• Food Science and Biotechnology
• /
• v.14 no.6
• /
• pp.803-807
• /
• 2005

This study examined the effects of ozone exposure alone (1, 3, and 5 ppm) as well as in combination with 1% acetic acid, citric acid, or lactic acid on the growth of indigenous microorganisms in enoki mushrooms. Populations of mesophilic bacteria, yeasts and molds in enoki mushrooms appeared to be decreased by stepwise increases in concentration (1 to 5 ppm) or exposure time (0.5 to 5 min) to ozone. Compared to untreated (control) enoki mushrooms, there were reductions of 1.03 to $2.61\;\log_{10}\;CFU/g$ in mesophilic bacteria and of 1.21 to $2.7\;\log_{10}\;CFU/g$ in yeasts and molds in all ozone- treated enoki mushrooms. Combination of 3 ppm ozone and 1% citric acid (p<0.05) synergistically brought about significant reductions in both mesophilic bacteria ($3.52\;\log_{10}\;CFU/g$) and fungi (yeasts and molds) ($2.77\;\log_{10}\;CFU/g$) from enoki mushrooms. The results of this study show that low concentrations of ozone inhibit indigenous microflora populations in enoki mushrooms. Combination treatments of 3 ppm ozone with 1% citric acid showed greater antimicrobial effectiveness than either 3 ppm ozone or 1% citric acid alone.

• The Korean Journal of Food And Nutrition
• /
• v.35 no.5
• /
• pp.378-388
• /
• 2022

This study was conducted to determine the proximate compositions, nutritional components, and antioxidant effects of white and brown enoki mushrooms (Flammulina velutipes). The crude protein and carbohydrate contents were higher in the brown than white mushrooms, whereas the moisture, crude ash, crude lipid, and dietary fiber levels were lower. The mineral contents of the white mushroom was higher than levels obtained in the brown mushroom for the detected components (Ca, Cu, K, Mn, Na, and P). The amount of vitamin B₃ in the brown mushroom was 1.51 mg/100 g, which was 4.5 times higher than that in the white mushroom. The major fatty acids detected were palmitic acid, linoleic acid, and α-linolenic acid. The total polyphenol and flavonoid contents were highest in 70% ethanol extracts of the white and brown mushrooms, respectively. For the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, a 70% methanol extract of the white enoki mushrooms showed an activity of 76.4% (p<0.05). For the ferric-reducing antioxidant power (FRAP) activity, a 70% methanol extract of the brown enoki mushrooms showed the highest value. Further, the total flavonoid contents were significantly correlated with the DPPH and FRAP activities.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.28 no.2
• /
• pp.133-142
• /
• 2022

Korean enoki mushrooms are exported to Southeast Asia and the United States, where there are complaints due to quality deterioration during the distribution process. In this study, we evaluated the efficacy of vacuum film packaging on quality maintenance in Korean enoki mushrooms during simulated vessel export to Vietnam using selected film, which was developed with vacuum packaging machine and oxygen absorber. We selected two MA film, one was 2-layerd 30 ㎛ CPP film (control) and the other was 3-layered 30 ㎛ CPP film (treatment) which is optimized film of higher gas and moisture permeability. The Korean enoki mushrooms were packaged with these two films using PAC-2000 or PAC-3000 vacuum packaging machine which was improved vacuuming of higher speed. Packed mushrooms were stored at 1℃ for 2 weeks and distributed at 20℃ for 2 days or 8℃ for 6 days. The efficiency of the film packaging was analyzed by vacuum maintaining index, and overall the quality characteristics such as off odor, color, cap cleavage, stem elongations and sensory evaluation were evaluated during storage and distribution. Results suggest that postharvest loss of fresh enoki mushroom could be reduced by packaging mushroom with 3-layered 30 ㎛ CPP films packaged using PAC-3000 machine during simulated vessel export to Vietnam due to vacuum maintaining. Oxygen absorber promoted off-odor at 20℃ distribution temperature, and did not affect storability at 1℃ storage compared to treated group without oxygen absorber treatment.

