초록 ▼

○ 연구결과
1) 셀레늄강화 팽이버섯과 폐배지의 셀레늄형태 및 팽이버섯내 셀레늄축적대사에 관한 연구(1년차 주관과제)
본 연구는 버섯을 키우는 배지에 무기태셀레늄을 배지 kg당 2mg을 첨가하여 셀레늄강화팽이 버섯을 생산하고, 인체 EH는 가축의 셀레늄급원으로서 버섯과 패배지 각각의 셀레늄함량 및 형태 그리고 버섯내에서 일어나는 셀레늄축적대사를 조사하였다. 셀레늄무처리버섯과 셀레늄처리버섯의 총 셀레늄함량은 셀레늄처리버섯이 건조g당 4.51ug의 셀레늄을 나타내어 셀레늄무처리버섯의 0.23ug에 비하여 약 20배정도 증가하

○ 연구결과
1) 셀레늄강화 팽이버섯과 폐배지의 셀레늄형태 및 팽이버섯내 셀레늄축적대사에 관한 연구(1년차 주관과제)
본 연구는 버섯을 키우는 배지에 무기태셀레늄을 배지 kg당 2mg을 첨가하여 셀레늄강화팽이 버섯을 생산하고, 인체 EH는 가축의 셀레늄급원으로서 버섯과 패배지 각각의 셀레늄함량 및 형태 그리고 버섯내에서 일어나는 셀레늄축적대사를 조사하였다. 셀레늄무처리버섯과 셀레늄처리버섯의 총 셀레늄함량은 셀레늄처리버섯이 건조g당 4.51ug의 셀레늄을 나타내어 셀레늄무처리버섯의 0.23ug에 비하여 약 20배정도 증가하였다(P<0.0001). 유기태셀레늄비율은 셀레늄처리버섯에서 72.3%를 나타내었고, 무처리버섯은 무기탤셀레늄이 검출되지 않아, 총 셀레늄 중 유기태셀레늄의 비율이 100%로 평가되었다(P<0.0001). 셀레늄처리버섯의 부위별 셀레늄분포는 상단부와 중간부가 각각 건조 g당 3.71 및 3.01ug을 나타내었고, 배지와 가까운 하단부와 6,86ug으로 가장 높았다(P<0.001).한편, 폐배지 내 셀레늄함량은 셀레늄처리버섯 폐배지에서 건조 g당 5.04ug으로 상당량의 셀레늄이 페배지에 존재하였고, 무처리 페배지에서는 0.08ug으로 유희하게 낮았다.
(P<0.0001). 셀레늄처리버섯 폐배지의 유기태셀레늄비율은 65.67%로 높게 나타났고, 이는 버섯재배시 첨가한 무기태셀레늄이 폐배지 내 잔여 버섯균사에 의해 상당량 유기태셀레늄으로 전환되었음을 시사한다. 버섯균 접종전 버섯배지의 멸균처리는 약 18%의 셀레늄손실을 가져왔다. 버섯체내 외관상 및 순수 셀레늄축적율은 각각 14.81 및 10.14%로 나타났다. 또한, 외관상 축적된 셀레늄의 4.67%가 버섯체내 대사에 의해 공기 중으로 휘발되는 것으로 나타났다.
이상의 결과로부터 배지 내 무기태셀레늄의 첨가는 버섯 내 셀레늄함량을 증가시켰고, 인체 내유용한 유기태셀레늄이 다량 존재하엿다. 그리고, 폐배지에서도 상당량의 유기태셀레늄이 존재하여 가축의 셀레늄공급원으로 충분한 가치가 있을 것으로 판단된다. 그리고 버섯재배전 배지의 멸균은 상당량의 셀레늄손실을 가져왔고, 버섯 체내 축적된 셀레늄의 일부가 버섯자체 대사과정에 의해 공기 중으로 휘발되는 것으로 나타났다.
