential and energy metabolism of shiitake were determined during storage. Results showed that NAI treatment for 40 min could reduce 29% of browning index and maintain the hardness of shiitake. NAI treatment groups had higher content of sweetness amino acids, umami amino acids, 5′-IMP, eight-carbon alcohols compounds and cyclic sulfides compounds than the control, and comprehensive quality of the group being treated for 40 min was the best. The mitochondria of shiitake swelled and the membrane potential decreased after being treated by NAI. However, NAI treatment for 40 min could improve the contents of ATP and ADP, maintain a relatively stable energy charge level, and promote energy utilization of shiitake during storage. The results demonstrated that NAI treatment had the potential to improve the quality shiitake during storage.

The dynamic changes in product attributes of shiitake mushroom pilei and stipes during dehydration by hot air drying

The dynamic changes in product attributes of shiitake mushroom pilei and stipes during dehydration by hot air drying (HAD) were analyzed. During dehydration, discoloration was greater during the fresh point (FP) to standard point (SP) than that during SP to the constant weight point (CWP). The hardness declined and then rose gradually from SP to CWP. C8 compounds (including 1-octen-3-ol, 3-octanol, 2-octen-1-ol, 1-octanol, octanal, 2-octenal, and 3-octanone) showed significant decline (p < .05) from FP to SP. However, the sulfur compounds (including the thioether compounds and cyclic sulfur compounds), 5′-GMP, and 5′-AMP increased significantly (p < .05) from the SP to CWP. The combined model fitted the quality changes with the highest Adj. R2. Besides, e-nose and e-tongue could distinguish samples in different moisture content. The study illustrated that SP was an important turning point for changes in shiitake mushroom product attributes during dehydration. Practical applications Shiitake mushrooms are the second most cultivated edible mushrooms in the world. However, fresh shiitake mushrooms are easy to undergo postharvest quality deterioration. Sun drying is the most common method to preserve agricultural products, but has disadvantages in industrialized production. Hot air drying (HAD) is another processing method. Texture, color, volatile compounds, and nucleotides are important product attributes and flavor qualities for dried products, which influence consumers’ acceptability and products’ market value. Moreover, pilei and stipes in mushrooms usually show different attributes. However, there have been few studies focusing on the quality changes of shiitake mushrooms following the moisture changes and the different parts of shiitake mushrooms treated by HAD. This study will investigate the dynamic changes in product attributes of shiitake mushroom pilei and stipes following moisture content loss during dehydration induced by HAD, and also provide a good basis for clarifying the effect of dehydration on edible fungi manufacture by HAD.

Effect of cold plasma pretreated hot‐air drying on the physicochemical characteristics, nutritional values and antioxidant activity of shiitake mushroom

Shiitake mushroom is one of the most popular delicious vegetables, although fresh shiitake mushroom has short shelf life as a result of biochemical degradation. Drying can prolong the shelf life of mushroom. Additionally, application of cold plasma pretreatments (CPT) before drying can preserve the product quality, processing costs and nutritional values. Therefore, we aimed to explore the effect of cold plasma pretreated hot-air drying at 50, 60 and 70 °C on the physicochemical characteristics, nutritional values and antioxidant activity of shiitake mushroom. Scanning electron microscopy micrographs showed that CPT induced the surface modification of fresh shiitake (such as cellular disarrangement, cellular shrinkages, disruption or break down of cell walls, and intracellular spaces and cavities) and facilitate the rapid drying than control samples. Furthermore, CPT improved the powder qualities (bulk density, water retention and swelling index) and preserved higher nutritional attributes (sugars, vitamins, phenolic acids contents and antioxidant activity) compared to the control groups. Conclusively, CPT could be a suitable alternative technique for improving drying characteristics and preserving nutritional attributes of agro-based products. © 2021 Society of Chemical Industry.

