Fresh Shiitake Mushrooms Research Articles

Analysis of Physicochemical, Antioxidant Properties and Sensory Characteristic of Shiitake Mushroom Pickles

Mushrooms are perishable foods; they required processing technologies that preserves chemical and nutritional characteristics of fresh forms. The principal objective of this research was to analyze the physicochemical changes and sensory properties of Shiitake pickles with and without mustard oil in order to contribute to the diversification of food. The antioxidant activity of fresh shiitake mushroom pickles with and without mustard oil demonstrated a significant result in Scavenging free radicals except for DDPH. The pH of MOVS and SWVS was reduced to 3.92±010 and 2.80±0.26 over time during 20 days of storage and the acidity was gradually increased for up to storage. However HPLC analysis of both pickles revealed the presence of four acids were present in the MOVS pickle (malic acid at 4.354 with the retention time of 4.2 minutes). The second peak indicates lactic acid at 5.069 with the retention time of 4.3 min. The third peak indicates citric acid at 5.489 with the retention time of 4.5 min. The fourth peak indicates succinic acid at 7.301 with the retention time of 6.8min. Whereas the SWVS pickle showed the peak for three acids present in the pickle sample, where the first peak indicates malic acid at 4.303 with the retention time of 4.2 min, the second peak indicates acetic acid acid at 6.573 with the retention time of 6.2 min, and the final peak was found of succinic acid at 7.304 with the retention time of 6.8 min. The pickle formulated with (MOVS) showed 5.70 for overall acceptability of pickle.

Secondary metabolism associated with softening of shiitake mushroom (Lentinula edodes) induced by O2 depletion and CO2 accumulation

AbstractIt is difficult to preserve fresh shiitake mushroom (Lentinula edodes (Berk.) sing) partly because of the rapid deterioration of texture (softening or lignification). In this study, we developed a storage model in which tissue softening was induced to analyse the relationship between changes in firmness and alterations in cell wall chemical components as well as their metabolism. The results showed that the treatment group accumulated more CO2 and contained less O2 because of the poorer permeability in package. The contents of glucan and chitin in the treatment group decreased from 241.3 ± 13.2 mg g−1 and 46.3 ± 1.2 mg g−1 to 157.3 ± 11.2 mg g−1 and 18.0 ± 1.0 mg g−1 (P < 0.05) with the accumulation of CO2. The activities of major cell wall degradation‐related enzymes were enhanced in the softening model, and the expression levels of major genes that encode enzymes related to cell wall degradation were upregulated. Our results suggested that the softening of shiitake mushrooms induced by high CO2 was associated with the degradation of polysaccharides and glycosaminoglycan and that these changes were systematically regulated by alterations in the activities and expression levels of related enzymes and genes.

Development of Multifunctional Active Film and Its Application in Modified Atmosphere Packaging of Shiitake Mushrooms

Agar-based films with multiple functions (CO2 absorption, water vapor absorption, and antimicrobial activity) were developed, tested for their properties, and then applied to the packaging of fresh shiitake mushrooms as an insert label. The films were cast from an agar-based aqueous solution containing a dissolving plasticizer (glycerol), a CO2 absorbent (sodium carbonate [SC] alone or a combination of SC and sodium glycinate [SC-SG]), and a volatile antimicrobial agent (carvacrol [CRV]). The agar of the film matrix is designed to serve as a water vapor absorbent. The multifunctional films tended to have poor mechanical properties, with a hard texture and an opaque and yellowish color. The CO2 absorbent, either SC alone or SC-SG, affected CRV retention and release along with the CO2 and water vapor absorption behavior. Both films (SC-CRV and SC-SG-CRV films) showed good inhibitory effects against Pseudomonas fluorescens and Saccharomyces cerevisiae . SC-CRV film had a higher and faster CO2 absorption property, higher retention and extended release of CRV, and lower and slower water vapor absorption and was assessed to be better suited for use in shiitake mushroom packaging. The packaging in which the SC-CRV film with an appropriate amount of CRV was used as an insert label was able to generate the desired atmosphere and less moisture condensation inside the package, producing the best preservation of quality in terms of mushroom color, firmness, flavor score, and microbial counts after 6 days of storage at 10°C. A tailored modified atmosphere packaging system using multifunctional film would be useful in the preservation of CO2-sensitive fresh commodities.