2) 버섯 폐배지를 이용한 발효사료의 제조와 유기셀레늄 강화에 관한 연구(1년차 주관과제)

Abstract ▼

Ⅲ. Contents and Results of Research & Development
1) Studies on the selenium type and metabolism of selenium accumulation in the selenium-enriched mushroom, Flammulina velutipes, and its spent mushroom composts
This study was conducted to determine the total amount and type of selenium (Se) in

Ⅲ. Contents and Results of Research & Development
1) Studies on the selenium type and metabolism of selenium accumulation in the selenium-enriched mushroom, Flammulina velutipes, and its spent mushroom composts
This study was conducted to determine the total amount and type of selenium (Se) in the Se-enriched mushroom and its spent mushroom composts (SMC), and to investigate the metabolism in relation to Se accumulation in the mushroom.
Mushrooms, Flammulina velutipes, used in this study were grown for 60 days by adding 2 ㎎ of inorganic Se (Na₂SeO₃) per ㎏ of mushroom composts (MC) on as-fed basis and were compared with normal mushrooms grown on the non Sesupplemented MC. Total Se contents for Se-treated mushrooms were significantly increased (P<0.0001) by 20-fold (4.51 ㎍j/g of dry) compared to Se-untreated (0.23 ㎍p/g of dry). On the contrary, organic Se ratio was significantly lower (P<0.0001) in the Se-treated mushroom (72.3%) than the Se-untreated one (100%, not analytically detected of inorganic Se). Se distribution upon a length in the Setreated mushrooms was the highest in the bottom part (6.86 ㎍j/g of dry) near to MC, and those in top and middle parts were significantly lower (3.71 and 3.01 ㎍p/g of dry, respectively; P<0.001) than those in the bottom parts. In the SMC from Se-treated mushrooms, the significant amount of Se (5.04 ㎍j/g of dry) was remained, but that from the Se-untreated mushrooms was significantly low (P<0.0001) as 0.08 ㎍p/g of dry. Se-treated SMC showed a high ratio of organic Se (65.67%), suggesting that the significant amount of inorganic Se in the SMC was converted to organic Se by mushroom mycelia. Prior to mycelia inoculation in the mushroom culture, the sterilization of MC brought approximately 18% of Se loss in the MC. This result is in accordance with facts generally known that Se is weak in the high temperature, and thus consequently volatilized under the sterilization. Apparent and net accumulation rates (%) for Se into mushrooms were 14.81 and 10.14%, respectively, resulting from the Se volatilization into the air via metabolic process of mushroom itself.
The result of this study shows that inorganic Se addition to MC for mushroom improved the Se content in the mushroom. However, SMC from Se-enriched mushrooms still contained a high concentration of Se. Fruiting bodies and mycelia from the mushroom and SMC converted inorganic Se in MC to organic Se, resulting in a high proportion of organic Se in the mushroom and SMC. This study showed the possibility that Se in Se-enriched mushroom and SMC could be utilized as Se sources of food for human as well as feed for livestock.
2) Studies on the manufacture of the fermented feed of spent mushroom composts for ruminants and the fortification of organic Se during fermentation
Main objectives of this study were to increase digestibilities of indigestible ingr edients in SMC consisted of sawdust mainly as well as to fortify conversion of in organic Se present in SMC to organic Se via fermentable microbial actions. We made fermented feeds containing the increasing level of selenium (0.06 ppm, 0.54 ppm, 1.26 ppm and 1.86 ppm) in combination with SMCs of Se-enriched and non-Se mushrooms being fermenting using commercial microbial feed additives (Sambae, Ltd., Korea) comprised Saccharomyces, Bacillus, Aspergillus, Streptococcus and A -ctinomycetes before feeding trial for ruminants (Hanwoo). Those are fermented for 0, 12, 24, and 48 hrs. Initial pH was linearly increased as Se concentration increa ses or the proportion of SMC of Se-enriched mushroom increased (P<0.0001). pH values of fermented feeds (0.54 ppm, 1.26 ppm and 1.86 ppm) containing SMC of Se-enriched mushroom were not different since 12 hrs of fermentation time and th eir pH was significantly lowered compared to control group. The increasing level of Se concentration in fermented feeds showed significant differences in organic and inorganic Se contents and proportion of organic Se among treatments. As a SMC proportion of Se-enriched mushrooms in the fermented feed was increased, orga nic Se proportion was significantly decreased (P<0.0001).