Coating shiitake mushrooms (Lentinus edodes) with a polysaccharide from Oudemansiella radicata improves product quality and flavor during postharvest storage

In this work, we investigated whether coating fresh shiitake mushrooms with a polysaccharide isolated from Oudemansiella radicata (ORWP) would impact key quality characteristics after 18 d of storage at 4 °C. We found that ORWP-coated mushrooms had significant improvements in many qualities during storage, including reduced weight loss, improved firmness, reduced browning, decreased malondialdehyde content, and an improved physical microstructure. Further, ORWP-coated mushrooms had higher contents of nutritional and cell wall compounds compared to control samples. ORWP-coated mushrooms had reduced activities of the following enzymes: protease, polyphenol oxidase, peroxidase, phenylalanine ammonia lyase, cellulase, and chitinase, relative to control samples. However, mushrooms coated with ORWP had higher concentrations of superoxide dismutase and catalase, as well as higher contents of certain key monosodium glutamate-resembling amino acids, umami 5′-nucleotides and 1-octen-3-ol. These findings suggest that ORWP coatings have potential value as a method to improve the postharvest quality of shiitake mushrooms.

Instrumental texture and sensory preference of vacuum-fried shiitake crisps as affected by isomalto-oligosaccharide pretreatment

ABSTRACT Shiitake (Lentinula edodes) is well-known for its distinct flavor and texture as well as its medicinal and nutritional properties. Small good grade fresh shiitake mushrooms are highly perishable and have a low commodity value in the Taiwan market. As a result, these are frequently used as raw materials for vacuum-fried crisps. However, manufacturers continue to use traditional maltose (MO) syrup with no functional properties as a sweetener, and shiitake stipes are frequently discarded, increasing production costs. Isomalto-oligosaccharide (IMO) is a functional oligosaccharide sweetener with health benefits. The purpose of this research is to study the use of functional IMO in the processing of shiitake crisps to replace MO, and the reusability of stipes. In the manufacture of vacuum-fried shiitake cap and stipe crisps, the 30–40°Brix IMO syrup replaces the 35°Brix MO syrup. Vacuum-fried crisps’ quality characteristics were determined using physicochemical and sensory evaluation. The results showed that centrifuged caps and stipes reach equilibrium after 3 h of being soaked in various concentrations of 90–95°C syrup. The L*, a*, b*, h*, and c* values for the cap crisps decreased with the increase in the level of IMO syrup. The breaking force for the stipe crisps was less than that for cap crisps. The crude protein and crude fat content of vacuum-fried cap and stipe crisps decreased as the level of IMO syrup increased, but the carbohydrate content increased. For a nine-point hedonic test, the sensory scores for cap and stipe crisps without seasoning powder were 6.9–7.4 and 6.1–6.5, respectively. Addition of seasoning powder increased the flavor and overall scores to 8.1–8.2 and 7.2–7.4, respectively. Overall, the addition of IMO syrup reduced the calories and increased the health benefits of vacuum-fried shiitake crisps. Furthermore, the result showed that stipes can also be used to make vacuum-fried crisps and increase profitability for manufacturers.

The effects of dielectric barrier discharge plasma gas and plasma‐activated water on texture, color, and bacterial characteristics of shiitake mushroom

This paper presents the first study on the effects of 20-min dielectric barrier discharge (DBD) gas plasma and arc plasma-activated water (PAW) on the total bacterial count (TBC), color values, and textural characteristics of shiitake on day 0 and day 7 of storage at 4 °C. The results were then compared to those of untreated samples (DC) and samples soaked in distilled water (WC). According to the results, after 7 days of storage, TBC of PAW- and DBD-treated samples were 0.89 ± 0.01 and 0.6 ± 0.05 log CFU/g lower than those of control samples, respectively. Furthermore, both DBD and PAW treatments reduced the overall color changes (∆E) in samples during storage. Besides, PAW-treated samples had the greatest texture firmness value (1.27 ± 0.16 N) after a week of storage. These findings along with a good potential for the upscaling process suggest PAW can be a prospective commercial technique for extending the shelf-life of fresh shiitake mushrooms. Practical applications The feasibility of shelf-life enhancement of fresh produce confers a great interest in cold plasma gas and plasma-activated water (PAW) with respect to their industrial application. Particularly, extending the shelf-life of shiitake is an important topic for exporters of this fresh agricultural product, considering the high demands for this product in many countries. The findings of the present study introduced cold plasma, especially arc PAW, as a promising technique for shelf-life enhancement of shiitake mushroom. The preservation method proposed in this study is scalable and further economic and engineering studies may result in its industrial application.