유통과정에서 생표고버섯에 대한 Active 마스터 포장 시스템의 적용 효과

유통과정에서 생표고버섯에 대한 Active 마스터 포장 시스템의 적용 효과

Evaluation of Microbial Loads on Dried and Fresh Shiitake Mushrooms (Lentinula edodes) as Obtained from Internet and Local Retail Markets, Respectively.

Consumer demand for shiitake mushrooms is increasing. However, food safety information regarding the prevalence of microbial pathogens on the products sold via the Internet or at local retail markets is limited. The present study was conducted to assess the microbial load on shiitake mushrooms sold through the Internet and at local (central Virginia) retail markets. A total of 90 shiitake mushroom products, consisting of locally-purchased whole (LW) and sliced (LS) and Internet-procured whole (IW), sliced (IS), and powdered (IP) forms, were tested. High levels of aerobic mesophiles (6.9 ± 1.3 to 7.5 ± 1.1 log CFU/g), yeast and mold (5.8 ± 0.9 to 6.0 ± 0.3 log CFU/g), and coliforms (1.6 ± 1.0 to 1.9 ± 1.1 log MPN/g) were found in locally-acquired mushrooms. One LW sample and 2 of LS contained Listeria spp. Our findings suggest that shiitake mushroom producers and retailers need to be aware of potential microbial hazards associated with handling fresh shiitake mushrooms and consumers should take appropriate precautions when handling fresh shiitake mushrooms to prevent cross-contamination and possible foodborne illness in the home.

Effect of active modified atmosphere packaging with different initial gas compositions on nutritional compounds of shiitake mushrooms (Lentinus edodes)

The effect of active modified atmosphere packaging with different initial gas compositions on fresh shiitake mushrooms was investigated. Shiitake mushrooms were packaged under each of the following conditions: (1) high oxygen packaging (HOP), 100% oxygen initially; (2) medium oxygen packaging (MOP), 50% O2 and balanced with N2 initially; (3) low oxygen packaging (LOP), 3% O2/5% CO2, balanced with N2 initially. Passive modified atmosphere packaging with air inside initially (AIR) was used as the control treatment. All the packaged samples were stored at 10°C with 90% RH for 7 days. During storage, gas compositions, electrolyte leakage, crude water-soluble polysaccharides, total phenolic content and free amino acid content were determined. The results showed that ethanol release was high in LOP and AIR but retarded in MOP and HOP. No packaging could prevent the decrease in polysaccharide content decreasing. Both the active and passive modified atmosphere packaging maintained the color and integrity of the mushrooms. The active modified atmosphere packaging had a significant effect on the increase of total phenolic content and total amount of free amino acids. LOP had a harmful impact on mushrooms with high levels of electrolyte leakage. In conclusion, HOP and MOP had a better effect on maintaining the nutritional compounds of shiitake mushrooms.

Effect of High-Oxygen Packaging on Respiratory Physiology and Sensorial Qualities of Fresh Shiitake Mushrooms (Lentinus edodes)

<p>In this research, the effect of high-oxygen packaging (HOP) with initial 80% and 100% oxygen on fresh shiitake mushrooms was studied. Initial air in package was the control treatment. All the samples were stored at 10 °C with RH 90% for 9 days. Respiration rate, hardness, TSS, and color were determined, and sensory quality was evaluated during the storage. Results indicated that high-oxygen packaging retarded the anaerobic metabolism occurrence and HOP with initial 100% oxygen could maintain the lightness of shitake mushroom better than 80% oxygen. Hardness and TSS did not show significant difference between high-oxygen packaging and control treatment. However, neither initial 100% O<sub>2</sub> nor 80% O<sub>2</sub> could reduce the respiration rate of fresh shiitake mushroom. Sensory quality especially the aroma, cap color and gill color of fresh shiitake mushroom could be better maintained in high-oxygen packaging than control treatment. The acceptability of the shiitake mushrooms after storage was the highest in HOP with initial 100% oxygen. In conclusion, high-oxygen packaging especially with initial 100% oxygen showed the obvious effect maintaining the sensory quality of fresh shiitake mushrooms although it could not reduce the respiration rate at 10 °C.<strong></strong></p>