The control treatment (0.06 ppm) comprising the non-Se SMC alone was estimated of the organic Se to be 100% and the treatment groups containing the increasing level of Se were estimated of organic Se to be approximately 70%.
3) Effects of spent composts of Se-enriched mushrooms on carcass characteristics, plasma GSH-Px activity, and Se deposition in finishing Hanwoo steers
This study was conducted to determine effects of spent composts of Se-enriched mushrooms (Se-SMC) as the dietary selenium source on carcass characteristics, plasma glutathione peroxidase (GSH-Px) activity and Se deposition in finishing Hanwoo steers. In combination with both Se-SMC and normal SMC, experimental treatment diets were formulated to contain 0.1, 0.3, 0.6 and 0.9 ppm of Se on a dry matter basis. A total of 20 finishing Hanwoo steers (average BW = 613 kg, average age = 20 to 24 mo) were allotted to treatments in four groups of five steers per pen for 12 wk preceding slaughter. While the experiment is employed, blood samples were taken to analyze Se concentration and GSH-Px activity, and muscle and liver samples were collected for analyses of Se contents in their tissues after slaughter. DMI and BW gain were not affected by dietary Se level and any toxic symptoms in treatments with a higher level of Se were not observed. Se concentration in whole blood and plasma GSH-Px activity were linearly increased with the increasing level of dietary Se (P < 0.01). Se content in the hind leg for Se-SMC supplemented groups significantly increased (P < 0.05) upon dietary Se level, with 0.27, 0.37, 0.40 and 0.46 μg/g dry, respectively.
However, Se content in the loin was not affected by dietary Se levels. Se content in the liver was significantly increased (P < 0.05) as dietary Se increased, with 0.79, 1.40, 2.39 and 3.10 μg/g dry, respectively. These results suggested that Se in the Se-SMC was highly bioavailable, and Se-SMC might be used not only as an inexpensive way of providing Se for ruminants but also as another way of producing Se-fortified beef.
4) Effects of supplementing spent composts of Se-enriched mushrooms on carcass characteristics and meat quality in longissimus muscle of Hanwoo Steers
The current study was conducted to investigate the effect of supplementing spent composts of Se-enriched mushrooms (Se-SMC) on beef quality in finishing Hanwoo steers. Each five of 20 Hanwoo steers (20 ∼24 month, approximately 613 kg) were assigned to four levels of the selenium content (0.1, 0.3, 0.6, 0.9 dry matter-based ppm), and the feeding treatments were enforced for 12 weeks. The results showed that m. longissimus from the 0.1 ppm feeding supplementation had greatly higher intramuscular fat content than other treatments (13.1 %). In meat color, the 0.1 ppm treatment showed the lowest lightness (CIE L*) with 35.93 (P < 0.05) and had a tendency to have lower redness (CIE a*) with 18.81.
The treatment had no noticeable effect on moisture, protein, and ash content, cooking loss, water-holding capacity and purge loss. The 0.3 ppm treatment resulted in the toughest meat (assessed by WB-shear force) with 4.54 kg / inch², while other groups showed a similar toughness ranging from 3.3 to 3.7 kg / inch². Sensory characteristics in juiciness and flavor intensity had a tendency of increasing as organic selenium concentration increased, but tenderness was not influenced by the contents. Ca, P, Mg, K, Na, Fe, Mn, Zn and Cu also were not affected by the treatments. For carcass characteristics, the 0.6 ppm group had a tendency to result in higher frequency of yield grade A, while the 0.3 ppm treatment resulted in the lowest frequency of 20%. The best treatment for the production of 1+quality beef were resulted from 0.1 and 0.6 ppm with both 20%. The result indicated that Se-SMC supplementation affects meat qualities to different extent, and further study is required to examine antioxidant effect of selenium in vivo.
