Airborne bacteria are an important environmental factor that affects the hygiene of mushroom cultivation houses, as they can act as contaminants or pathogens in mushroom cultivation. To determine the distribution of airborne bacteria in the air of wood ear mushroom cultivation houses, air sampling and temperature and humidity measurements were conducted at three wood ear mushroom farms located in Iksan and Wando in 2022. Sampled air was analyzed to measure bacterial concentration levels and identify bacterial species. There was no significant difference in temperature and humidity changes detected between the three mushroom growing houses. Additionally, the concentration of bacteria in the air did not exceed 800 CFU/m², which is the maximum amount of airborne bacteria allowed by the Ministry of Environment’s indoor air quality maintenance standards. Eleven species of bacteria belonging to 11 genera were isolated and identified from air samples. These include five species of Micrococcales, four species of Bacilli, one species of Actinomycetia, and one species of Mycobacteriales. Of the 11 species identified, five are known to affect human health. However, no mushroom pathogens or species causing food poisoning were found.

In order to investigate the optimal UVB (ultraviolet B) treatment conditions for vitamin D2 enhancement of freeze-dried ear mushroom, sample size (below 300 μm~whole), UV treatment temperature (30~60℃), treatment density (6.25~50.0 mg/cm2) and the samples mixing frequency (1~32 times) were treated differently. After that, chromaticity, vitamin D2 and ergosterol (vitamin D2 precursor) contents were investigated. As a result of the investigating, effective UVB treatment conditions for vitamin D2 enhancement are as follows. The sample sizes were 2~4 mm and finely crushed pieces. The treatment temperatures were 50℃ and 60℃. The treatment density was 12.5 to 25.0 mg/cm2, and the number of sample mixing was 8 times or more. As the amount of vitamin D2 increased by UVB treatment, the ergosterol content generally tended to decrease. However, under some UVB treatment conditions, the vitamin D2 content was not high despite the decrease of ergosterol content. Under the conditions set in this experiment, it was possible to obtain ear mushrooms with enhanced vitamin D2 up to 26,968.7 μg/100 g. Therefore, it is thought that the ear mushroom is highly likely to be used as a vitamin D source and nutritionally fortified food ingredient.

2021년 4월부터 8월에 제주시의 비닐하우스에서 재배되는 목이버섯에서 거저리 일종이 발견되었으며, 그를 동정한 결과 제주진주거저리 (Platydema takeii Nakane, 1956)로 확인되었다. 상업적으로 재배되는 버섯에 있어서 거저리 해충으로 인한 우리나라의 첫 번째 피해 사례이다. 여 기서는 이 해충의 피해 증상과 성충 및 유충의 진단형질을 제공하고자 한다.

This study was conducted to effectively supplement vitamin D and increase the consumption of ear mushroom based on the investigation of the quality characteristics of cookies containing ear mushroom supplemented with vitamin D. Cookies were made of 0%, 1%, 3%, and 5% ear mushroom powder treated by ultraviolet B. Increased addition of ear mushroom powder led to a decrease in the bulk density of the dough as well as a spread factor, color value, and hardness of the cookies. There was no significant difference in the loss rate, but the water content of the dough and cookies was increased. The total polyphenol content of cookies added with 1~5% ear mushroom powder was higher than that of the 0%. The DPPH free radical scavenging activity of cookies added with 5% ear mushroom powder (23.8%) was 2 times higher than that of the 0% (10.9%). The vitamin D2 content of cookies added with 5% ear mushroom powder (835.5 μg/100 g D.W.) was 44 times higher than that of the 0% (19.0 μg/100 g D.W.). Consequently, ear mushroom powder is considered to be suitable for the production of functional cookies because of high values of antioxidant activity and vitamin D2 content.