• Journal of Food Hygiene and Safety
• /
• v.35 no.6
• /
• pp.630-636
• /
• 2020

Listeria monocytogenes (L. monocytogenes) was responsible for several recall cases owing to its incidence in mushrooms exported from the Republic of Korea. In this study, we investigated the survival of L. monocytogenes in enoki mushroom (Flammulina velutipes) at different temperatures and the antilisterial effect of its organic acids. Enoki mushrooms were innoculated with L. monocytogenes (initial concentration 4.5 log CFU/g) and stored at 1-35℃, No growth of L. monocytogenes in enoki mushrooms was observed at 1℃ for 30 days. 3.0 log CFU/g growth of L. monocytogenes was also achieved after 36 h and 24 h at 30℃ and 35℃, respectively. To evaluate the antilisterial effect of the organic acids (acetic acid, lactic acid, malic acid), enoki mushrooms were treated with 1-3% of each acid for 10-30 min. The efficacy of malic acid and lactic acid was significantly higher than that of acetic acid. Over 3.0 log reductions were observed when L. monocytogenes in enoki mushrooms was immersed in 3% lactic acid and malic acid over 10 minutes or more. Therefore, it is necessary to keep enoki mushrooms at 1℃ during the export process and treat them with 3% lactic acid and malic acid for 10 min prior to consumption.

• Journal of Food Hygiene and Safety
• /
• v.38 no.6
• /
• pp.508-516
• /
• 2023

The consumption of enoki mushrooms has been associated with cases of listeriosis produced by Listeria monocytogenes, highlighting the significance of sanitizing food-contact surface, such as the velcro used in welding processing of enoki mushrooms, to ensure microbial safety. We investigated the inhibitory activity of nine chemical disinfectants at regular concentrations against L. monocytogenes isolated from a mushroom farm environment. The bacterial suspension was prepared in phosphate buffered saline and mushroom extract broth and inoculated onto the velcro surface. After inoculation, most disinfectants reduced the initial 8 log CFU/coupon concentration by less than 2 log CFU/coupon during a 5-min treatment. Slightly acidic hypochlorous water showed a reduction of approximately 4 log CFU/coupon when tested for more than 30 min at the maximum allowable concentration of 200 mg/L. Sodium hypochlorite solution showed a reduction of approximately 5 log CFU/coupon when used at 100 mg/L for 60 min. Peracetic acid, at the maximum allowable concentration of 300 mg/L, showed the most effective reduction of 5 log CFU/coupon or more when the surface was treated with 37.5 mg/L for 30 min. These results indicate that peracetic acid can be used as the disinfectant strategy to control cross-contamination of L. monocytogenes on the velcro surface of plastic wrappers used in the welding processing of enoki mushrooms.

• Food Science and Preservation
• /
• v.16 no.2
• /
• pp.179-185
• /
• 2009

To develop an Enoki mushroom packaging method, mushrooms were stored at $1^{\circ}C$ for 12 days after passive MAP packaging(PM), vacuum packaging(VM), and gas flushing packaging(AM), after investigation of film thickness influences on respiration rates and gas compositions(LDPE films 20, 40, and 60 m in thickness were tested). Enoki mushrooms had respiration rates of 26.4 mL $CO_2/kg/hour$ at $0^{\circ}C$, 80.0 mL $CO_2/kg/hour$ at $10^{\circ}C$, 130.9 mL $CO_2/kg/hour$ at $20^{\circ}C$, and 130.9 mL $CO_2/kg/hour$ at $30^{\circ}C$. A film thickness of 20 m was chosen for further tests to maintain the oxygen concentration above the minimum growth level; the thinnest film offered a higher gas transmittance rate than did the thicker films. No anaerobic respiration was evident over 12 days of storage using any packaging method, with the exception of VM. AM, using a high concentration of $CO_2$, restricted respiration rate. Mushrooms packaged using the VM method showed the greatest weight loss and extent of discoloration among the packaging methods tested, followed by AM mushrooms using 50% $CO_2/10%\;O_2/40%\;N_2$. Mushrooms packaged by the VM and PM methods developed a serious off-flavor after 2 days of storage, and a high stipe elongation rate after 5 days of storage, respectively. However, AM using 50% $CO_2/10%\;O_2/40%\;N_2$ of various gas ratios tested, allowed Enoki mushrooms to be maintained for up to 12 days without development of off-flavor, discoloration, or moldiness.

• Journal of Mushroom
• /
• v.13 no.3
• /
• pp.199-202
• /
• 2015

The purpose of this study is to address a current mushroom export situation in Gyeongbuk area for establishing exports strategy, and policy of mushrooms export. Mushroom industry has made a rapid growth over the past 20 years in Korea. Gyeongbuk province exports volume of enoki and king oyster mushrooms account for about half of the country, enoki and total exports in 2009, and 81%, increased to 14% in 2010 and 2010, the maximum exports (9,415 tons) and the maximum exports (14,840 grand)was recorded. But, enoki and total exports in 2011, and -15%, decreased to -19% in 2012, and increased to 32% in 2013, 1% in 2014. King oyster mushroom to represent the Netherlands in Europe, exports were higher exports to China is negligible. In the case of China in 2001, 5 spots automated mushroom factory, production, but only 8,000 tons in 2011, 652 mushroom factory, production of 1,100,000 tons and in 2012, 788 mushroom factory, production of 1,520,000 tons quickly grew.