5) Effects of the feeding periods of spent mushroom composts from selenium-enriched mushroom on selenium deposition in finishing Hanwoo steers
This study was carried out to determine effects of the feeding period of spent mushroom composts from selenium-enriched mushroom (Se-SMC) on muscular selenium deposition in finishing Hanwoo steers. A total of 30 steers were allotted to an experiment with a 3 × 2 factorial arrangement. Treatments were 2 groups of with and without Se-SMC at three different feeding periods (2, 4, and 6 months) by body weight (BW). And then dry matter intake, body weight gain, Se concentration and/or content in blood and/or muscle were investigated. Dry matter intake was not affected by feeding period and Se-SMC supplementation. As the feeding period was prolonged, initial and final BW was significantly lowered (P<0.01) with no Se-SMC effect. However, total BW gain was significantly increased (P<0.0001) with increasing feeding period with no effect of Se-SMC.
Se-SMC supplementation significantly increased Se concentration in whole blood and plasma GSH-Px activity, but there was no effect on feeding period. Se contents in muscles, especially hind-leg, were significantly increased (P<0.05) as the feeding period was increased. However, there was no difference for Se content between four and six months feeding groups of Se-SMC and also hepatic Se content was not affected by feeding period. On the contrast, hepatic Se content for Se-SMC group within each feeding period was significantly increased (P<0.0001) compared with no Se-SMC supplementation.
In conclusion, our results suggested that optimum feeding period of Se-SMC as a strategy for the production of Se-fortified beef might be approximately 4 months.
6) Effects of spent mushroom composts from selenium-enriched mushroom feeding periods on meat quality in Hanwoo steers
Current study was conducted to investigate the effect of spent mushroom composts from selenium-enriched mushroom (Se-SMC) on beef quality of longissimus muscle. The results showed that Se-SMC supplementation of 0.9 ppm (DM based ratio) for 2 (T1), 4 (T2) and 6 (T3) months had no effect on water moisture contents, with 63 to 66%, compared to those of non-supplemented control group. Similarly, intramuscular fat content, ranged from 11.7 to 16.4%, did not differ among the treatment groups (P>0.05). T3 group showed the highest protein content with 20.8%, while T2 group had the lowest content with 19.2%. The data indicated that Se-SMC supplementation to the experimental diets had indictable effect on proximate muscle composition.
The treatments similarly had no influence on physical and biological characteristics of longissimus muscle, where cooking loss and shear force ranged from 20 to 21% and from 3.6 to 4.4 kg, respectively. On the other hand, muscle pH at 24 h postmortem showed 5.52, 5.57, 5.50, 5.50 for control, T1, T2 and T3, respectively, indicating that the longer feeding period had the lower ultimate pH.
The similar trend was observed from water-holding capacity where the treatment groups (63.8, 64.4 and 64.2% for T1, T2 and T3, respectively) showed significantly higher water-holding capacities than control group (59.5%) did. For sensory evaluation, juiciness was not different among the treatment groups, but T1 and T2 (5.30 and 5.28, respectively) showed significantly tender meat. Particularly, T2 group received significantly higher flavor scores among the treatment groups including controls.
For mineral contents, Ca, P, K, Na, Mg, Fe, Mn, Zn and Cu showed a similar levels among treatments. The frequency of 1+ quality grade was 80% for both T1 and T2 groups, and 20% for T3 group which was generally higher than 13% for control group. However, X² analysis (X² value=14.167, P<0.1167) indicated that the treatment had no effect on carcass quality. In the case of yield grade, the treatment groups had a higher (20%) grade of A than control group (6.7%). CIE L* value showed a higher value with an exception for 2 month group, than control group (37.46) which CIE a* and b* values were similar between groups including control, indicating that the treatment had no effect of initial meat color of longissimus muscle.