국내 유통 중인 건조 목이 8건(국내산 3건, 중국산 5건) 을 수집하여 잔류농약 321종, 중금속 7종, 방사능 3종의 유해물질 잔류성분을 조사하였다. 잔류농약 검사결과 국내산 3건에서는 검출되지 않았으나, 중국산 5건 중 4건에서 Chlorpyrifos, Isoprocarb, Mepiquat chloride, Carbendazim이 검출되었다. 농산물 농약 잔류허용기준에 의하면 목이는 Mepiquat chloride (0.5 mg/kg 이하)만 기준치가 설정되어 있다. 또한 중금속 검사결과는 모든 건조 목이에서 미량의 중금속이 검출되었으나, 기준치 이하로 낮게 나타났다. 다만 국내산 시료 1건에서 납 함량이 기준치(0.3 mg/kg)보다 높게 나타나 정확한 원인 규명을 위해서는 톱밥배지, 지 하수, 보관·유통 과정에 대한 추가적인 조사가 필요할 것 으로 보여진다. 방사능 조사결과에서는 모든 건조 목이에서 방사능 농도가 MDA값 이하로 불검출 수준으로 나타났다. 국내산과 중국산의 평균 방사능 농도는 요오드( 131 I)와 세슘 ( 134 Cs)은 비슷한 수준으로 나타났으며, 세슘( 137 Cs)은 국내산보다 중국산에서 다소 높게 나타났다. 방사성 세슘 ( 137 Cs)은 버섯류에 잘 농축되는 것으로 알려져 있는데 이번 조사에서는 국내 유통 중인 건조 목이는 방사능에 안전하게 나타났다.

To examine the possibility of ear mushroom (EM) as a source of natural vitamin D, the UVB (ultraviolet B) was treated according to sample drying status, drying methods before UVB treatment and harvest time. And then, vitamin D2 and ergosterol contents were investigated. According to the sample drying status, the vitamin D2 contents of fresh and freeze-dried EM (whole) increased to 4,634.4~4,780.9 μg/100 g D.W. (dry weight) under UVB dose 52.5~70.0 kJ/m2 and above 18,693.1 μg/100 g D.W. under above 105 kJ/m2, respectively. By drying methods before UVB treatment, vitamin D2 contents of EM powder (below 500 μm) that dried in the vinyl house and freeze-dryer increased to 4,886.2~5,132.9 μg/100 g D.W. under above 105 kJ/m2 and 17,103.7 μg/100 g D.W. under 70 kJ/m2, respectively. Ergosterol content decreased with increasing UVB dose in all experiments. According to the harvest time, vitamin D2 content under UVB dose 210 kJ/m2 showed marked difference and in order of June, July, August, October and April. As for the results, the optimum harvest time, drying method before UVB treatment, sample size, UVB dose for the EM contained high vitamin D2 content were June, freeze-drying, whole, and 105 kJ/m2, respectively.

Although ear mushroom (Auricularia auricula-judae) was a world-widely cultivated there was a limited number of commercial cultivars in Korea. Recent increase of import of ear mushroom from China threatens domestic farmhouse. A present study introduced a thermo-tolerant new cultivar of ear mushroom ‘Hyeonyu’, which was made by mating monokaryons obtained from JBAA11 and CAA1 strains. The optimal temperature for growth was 26-36°C. The periods of primordia formation and fruit-body growth were 27 and 15 days, respectively. The average mushroom yield per bag (1kg) was 350g. As a result of RAPD with OPA1 and OPA7 primers, there were polymorphic DNA bands among control, new variety and china variety.

Although ear mushroom (Auricularia auricula-judae) is cultivated worldwide, there are a limited number of commercial cultivars in Korea. Recent increase in the import of ear mushroom from China threatens the domestic farming. The present study introduces a new thermotolerant cultivar of ear mushroom, designated ‘Hyeonyu’, developed by mating monokaryons obtained from JBAA11 and CAA1 strains. The optimal growth temperature for Hyeonyu was 26-36?. The periods of primordia formation and fruit-body growth were 27 and 15 days, respectively. The average mushroom yield per bag (1 kg) was 350 g. Random amplification of polymorphic DNA (RAPD) analysis with OPA1 and OPA7 primers identified polymorphic DNA bands between the control, the new variety Hyeonyu, and a Chinese variety.