저온성 표고버섯의 빙점하 저장 잠재력

This study was aimed to find the storage potential of low temperature adapted shiitake mushroom under freezing temperature (<TEX>$-3^{\circ}C$</TEX>). Fresh shiitake mushroom was harvested at late Feb. and cooled to target temperature, <TEX>$-3^{\circ}C$</TEX> in the cooling room for 24 hr. Cooled mushroom were then placed in plastic boxes, wrapped with plastic film (<TEX>$30{\mu}m$</TEX>), and stored at <TEX>$-3^{\circ}C$</TEX> for 2 months. Weight loss of mushroom was ranged from 2.1 to 3.2%. Dry weight per unit fresh weight, however, was slightly increased because of moisture loss. Firmness of fruit body increased from <TEX>$0.95kg/cm^{-2}$</TEX> (before storage) to <TEX>$1.13kg/cm^{-2}$</TEX> (after 2 month storage). About half amount of starch was lost during 2 month storage. The amount of total and reducing sugars remained relatively constant. After storage, freshness of mushroom was recovered by thawing treatment. When recovered mushroom were packaged with styrofoam tray and PVC wrapping, and exposed to ambient and <TEX>$10^{\circ}C$</TEX>, respectively, brown spot on the gill of fruit body was found and slight decay symptom was also found at ambient temperature only but not at <TEX>$10^{\circ}C$</TEX>. Results indicated that low temperature adapted shiitake mushroom has a storage potential under freezing temperature (<TEX>$-3^{\circ}C$</TEX>). Freezing storage technology of fresh shiitake mushroom will contribute the increase of storability up to 2 months.

Absorbed‐dose estimation and quality attributes of gamma‐irradiated fresh shiitake mushrooms

The general use of food irradiation requires reliable identification methods as well as extensive quality characterization. Shiitake (Lentinus edodes) mushrooms, packed in polystyrene trays and covered with polyvinylchloride film, were investigated for dose-dependent identification and quality characterization upon gamma irradiation (0, 1, 2, and 3 kGy). Thermoluminescence (TL) analysis of separated minerals provided excellent results to characterize the irradiated mushrooms. Low-dose re-irradiation (200-600 Gy), medium-dose re-irradiation (1-3 kGy) and high-dose re-irradiation (2-6 kGy) were performed and compared using an additive dose method. An electronic-nose analysis showed a difference in the volatile profiles of mushrooms following irradiation. One-kGy-irradiated mushrooms showed similar or better quality attributes to those of the control samples. Scanning electron microscopy revealed the dose-dependent degradation in microstructure of mushrooms upon irradiation. An absorbed dosed estimation was possible using TL analysis in which 1-3 kGy re-irradiation technique gave most promising results. An E-nose analysis effectively distinguished the samples based on irradiation history. The best quality attributes were observed at 1 kGy irradiation. However, the drastic effects of irradiation were prominent in 2 and 3 kGy-irradiated mushrooms.

Effects of Concentrations of Oxygen and Carbon Dioxide and Elapsed Time on Respiration Rate of Fresh Shiitake Mushroom

Effects of Concentrations of Oxygen and Carbon Dioxide and Elapsed Time on Respiration Rate of Fresh Shiitake Mushroom

Respiratory Characteristics of fresh Shiitake Mushroom

Respiratory Characteristics of fresh Shiitake Mushroom

Determination of the Textural Properties of Cooked Fresh Shiitake Mushroom

Determination of the Textural Properties of Cooked Fresh Shiitake Mushroom

Ultraviolet irradiation: The generator of Vitamin D 2 in edible mushrooms

Fresh Shiitake mushrooms ( Lentinula edodes), Oyster mushrooms ( Pleurotus ostreatus), Button mushrooms ( Agaricus bisporus), and Abalone mushrooms ( Pleurotus cystidus) were irradiated with Ultraviolet-A (UV-A; wavelength 315–400 nm), Ultraviolet-B (UV-B; wavelength 290–315 nm), and Ultraviolet-C (UV-C; wavelength 190–290 nm). Irradiation of each side of the mushrooms for 1 h, was found to be the optimum period of irradiation in this conversion. The conversions of ergosterol to vitamin D 2 under UV-A, UV-B, and UV-C were shown to be significantly different ( p < 0.01). The highest vitamin D 2 content (184 ± 5.71 μg/g DM) was observed in Oyster mushrooms irradiated with UV-B at 35 °C and around 80% moisture. On the other hand, under the same conditions of irradiation, the lowest vitamin D 2 content (22.9 ± 2.68 μg/g DM) was observed in Button mushrooms.