Myoglobin content in longissimus muscle for the treated cattle were similarly 6.39% which was lower than control (14.18%). On the other hand, Oxy-myoglobin content was significantly higher for control (89.07%) than the treatment group (83.47%) (P<0.05). In the case of Met-myoglobin content, control (4.56%) group showed a higher level than the treatment group (2.35%). Collectively, the pigment analysis indicated that Se-SMC supplementation can stabilize meat color and consequently improve color stability during chiller ageing. The data indicated that Se-SMC supplementation to the experimental concentration had no effect on beef quality, but the treatment effect on antioxidation function remains for further studies.
7) Effects of different selenium sources on performances and Se depositions in tissues of finishing Hanwoo steers
This study was conducted to determine effects of different selenium sources on performances and Se depositions in tissues of finishing Hawoo steers. Treatments were controls (no Se-supplement), spent composts of Se-enriched mushrooms (Se-SMC), Se-yeast, and sodium selenite. Treatment groups barring controls contained 0.9 mg/kg Se in the diets by adding three different selenium sources to their each treatment diet. Twenty finishing Hanwoo steers initially weighing 536 kg (approx. 20 months old) were randomly allotted to one of four treatments with five steers per each diet and feeding trial lasted for 16 weeks. While the trial was employed, blood samples were collected to analyze their Se concentrations and
GSH-Px activity. At experiment termination, tissue sample (loin, hind leg and liver) were collected in the slaughter house to analyze their Se contents. Dry matter intake and liveweight gain were not affected by dietary selenium source and level. Whole blood Se concentration and GSH-Px activtiy were significantly (P<0.05) different among treatments with the order of Se-yeast > Se-SMC > sodium selenite ≥control. The distribution of Se in hind leg and liver were significantly (P<0.05) different among treatments, with controls = sodium selenite ≤Se-SMC < Se-yeast (0.45, 0.57, 0.71, 1.11 ppm for hind leg; P<0.01) and controls = sodium selenite ≤Se-SMC ≤Se-yeast (1.10, 1.80, 2.32, 3.36 ppm for liver; P<0.05). However, Se contents in the loin were not significantly different among treatments due to its high proportion of intramuscular fats.
Our results showed that both Se-SMC and Se-yeast had greater not only whole blood Se concentrations and GSH-Px activity, but also Se deposition in tissues compared with control and sodium selenite treatments, suggesting that they contained a high proportion of organic selenium. Though they had greater bioavailability, Se in the Se-SMC treatment was less than that of Se-yeast.
However, Se-SMC may contribute to the improvement of farm income and human health in the aspect of reducing feed costs and promoting functional animal products.
8) Effect of different selenium sources on carcass characteristics and meat quality of Hanwoo steers during cold storage
When different selenium sources such as spent mushroom composts from selenium-enriched mushroom (Se-SMC), Se-yeast and sodium selenite were supplemented to finishing Hanwoo steer diets, we determined the effect of selenium sources on meat quality after the slaughter. Sodium selenite treatments had the highest cooking loss (24.01%), while Se-yeast and Se-SMC were 20.88 and 21.90%, respectively, which was significantly higher than 16.89% for control group. WB-shear force was not different among treatments, but Se-SMC groups showed a significantly lower value (3.69; P<0.05). Sodium selenite treatments had a significantly lower pH (5.46) than those (5.50) of both control and Se-SMC.
Intramuscular fat content did not differ among the treatment groups, but there was a tendency of higher levels for control and Se-SMC with 16.35% and 16.01%, respectively, compared to sodium selenite (12.22%) and Se-yeast (11.69%). All experimental groups showed a similar protein content of 19.26∼9.85%. The results indicated that dietary selenium sources had no influence on muscle composition, water-holding capacity and meat tenderness. On the other hand, sodium selenite groups showed a poor meat quality in objective measurements due to higher cooking loss and lower pH compared to the other group. In sensory evaluation, juiciness for control(5.40), Se-SMC (5.40), sodium selenite and for Se-yeast (4.48) did not significantly differ. Tenderness was highest for Se-SMC (5.08), followed by Se-yeast (4.96), control (4.72) and sodium selenite (4.48). In flavor intensity evaluation, Se-SMC received the highest score (5.40), followed by Se-yeast (5.04), control (4.88) and sodium selenite (4.48).