본 연구는 국내 재배면적이 확대되고 있는 목이버섯의 부가가치 향상과 소비량 확대를 위해 팽화기술을 접목한 목이버섯 즉석죽을 제조하고, 품질특성을 조사하여 실버층에 쉽게 적용할 수 있는 제품을 개발하고자 하였다. 백미와 흑미를 75~100%와 25~0%로 혼합한 후 비타민 D2와 식이섬유 함량이 높은 건목이버섯을 0~4%로 첨가하여 호화도, 영양성분, 항산화성 및 관능 등을 조사하였다. 즉석죽 분말의 호화도는 건목이버섯 첨가량이 증가할수록, 흑미 첨가량이 감소할수록 최고점도와 유지강도, 강하점도, 최종점도, 노화점도가 증가하는 경향이었다. 백미 80%와 흑미 20%를 혼합한 후 건목이버섯 3%를 첨가한 즉석죽은 비타민 D2 18.53 μg/100 g, 식이섬유 3.73 g/100 g이 함유되어 있어 뼈의 형성과 유지와 배변활동 촉진 효과가 기대되었다. 또한 DPPH free radical 소거능도 56.79%로 나타나, 항산화성이 높아 실버층의 건강에 기여할 것으로 기대되었다. 본 실험 결과, 목이버섯은 기능성 가공제품 개발의 소재로서 사용가치가 매우 높아 실버층뿐 아니라, 다양한 연령층에 적합한 가공제품 생산에 응용가능하리라 생각된다.

목이버섯의 톱밥종균을 제조하는데 참나무톱밥은영양원으로 미강을 20%첨가하고, 포플러톱밥은 밀기울을 10%첨가하였을 때 목이버섯의 균사와 밀도가 양호하였다. 이때 봉지재배에 적합한 종균 접종양은 참나무톱밥종균은 15g, 포플러톱밥종균은 25g를접종할 때 오염발생률이 줄고 배양완성률이 높아 적합한 접종양 이었다.

목이의 균사생육에 일반적인 특성을 조사한 결과 최적온도는 25℃, pH는 6~7범위에서 균사생육이 양호하였다. 배지원 선발로 무기염류종류와 농도는 MgSO4·7H2Os 0.05%, KH2PO4 0.1%에서 균사생육이 양호하였고, 탄소원은 흑설탕 2%첨가에서 균사생육이 양호하였으며, 질소원은 콩가루를 0.3~0.5%로 첨가하였을 때 목이버섯의 균사생육이 제일 양호하였다.

In order to produce the high quality of dried-ear mushroom, various drying methods such as hot-air drying at 40~80˚C, freeze drying and drying in vinyl house were carried out. Drying hours of hot-air drying, freeze drying and drying in vinyl house were 12.5~21.5, 36.0 and 72.0 hrs, respectively. Vitamin D2 content of sample was the highest as 6.77μg/g DW in drying in vinyl house and then followed by freeze drying as 5.90μg/g DW and hot-air drying as 1.89~5.01μg/g DW. After dry, external appearance and color of mushrooms applied hot-air drying and drying in vinyl house were better than freeze-dried one. After rehydration, water uptake of sample in drying in vinyl house and hot-air drying at 50~60˚C were 17.8 and 19.3~21.0 times, respectively. The methods of drying in vinyl house and hot-air drying at 50~60˚C also led to high hardness, good shape and resilience. As the results of production of dried-ear mushroom with high quality, we suggest that the best method for drying is the drying in vinyl house due to not only high vitamin D2 content, good external appearance and color after drying but also high hardness and good shape after rehydration.