• Journal of Mushroom
• /
• v.21 no.1
• /
• pp.1-7
• /
• 2023

This study addresses the current demand of the Korean mushroom export industry to establish an export strategy and governing policies.The enoki mushroom exports increased by 89% in 2009 and 23% in 2010, resulting in the largest export volume (17,163 tons) and export value ($26,292,000) being recorded in 2010. In contrast, exports in 2020 yielded only $18,525,000, which was 29% lower than that in 2010. In case of king oyster mushrooms, exports increased by 10% in 2012, 13% in 2013, and 2% in 2014, maintaining a moderate-growth trend. Moreover, Korea's mushroom exports are focused on a few specific countries. Enoki mushrooms accounted for more than 50% of the total exports to North America and Vietnam from 2012 to 2022, whereas king oyster mushrooms accounted for more than 50% of the total exports to Europe and North America (USA and Canada) from 2009 to 2022. Another characteristic trend in Korean mushroom exports is the diversification of export markets. The number of countries importing enoki mushrooms and king oyster mushrooms from Korea is increasing.

• Korean Journal of Food Science and Technology
• /
• v.44 no.6
• /
• pp.666-672
• /
• 2012

The present study was carried out in order to assess the dietary exposure as well as the risk for lead (Pb) and cadmium (Cd) exposure through mushrooms among the Korean population. Various samples (n=536) covering 17 kinds of mushrooms were collected from retail outlets and markets in Korea. The contents of Pb were 0.005 (King oyster)-0.026 (Matsutake) mg/kg in raw mushrooms and 0.014 (Oyster)-16.411 (Manna lichen) mg/kg in dry mushrooms, respectively. The contents of Cd were 0.002 (Enoki)-0.205 (Hericium erinaciium) mg/kg in raw mushrooms and 0.021 (Vegetable worms)-2.650 (Agaricus blazei Muill) mg/kg in dry mushrooms, respectively. The mean dietary exposure of Pb for the general population was $0.053{\mu}g/day$, taking 0.03% of provisional tolerable weekly intake (PTWI). The mean dietary exposure of Cd for the general population was $0.168{\mu}g/day$, corresponding to 0.37% of provisional tolerable monthly intake (PTMI). Therefore, the level of the overall dietary exposure to heavy metals through mushroom for the Korean population was far below the recommended JECFA levels, indicating little possibility of concern.

• Journal of Food Hygiene and Safety
• /
• v.39 no.1
• /
• pp.9-15
• /
• 2024

This study was performed to survey the distribution of Listeria spp. in fresh agricultural products in the Busan area, the Republic of Korea, from January to November 2022. We investigated the pathogenicity and epidemiological relationships by tracing isolated strains using polymerase chain reaction and pulsed-field gel electro-phoresis (PFGE) methods. Forty cases of Listeria spp. were detected in the 210 samples of fresh agricultural products analyzed. Four species, Listeria rocourtiae, L. innocua, L. grayi, and L. monocytogenes were detected only in green vegetables (lettuce, perilla leaps) and the others (L. innocua, L. monocytogenes, and L. grayi) were detected in enoki and oyster mushrooms. L. innocua was detected in 22 samples and L. grayi in six samples. L. monocytogenes, which causes foodborne diseases, was only detected in enoki mushrooms and the strains that were isolated had genes responsible for the pathogenicity of listeriosis (iap, prfA, inlA, inlC, inlJ, and hly). To investigate the genetic similarity and contamination route of L. monocytogenes, serotyping and PFGE were conducted for 12 strains isolated from fresh agricultural (10 strains) and poultry (2 strains) products distributed at a market in the Busan area. Two serotypes (1/2a, 1/2b) were detected in strains isolated from the agricultural and poultry products, but serotype 1/2b was only detected in strains isolated from agricultural products. PFGE analysis showed index of similarity values of 45.7 to 100% and the same patterns were represented in isolates from some enoki mushrooms. These isolates had the same serotypes and showed significant epidemiological relationships.