Sodium (Na) content for sodium selenite was higher with 488.24 ppm than other groups of 417.63∼24.00 ppm, which Fe for Se-SMC was lower (18.77 ppm) than other group (21.52∼4.84 ppm) (P<0.05). C16:0 fatty acid was significantly higher for sodium selenite and control of 28.29% and 27.11%, respectively, than Se-yeast and Se-SMC of 25.46% and 24.93%, respectively (P<0.05). C18:1:n9 fatty acid showed that sodium selenite (47.81%) had a lower level than the other groups, while control groups (0.14%) had the lowest C18:3n3 content (P<0.05).
In yield grade, Se-yeast groups resulted in higher frequency of grade A (40%). On the other hand, 40% of grade C was resulted from sodium selenite groups which had significantly higher level than controls, but Chi-Square analysis for all treatment groups indicated that there was no treatment effect on yields (P<0.05).
Quality grade 1+ was highest for Se-SMC (80%), followed by sodium selenite (40%) and Se-yeast and control groups (20%). TBA and VBN values during chiller ageing indicated that there was no effect of different selenium sources on fat and protein degradation. Furthermore, Se supplemented treatments had no effect of changes in fatty acid composition during chiller ageing.

목차 Contents

• 표지 ... 1
• 제출문 ... 2
• 요약문 ... 3
• SUMMARY ... 15
• CONTENTS ... 25
• 목차 ... 27
• 제1장 연구개발과제의 개요 ... 29
• 제1절 연구개발의 목적 ... 29
• 제2절 연구개발의 필요성 ... 29
• 제3절 연구개발의 범위 ... 32
• 제2장 국내외 기술개발 현황 ... 34
• 제1절 국내·외 관련기술의 현황 및 문제점 ... 34
• 제2절 앞으로의 전망 ... 34
• 제3장 연구개발수행 내용 및 결과 ... 36
• 제1절 셀레늄강화 팽이버섯과 폐배지의 셀레늄형태 및 팽이버섯내 셀레늄축적 대사에 관한 연구 ... 36
• 제2절 버섯 폐배지를 이용한 발효사료의 제조와 유기셀레늄 강화에 관한 연구 ... 48
• 제3절 셀레늄강화버섯 폐배지의 수준별 첨가가 한우육내 셀레늄축적 및 혈중 GSH-Px활성연구 ... 57
• 제4절 유기셀레늄강화버섯 폐배지의 급여수준에 따른 거세한우의 도체 등급 및 채끝육의 육질특성 ... 71
• 제5절 셀레늄의 포화축적 기간 결정을 위한 한우사양시험 ... 80
• 제6절 유기셀레늄강화 버섯 폐배지 급여기간이 쇠고기육질과 육색의 안정성에 미치는 영향 ... 91
• 제7절 유기셀레늄 강화버섯 폐배지와 타셀레늄원과의 차별성을 위한 비육후기 한우의 사양연구 ... 107
• 제8절 유기셀레늄 급여원에 따른 한우 거세 비육우의 도체, 육질 특성 및 저장 기간 중 선도변화 구명 ... 117
• 제4장 목표달성도 및 관련분야에의 기여도 ... 129
• 제1절 연구개발의 목표 달성도 ... 129
• 제2절 대외 기여도 ... 130
• 제5장 연구개발결과의 활용계획 ... 131
• 제6장 연구개발과정에서 수집한 해외과학기술정보 ... 132
• 제7장 참고문헌 ... 133
• 끝페이지 ... 150