Water status and distribution in shiitake mushroom and the effects of drying on water dynamics assessed by LF-NMR and MRI

Water status and distribution in shiitake mushroom and the effects of drying temperature on water migration were investigated by low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) technique. Three water components assigned to bound, immobilized water and free water were observed in fresh shiitake mushroom by LF-NMR, and higher moisture content was found in the lamella and outer layer of stalk by MRI. During drying, the transverse relaxation time and peak area of immobilized and free water in pileus significantly decreased. Higher drying temperature could promote the changes in water mobility and population. MRI results revealed the water evaporated from external surface of shiitake mushroom, then the water in inner region migrated to the surface during the drying. The drying properties, color and shrinkage of shiitake mushroom were also measured. The strong correlation between moisture content and total peak area of water with a coefficient of 0.9792 revealed the potential of LF-NMR as a rapid and nondestructive method to monitor drying degree of shiitake mushroom.

Comparative analysis of taste compounds in shiitake mushrooms processed by hot-air drying and freeze drying

ABSTRACTShiitake mushrooms were processed by hot-air drying (HD) and freeze-drying (FD) to investigate the taste compounds. The total free amino acids in HD samples treated at 60°C was the highest as compared to the other three dried samples. Although cysteine was not detected in fresh shiitake mushroom (FSM), it was released during the drying process and its content increased with the temperature increase from 50°C to 70°C. The content of total organic acids was the highest in the HD sample treated at 60°C (56579.6 µg/g DW). Based on the obtained moisture contents, all compounds were calculated to their contents in respective FSMs, the content of Glu, citric acid, and succinic acid increased during drying as temperature increase from 50°C to 70°C. It indicated that new taste compounds were produced during the HD process. The content of total nucleotides was the highest in HD samples treated at 50°C, and the lowest in FD sample. The HD samples treated at 70°C showed the highest equivalent umami concentrations (EUC) (25.2 g MSG/100 g), followed by at 60°C (19.7 g MSG/100 g), 50°C (14.7 g MSG/100 g) and FD samples (12.0 g MSG/100 g). Our results indicated that different drying treatments led to different physiochemical properties and nutritional contents in Shiitake mushrooms.

Simultaneous separation and determination of six arsenic species in Shiitake (Lentinus edodes) mushrooms: Method development and applications

A method for simultaneously separating six arsenic (As) species was established by ultrasound-assisted extraction-anion exchange chromatography coupled with inductively coupled plasma mass spectrometry. Six As species could be well separated within 15 min when 0.3 M acetic acid and 25 mM NH4H2PO4 were used as the extraction solvent and mobile phase, respectively. Under optimized conditions, the limits of detection and recovery of As species and the relative standard deviation were in the ranges of 0.31–0.59 μg/L, 94.30–102.75%, and 1.63–3.72%, respectively. Furthermore, the established method was successfully applied to fresh Shiitake (Lentinus edodes) mushrooms and processed products. The inorganic As contents of all samples ranged from 0.204 to 0.500 mg/kg, half of samples (>0.400 mg/kg) were close to the maximum contaminant level allowed by the Chinese (0.5 mg/kg). The health risk index estimation results indicated that no particular risk of As exposure to Chinese consumers existed in L. edodes.

Optimization of UV irradiation conditions for the vitamin D2-fortified shiitake mushroom (Lentinula edodes) using response surface methodology.

The aim of this study was to investigate the optimal conditions to process vitamin D2-fortified shiitake mushrooms through UV irradiation for industrial processing. Response surface methodology was used to identify the optimum conditions of the following highly influential factors on vitamin D2 synthesis: temperature, UV dosage, and moisture content. The optimal conditions of those variables were 40.56°C, 36.27kJ/m2, and 80.46%, respectively, and UV dosage was the most effective variable. The amount of vitamin D2 obtained under the optimal conditions was 29.87±1.38μg/g (dry mass: DM) which was well matched with the predicted value of 32.33μg/g DM. The effects on the texture and color of shiitake mushrooms were also evaluated after the fortification process under the optimal conditions, and no adverse effects were observed compared to those of fresh shiitake mushrooms.