연잎의 생리활성과 연잎밥의 품질 특성 = Physiological activity of lotus(Nelumbo nucifera) leaf and Quality characteristics of Cooked rice with lotus leaf extract

다국어 초록 (Multilingual Abstract)

This studies were carried out to investigate the potential use of lotus leaf as functional materials in food industry. The physiological characteristics of lotus leaf extract, such as antimicrobial activity against pathogens, antioxidant, anticancer activity and anti obesity activity, and the effects of lotus leaf extract on shelf life of cooked rice contaminated artificially with Bacillus cereus were investigated.
Antimicrobial activity of lotus leaf ethanol extracts(LLE) was igher than that of hot water extracts. Antimicrobial activity of LLE against Bacillus sp. such as B. cereus, B. subtilis and B. megaterium was higher than that of other tested pathogens. Spore germination of Bacillus sp. was inhibited by LLE and minimum inhibitory concentration(MIC) of LLE against Bacillus sp. was 3%
Antioxidant activity of LLE measured by DPPH-radical scavenging activity and nitrite scavenging activity was increased with increasing the concentration of LLE.
DPPH-radical scavenging activity of 0.1% LLE was 90.08% and nitrite scavenging activity of 0.5% LLE was 97.72%.
Total polyphenol contents of LLE(1%) was 271 ㎍/mL. The growth of SNU-1(stomach cancer) and MCF-7(breast cancer) cells was inhibited by LLE and rate of growth inhibition(%) was depended on the concentration.
Anticancer activity of LLE against MCF-7 cell was higher than against SNU-1 cell. Growth and differentiation of 3T3-L1 cells were inhibited by the addition LLE. Growth of 3T3-L1 cells were inhibited 93.10% by 60 ㎍/mL of LLEE. Lipid droplet number of 3T3-L1 cells during differentiation decreased at 50 ㎍/mL of LLE and did not show at 100 ㎍/mL.
Quality characteristics of cooked rice artificially inoculated with B. cereus spore(CRB), such as number of viable cell, pH, color, hardness, cohesiveness, brittleness, springiness, chewiness, DPPH-radical scavenging activity, total polyphenol contents and sensory quality, were investigated and compared with CRB added 0.5, 1.0, 1.5% LLE(CRBL) during storage at 30℃ for 5 days.
The growth of B. cereus was apparently inhibited in cooked rice inoculated Bacillus spore(103 CFU/g) containing above 1% LLE during storage for 5 days at 30 C. The shelf life of 1% LLE containing cooked rice extended for 1 to 2 days compared to control.
The pH of cooked rice containing LLE was lower than that of control. The pH value decreased during storage for 3 days in control, 0.5%, 1% LLE containing cooked rice but gradually decreased in 1.5% LLE containing cooked rice.
The lightness of cooked rice containing LLE(CRBL) was low but redness and yellowness was high compared to control. The lightness of cooked rice decreased but redness and yellowness increased during storage. The color (L, a, b) of CRBL did not show significant difference in CRBL during storage.
Hardness of cooked rice decreased during storage but the change was delayed by addition of LLE. The cohesiveness, brittleness, springiness, and chewiness of CRBL were apparantly higher than those of control.
Antioxidative activity measured by DPPH scavenging activity and total polyphenol content of cooked rice were significantly increased by addition of LLE. Antioxidative activity of control and 1.0% LLE added cooked rice were 446% and 88.91%, respectively.
The taste, color and overall acceptability showed the best value in 0.5% CRLE and flavor and texture were in 1.0% CRBL.
The lotus leaf extract were found to be highly effective in extending the shelf life and improve the physiological properties of cooked rice

목차 (Table of Contents)

• Ⅰ. 서론 = 1
• Ⅱ. 재료 및 방법 = 4
• 1. 연잎 추출물의 생리활성 = 4
• 1) 연잎 추출물의 제조 = 4
• 2) 사용균주 및 배지 = 4
• 3) 항균활성 검색 = 4
• 4) 병원성 미생물에 성장억제효과 측정 = 5
• 5) 추출물의 항균활성 열안전성 검색 = 5
• 6) 병원성 미생물에 대한 연잎 에탄올 추출물의 최소 저해 농도(Minimum inhibitory concentration; MIC) 측정 = 5
• 7) Bacillus sp.에 대한 연잎 에탄올 추출물의 농도별 항균활성 측정 = 5
• 8) Bacillus sp. 포자현탁액의 조제 = 6
• 9) Bacillus sp. 포자에 대한 발아 억제 활성 측정 = 6
• 10) 전자공여능 측정 = 6
• 11) 아질산염 소거능 = 7
• 12) 총 페놀함량 측정 = 7
• 13) 암세포의 성장 억제율 측정 = 7
• 14) 지방세포 성장 및 분화에 미치는 효과 = 8
• 2. 연잎 에탄올 추출물을 첨가가 Bacillus sp.가 오염된 쌀밥의 저장에 미치는 영향 = 9
• 1) 취반방법 및 쌀밥의 저장 = 9
• 2) 미생물수 측정 = 9
• 3) pH 측정 = 10
• 4) 색도 측정 = 10
• 5) 조직감 측정 = 10
• 6) 전자공여능 및 폴리페놀 함량 측정 = 10
• 7) 관능검사 = 11
• 8) 통계처리 = 11
• Ⅲ. 결과 및 고찰 = 12
• 1. 연잎 추출물의 생리활성 = 12
• 1) 연잎 추출물의 항균성 검색 = 12
• 2) 연잎 에탄올 추출물에 대한 병원성 미생물 및 부패 미생물의 항균활성 = 14
• 3) 연잎 에탄올 추출물의 열안전성 = 17
• 4) 연잎 에탄올 추출물의 최소저해농도(Minimum inhibitory concentration ;MIC) 측정 = 19
• 5) 연잎 에탄올 추출물의 농도별 항균활성 = 20
• 6) Bacillus sp. 포자의 발아에 미치는 연잎 에탄올 추출물의 효과 = 22
• 7) 연잎 에탄올 추출물의 항산화성 및 폴리페놀 함량 = 24
• 8) 암세포에 대한 연잎 에탄올 추출물의 성장저해율 = 26
• 9) 지방세포의 성장 및 분화에 미치는 연잎 에탄올 추출물의 효과 = 27
• 2. 연잎 에탄올 추출물을 첨가가 Bacillus sp. 가 오염된 쌀밥의 저장에 미치는 영향 = 29
• 1) 미생물 변화 = 29
• 2) pH 변화 = 31
• 3) 연잎 에탄올 추출물을 첨가한 쌀밥의 저장 중 색도변화 = 33
• 4) 연잎 에탄올 추출물을 첨가한 쌀밥의 저장 중 조직감의 변화 = 36
• 5) 연잎 추출물을 첨가한 밥의 항산화 활성 및 폴리페놀 함량 = 39
• 6) 연잎 에탄올 추출물을 첨가한 쌀밥의 관능검사 = 40
• Ⅳ. 요약 = 42
• 1. 연잎 추출물의 생리활성 = 42
• 2. 연잎 에탄올 추출물을 첨가가 Bacillus sp. 가 오염된 쌀밥의 저장에 미치는 영향 = 43
• 참고문헌 = 45