Atmospheric Composition and Respiration of Fresh shiitake Mushroom in Modified Atmosphere Packages

Atmospheric Composition and Respiration of Fresh shiitake Mushroom in Modified Atmosphere Packages

The Effect of Moisture Content on the Conversion of Ergosterol to Vitamin D in Shiitake Mushrooms

The distribution of ergosterol in different parts of shiitake mushrooms was studied in order to optimize the conversion of ergosterol to vitamin D2 during drying. The effect of moisture on the conversion of ergosterol to vitamin D2 was also investigated by adjusting the moisture content of fresh mushrooms to different levels in a large vacuum desiccator and subjecting them to UV irradiation at 290–320 nm wavelength, for 2 h. The moisture, ergosterol and vitamin D2 contents were determined using standard procedures. It was found that the ergosterol content on a dry matter basis of fresh shiitake mushroom was highest in the gills (10.6 ± 0.99 mg/g DM), followed by the cap or pileus (5.34 ± 0.64 mg/g DM) and was least in the stalk or stipe (2.97 ± 0.56). The moisture content had a marked influence on the conversion of ergosterol to vitamin D2, the best conversion taking place at a moisture content of about 70% on a wet basis.

Respiration Rate of Shiitake Mushroom in Modified Atmosphere Packages

The respiration rate of fresh shiitake mushroom (Lentinus edodes Sing.) was measured by pouch method at 0, 5, 15, 20 and 30°C. The results indicated that respiration rates were suppressed by decreasing O and increasing CO concentrations at 5, 15, 20 and 30°C. The lower oxygen limit (LOL) was mainly controlled by O concentration and little affected by CO concentration. Moreover, the LOL was increased with rise in temperature. For the multiple regression analysis, among three factors of the elapsed time, O and CO concentrations, the respiration rate was also affected by O concentration markedly.

II. Breeding and cultivation of shiitake (Lentinus edodes) mushrooms

This article describes methods of breeding, differentiation of commercial cultivars, and production of spawn of shiitake (Lentinus edodes). In the past, shiitake was cultivated in Japan with logs as the medium, either in forests for dry shiitake mushrooms or in buildings for fresh shiitake mushrooms. Cultivars were selected depending on the culture systems. Recently, sawdust medium is being widely used for cultivation of fresh shiitake mushrooms in buildings. Practical procedures of shiitake cultivation and processing of fruiting bodies are given in detail with logs and sawdust as culture media. Cultivation on logs is described for production of dry shiitake mushroom in season, and for production of fresh shiitake during off‐season. Cultivation during off‐season is divided into two systems of forced fruiting during winter and summer. Different systems of production with sawdust are also described.

Shiitake Cultivation on Sawdust: Evaluation of Selected Genotypes for Biological Efficiency and Mushroom Size

Twenty-four unique genotypes of Lentinus edodes were evaluated for their biological efficiency (BE), mushroom size and mushroom quality on a nutrient enriched sawdust substrate. Significant differences among lines were found for these parameters. Biological efficiencies ranged from 124% (WC 305) to 6.1% (WC 295). Percentages of mushrooms produced with abnormal morphology ranged from a low of 0% to a high of 88%. Breeding and selection of shiitake lines for improved biological efficiency, size and quality would reduce production costs and may help to increase consumption of fresh shiitake mushrooms.

Shiitake Cultivation on Sawdust: Evaluation of Selected Genotypes for Biological Efficiency and Mushroom Size

Twenty-four unique genotypes of Lentinus edodes were evaluated for their biological efficiency (BE), mushroom size and mushroom quality on a nutrient enriched sawdust substrate. Significant differences among lines were found for these parameters. Biological efficiencies ranged from 124% (WC 305) to 6.1% (WC 295). Percentages of mushrooms produced with abnormal morphology ranged from a low of 0% to a high of 88%. Breeding and selection of shiitake lines for improved biological efficiency, size and quality would reduce production costs and may help to increase consumption of fresh shiitake mushrooms.